Replace NetMQ with custom TCP logic

Caused by 72ddaf91.

.config/dotnet-tools.json

@@ -3,7 +3,7 @@
   "isRoot": true,
   "tools": {
     "dotnet-ef": {
-      "version": "7.0.0-rc.1.22426.7",
+      "version": "8.0.3",
       "commands": [
         "dotnet-ef"
       ]

.dockerignore

@@ -0,0 +1,9 @@
+# Ignore hidden files
+.*
+
+# Include .git for build version information
+!.git
+
+# Not needed for building
+AddMigration.*
+*.DotSettings.user

.gitignore

@@ -192,7 +192,6 @@ ClientBin/
 *.dbmdl
 *.dbproj.schemaview
 *.jfm
-*.pfx
 *.publishsettings
 orleans.codegen.cs
 

.run/Agent 1.run.xml

@@ -1,28 +1,33 @@
 <component name="ProjectRunConfigurationManager">
   <configuration default="false" name="Agent 1" type="DotNetProject" factoryName=".NET Project">
-    <option name="EXE_PATH" value="$PROJECT_DIR$/Agent/Phantom.Agent/bin/Debug/net7.0/Phantom.Agent.exe" />
+    <option name="EXE_PATH" value="$PROJECT_DIR$/.artifacts/bin/Phantom.Agent/debug/Phantom.Agent.exe" />
     <option name="PROGRAM_PARAMETERS" value="" />
     <option name="WORKING_DIRECTORY" value="$PROJECT_DIR$/.workdir/Agent1" />
     <option name="PASS_PARENT_ENVS" value="1" />
     <envs>
+      <env name="AGENT_KEY" value="K5ZRZYYJ9GWM2FS6XH5N5QQ7WZRPNDGHYMN5QP7RP6PPY27KRPMSYGCN" />
       <env name="AGENT_NAME" value="Agent 1" />
       <env name="ALLOWED_RCON_PORTS" value="25575,27000,27001" />
       <env name="ALLOWED_SERVER_PORTS" value="25565,26000,26001" />
+      <env name="CONTROLLER_HOST" value="localhost" />
       <env name="JAVA_SEARCH_PATH" value="~/.jdks" />
       <env name="MAX_INSTANCES" value="3" />
       <env name="MAX_MEMORY" value="12G" />
-      <env name="SERVER_AUTH_TOKEN_FILE" value="./secrets/agent.token" />
-      <env name="SERVER_HOST" value="localhost" />
     </envs>
     <option name="USE_EXTERNAL_CONSOLE" value="0" />
+    <option name="ENV_FILE_PATHS" value="" />
+    <option name="REDIRECT_INPUT_PATH" value="" />
+    <option name="PTY_MODE" value="Auto" />
     <option name="USE_MONO" value="0" />
     <option name="RUNTIME_ARGUMENTS" value="" />
+    <option name="AUTO_ATTACH_CHILDREN" value="0" />
+    <option name="MIXED_MODE_DEBUG" value="0" />
     <option name="PROJECT_PATH" value="$PROJECT_DIR$/Agent/Phantom.Agent/Phantom.Agent.csproj" />
     <option name="PROJECT_EXE_PATH_TRACKING" value="1" />
     <option name="PROJECT_ARGUMENTS_TRACKING" value="1" />
     <option name="PROJECT_WORKING_DIRECTORY_TRACKING" value="0" />
     <option name="PROJECT_KIND" value="DotNetCore" />
-    <option name="PROJECT_TFM" value="net7.0" />
+    <option name="PROJECT_TFM" value="net9.0" />
     <method v="2">
       <option name="Build" />
     </method>

.run/Agent 2.run.xml

@@ -1,28 +1,33 @@
 <component name="ProjectRunConfigurationManager">
   <configuration default="false" name="Agent 2" type="DotNetProject" factoryName=".NET Project">
-    <option name="EXE_PATH" value="$PROJECT_DIR$/Agent/Phantom.Agent/bin/Debug/net7.0/Phantom.Agent.exe" />
+    <option name="EXE_PATH" value="$PROJECT_DIR$/.artifacts/bin/Phantom.Agent/debug/Phantom.Agent.exe" />
     <option name="PROGRAM_PARAMETERS" value="" />
     <option name="WORKING_DIRECTORY" value="$PROJECT_DIR$/.workdir/Agent2" />
     <option name="PASS_PARENT_ENVS" value="1" />
     <envs>
+      <env name="AGENT_KEY" value="K5ZRZYYJ9GWM2FS6XH5N5QQ7WZRPNDGHYMN5QP7RP6PPY27KRPMSYGCN" />
       <env name="AGENT_NAME" value="Agent 2" />
       <env name="ALLOWED_RCON_PORTS" value="27002-27006" />
       <env name="ALLOWED_SERVER_PORTS" value="26002-26006" />
+      <env name="CONTROLLER_HOST" value="localhost" />
       <env name="JAVA_SEARCH_PATH" value="~/.jdks" />
       <env name="MAX_INSTANCES" value="5" />
       <env name="MAX_MEMORY" value="10G" />
-      <env name="SERVER_AUTH_TOKEN_FILE" value="./secrets/agent.token" />
-      <env name="SERVER_HOST" value="localhost" />
     </envs>
     <option name="USE_EXTERNAL_CONSOLE" value="0" />
+    <option name="ENV_FILE_PATHS" value="" />
+    <option name="REDIRECT_INPUT_PATH" value="" />
+    <option name="PTY_MODE" value="Auto" />
     <option name="USE_MONO" value="0" />
     <option name="RUNTIME_ARGUMENTS" value="" />
+    <option name="AUTO_ATTACH_CHILDREN" value="0" />
+    <option name="MIXED_MODE_DEBUG" value="0" />
     <option name="PROJECT_PATH" value="$PROJECT_DIR$/Agent/Phantom.Agent/Phantom.Agent.csproj" />
     <option name="PROJECT_EXE_PATH_TRACKING" value="1" />
     <option name="PROJECT_ARGUMENTS_TRACKING" value="1" />
     <option name="PROJECT_WORKING_DIRECTORY_TRACKING" value="0" />
     <option name="PROJECT_KIND" value="DotNetCore" />
-    <option name="PROJECT_TFM" value="net7.0" />
+    <option name="PROJECT_TFM" value="net9.0" />
     <method v="2">
       <option name="Build" />
     </method>

.run/Agent 3.run.xml

@@ -1,28 +1,33 @@
 <component name="ProjectRunConfigurationManager">
   <configuration default="false" name="Agent 3" type="DotNetProject" factoryName=".NET Project">
-    <option name="EXE_PATH" value="$PROJECT_DIR$/Agent/Phantom.Agent/bin/Debug/net7.0/Phantom.Agent.exe" />
+    <option name="EXE_PATH" value="$PROJECT_DIR$/.artifacts/bin/Phantom.Agent/debug/Phantom.Agent.exe" />
     <option name="PROGRAM_PARAMETERS" value="" />
     <option name="WORKING_DIRECTORY" value="$PROJECT_DIR$/.workdir/Agent3" />
     <option name="PASS_PARENT_ENVS" value="1" />
     <envs>
+      <env name="AGENT_KEY" value="K5ZRZYYJ9GWM2FS6XH5N5QQ7WZRPNDGHYMN5QP7RP6PPY27KRPMSYGCN" />
       <env name="AGENT_NAME" value="Agent 3" />
       <env name="ALLOWED_RCON_PORTS" value="27007" />
       <env name="ALLOWED_SERVER_PORTS" value="26007" />
+      <env name="CONTROLLER_HOST" value="localhost" />
       <env name="JAVA_SEARCH_PATH" value="~/.jdks" />
       <env name="MAX_INSTANCES" value="1" />
       <env name="MAX_MEMORY" value="2560M" />
-      <env name="SERVER_AUTH_TOKEN_FILE" value="./secrets/agent.token" />
-      <env name="SERVER_HOST" value="localhost" />
     </envs>
     <option name="USE_EXTERNAL_CONSOLE" value="0" />
+    <option name="ENV_FILE_PATHS" value="" />
+    <option name="REDIRECT_INPUT_PATH" value="" />
+    <option name="PTY_MODE" value="Auto" />
     <option name="USE_MONO" value="0" />
     <option name="RUNTIME_ARGUMENTS" value="" />
+    <option name="AUTO_ATTACH_CHILDREN" value="0" />
+    <option name="MIXED_MODE_DEBUG" value="0" />
     <option name="PROJECT_PATH" value="$PROJECT_DIR$/Agent/Phantom.Agent/Phantom.Agent.csproj" />
     <option name="PROJECT_EXE_PATH_TRACKING" value="1" />
     <option name="PROJECT_ARGUMENTS_TRACKING" value="1" />
     <option name="PROJECT_WORKING_DIRECTORY_TRACKING" value="0" />
     <option name="PROJECT_KIND" value="DotNetCore" />
-    <option name="PROJECT_TFM" value="net7.0" />
+    <option name="PROJECT_TFM" value="net9.0" />
     <method v="2">
       <option name="Build" />
     </method>

.run/Compile Bootstrap.run.xml

@@ -1,6 +1,6 @@
 <component name="ProjectRunConfigurationManager">
   <configuration default="false" name="Compile Bootstrap" type="js.build_tools.npm">
-    <package-json value="$PROJECT_DIR$/Server/Phantom.Server.Web.Bootstrap/package.json" />
+    <package-json value="$PROJECT_DIR$/Web/Phantom.Web.Bootstrap/package.json" />
     <command value="run" />
     <scripts>
       <script value="compile" />
@@ -9,4 +9,4 @@
     <envs />
     <method v="2" />
   </configuration>
-</component>
+</component>

.run/Controller + Web + Agent x3.run.xml

@@ -1,9 +1,10 @@
 <component name="ProjectRunConfigurationManager">
-  <configuration default="false" name="Server + Agent x3" type="CompoundRunConfigurationType">
+  <configuration default="false" name="Controller + Web + Agent x3" type="CompoundRunConfigurationType">
     <toRun name="Agent 1" type="DotNetProject" />
     <toRun name="Agent 2" type="DotNetProject" />
     <toRun name="Agent 3" type="DotNetProject" />
-    <toRun name="Server" type="DotNetProject" />
+    <toRun name="Controller" type="DotNetProject" />
+    <toRun name="Web" type="DotNetProject" />
     <method v="2" />
   </configuration>
-</component>
+</component>

.run/Controller + Web + Agent.run.xml

@@ -0,0 +1,8 @@
+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="Controller + Web + Agent" type="CompoundRunConfigurationType">
+    <toRun name="Agent 1" type="DotNetProject" />
+    <toRun name="Controller" type="DotNetProject" />
+    <toRun name="Web" type="DotNetProject" />
+    <method v="2" />
+  </configuration>
+</component>

.run/Controller.run.xml

@@ -1,30 +1,34 @@
 <component name="ProjectRunConfigurationManager">
-  <configuration default="false" name="Server" type="DotNetProject" factoryName=".NET Project">
-    <option name="EXE_PATH" value="$PROJECT_DIR$/Server/Phantom.Server/bin/Debug/net7.0/Phantom.Server.exe" />
+  <configuration default="false" name="Controller" type="DotNetProject" factoryName=".NET Project">
+    <option name="EXE_PATH" value="$PROJECT_DIR$/.artifacts/bin/Phantom.Controller/debug/Phantom.Controller.exe" />
     <option name="PROGRAM_PARAMETERS" value="" />
-    <option name="WORKING_DIRECTORY" value="$PROJECT_DIR$/.workdir/Server" />
+    <option name="WORKING_DIRECTORY" value="$PROJECT_DIR$/.workdir/Controller" />
     <option name="PASS_PARENT_ENVS" value="1" />
     <envs>
-      <env name="ASPNETCORE_ENVIRONMENT" value="Development" />
+      <env name="AGENT_RPC_SERVER_HOST" value="localhost" />
       <env name="PG_DATABASE" value="postgres" />
       <env name="PG_HOST" value="localhost" />
       <env name="PG_PASS" value="development" />
-      <env name="PG_PORT" value="9402" />
+      <env name="PG_PORT" value="9403" />
       <env name="PG_USER" value="postgres" />
-      <env name="RPC_SERVER_HOST" value="localhost" />
-      <env name="WEB_SERVER_HOST" value="localhost" />
+      <env name="WEB_RPC_SERVER_HOST" value="localhost" />
     </envs>
     <option name="USE_EXTERNAL_CONSOLE" value="0" />
+    <option name="ENV_FILE_PATHS" value="" />
+    <option name="REDIRECT_INPUT_PATH" value="" />
+    <option name="PTY_MODE" value="Auto" />
     <option name="USE_MONO" value="0" />
     <option name="RUNTIME_ARGUMENTS" value="" />
-    <option name="PROJECT_PATH" value="$PROJECT_DIR$/Server/Phantom.Server/Phantom.Server.csproj" />
+    <option name="AUTO_ATTACH_CHILDREN" value="0" />
+    <option name="MIXED_MODE_DEBUG" value="0" />
+    <option name="PROJECT_PATH" value="$PROJECT_DIR$/Controller/Phantom.Controller/Phantom.Controller.csproj" />
     <option name="PROJECT_EXE_PATH_TRACKING" value="1" />
     <option name="PROJECT_ARGUMENTS_TRACKING" value="1" />
     <option name="PROJECT_WORKING_DIRECTORY_TRACKING" value="0" />
     <option name="PROJECT_KIND" value="DotNetCore" />
-    <option name="PROJECT_TFM" value="net7.0" />
+    <option name="PROJECT_TFM" value="net9.0" />
     <method v="2">
       <option name="Build" />
     </method>
   </configuration>
-</component>
+</component>

.run/Server + Agent.run.xml

@@ -1,7 +0,0 @@
-<component name="ProjectRunConfigurationManager">
-  <configuration default="false" name="Server + Agent" type="CompoundRunConfigurationType">
-    <toRun name="Agent 1" type="DotNetProject" />
-    <toRun name="Server" type="DotNetProject" />
-    <method v="2" />
-  </configuration>
-</component>

.run/Web.run.xml

@@ -0,0 +1,31 @@
+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="Web" type="DotNetProject" factoryName=".NET Project">
+    <option name="EXE_PATH" value="$PROJECT_DIR$/.artifacts/bin/Phantom.Web/debug/Phantom.Web.exe" />
+    <option name="PROGRAM_PARAMETERS" value="" />
+    <option name="WORKING_DIRECTORY" value="$PROJECT_DIR$/.workdir/Web" />
+    <option name="PASS_PARENT_ENVS" value="1" />
+    <envs>
+      <env name="ASPNETCORE_ENVIRONMENT" value="Development" />
+      <env name="CONTROLLER_HOST" value="localhost" />
+      <env name="WEB_KEY" value="T5Y722D2GZBXT2H27QS95P2YQRFB2GCTKHSWT5CZFDTFKW52TCM9GDRW" />
+      <env name="WEB_SERVER_HOST" value="localhost" />
+    </envs>
+    <option name="USE_EXTERNAL_CONSOLE" value="0" />
+    <option name="ENV_FILE_PATHS" value="" />
+    <option name="REDIRECT_INPUT_PATH" value="" />
+    <option name="PTY_MODE" value="Auto" />
+    <option name="USE_MONO" value="0" />
+    <option name="RUNTIME_ARGUMENTS" value="" />
+    <option name="AUTO_ATTACH_CHILDREN" value="0" />
+    <option name="MIXED_MODE_DEBUG" value="0" />
+    <option name="PROJECT_PATH" value="$PROJECT_DIR$/Web/Phantom.Web/Phantom.Web.csproj" />
+    <option name="PROJECT_EXE_PATH_TRACKING" value="1" />
+    <option name="PROJECT_ARGUMENTS_TRACKING" value="1" />
+    <option name="PROJECT_WORKING_DIRECTORY_TRACKING" value="0" />
+    <option name="PROJECT_KIND" value="DotNetCore" />
+    <option name="PROJECT_TFM" value="net9.0" />
+    <method v="2">
+      <option name="Build" />
+    </method>
+  </configuration>
+</component>

.workdir/.gitignore

@@ -1,2 +0,0 @@
-/Agent*/data
-/Agent*/temp

.workdir/Agent1/.gitignore

@@ -0,0 +1,2 @@
+*
+!.gitignore

.workdir/Agent1/secrets/agent.key

@@ -1 +0,0 @@
-tLkn<EFBFBD>Z<EFBFBD><EFBFBD>}ы<><D18B>|~2<><32>><3E><>р<EFBFBD><D180>O*<2A>	p

.workdir/Agent1/secrets/agent.token

@@ -1 +0,0 @@
-TH7Z2MJKMR975N6HFBKQP9WQFMWWN5

.workdir/Agent2/.gitignore

@@ -0,0 +1,2 @@
+*
+!.gitignore

.workdir/Agent2/secrets/agent.key

@@ -1 +0,0 @@
-tLkn<EFBFBD>Z<EFBFBD><EFBFBD>}ы<><D18B>|~2<><32>><3E><>р<EFBFBD><D180>O*<2A>	p

.workdir/Agent2/secrets/agent.token

@@ -1 +0,0 @@
-TH7Z2MJKMR975N6HFBKQP9WQFMWWN5

.workdir/Agent3/.gitignore

@@ -0,0 +1,2 @@
+*
+!.gitignore

.workdir/Agent3/secrets/agent.key

@@ -1 +0,0 @@
-tLkn<EFBFBD>Z<EFBFBD><EFBFBD>}ы<><D18B>|~2<><32>><3E><>р<EFBFBD><D180>O*<2A>	p

.workdir/Agent3/secrets/agent.token

@@ -1 +0,0 @@
-TH7Z2MJKMR975N6HFBKQP9WQFMWWN5

.workdir/Controller/.gitignore

@@ -0,0 +1 @@
+

.workdir/Controller/secrets/agent.auth

@@ -0,0 +1 @@
+满<EFBFBD>H<EFBFBD>c<EFBFBD>og<EFBFBD>

.workdir/Controller/secrets/web.auth

@@ -0,0 +1 @@
+<07>U<EFBFBD>/<2F><04><><EFBFBD>q

.workdir/Server/secrets/agent.key

@@ -1 +0,0 @@
-tLkn<EFBFBD>Z<EFBFBD><EFBFBD>}ы<><D18B>|~2<><32>><3E><>р<EFBFBD><D180>O*<2A>	p

.workdir/Server/secrets/agent.token

@@ -1 +0,0 @@
-TH7Z2MJKMR975N6HFBKQP9WQFMWWN5

.workdir/Server/secrets/secret.key

@@ -1 +0,0 @@
-+<2B><><EFBFBD><EFBFBD><<3C>f:<3A>bJ"e<18>׸ބ<D7B8><1F><><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD>

.workdir/Web/.gitignore

@@ -0,0 +1 @@
+/keys

AddMigration.bat

@@ -5,4 +5,4 @@ if [%1]==[] (
     exit
 )
 
-dotnet ef migrations add %~1 --project Server/Phantom.Server.Database.Postgres
+dotnet ef migrations add %~1 --project Controller/Phantom.Controller.Database.Postgres --msbuildprojectextensionspath .artifacts/obj/Phantom.Controller.Database.Postgres

AddMigration.sh

@@ -3,4 +3,4 @@ if [ -z "$1" ]; then
     exit 1
 fi
 
-dotnet ef migrations add "$1" --project Server/Phantom.Server.Database.Postgres
+dotnet ef migrations add "$1" --project Controller/Phantom.Controller.Database.Postgres --msbuildprojectextensionspath .artifacts/obj/Phantom.Controller.Database.Postgres

Agent/Phantom.Agent.Minecraft/Command/MinecraftCommand.cs

@@ -0,0 +1,15 @@
+namespace Phantom.Agent.Minecraft.Command;
+
+public static class MinecraftCommand {
+	public const string SaveOn = "save-on";
+	public const string SaveOff = "save-off";
+	public const string Stop = "stop";
+	
+	public static string Say(string message) {
+		return "say " + message;
+	}
+	
+	public static string SaveAll(bool flush) {
+		return flush ? "save-all flush" : "save-all";
+	}
+}

Agent/Phantom.Agent.Minecraft/Instance/InstanceProcess.cs

@@ -0,0 +1,67 @@
+using Phantom.Utils.Collections;
+using Phantom.Utils.Processes;
+using Phantom.Utils.Tasks;
+
+namespace Phantom.Agent.Minecraft.Instance;
+
+public sealed class InstanceProcess : IDisposable {
+	public InstanceProperties InstanceProperties { get; }
+	
+	private readonly RingBuffer<string> outputBuffer = new (100);
+	private event EventHandler<string>? OutputEvent;
+	
+	public event EventHandler? Ended;
+	public bool HasEnded { get; private set; }
+	
+	private readonly Process process;
+	private readonly TaskCompletionSource processExited = AsyncTasks.CreateCompletionSource();
+	
+	internal InstanceProcess(InstanceProperties instanceProperties, Process process) {
+		this.InstanceProperties = instanceProperties;
+		this.process = process;
+		this.process.Exited += ProcessOnExited;
+		this.process.OutputReceived += ProcessOutputReceived;
+	}
+	
+	public async Task SendCommand(string command, CancellationToken cancellationToken) {
+		await process.StandardInput.WriteLineAsync(command.AsMemory(), cancellationToken);
+	}
+	
+	public void AddOutputListener(EventHandler<string> listener, uint maxLinesToReadFromHistory = uint.MaxValue) {
+		OutputEvent += listener;
+		
+		foreach (var line in outputBuffer.EnumerateLast(maxLinesToReadFromHistory)) {
+			listener(this, line);
+		}
+	}
+	
+	public void RemoveOutputListener(EventHandler<string> listener) {
+		OutputEvent -= listener;
+	}
+	
+	private void ProcessOutputReceived(object? sender, Process.Output output) {
+		outputBuffer.Add(output.Line);
+		OutputEvent?.Invoke(this, output.Line);
+	}
+	
+	private void ProcessOnExited(object? sender, EventArgs e) {
+		OutputEvent = null;
+		HasEnded = true;
+		Ended?.Invoke(this, EventArgs.Empty);
+		processExited.SetResult();
+	}
+	
+	public void Kill() {
+		process.Kill(true);
+	}
+	
+	public async Task WaitForExit(TimeSpan timeout) {
+		await processExited.Task.WaitAsync(timeout);
+	}
+	
+	public void Dispose() {
+		process.Dispose();
+		OutputEvent = null;
+		Ended = null;
+	}
+}

Agent/Phantom.Agent.Minecraft/Instance/InstanceProperties.cs

@@ -1,12 +1,17 @@
-using Phantom.Agent.Minecraft.Java;
+using System.Collections.Immutable;
+using Phantom.Agent.Minecraft.Java;
 using Phantom.Agent.Minecraft.Properties;
+using Phantom.Common.Data.Instance;
 
 namespace Phantom.Agent.Minecraft.Instance;
 
 public sealed record InstanceProperties(
+	Guid InstanceGuid,
 	Guid JavaRuntimeGuid,
 	JvmProperties JvmProperties,
+	ImmutableArray<string> JvmArguments,
 	string InstanceFolder,
 	string ServerVersion,
-	ServerProperties ServerProperties
+	ServerProperties ServerProperties,
+	InstanceLaunchProperties LaunchProperties
 );

Agent/Phantom.Agent.Minecraft/Instance/InstanceSession.cs

@@ -1,67 +0,0 @@
-using System.Diagnostics;
-using Phantom.Utils.Collections;
-
-namespace Phantom.Agent.Minecraft.Instance; 
-
-public sealed class InstanceSession : IDisposable {
-	private readonly RingBuffer<string> outputBuffer = new (10000);
-	private event EventHandler<string>? OutputEvent;
-
-	public event EventHandler? SessionEnded;
-	public bool HasEnded { get; private set; }
-
-	private readonly Process process;
-
-	internal InstanceSession(Process process) {
-		this.process = process;
-		this.process.EnableRaisingEvents = true;
-		this.process.Exited += ProcessOnExited;
-		this.process.OutputDataReceived += HandleOutputLine;
-		this.process.ErrorDataReceived += HandleOutputLine;
-	}
-
-	public async Task SendCommand(string command, CancellationToken cancellationToken) {
-		await process.StandardInput.WriteLineAsync(command.AsMemory(), cancellationToken);
-	}
-
-	public void AddOutputListener(EventHandler<string> listener, uint maxLinesToReadFromHistory = uint.MaxValue) {
-		OutputEvent += listener;
-		
-		foreach (var line in outputBuffer.EnumerateLast(maxLinesToReadFromHistory)) {
-			listener(this, line);
-		}
-	}
-
-	public void RemoveOutputListener(EventHandler<string> listener) {
-		OutputEvent -= listener;
-	}
-
-	private void HandleOutputLine(object sender, DataReceivedEventArgs args) {
-		if (args.Data is {} line) {
-			outputBuffer.Add(line);
-			OutputEvent?.Invoke(this, line);
-		}
-	}
-
-	private void ProcessOnExited(object? sender, EventArgs e) {
-		OutputEvent = null;
-		HasEnded = true;
-		SessionEnded?.Invoke(this, EventArgs.Empty);
-	}
-
-	public void Kill() {
-		process.Kill(true);
-	}
-
-	public async Task WaitForExit(CancellationToken cancellationToken) {
-		if (!HasEnded) {
-			await process.WaitForExitAsync(cancellationToken);
-		}
-	}
-
-	public void Dispose() {
-		process.Dispose();
-		OutputEvent = null;
-		SessionEnded = null;
-	}
-}

Agent/Phantom.Agent.Minecraft/Java/JavaPropertiesFileEditor.cs

@@ -0,0 +1,92 @@
+using System.Text;
+using Kajabity.Tools.Java;
+
+namespace Phantom.Agent.Minecraft.Java;
+
+sealed class JavaPropertiesFileEditor {
+	private static readonly Encoding Encoding = Encoding.GetEncoding("ISO-8859-1");
+	
+	private readonly Dictionary<string, string> overriddenProperties = new ();
+	
+	public void Set(string key, string value) {
+		overriddenProperties[key] = value;
+	}
+	
+	public async Task EditOrCreate(string filePath) {
+		if (File.Exists(filePath)) {
+			string tmpFilePath = filePath + ".tmp";
+			File.Copy(filePath, tmpFilePath, overwrite: true);
+			await EditFromCopyOrCreate(filePath, tmpFilePath);
+			File.Move(tmpFilePath, filePath, overwrite: true);
+		}
+		else {
+			await EditFromCopyOrCreate(null, filePath);
+		}
+	}
+	
+	private async Task EditFromCopyOrCreate(string? sourceFilePath, string targetFilePath) {
+		var properties = new JavaProperties();
+		
+		if (sourceFilePath != null) {
+			// TODO replace with custom async parser
+			await using var sourceStream = new FileStream(sourceFilePath, FileMode.Open, FileAccess.Read, FileShare.Read);
+			properties.Load(sourceStream, Encoding);
+		}
+		
+		foreach (var (key, value) in overriddenProperties) {
+			properties[key] = value;
+		}
+		
+		await using var targetStream = new FileStream(targetFilePath, FileMode.Create, FileAccess.Write, FileShare.Read);
+		await using var targetWriter = new StreamWriter(targetStream, Encoding);
+		
+		await targetWriter.WriteLineAsync("# Properties");
+		
+		foreach (var (key, value) in properties) {
+			await WriteProperty(targetWriter, key, value);
+		}
+	}
+	
+	private static async Task WriteProperty(StreamWriter writer, string key, string value) {
+		await WritePropertyComponent(writer, key, escapeSpaces: true);
+		await writer.WriteAsync('=');
+		await WritePropertyComponent(writer, value, escapeSpaces: false);
+		await writer.WriteLineAsync();
+	}
+	
+	private static async Task WritePropertyComponent(TextWriter writer, string component, bool escapeSpaces) {
+		for (int index = 0; index < component.Length; index++) {
+			var c = component[index];
+			switch (c) {
+				case '\\':
+				case '#':
+				case '!':
+				case '=':
+				case ':':
+				case ' ' when escapeSpaces || index == 0:
+					await writer.WriteAsync('\\');
+					await writer.WriteAsync(c);
+					break;
+				case var _ when c > 31 && c < 127:
+					await writer.WriteAsync(c);
+					break;
+				case '\t':
+					await writer.WriteAsync("\\t");
+					break;
+				case '\n':
+					await writer.WriteAsync("\\n");
+					break;
+				case '\r':
+					await writer.WriteAsync("\\r");
+					break;
+				case '\f':
+					await writer.WriteAsync("\\f");
+					break;
+				default:
+					await writer.WriteAsync("\\u");
+					await writer.WriteAsync(((int) c).ToString("X4"));
+					break;
+			}
+		}
+	}
+}

Agent/Phantom.Agent.Minecraft/Java/JavaRuntimeDiscovery.cs

@@ -1,24 +1,24 @@
 using System.Diagnostics;
 using Phantom.Common.Data.Java;
-using Phantom.Common.Logging;
 using Phantom.Utils.IO;
+using Phantom.Utils.Logging;
 using Serilog;
 
 namespace Phantom.Agent.Minecraft.Java;
 
 public sealed class JavaRuntimeDiscovery {
-	private static readonly ILogger Logger = PhantomLogger.Create(typeof(JavaRuntimeDiscovery));
-
+	private static readonly ILogger Logger = PhantomLogger.Create(nameof(JavaRuntimeDiscovery));
+	
 	public static string? GetSystemSearchPath() {
 		const string LinuxJavaPath = "/usr/lib/jvm";
-
+		
 		if (OperatingSystem.IsLinux() && Directory.Exists(LinuxJavaPath)) {
 			return LinuxJavaPath;
 		}
-
+		
 		return null;
 	}
-
+	
 	public static IAsyncEnumerable<JavaRuntimeExecutable> Scan(string folderPath) {
 		return new JavaRuntimeDiscovery().ScanInternal(folderPath);
 	}
@@ -27,9 +27,9 @@ public sealed class JavaRuntimeDiscovery {
 	
 	private async IAsyncEnumerable<JavaRuntimeExecutable> ScanInternal(string folderPath) {
 		Logger.Information("Starting Java runtime scan in: {FolderPath}", folderPath);
-
+		
 		string javaExecutableName = OperatingSystem.IsWindows() ? "java.exe" : "java";
-
+		
 		foreach (var binFolderPath in Directory.EnumerateDirectories(Paths.ExpandTilde(folderPath), "bin", new EnumerationOptions {
 			MatchType = MatchType.Simple,
 			RecurseSubdirectories = true,
@@ -38,51 +38,60 @@ public sealed class JavaRuntimeDiscovery {
 			AttributesToSkip = FileAttributes.Hidden | FileAttributes.ReparsePoint | FileAttributes.System
 		}).Order()) {
 			var javaExecutablePath = Paths.NormalizeSlashes(Path.Combine(binFolderPath, javaExecutableName));
-			if (File.Exists(javaExecutablePath)) {
-				Logger.Information("Found candidate Java executable: {JavaExecutablePath}", javaExecutablePath);
-
-				JavaRuntime? foundRuntime;
-				try {
-					foundRuntime = await TryReadJavaRuntimeInformationFromProcess(javaExecutablePath);
-				} catch (OperationCanceledException) {
-					Logger.Error("Java process did not exit in time.");
-					continue;
-				} catch (Exception e) {
-					Logger.Error(e, "Caught exception while reading Java version information.");
-					continue;
-				}
-
-				if (foundRuntime == null) {
-					Logger.Error("Java executable did not output version information.");
-					continue;
-				}
-
-				Logger.Information("Found Java {DisplayName} at: {Path}", foundRuntime.DisplayName, javaExecutablePath);
-				yield return new JavaRuntimeExecutable(javaExecutablePath, foundRuntime);
+			
+			FileAttributes javaExecutableAttributes;
+			try {
+				javaExecutableAttributes = File.GetAttributes(javaExecutablePath);
+			} catch (Exception) {
+				continue;
 			}
+			
+			if (javaExecutableAttributes.HasFlag(FileAttributes.ReparsePoint)) {
+				continue;
+			}
+			
+			Logger.Information("Found candidate Java executable: {JavaExecutablePath}", javaExecutablePath);
+			
+			JavaRuntime? foundRuntime;
+			try {
+				foundRuntime = await TryReadJavaRuntimeInformationFromProcess(javaExecutablePath);
+			} catch (OperationCanceledException) {
+				Logger.Error("Java process did not exit in time.");
+				continue;
+			} catch (Exception e) {
+				Logger.Error(e, "Caught exception while reading Java version information.");
+				continue;
+			}
+			
+			if (foundRuntime == null) {
+				Logger.Error("Java executable did not output version information.");
+				continue;
+			}
+			
+			Logger.Information("Found Java {DisplayName} at: {Path}", foundRuntime.DisplayName, javaExecutablePath);
+			yield return new JavaRuntimeExecutable(javaExecutablePath, foundRuntime);
 		}
 	}
-
+	
 	private async Task<JavaRuntime?> TryReadJavaRuntimeInformationFromProcess(string javaExecutablePath) {
 		var startInfo = new ProcessStartInfo {
 			FileName = javaExecutablePath,
 			WorkingDirectory = Path.GetDirectoryName(javaExecutablePath),
 			Arguments = "-XshowSettings:properties -version",
 			RedirectStandardInput = false,
-			RedirectStandardOutput = true,
+			RedirectStandardOutput = false,
 			RedirectStandardError = true,
-			UseShellExecute = false,
-			CreateNoWindow = false
+			UseShellExecute = false
 		};
-
+		
 		var process = new Process { StartInfo = startInfo };
 		var cancellationTokenSource = new CancellationTokenSource(TimeSpan.FromSeconds(5));
-
+		
 		try {
 			process.Start();
-
+			
 			JavaRuntimeBuilder runtimeBuilder = new ();
-
+			
 			while (await process.StandardError.ReadLineAsync(cancellationTokenSource.Token) is {} line) {
 				ExtractJavaVersionPropertiesFromLine(line, runtimeBuilder);
 				
@@ -91,7 +100,7 @@ public sealed class JavaRuntimeDiscovery {
 					return runtime;
 				}
 			}
-
+			
 			await process.WaitForExitAsync(cancellationTokenSource.Token);
 			return null;
 		} finally {
@@ -99,15 +108,15 @@ public sealed class JavaRuntimeDiscovery {
 			cancellationTokenSource.Dispose();
 		}
 	}
-
+	
 	private static void ExtractJavaVersionPropertiesFromLine(ReadOnlySpan<char> line, JavaRuntimeBuilder runtimeBuilder) {
 		line = line.TrimStart();
-
+		
 		int separatorIndex = line.IndexOf('=');
 		if (separatorIndex == -1) {
 			return;
 		}
-
+		
 		var propertyName = line[..separatorIndex].TrimEnd();
 		if (propertyName.Equals("java.specification.version", StringComparison.Ordinal)) {
 			runtimeBuilder.MainVersion = ExtractValue(line, separatorIndex);
@@ -119,16 +128,16 @@ public sealed class JavaRuntimeDiscovery {
 			runtimeBuilder.Vendor = ExtractValue(line, separatorIndex);
 		}
 	}
-
+	
 	private static string ExtractValue(ReadOnlySpan<char> line, int separatorIndex) {
 		return line[(separatorIndex + 1)..].Trim().ToString();
 	}
-
+	
 	private sealed class JavaRuntimeBuilder {
 		public string? MainVersion { get; set; } = null;
 		public string? FullVersion { get; set; } = null;
 		public string? Vendor { get; set; } = null;
-
+		
 		public JavaRuntime? TryBuild(Dictionary<string, int> duplicateDisplayNames) {
 			if (MainVersion == null || FullVersion == null || Vendor == null) {
 				return null;

Agent/Phantom.Agent.Minecraft/Java/JavaRuntimeExecutable.cs

@@ -1,11 +1,11 @@
 using Phantom.Common.Data.Java;
 
-namespace Phantom.Agent.Minecraft.Java; 
+namespace Phantom.Agent.Minecraft.Java;
 
 public sealed class JavaRuntimeExecutable {
 	internal string ExecutablePath { get; }
 	internal JavaRuntime Runtime { get; }
-
+	
 	internal JavaRuntimeExecutable(string executablePath, JavaRuntime runtime) {
 		this.ExecutablePath = executablePath;
 		this.Runtime = runtime;

Agent/Phantom.Agent.Minecraft/Java/JavaRuntimeRepository.cs

@@ -9,7 +9,7 @@ public sealed class JavaRuntimeRepository {
 	private readonly Dictionary<string, Guid> guidsByPath = new ();
 	private readonly Dictionary<Guid, JavaRuntimeExecutable> runtimesByGuid = new ();
 	private readonly ReaderWriterLockSlim rwLock = new (LockRecursionPolicy.NoRecursion);
-
+	
 	public ImmutableArray<TaggedJavaRuntime> All {
 		get {
 			rwLock.EnterReadLock();
@@ -20,20 +20,20 @@ public sealed class JavaRuntimeRepository {
 			}
 		}
 	}
-
+	
 	public void Include(JavaRuntimeExecutable runtime) {
 		rwLock.EnterWriteLock();
 		try {
 			if (!guidsByPath.TryGetValue(runtime.ExecutablePath, out var guid)) {
 				guidsByPath[runtime.ExecutablePath] = guid = GenerateStableGuid(runtime.ExecutablePath);
 			}
-
+			
 			runtimesByGuid[guid] = runtime;
 		} finally {
 			rwLock.ExitWriteLock();
 		}
 	}
-
+	
 	public bool TryGetByGuid(Guid guid, [MaybeNullWhen(false)] out JavaRuntimeExecutable runtime) {
 		rwLock.EnterReadLock();
 		try {
@@ -42,7 +42,7 @@ public sealed class JavaRuntimeRepository {
 			rwLock.ExitReadLock();
 		}
 	}
-
+	
 	private static Guid GenerateStableGuid(string executablePath) {
 		Random rand = new Random(StableHashCode.ForString(executablePath));
 		Span<byte> bytes = stackalloc byte[16];

Agent/Phantom.Agent.Minecraft/Java/JvmArgumentBuilder.cs

@@ -4,22 +4,27 @@ namespace Phantom.Agent.Minecraft.Java;
 
 sealed class JvmArgumentBuilder {
 	private readonly JvmProperties basicProperties;
-	private readonly List<string> customProperties = new ();
-
+	private readonly List<string> customArguments = new ();
+	
 	public JvmArgumentBuilder(JvmProperties basicProperties) {
 		this.basicProperties = basicProperties;
 	}
-
-	public void AddProperty(string key, string value) {
-		customProperties.Add("-D" + key + "=\"" + value + "\""); // TODO test quoting?
+	
+	public void Add(string argument) {
+		customArguments.Add(argument);
 	}
-
+	
+	public void AddProperty(string key, string value) {
+		customArguments.Add("-D" + key + "=\"" + value + "\""); // TODO test quoting?
+	}
+	
 	public void Build(Collection<string> target) {
-		target.Add("-Xms" + basicProperties.InitialHeapMegabytes + "M");
-		target.Add("-Xmx" + basicProperties.MaximumHeapMegabytes + "M");
-
-		foreach (var property in customProperties) {
+		foreach (var property in customArguments) {
 			target.Add(property);
 		}
+		
+		// In case of duplicate JVM arguments, typically the last one wins.
+		target.Add("-Xms" + basicProperties.InitialHeapMegabytes + "M");
+		target.Add("-Xmx" + basicProperties.MaximumHeapMegabytes + "M");
 	}
 }

Agent/Phantom.Agent.Minecraft/Launcher/BaseLauncher.cs

@@ -1,87 +1,116 @@
-using System.Diagnostics;
-using System.Text;
-using Kajabity.Tools.Java;
+using System.Text;
 using Phantom.Agent.Minecraft.Instance;
 using Phantom.Agent.Minecraft.Java;
 using Phantom.Agent.Minecraft.Server;
+using Phantom.Utils.Processes;
+using Serilog;
 
 namespace Phantom.Agent.Minecraft.Launcher;
 
-public abstract class BaseLauncher {
+public abstract class BaseLauncher : IServerLauncher {
 	private readonly InstanceProperties instanceProperties;
-
+	
+	protected string MinecraftVersion => instanceProperties.ServerVersion;
+	
 	private protected BaseLauncher(InstanceProperties instanceProperties) {
 		this.instanceProperties = instanceProperties;
 	}
-
-	public async Task<LaunchResult> Launch(LaunchServices services, EventHandler<DownloadProgressEventArgs> downloadProgressEventHandler, CancellationToken cancellationToken) {
+	
+	public async Task<LaunchResult> Launch(ILogger logger, LaunchServices services, EventHandler<DownloadProgressEventArgs> downloadProgressEventHandler, CancellationToken cancellationToken) {
 		if (!services.JavaRuntimeRepository.TryGetByGuid(instanceProperties.JavaRuntimeGuid, out var javaRuntimeExecutable)) {
 			return new LaunchResult.InvalidJavaRuntime();
 		}
-
-		var vanillaServerJarPath = await services.ServerExecutables.DownloadAndGetPath(instanceProperties.ServerVersion, downloadProgressEventHandler, cancellationToken);
+		
+		var vanillaServerJarPath = await services.ServerExecutables.DownloadAndGetPath(instanceProperties.LaunchProperties.ServerDownloadInfo, MinecraftVersion, downloadProgressEventHandler, cancellationToken);
 		if (vanillaServerJarPath == null) {
 			return new LaunchResult.CouldNotDownloadMinecraftServer();
 		}
-
-		var startInfo = new ProcessStartInfo {
-			FileName = javaRuntimeExecutable.ExecutablePath,
-			WorkingDirectory = instanceProperties.InstanceFolder,
-			RedirectStandardInput = true,
-			RedirectStandardOutput = true,
-			RedirectStandardError = true,
-			UseShellExecute = false,
-			CreateNoWindow = false
-		};
-
-		var jvmArguments = new JvmArgumentBuilder(instanceProperties.JvmProperties);
-		CustomizeJvmArguments(jvmArguments);
-
-		var serverJarPath = await PrepareServerJar(vanillaServerJarPath, instanceProperties.InstanceFolder, cancellationToken);
-		var processArguments = startInfo.ArgumentList;
-		jvmArguments.Build(processArguments);
-		processArguments.Add("-jar");
-		processArguments.Add(serverJarPath);
-		processArguments.Add("nogui");
-
-		var process = new Process { StartInfo = startInfo };
-		var session = new InstanceSession(process);
-
-		await AcceptEula(instanceProperties);
-		await UpdateServerProperties(instanceProperties);
-
-		process.Start();
-		process.BeginOutputReadLine();
-		process.BeginErrorReadLine();
-
-		return new LaunchResult.Success(session);
-	}
-
-	private protected virtual void CustomizeJvmArguments(JvmArgumentBuilder arguments) {}
-
-	private protected virtual Task<string> PrepareServerJar(string serverJarPath, string instanceFolderPath, CancellationToken cancellationToken) {
-		return Task.FromResult(serverJarPath);
-	}
-
-	private static async Task AcceptEula(InstanceProperties instanceProperties) {
-		var eulaFilePath = Path.Combine(instanceProperties.InstanceFolder, "eula.txt");
-		await File.WriteAllLinesAsync(eulaFilePath, new [] { "# EULA", "eula=true" }, Encoding.UTF8);
-	}
-
-	private static async Task UpdateServerProperties(InstanceProperties instanceProperties) {
-		var serverPropertiesFilePath = Path.Combine(instanceProperties.InstanceFolder, "server.properties");
-		var serverPropertiesData = new JavaProperties();
-
+		
+		ServerJarInfo? serverJar;
 		try {
-			await using var readStream = new FileStream(serverPropertiesFilePath, FileMode.Open, FileAccess.Read, FileShare.Read);
-			serverPropertiesData.Load(readStream);
-		} catch (FileNotFoundException) {
-			// ignore
+			serverJar = await PrepareServerJar(logger, vanillaServerJarPath, cancellationToken);
+		} catch (OperationCanceledException) {
+			throw;
+		} catch (Exception e) {
+			logger.Error(e, "Caught exception while preparing the server jar.");
+			return new LaunchResult.CouldNotPrepareMinecraftServerLauncher();
 		}
 		
-		instanceProperties.ServerProperties.SetTo(serverPropertiesData);
-
-		await using var writeStream = new FileStream(serverPropertiesFilePath, FileMode.OpenOrCreate, FileAccess.Write, FileShare.None);
-		serverPropertiesData.Store(writeStream, true);
+		if (!File.Exists(serverJar.FilePath)) {
+			logger.Error("Missing prepared server or launcher jar: {FilePath}", serverJar.FilePath);
+			return new LaunchResult.CouldNotPrepareMinecraftServerLauncher();
+		}
+		
+		try {
+			await AcceptEula(instanceProperties);
+			await UpdateServerProperties(instanceProperties);
+		} catch (Exception e) {
+			logger.Error(e, "Caught exception while configuring the server.");
+			return new LaunchResult.CouldNotConfigureMinecraftServer();
+		}
+		
+		var processConfigurator = new ProcessConfigurator {
+			FileName = javaRuntimeExecutable.ExecutablePath,
+			WorkingDirectory = instanceProperties.InstanceFolder,
+			RedirectInput = true,
+			UseShellExecute = false
+		};
+		
+		var processArguments = processConfigurator.ArgumentList;
+		PrepareJvmArguments(serverJar).Build(processArguments);
+		processArguments.Add("-jar");
+		processArguments.Add(serverJar.FilePath);
+		processArguments.Add("nogui");
+		
+		var process = processConfigurator.CreateProcess();
+		var instanceProcess = new InstanceProcess(instanceProperties, process);
+		
+		try {
+			process.Start();
+		} catch (Exception launchException) {
+			logger.Error(launchException, "Caught exception launching the server process.");
+			
+			try {
+				process.Kill();
+			} catch (Exception killException) {
+				logger.Error(killException, "Caught exception trying to kill the server process after a failed launch.");
+			}
+			
+			return new LaunchResult.CouldNotStartMinecraftServer();
+		}
+		
+		return new LaunchResult.Success(instanceProcess);
+	}
+	
+	private JvmArgumentBuilder PrepareJvmArguments(ServerJarInfo serverJar) {
+		var builder = new JvmArgumentBuilder(instanceProperties.JvmProperties);
+		
+		foreach (string argument in instanceProperties.JvmArguments) {
+			builder.Add(argument);
+		}
+		
+		foreach (var argument in serverJar.ExtraArgs) {
+			builder.Add(argument);
+		}
+		
+		CustomizeJvmArguments(builder);
+		return builder;
+	}
+	
+	private protected virtual void CustomizeJvmArguments(JvmArgumentBuilder arguments) {}
+	
+	private protected virtual Task<ServerJarInfo> PrepareServerJar(ILogger logger, string serverJarPath, CancellationToken cancellationToken) {
+		return Task.FromResult(new ServerJarInfo(serverJarPath));
+	}
+	
+	private static async Task AcceptEula(InstanceProperties instanceProperties) {
+		var eulaFilePath = Path.Combine(instanceProperties.InstanceFolder, "eula.txt");
+		await File.WriteAllLinesAsync(eulaFilePath, new[] { "# EULA", "eula=true" }, Encoding.UTF8);
+	}
+	
+	private static async Task UpdateServerProperties(InstanceProperties instanceProperties) {
+		var serverPropertiesEditor = new JavaPropertiesFileEditor();
+		instanceProperties.ServerProperties.SetTo(serverPropertiesEditor);
+		await serverPropertiesEditor.EditOrCreate(Path.Combine(instanceProperties.InstanceFolder, "server.properties"));
 	}
 }

Agent/Phantom.Agent.Minecraft/Launcher/IServerLauncher.cs

@@ -0,0 +1,8 @@
+using Phantom.Agent.Minecraft.Server;
+using Serilog;
+
+namespace Phantom.Agent.Minecraft.Launcher;
+
+public interface IServerLauncher {
+	Task<LaunchResult> Launch(ILogger logger, LaunchServices services, EventHandler<DownloadProgressEventArgs> downloadProgressEventHandler, CancellationToken cancellationToken);
+}

Agent/Phantom.Agent.Minecraft/Launcher/LaunchResult.cs

@@ -4,10 +4,16 @@ namespace Phantom.Agent.Minecraft.Launcher;
 
 public abstract record LaunchResult {
 	private LaunchResult() {}
-
-	public sealed record Success(InstanceSession Session) : LaunchResult;
-
+	
+	public sealed record Success(InstanceProcess Process) : LaunchResult;
+	
 	public sealed record InvalidJavaRuntime : LaunchResult;
-
+	
 	public sealed record CouldNotDownloadMinecraftServer : LaunchResult;
+	
+	public sealed record CouldNotPrepareMinecraftServerLauncher : LaunchResult;
+	
+	public sealed record CouldNotConfigureMinecraftServer : LaunchResult;
+	
+	public sealed record CouldNotStartMinecraftServer : LaunchResult;
 }

Agent/Phantom.Agent.Minecraft/Launcher/LaunchServices.cs

@@ -1,6 +1,6 @@
 using Phantom.Agent.Minecraft.Java;
 using Phantom.Agent.Minecraft.Server;
 
-namespace Phantom.Agent.Minecraft.Launcher; 
+namespace Phantom.Agent.Minecraft.Launcher;
 
 public sealed record LaunchServices(MinecraftServerExecutables ServerExecutables, JavaRuntimeRepository JavaRuntimeRepository);

Agent/Phantom.Agent.Minecraft/Launcher/ServerJarInfo.cs

@@ -0,0 +1,7 @@
+using System.Collections.Immutable;
+
+namespace Phantom.Agent.Minecraft.Launcher;
+
+sealed record ServerJarInfo(string FilePath, ImmutableArray<string> ExtraArgs) {
+	public ServerJarInfo(string filePath) : this(filePath, ImmutableArray<string>.Empty) {}
+}

Agent/Phantom.Agent.Minecraft/Launcher/Types/FabricLauncher.cs

@@ -0,0 +1,55 @@
+using System.Collections.Immutable;
+using Phantom.Agent.Minecraft.Instance;
+using Phantom.Utils.IO;
+using Serilog;
+
+namespace Phantom.Agent.Minecraft.Launcher.Types;
+
+public sealed class FabricLauncher : BaseLauncher {
+	public FabricLauncher(InstanceProperties instanceProperties) : base(instanceProperties) {}
+	
+	private protected override async Task<ServerJarInfo> PrepareServerJar(ILogger logger, string serverJarPath, CancellationToken cancellationToken) {
+		var serverJarParentFolderPath = Directory.GetParent(serverJarPath);
+		if (serverJarParentFolderPath == null) {
+			throw new ArgumentException("Could not get parent folder from: " + serverJarPath, nameof(serverJarPath));
+		}
+		
+		var launcherJarPath = Path.Combine(serverJarParentFolderPath.FullName, "fabric.jar");
+		
+		if (!File.Exists(launcherJarPath)) {
+			await DownloadLauncher(logger, launcherJarPath, cancellationToken);
+		}
+		
+		return new ServerJarInfo(launcherJarPath, ImmutableArray.Create("-Dfabric.installer.server.gameJar=" + Paths.NormalizeSlashes(serverJarPath)));
+	}
+	
+	private async Task DownloadLauncher(ILogger logger, string targetFilePath, CancellationToken cancellationToken) {
+		// TODO customizable loader version, probably with a dedicated temporary folder
+		string installerUrl = $"https://meta.fabricmc.net/v2/versions/loader/{MinecraftVersion}/stable/stable/server/jar";
+		logger.Information("Downloading Fabric launcher from: {Url}", installerUrl);
+		
+		using var http = new HttpClient();
+		
+		var response = await http.GetAsync(installerUrl, HttpCompletionOption.ResponseHeadersRead, cancellationToken);
+		response.EnsureSuccessStatusCode();
+		
+		try {
+			await using var fileStream = new FileStream(targetFilePath, FileMode.CreateNew, FileAccess.Write, FileShare.Read);
+			await using var responseStream = await response.Content.ReadAsStreamAsync(cancellationToken);
+			await responseStream.CopyToAsync(fileStream, cancellationToken);
+		} catch (Exception) {
+			TryDeleteLauncherAfterFailure(logger, targetFilePath);
+			throw;
+		}
+	}
+	
+	private static void TryDeleteLauncherAfterFailure(ILogger logger, string filePath) {
+		if (File.Exists(filePath)) {
+			try {
+				File.Delete(filePath);
+			} catch (Exception e) {
+				logger.Warning(e, "Could not clean up partially downloaded Fabric launcher: {FilePath}", filePath);
+			}
+		}
+	}
+}

Agent/Phantom.Agent.Minecraft/Launcher/Types/InvalidLauncher.cs

@@ -0,0 +1,14 @@
+using Phantom.Agent.Minecraft.Server;
+using Serilog;
+
+namespace Phantom.Agent.Minecraft.Launcher.Types;
+
+public sealed class InvalidLauncher : IServerLauncher {
+	public static InvalidLauncher Instance { get; } = new ();
+	
+	private InvalidLauncher() {}
+	
+	public Task<LaunchResult> Launch(ILogger logger, LaunchServices services, EventHandler<DownloadProgressEventArgs> downloadProgressEventHandler, CancellationToken cancellationToken) {
+		return Task.FromResult<LaunchResult>(new LaunchResult.CouldNotPrepareMinecraftServerLauncher());
+	}
+}

Agent/Phantom.Agent.Minecraft/Launcher/Types/VanillaLauncher.cs

@@ -1,6 +1,6 @@
 using Phantom.Agent.Minecraft.Instance;
 
-namespace Phantom.Agent.Minecraft.Launcher.Types; 
+namespace Phantom.Agent.Minecraft.Launcher.Types;
 
 public sealed class VanillaLauncher : BaseLauncher {
 	public VanillaLauncher(InstanceProperties instanceProperties) : base(instanceProperties) {}

Agent/Phantom.Agent.Minecraft/Phantom.Agent.Minecraft.csproj

@@ -1,21 +1,18 @@
 <Project Sdk="Microsoft.NET.Sdk">
   
   <PropertyGroup>
-    <TargetFramework>net7.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   
   <ItemGroup>
-    <PackageReference Include="Kajabity.Tools.Java" Version="0.3.7879.40798" />
+    <PackageReference Include="Kajabity.Tools.Java" />
   </ItemGroup>
   
   <ItemGroup>
     <ProjectReference Include="..\..\Common\Phantom.Common.Data\Phantom.Common.Data.csproj" />
-    <ProjectReference Include="..\..\Common\Phantom.Common.Logging\Phantom.Common.Logging.csproj" />
-    <ProjectReference Include="..\..\Utils\Phantom.Utils.Collections\Phantom.Utils.Collections.csproj" />
-    <ProjectReference Include="..\..\Utils\Phantom.Utils.Cryptography\Phantom.Utils.Cryptography.csproj" />
-    <ProjectReference Include="..\..\Utils\Phantom.Utils.IO\Phantom.Utils.IO.csproj" />
+    <ProjectReference Include="..\..\Utils\Phantom.Utils\Phantom.Utils.csproj" />
+    <ProjectReference Include="..\..\Utils\Phantom.Utils.Logging\Phantom.Utils.Logging.csproj" />
   </ItemGroup>
 
 </Project>

Agent/Phantom.Agent.Minecraft/Properties/MinecraftServerProperties.cs

@@ -14,8 +14,9 @@ static class MinecraftServerProperties {
 		protected override ushort Read(string value) => ushort.Parse(value);
 		protected override string Write(ushort value) => value.ToString();
 	}
-
+	
 	public static readonly MinecraftServerProperty<ushort> ServerPort = new UnsignedShort("server-port");
 	public static readonly MinecraftServerProperty<ushort> RconPort = new UnsignedShort("rcon.port");
 	public static readonly MinecraftServerProperty<bool> EnableRcon = new Boolean("enable-rcon");
+	public static readonly MinecraftServerProperty<bool> SyncChunkWrites = new Boolean("sync-chunk-writes");
 }

Agent/Phantom.Agent.Minecraft/Properties/MinecraftServerProperty.cs

@@ -1,18 +1,18 @@
-using Kajabity.Tools.Java;
+using Phantom.Agent.Minecraft.Java;
 
-namespace Phantom.Agent.Minecraft.Properties; 
+namespace Phantom.Agent.Minecraft.Properties;
 
 abstract class MinecraftServerProperty<T> {
 	private readonly string key;
-
+	
 	protected MinecraftServerProperty(string key) {
 		this.key = key;
 	}
 	
 	protected abstract T Read(string value);
 	protected abstract string Write(T value);
-
-	public void Set(JavaProperties properties, T value) {
-		properties.SetProperty(key, Write(value));
+	
+	public void Set(JavaPropertiesFileEditor properties, T value) {
+		properties.Set(key, Write(value));
 	}
 }

Agent/Phantom.Agent.Minecraft/Properties/ServerProperties.cs

@@ -1,15 +1,17 @@
-using Kajabity.Tools.Java;
+using Phantom.Agent.Minecraft.Java;
 
 namespace Phantom.Agent.Minecraft.Properties;
 
 public sealed record ServerProperties(
 	ushort ServerPort,
 	ushort RconPort,
-	bool EnableRcon = true
+	bool EnableRcon = true,
+	bool SyncChunkWrites = false
 ) {
-	internal void SetTo(JavaProperties properties) {
+	internal void SetTo(JavaPropertiesFileEditor properties) {
 		MinecraftServerProperties.ServerPort.Set(properties, ServerPort);
 		MinecraftServerProperties.RconPort.Set(properties, RconPort);
 		MinecraftServerProperties.EnableRcon.Set(properties, EnableRcon);
+		MinecraftServerProperties.SyncChunkWrites.Set(properties, SyncChunkWrites);
 	}
 }

Agent/Phantom.Agent.Minecraft/Server/DownloadProgressEventArgs.cs

@@ -1,4 +1,4 @@
-namespace Phantom.Agent.Minecraft.Server; 
+namespace Phantom.Agent.Minecraft.Server;
 
 public sealed class DownloadProgressEventArgs : EventArgs {
 	public ulong DownloadedBytes { get; }

Agent/Phantom.Agent.Minecraft/Server/MinecraftServerExecutableDownloadListener.cs

@@ -1,3 +1,3 @@
-namespace Phantom.Agent.Minecraft.Server; 
+namespace Phantom.Agent.Minecraft.Server;
 
 sealed record MinecraftServerExecutableDownloadListener(EventHandler<DownloadProgressEventArgs> DownloadProgressEventHandler, CancellationToken CancellationToken);

Agent/Phantom.Agent.Minecraft/Server/MinecraftServerExecutableDownloader.cs

@@ -1,151 +1,137 @@
-using System.Net.Http.Json;
-using System.Security.Cryptography;
-using System.Text.Json;
-using Phantom.Common.Logging;
+using System.Security.Cryptography;
+using Phantom.Common.Data.Minecraft;
 using Phantom.Utils.Cryptography;
 using Phantom.Utils.IO;
+using Phantom.Utils.Logging;
+using Phantom.Utils.Runtime;
 using Serilog;
 
 namespace Phantom.Agent.Minecraft.Server;
 
 sealed class MinecraftServerExecutableDownloader {
 	private static readonly ILogger Logger = PhantomLogger.Create<MinecraftServerExecutableDownloader>();
-
-	private const string VersionManifestUrl = "https://launchermeta.mojang.com/mc/game/version_manifest.json";
-
+	
 	public Task<string?> Task { get; }
 	public event EventHandler<DownloadProgressEventArgs>? DownloadProgress;
 	public event EventHandler? Completed;
 	
 	private readonly CancellationTokenSource cancellationTokenSource = new ();
-	private int listeners = 0;
-
-	public MinecraftServerExecutableDownloader(string version, string filePath, MinecraftServerExecutableDownloadListener listener) {
+	
+	private readonly List<CancellationTokenRegistration> listenerCancellationRegistrations = new ();
+	private int listenerCount = 0;
+	
+	public MinecraftServerExecutableDownloader(FileDownloadInfo fileDownloadInfo, string minecraftVersion, string filePath, MinecraftServerExecutableDownloadListener listener) {
 		Register(listener);
-		Task = DownloadAndGetPath(version, filePath);
+		Task = DownloadAndGetPath(fileDownloadInfo, minecraftVersion, filePath, new DownloadProgressCallback(this), cancellationTokenSource.Token);
 		Task.ContinueWith(OnCompleted, TaskScheduler.Default);
 	}
-
+	
 	public void Register(MinecraftServerExecutableDownloadListener listener) {
-		++listeners;
-		Logger.Verbose("Registered download listener, current listener count: {Listeners}", listeners);
+		int newListenerCount;
 		
-		DownloadProgress += listener.DownloadProgressEventHandler;
-		listener.CancellationToken.Register(Unregister, listener);
+		lock (this) {
+			newListenerCount = ++listenerCount;
+			
+			DownloadProgress += listener.DownloadProgressEventHandler;
+			listenerCancellationRegistrations.Add(listener.CancellationToken.Register(Unregister, listener));
+		}
+		
+		Logger.Debug("Registered download listener, current listener count: {Listeners}", newListenerCount);
 	}
-
+	
 	private void Unregister(object? listenerObject) {
-		MinecraftServerExecutableDownloadListener listener = (MinecraftServerExecutableDownloadListener) listenerObject!;
-		DownloadProgress -= listener.DownloadProgressEventHandler;
-
-		if (--listeners <= 0) {
-			Logger.Verbose("Unregistered last download listener, cancelling download.");
-			cancellationTokenSource.Cancel();
+		int newListenerCount;
+		
+		lock (this) {
+			MinecraftServerExecutableDownloadListener listener = (MinecraftServerExecutableDownloadListener) listenerObject!;
+			DownloadProgress -= listener.DownloadProgressEventHandler;
+			
+			newListenerCount = --listenerCount;
+			if (newListenerCount <= 0) {
+				cancellationTokenSource.Cancel();
+			}
+		}
+		
+		if (newListenerCount <= 0) {
+			Logger.Debug("Unregistered last download listener, cancelling download.");
 		}
 		else {
-			Logger.Verbose("Unregistered download listener, current listener count: {Listeners}", listeners);
+			Logger.Debug("Unregistered download listener, current listener count: {Listeners}", newListenerCount);
 		}
 	}
-
+	
 	private void ReportDownloadProgress(DownloadProgressEventArgs args) {
 		DownloadProgress?.Invoke(this, args);
 	}
-
+	
 	private void OnCompleted(Task task) {
-		Logger.Verbose("Download task completed.");
-		Completed?.Invoke(this, EventArgs.Empty);
-		Completed = null;
-		DownloadProgress = null;
+		Logger.Debug("Download task completed.");
+		
+		lock (this) {
+			Completed?.Invoke(this, EventArgs.Empty);
+			Completed = null;
+			DownloadProgress = null;
+			
+			foreach (var registration in listenerCancellationRegistrations) {
+				registration.Dispose();
+			}
+			
+			listenerCancellationRegistrations.Clear();
+			cancellationTokenSource.Dispose();
+		}
 	}
-
+	
 	private sealed class DownloadProgressCallback {
 		private readonly MinecraftServerExecutableDownloader downloader;
-
+		
 		public DownloadProgressCallback(MinecraftServerExecutableDownloader downloader) {
 			this.downloader = downloader;
 		}
-
+		
 		public void ReportProgress(ulong downloadedBytes, ulong totalBytes) {
 			downloader.ReportDownloadProgress(new DownloadProgressEventArgs(downloadedBytes, totalBytes));
 		}
 	}
-
-	private async Task<string?> DownloadAndGetPath(string version, string filePath) {
-		Logger.Information("Downloading server version {Version}...", version);
-
-		HttpClient http = new HttpClient();
+	
+	private static async Task<string?> DownloadAndGetPath(FileDownloadInfo fileDownloadInfo, string minecraftVersion, string filePath, DownloadProgressCallback progressCallback, CancellationToken cancellationToken) {
 		string tmpFilePath = filePath + ".tmp";
-
-		var cancellationToken = cancellationTokenSource.Token;
+		
 		try {
-			Logger.Information("Fetching version manifest from: {Url}", VersionManifestUrl);
-			var versionManifest = await FetchVersionManifest(http, cancellationToken);
-			var metadataUrl = GetVersionMetadataUrlFromManifest(version, versionManifest);
-
-			Logger.Information("Fetching metadata for version {Version} from: {Url}", version, metadataUrl);
-			var versionMetadata = await FetchVersionMetadata(http, metadataUrl, cancellationToken);
-			var serverExecutableInfo = GetServerExecutableUrlFromMetadata(versionMetadata);
-
-			Logger.Information("Downloading server executable from: {Url} ({Size})", serverExecutableInfo.DownloadUrl, serverExecutableInfo.Size.ToHumanReadable(decimalPlaces: 1));
+			Logger.Information("Downloading server version {Version} from: {Url} ({Size})", minecraftVersion, fileDownloadInfo.DownloadUrl, fileDownloadInfo.Size.ToHumanReadable(decimalPlaces: 1));
 			try {
-				await FetchServerExecutableFile(http, new DownloadProgressCallback(this), serverExecutableInfo, tmpFilePath, cancellationToken);
+				using var http = new HttpClient();
+				await FetchServerExecutableFile(http, progressCallback, fileDownloadInfo, tmpFilePath, cancellationToken);
 			} catch (Exception) {
 				TryDeleteExecutableAfterFailure(tmpFilePath);
 				throw;
 			}
-
+			
 			File.Move(tmpFilePath, filePath, true);
-			Logger.Information("Server version {Version} downloaded.", version);
-
+			Logger.Information("Server version {Version} downloaded.", minecraftVersion);
+			
 			return filePath;
 		} catch (OperationCanceledException) {
-			Logger.Information("Download for server version {Version} was cancelled.", version);
+			Logger.Information("Download for server version {Version} was cancelled.", minecraftVersion);
 			throw;
 		} catch (StopProcedureException) {
 			return null;
 		} catch (Exception e) {
 			Logger.Error(e, "An unexpected error occurred.");
 			return null;
-		} finally {
-			cancellationTokenSource.Dispose();
 		}
 	}
-
-	private static async Task<JsonElement> FetchVersionManifest(HttpClient http, CancellationToken cancellationToken) {
-		try {
-			return await http.GetFromJsonAsync<JsonElement>(VersionManifestUrl, cancellationToken);
-		} catch (HttpRequestException e) {
-			Logger.Error(e, "Unable to download version manifest.");
-			throw StopProcedureException.Instance;
-		} catch (Exception e) {
-			Logger.Error(e, "Unable to parse version manifest as JSON.");
-			throw StopProcedureException.Instance;
-		}
-	}
-
-	private static async Task<JsonElement> FetchVersionMetadata(HttpClient http, string metadataUrl, CancellationToken cancellationToken) {
-		try {
-			return await http.GetFromJsonAsync<JsonElement>(metadataUrl, cancellationToken);
-		} catch (HttpRequestException e) {
-			Logger.Error(e, "Unable to download version metadata.");
-			throw StopProcedureException.Instance;
-		} catch (Exception e) {
-			Logger.Error(e, "Unable to parse version metadata as JSON.");
-			throw StopProcedureException.Instance;
-		}
-	}
-
-	private static async Task FetchServerExecutableFile(HttpClient http, DownloadProgressCallback progressCallback, ServerExecutableInfo info, string filePath, CancellationToken cancellationToken) {
+	
+	private static async Task FetchServerExecutableFile(HttpClient http, DownloadProgressCallback progressCallback, FileDownloadInfo fileDownloadInfo, string filePath, CancellationToken cancellationToken) {
 		Sha1String downloadedFileHash;
-
+		
 		try {
-			var response = await http.GetAsync(info.DownloadUrl, HttpCompletionOption.ResponseHeadersRead, cancellationToken);
+			var response = await http.GetAsync(fileDownloadInfo.DownloadUrl, HttpCompletionOption.ResponseHeadersRead, cancellationToken);
 			response.EnsureSuccessStatusCode();
-
+			
 			await using var fileStream = new FileStream(filePath, FileMode.CreateNew, FileAccess.Write, FileShare.Read);
 			await using var responseStream = await response.Content.ReadAsStreamAsync(cancellationToken);
-
-			using var streamCopier = new MinecraftServerDownloadStreamCopier(progressCallback, info.Size.Bytes);
+			
+			using var streamCopier = new MinecraftServerDownloadStreamCopier(progressCallback, fileDownloadInfo.Size.Bytes);
 			downloadedFileHash = await streamCopier.Copy(responseStream, fileStream, cancellationToken);
 		} catch (OperationCanceledException) {
 			throw;
@@ -153,13 +139,13 @@ sealed class MinecraftServerExecutableDownloader {
 			Logger.Error(e, "Unable to download server executable.");
 			throw StopProcedureException.Instance;
 		}
-
-		if (!downloadedFileHash.Equals(info.Hash)) {
-			Logger.Error("Downloaded server executable has mismatched SHA1 hash. Expected {Expected}, got {Actual}.", info.Hash, downloadedFileHash);
+		
+		if (!downloadedFileHash.Equals(fileDownloadInfo.Hash)) {
+			Logger.Error("Downloaded server executable has mismatched SHA1 hash. Expected {Expected}, got {Actual}.", fileDownloadInfo.Hash, downloadedFileHash);
 			throw StopProcedureException.Instance;
 		}
 	}
-
+	
 	private static void TryDeleteExecutableAfterFailure(string filePath) {
 		if (File.Exists(filePath)) {
 			try {
@@ -169,119 +155,36 @@ sealed class MinecraftServerExecutableDownloader {
 			}
 		}
 	}
-
-	private static string GetVersionMetadataUrlFromManifest(string serverVersion, JsonElement versionManifest) {
-		JsonElement versionsElement = GetJsonPropertyOrThrow(versionManifest, "versions", JsonValueKind.Array, "version manifest");
-		JsonElement versionElement;
-		try {
-			versionElement = versionsElement.EnumerateArray().Single(ele => ele.TryGetProperty("id", out var id) && id.ValueKind == JsonValueKind.String && id.GetString() == serverVersion);
-		} catch (Exception) {
-			Logger.Error("Version {Version} was not found in version manifest.", serverVersion);
-			throw StopProcedureException.Instance;
-		}
-
-		JsonElement urlElement = GetJsonPropertyOrThrow(versionElement, "url", JsonValueKind.String, "version entry in version manifest");
-		string? url = urlElement.GetString();
-
-		if (!Uri.TryCreate(url, UriKind.Absolute, out var uri)) {
-			Logger.Error("The \"url\" key in version entry in version manifest does not contain a valid URL: {Url}", url);
-			throw StopProcedureException.Instance;
-		}
-
-		if (uri.Scheme != "https" || !uri.AbsolutePath.EndsWith(".json", StringComparison.OrdinalIgnoreCase)) {
-			Logger.Error("The \"url\" key in version entry in version manifest does not contain a accepted URL: {Url}", url);
-			throw StopProcedureException.Instance;
-		}
-
-		return url;
-	}
-
-	private static ServerExecutableInfo GetServerExecutableUrlFromMetadata(JsonElement versionMetadata) {
-		JsonElement downloadsElement = GetJsonPropertyOrThrow(versionMetadata, "downloads", JsonValueKind.Object, "version metadata");
-		JsonElement serverElement = GetJsonPropertyOrThrow(downloadsElement, "server", JsonValueKind.Object, "downloads object in version metadata");
-		JsonElement urlElement = GetJsonPropertyOrThrow(serverElement, "url", JsonValueKind.String, "downloads.server object in version metadata");
-		string? url = urlElement.GetString();
-
-		if (!Uri.TryCreate(url, UriKind.Absolute, out var uri)) {
-			Logger.Error("The \"url\" key in downloads.server object in version metadata does not contain a valid URL: {Url}", url);
-			throw StopProcedureException.Instance;
-		}
-
-		if (uri.Scheme != "https" || !uri.AbsolutePath.EndsWith(".jar", StringComparison.OrdinalIgnoreCase)) {
-			Logger.Error("The \"url\" key in downloads.server object in version metadata does not contain a accepted URL: {Url}", url);
-			throw StopProcedureException.Instance;
-		}
-
-		JsonElement sizeElement = GetJsonPropertyOrThrow(serverElement, "size", JsonValueKind.Number, "downloads.server object in version metadata");
-		ulong size;
-		try {
-			size = sizeElement.GetUInt64();
-		} catch (FormatException) {
-			Logger.Error("The \"size\" key in downloads.server object in version metadata contains an invalid file size: {Size}", sizeElement);
-			throw StopProcedureException.Instance;
-		}
-
-		JsonElement sha1Element = GetJsonPropertyOrThrow(serverElement, "sha1", JsonValueKind.String, "downloads.server object in version metadata");
-		Sha1String hash;
-		try {
-			hash = Sha1String.FromString(sha1Element.GetString());
-		} catch (Exception) {
-			Logger.Error("The \"sha1\" key in downloads.server object in version metadata does not contain a valid SHA-1 hash: {Sha1}", sha1Element.GetString());
-			throw StopProcedureException.Instance;
-		}
-
-		return new ServerExecutableInfo(url, hash, new FileSize(size));
-	}
-
-	private static JsonElement GetJsonPropertyOrThrow(JsonElement parentElement, string propertyKey, JsonValueKind expectedKind, string location) {
-		if (!parentElement.TryGetProperty(propertyKey, out var valueElement)) {
-			Logger.Error("Missing \"{Property}\" key in " + location + ".", propertyKey);
-			throw StopProcedureException.Instance;
-		}
-
-		if (valueElement.ValueKind != expectedKind) {
-			Logger.Error("The \"{Property}\" key in " + location + " does not contain a JSON {ExpectedType}. Actual type: {ActualType}", propertyKey, expectedKind, valueElement.ValueKind);
-			throw StopProcedureException.Instance;
-		}
-
-		return valueElement;
-	}
-
+	
 	private sealed class MinecraftServerDownloadStreamCopier : IDisposable {
 		private readonly StreamCopier streamCopier = new ();
 		private readonly IncrementalHash sha1 = IncrementalHash.CreateHash(HashAlgorithmName.SHA1);
-
+		
 		private readonly DownloadProgressCallback progressCallback;
 		private readonly ulong totalBytes;
 		private ulong readBytes;
-
+		
 		public MinecraftServerDownloadStreamCopier(DownloadProgressCallback progressCallback, ulong totalBytes) {
 			this.progressCallback = progressCallback;
 			this.totalBytes = totalBytes;
 			this.streamCopier.BufferReady += OnBufferReady;
 		}
-
+		
 		private void OnBufferReady(object? sender, StreamCopier.BufferEventArgs args) {
 			sha1.AppendData(args.Buffer.Span);
-
+			
 			readBytes += (uint) args.Buffer.Length;
 			progressCallback.ReportProgress(readBytes, totalBytes);
 		}
-
+		
 		public async Task<Sha1String> Copy(Stream source, Stream destination, CancellationToken cancellationToken) {
 			await streamCopier.Copy(source, destination, cancellationToken);
 			return Sha1String.FromBytes(sha1.GetHashAndReset());
 		}
-
+		
 		public void Dispose() {
 			sha1.Dispose();
 			streamCopier.Dispose();
 		}
 	}
-
-	private sealed class StopProcedureException : Exception {
-		public static StopProcedureException Instance { get; } = new ();
-
-		private StopProcedureException() {}
-	}
 }

Agent/Phantom.Agent.Minecraft/Server/MinecraftServerExecutables.cs

@@ -1,56 +1,64 @@
 using System.Text.RegularExpressions;
-using Phantom.Common.Logging;
+using Phantom.Common.Data.Minecraft;
+using Phantom.Utils.IO;
+using Phantom.Utils.Logging;
 using Serilog;
 
 namespace Phantom.Agent.Minecraft.Server;
 
-public sealed class MinecraftServerExecutables {
+public sealed partial class MinecraftServerExecutables {
 	private static readonly ILogger Logger = PhantomLogger.Create<MinecraftServerExecutables>();
-
-	private static readonly Regex VersionFolderSanitizeRegex = new (@"[^a-zA-Z0-9_\-\.]", RegexOptions.Compiled);
-
+	
+	[GeneratedRegex(@"[^a-zA-Z0-9_\-\.]", RegexOptions.Compiled)]
+	private static partial Regex SanitizePathRegex();
+	
 	private readonly string basePath;
 	private readonly Dictionary<string, MinecraftServerExecutableDownloader> runningDownloadersByVersion = new ();
-
+	
 	public MinecraftServerExecutables(string basePath) {
 		this.basePath = basePath;
 	}
-
-	internal async Task<string?> DownloadAndGetPath(string version, EventHandler<DownloadProgressEventArgs> progressEventHandler, CancellationToken cancellationToken) {
-		string serverExecutableFolderPath = Path.Combine(basePath, VersionFolderSanitizeRegex.Replace(version, "_"));
+	
+	internal async Task<string?> DownloadAndGetPath(FileDownloadInfo? fileDownloadInfo, string minecraftVersion, EventHandler<DownloadProgressEventArgs> progressEventHandler, CancellationToken cancellationToken) {
+		string serverExecutableFolderPath = Path.Combine(basePath, SanitizePathRegex().IsMatch(minecraftVersion) ? SanitizePathRegex().Replace(minecraftVersion, "_") : minecraftVersion);
 		string serverExecutableFilePath = Path.Combine(serverExecutableFolderPath, "server.jar");
-
+		
 		if (File.Exists(serverExecutableFilePath)) {
 			return serverExecutableFilePath;
 		}
-
+		
+		if (fileDownloadInfo == null) {
+			Logger.Error("Unable to download server executable for version {Version} because no download info was provided.", minecraftVersion);
+			return null;
+		}
+		
 		try {
-			Directory.CreateDirectory(serverExecutableFolderPath);
+			Directories.Create(serverExecutableFolderPath, Chmod.URWX_GRX);
 		} catch (Exception e) {
 			Logger.Error(e, "Unable to create folder for server executable: {ServerExecutableFolderPath}", serverExecutableFolderPath);
 			return null;
 		}
-
+		
 		MinecraftServerExecutableDownloader? downloader;
 		MinecraftServerExecutableDownloadListener listener = new (progressEventHandler, cancellationToken);
-
+		
 		lock (this) {
-			if (runningDownloadersByVersion.TryGetValue(version, out downloader)) {
-				Logger.Information("A download for server version {Version} is already running, waiting for it to finish...", version);
+			if (runningDownloadersByVersion.TryGetValue(minecraftVersion, out downloader)) {
+				Logger.Information("A download for server version {Version} is already running, waiting for it to finish...", minecraftVersion);
 				downloader.Register(listener);
 			}
 			else {
-				downloader = new MinecraftServerExecutableDownloader(version, serverExecutableFilePath, listener);
+				downloader = new MinecraftServerExecutableDownloader(fileDownloadInfo, minecraftVersion, serverExecutableFilePath, listener);
 				downloader.Completed += (_, _) => {
 					lock (this) {
-						runningDownloadersByVersion.Remove(version);
+						runningDownloadersByVersion.Remove(minecraftVersion);
 					}
 				};
 				
-				runningDownloadersByVersion[version] = downloader;
+				runningDownloadersByVersion[minecraftVersion] = downloader;
 			}
 		}
-
+		
 		return await downloader.Task.WaitAsync(cancellationToken);
 	}
 }

Agent/Phantom.Agent.Minecraft/Server/ServerExecutableInfo.cs

@@ -1,10 +0,0 @@
-using Phantom.Utils.Cryptography;
-using Phantom.Utils.IO;
-
-namespace Phantom.Agent.Minecraft.Server; 
-
-sealed record ServerExecutableInfo(
-	string DownloadUrl,
-	Sha1String Hash,
-	FileSize Size
-);

Agent/Phantom.Agent.Minecraft/Server/ServerStatusProtocol.cs

@@ -0,0 +1,94 @@
+using System.Buffers;
+using System.Buffers.Binary;
+using System.Net;
+using System.Net.Sockets;
+using System.Text;
+using Phantom.Common.Data.Instance;
+
+namespace Phantom.Agent.Minecraft.Server;
+
+public static class ServerStatusProtocol {
+	public static async Task<InstancePlayerCounts> GetPlayerCounts(ushort serverPort, CancellationToken cancellationToken) {
+		using var tcpClient = new TcpClient();
+		await tcpClient.ConnectAsync(IPAddress.Loopback, serverPort, cancellationToken);
+		var tcpStream = tcpClient.GetStream();
+		
+		// https://wiki.vg/Server_List_Ping
+		tcpStream.WriteByte(0xFE);
+		await tcpStream.FlushAsync(cancellationToken);
+		
+		short messageLength = await ReadStreamHeader(tcpStream, cancellationToken);
+		return await ReadPlayerCounts(tcpStream, messageLength * 2, cancellationToken);
+	}
+	
+	private static async Task<short> ReadStreamHeader(NetworkStream tcpStream, CancellationToken cancellationToken) {
+		var headerBuffer = ArrayPool<byte>.Shared.Rent(3);
+		try {
+			await tcpStream.ReadExactlyAsync(headerBuffer, 0, 3, cancellationToken);
+			
+			if (headerBuffer[0] != 0xFF) {
+				throw new ProtocolException("Unexpected first byte in response from server: " + headerBuffer[0]);
+			}
+			
+			short messageLength = BinaryPrimitives.ReadInt16BigEndian(headerBuffer.AsSpan(1));
+			if (messageLength <= 0) {
+				throw new ProtocolException("Unexpected message length in response from server: " + messageLength);
+			}
+			
+			return messageLength;
+		} finally {
+			ArrayPool<byte>.Shared.Return(headerBuffer);
+		}
+	}
+	
+	private static async Task<InstancePlayerCounts> ReadPlayerCounts(NetworkStream tcpStream, int messageLength, CancellationToken cancellationToken) {
+		var messageBuffer = ArrayPool<byte>.Shared.Rent(messageLength);
+		try {
+			await tcpStream.ReadExactlyAsync(messageBuffer, 0, messageLength, cancellationToken);
+			return ReadPlayerCountsFromResponse(messageBuffer.AsSpan(0, messageLength));
+		} finally {
+			ArrayPool<byte>.Shared.Return(messageBuffer);
+		}
+	}
+	
+	/// <summary>
+	/// Legacy query protocol uses the paragraph symbol (§) as separator encoded in UTF-16BE.
+	/// </summary>
+	private static readonly byte[] Separator = { 0x00, 0xA7 };
+	
+	private static InstancePlayerCounts ReadPlayerCountsFromResponse(ReadOnlySpan<byte> messageBuffer) {
+		int lastSeparator = messageBuffer.LastIndexOf(Separator);
+		int middleSeparator = messageBuffer[..lastSeparator].LastIndexOf(Separator);
+		
+		if (lastSeparator == -1 || middleSeparator == -1) {
+			throw new ProtocolException("Could not find message separators in response from server.");
+		}
+		
+		var onlinePlayerCountBuffer = messageBuffer[(middleSeparator + Separator.Length)..lastSeparator];
+		var maximumPlayerCountBuffer = messageBuffer[(lastSeparator + Separator.Length)..];
+		
+		// Player counts are integers, whose maximum string length is 10 characters.
+		Span<char> integerStringBuffer = stackalloc char[10];
+		
+		return new InstancePlayerCounts(
+			DecodeAndParsePlayerCount(onlinePlayerCountBuffer, integerStringBuffer, "online"),
+			DecodeAndParsePlayerCount(maximumPlayerCountBuffer, integerStringBuffer, "maximum")
+		);
+	}
+	
+	private static int DecodeAndParsePlayerCount(ReadOnlySpan<byte> inputBuffer, Span<char> tempCharBuffer, string countType) {
+		if (!Encoding.BigEndianUnicode.TryGetChars(inputBuffer, tempCharBuffer, out int charCount)) {
+			throw new ProtocolException("Could not decode " + countType + " player count in response from server.");
+		}
+		
+		if (!int.TryParse(tempCharBuffer, out int playerCount)) {
+			throw new ProtocolException("Could not parse " + countType + " player count in response from server: " + tempCharBuffer[..charCount].ToString());
+		}
+		
+		return playerCount;
+	}
+	
+	public sealed class ProtocolException : Exception {
+		internal ProtocolException(string message) : base(message) {}
+	}
+}

Agent/Phantom.Agent.Rpc/RpcExtensions.cs

@@ -1,19 +0,0 @@
-using NetMQ;
-using NetMQ.Sockets;
-using Phantom.Common.Messages;
-using Phantom.Common.Messages.ToServer;
-
-namespace Phantom.Agent.Rpc; 
-
-public static class RpcExtensions {
-	internal static async Task SendMessage<TMessage>(this ClientSocket socket, TMessage message) where TMessage : IMessageToServer {
-		byte[] bytes = MessageRegistries.ToServer.Write(message).ToArray();
-		if (bytes.Length > 0) {
-			await socket.SendAsync(bytes);
-		}
-	}
-	
-	public static Task SendSimpleReply<TMessage, TReplyEnum>(this ClientSocket socket, TMessage message, TReplyEnum reply) where TMessage : IMessageWithReply where TReplyEnum : Enum {
-		return SendMessage(socket, SimpleReplyMessage.FromEnum(message.SequenceId, reply));
-	}
-}

Agent/Phantom.Agent.Rpc/RpcLauncher.cs

@@ -1,73 +0,0 @@
-using NetMQ;
-using NetMQ.Sockets;
-using Phantom.Common.Data.Agent;
-using Phantom.Common.Messages;
-using Phantom.Common.Messages.ToServer;
-using Phantom.Utils.Rpc;
-using Serilog.Events;
-
-namespace Phantom.Agent.Rpc;
-
-public sealed class RpcLauncher : RpcRuntime<ClientSocket> {
-	public static async Task Launch(RpcConfiguration config, AgentAuthToken authToken, AgentInfo agentInfo, Func<ClientSocket, IMessageToAgentListener> listenerFactory) {
-		var socket = new ClientSocket();
-		var options = socket.Options;
-
-		options.CurveServerCertificate = config.ServerCertificate;
-		options.CurveCertificate = new NetMQCertificate();
-		options.HelloMessage = MessageRegistries.ToServer.Write(new RegisterAgentMessage(authToken, agentInfo)).ToArray();
-		
-		await new RpcLauncher(config, socket, agentInfo.Guid, listenerFactory).Launch();
-	}
-
-	private readonly RpcConfiguration config;
-	private readonly Guid agentGuid;
-	private readonly Func<ClientSocket, IMessageToAgentListener> messageListenerFactory;
-
-	private RpcLauncher(RpcConfiguration config, ClientSocket socket, Guid agentGuid, Func<ClientSocket, IMessageToAgentListener> messageListenerFactory) : base(socket, config.CancellationToken) {
-		this.config = config;
-		this.agentGuid = agentGuid;
-		this.messageListenerFactory = messageListenerFactory;
-	}
-
-	protected override void Connect(ClientSocket socket) {
-		var logger = config.Logger;
-		var url = config.TcpUrl;
-
-		logger.Information("Starting ZeroMQ client and connecting to {Url}...", url);
-		socket.Connect(url);
-		logger.Information("ZeroMQ client ready.");
-	}
-
-	protected override async Task Run(ClientSocket socket, CancellationToken cancellationToken) {
-		var logger = config.Logger;
-		
-		var listener = messageListenerFactory(socket);
-		
-		ServerMessaging.SetCurrentSocket(socket, cancellationToken);
-
-		// TODO optimize msg
-		await foreach (var bytes in socket.ReceiveBytesAsyncEnumerable(cancellationToken)) {
-			if (logger.IsEnabled(LogEventLevel.Verbose)) {
-				if (bytes.Length > 0 && MessageRegistries.ToAgent.TryGetType(bytes, out var type)) {
-					logger.Verbose("Received {MessageType} ({Bytes} B) from server.", type.Name, bytes.Length);
-				}
-				else {
-					logger.Verbose("Received {Bytes} B message from server.", bytes.Length);
-				}
-			}
-
-			if (bytes.Length > 0) {
-				MessageRegistries.ToAgent.Handle(bytes, listener, cancellationToken);
-			}
-		}
-	}
-
-	protected override async Task Disconnect(ClientSocket socket) {
-		var timeoutTask = Task.Delay(TimeSpan.FromSeconds(5));
-		var finishedTask = await Task.WhenAny(socket.SendMessage(new UnregisterAgentMessage(agentGuid)), timeoutTask);
-		if (finishedTask == timeoutTask) {
-			config.Logger.Error("Timed out communicating agent shutdown with the server.");
-		}
-	}
-}

Agent/Phantom.Agent.Rpc/ServerMessaging.cs

@@ -1,55 +0,0 @@
-using NetMQ.Sockets;
-using Phantom.Common.Logging;
-using Phantom.Common.Messages;
-using Phantom.Common.Messages.ToServer;
-using Serilog;
-
-namespace Phantom.Agent.Rpc;
-
-public static class ServerMessaging {
-	private static readonly ILogger Logger = PhantomLogger.Create(typeof(ServerMessaging));
-	
-	private static readonly TimeSpan KeepAliveInterval = TimeSpan.FromSeconds(10);
-
-	private static ClientSocket? CurrentSocket { get; set; }
-	private static readonly object SetCurrentSocketLock = new ();
-
-	internal static void SetCurrentSocket(ClientSocket socket, CancellationToken cancellationToken) {
-		Logger.Information("Server socket ready.");
-		
-		bool isFirstSet = false;
-		lock (SetCurrentSocketLock) {
-			if (CurrentSocket == null) {
-				isFirstSet = true;
-			}
-
-			CurrentSocket = socket;
-		}
-
-		if (isFirstSet) {
-			Task.Factory.StartNew(static o => SendKeepAliveLoop((CancellationToken) o!), cancellationToken, cancellationToken, TaskCreationOptions.LongRunning, TaskScheduler.Default);
-		}
-	}
-
-	public static async Task SendMessage<TMessage>(TMessage message) where TMessage : IMessageToServer {
-		var currentSocket = CurrentSocket ?? throw new InvalidOperationException("Server socket not ready.");
-		await currentSocket.SendMessage(message);
-	}
-
-	private static async Task SendKeepAliveLoop(CancellationToken cancellationToken) {
-		try {
-			while (true) {
-				await Task.Delay(KeepAliveInterval, cancellationToken);
-
-				var currentSocket = CurrentSocket;
-				if (currentSocket != null) {
-					await currentSocket.SendMessage(new AgentIsAliveMessage());
-				}
-			}
-		} catch (OperationCanceledException) {
-			// Ignore.
-		} finally {
-			Logger.Information("Stopped keep-alive loop.");
-		}
-	}
-}

Agent/Phantom.Agent.Services/AgentFolders.cs

@@ -1,42 +1,45 @@
-using Phantom.Common.Logging;
-using Phantom.Utils.IO;
+using Phantom.Utils.IO;
+using Phantom.Utils.Logging;
 using Serilog;
 
 namespace Phantom.Agent.Services;
 
 public sealed class AgentFolders {
 	private static readonly ILogger Logger = PhantomLogger.Create<AgentFolders>();
-
+	
 	public string DataFolderPath { get; }
 	public string InstancesFolderPath { get; }
-
+	public string BackupsFolderPath { get; }
+	
 	public string TemporaryFolderPath { get; }
 	public string ServerExecutableFolderPath { get; }
-
+	
 	public string JavaSearchFolderPath { get; }
-
+	
 	public AgentFolders(string dataFolderPath, string temporaryFolderPath, string javaSearchFolderPath) {
 		this.DataFolderPath = Path.GetFullPath(dataFolderPath);
 		this.InstancesFolderPath = Path.Combine(DataFolderPath, "instances");
+		this.BackupsFolderPath = Path.Combine(DataFolderPath, "backups");
 		
 		this.TemporaryFolderPath = Path.GetFullPath(temporaryFolderPath);
 		this.ServerExecutableFolderPath = Path.Combine(TemporaryFolderPath, "servers");
 		
 		this.JavaSearchFolderPath = javaSearchFolderPath;
 	}
-
+	
 	public bool TryCreate() {
 		return TryCreateFolder(DataFolderPath) &&
 		       TryCreateFolder(InstancesFolderPath) &&
+		       TryCreateFolder(BackupsFolderPath) &&
 		       TryCreateFolder(TemporaryFolderPath) &&
 		       TryCreateFolder(ServerExecutableFolderPath);
 	}
-
+	
 	private static bool TryCreateFolder(string folderPath) {
 		if (Directory.Exists(folderPath)) {
 			return true;
 		}
-
+		
 		try {
 			Directories.Create(folderPath, Chmod.URWX_GRX);
 			return true;

Agent/Phantom.Agent.Services/AgentServiceConfiguration.cs

@@ -0,0 +1,3 @@
+namespace Phantom.Agent.Services;
+
+public readonly record struct AgentServiceConfiguration(int MaxConcurrentCompressionTasks);

Agent/Phantom.Agent.Services/AgentServices.cs

@@ -1,28 +1,97 @@
-using Phantom.Agent.Minecraft.Java;
+using System.Collections.Immutable;
+using Akka.Actor;
+using Phantom.Agent.Minecraft.Java;
+using Phantom.Agent.Services.Backups;
 using Phantom.Agent.Services.Instances;
+using Phantom.Agent.Services.Rpc;
 using Phantom.Common.Data.Agent;
+using Phantom.Common.Data.Replies;
+using Phantom.Common.Messages.Agent.ToAgent;
+using Phantom.Common.Messages.Agent.ToController;
+using Phantom.Utils.Actor;
+using Phantom.Utils.Logging;
+using Serilog;
 
 namespace Phantom.Agent.Services;
 
 public sealed class AgentServices {
+	private static readonly ILogger Logger = PhantomLogger.Create<AgentServices>();
+	
+	public ActorSystem ActorSystem { get; }
+	
+	private AgentInfo AgentInfo { get; }
 	private AgentFolders AgentFolders { get; }
+	private AgentState AgentState { get; }
+	private BackupManager BackupManager { get; }
 	
 	internal JavaRuntimeRepository JavaRuntimeRepository { get; }
-	internal InstanceSessionManager InstanceSessionManager { get; }
-
-	public AgentServices(AgentInfo agentInfo, AgentFolders agentFolders) {
+	internal InstanceTicketManager InstanceTicketManager { get; }
+	internal ActorRef<InstanceManagerActor.ICommand> InstanceManager { get; }
+	
+	public AgentServices(AgentInfo agentInfo, AgentFolders agentFolders, AgentServiceConfiguration serviceConfiguration, ControllerConnection controllerConnection) {
+		this.ActorSystem = ActorSystemFactory.Create("Agent");
+		
+		this.AgentInfo = agentInfo;
 		this.AgentFolders = agentFolders;
+		this.AgentState = new AgentState();
+		this.BackupManager = new BackupManager(agentFolders, serviceConfiguration.MaxConcurrentCompressionTasks);
+		
 		this.JavaRuntimeRepository = new JavaRuntimeRepository();
-		this.InstanceSessionManager = new InstanceSessionManager(agentInfo, agentFolders, JavaRuntimeRepository);
+		this.InstanceTicketManager = new InstanceTicketManager(agentInfo, controllerConnection);
+		
+		var instanceManagerInit = new InstanceManagerActor.Init(controllerConnection, agentFolders, AgentState, JavaRuntimeRepository, InstanceTicketManager, BackupManager);
+		this.InstanceManager = ActorSystem.ActorOf(InstanceManagerActor.Factory(instanceManagerInit), "InstanceManager");
 	}
-
+	
 	public async Task Initialize() {
 		await foreach (var runtime in JavaRuntimeDiscovery.Scan(AgentFolders.JavaSearchFolderPath)) {
 			JavaRuntimeRepository.Include(runtime);
 		}
 	}
-
+	
+	public  async Task<bool> Register(ControllerConnection connection, CancellationToken cancellationToken) {
+		Logger.Information("Registering with the controller...");
+		
+		ImmutableArray<ConfigureInstanceMessage> configureInstanceMessages;
+		try {
+			configureInstanceMessages = await connection.Send<RegisterAgentMessage, ImmutableArray<ConfigureInstanceMessage>>(new RegisterAgentMessage(AgentInfo), TimeSpan.FromMinutes(1), cancellationToken);
+		} catch (Exception e) {
+			Logger.Fatal(e, "Registration failed.");
+			return false;
+		}
+		
+		foreach (var configureInstanceMessage in configureInstanceMessages) {
+			var configureInstanceCommand = new InstanceManagerActor.ConfigureInstanceCommand(
+				configureInstanceMessage.InstanceGuid,
+				configureInstanceMessage.Configuration,
+				configureInstanceMessage.LaunchProperties,
+				configureInstanceMessage.LaunchNow,
+				AlwaysReportStatus: true
+			);
+			
+			var configureInstanceResult = await InstanceManager.Request(configureInstanceCommand, cancellationToken);
+			if (!configureInstanceResult.Is(ConfigureInstanceResult.Success)) {
+				Logger.Fatal("Unable to configure instance \"{Name}\" (GUID {Guid}), shutting down.", configureInstanceMessage.Configuration.InstanceName, configureInstanceMessage.InstanceGuid);
+				return false;
+			}
+		}
+		
+		await connection.Send(new AdvertiseJavaRuntimesMessage(JavaRuntimeRepository.All), cancellationToken);
+		InstanceTicketManager.RefreshAgentStatus();
+		
+		return true;
+	}
+	
 	public async Task Shutdown() {
-		await InstanceSessionManager.StopAll();
+		Logger.Information("Stopping services...");
+		
+		await InstanceManager.Stop(new InstanceManagerActor.ShutdownCommand());
+		
+		BackupManager.Dispose();
+		
+		await ActorSystem.Terminate();
+		ActorSystem.Dispose();
+		
+		Logger.Information("Services stopped.");
 	}
 }

Agent/Phantom.Agent.Services/AgentState.cs

@@ -0,0 +1,15 @@
+using System.Collections.Immutable;
+using Phantom.Agent.Services.Instances;
+using Phantom.Utils.Actor.Event;
+
+namespace Phantom.Agent.Services;
+
+sealed class AgentState {
+	private readonly ObservableState<ImmutableDictionary<Guid, Instance>> instancesByGuid = new (ImmutableDictionary<Guid, Instance>.Empty);
+	
+	public ImmutableDictionary<Guid, Instance> InstancesByGuid => instancesByGuid.State;
+	
+	public void UpdateInstance(Instance instance) {
+		instancesByGuid.PublisherSide.Publish(static (instancesByGuid, instance) => instancesByGuid.SetItem(instance.InstanceGuid, instance), instance);
+	}
+}

Agent/Phantom.Agent.Services/Backups/BackupArchiver.cs

@@ -0,0 +1,180 @@
+using System.Collections.Immutable;
+using System.Diagnostics.CodeAnalysis;
+using System.Formats.Tar;
+using Phantom.Agent.Minecraft.Instance;
+using Phantom.Common.Data.Backups;
+using Phantom.Utils.IO;
+using Phantom.Utils.Logging;
+using Serilog;
+
+namespace Phantom.Agent.Services.Backups;
+
+sealed class BackupArchiver {
+	private readonly string destinationBasePath;
+	private readonly string temporaryBasePath;
+	private readonly ILogger logger;
+	private readonly InstanceProperties instanceProperties;
+	private readonly CancellationToken cancellationToken;
+	
+	public BackupArchiver(string destinationBasePath, string temporaryBasePath, string loggerName, InstanceProperties instanceProperties, CancellationToken cancellationToken) {
+		this.destinationBasePath = destinationBasePath;
+		this.temporaryBasePath = temporaryBasePath;
+		this.logger = PhantomLogger.Create<BackupArchiver>(loggerName);
+		this.instanceProperties = instanceProperties;
+		this.cancellationToken = cancellationToken;
+	}
+	
+	private bool IsFolderSkipped(ImmutableList<string> relativePath) {
+		return relativePath is ["cache" or "crash-reports" or "debug" or "libraries" or "logs" or "mods" or "versions"];
+	}
+	
+	[SuppressMessage("ReSharper", "ConvertIfStatementToReturnStatement")]
+	private bool IsFileSkipped(ImmutableList<string> relativePath) {
+		var name = relativePath[^1];
+		
+		if (relativePath.Count == 2 && name == "session.lock") {
+			return true;
+		}
+		
+		var extension = Path.GetExtension(name);
+		if (extension is ".jar" or ".zip") {
+			return true;
+		}
+		
+		return false;
+	}
+	
+	public async Task<string?> ArchiveWorld(BackupCreationResult.Builder resultBuilder) {
+		string guid = instanceProperties.InstanceGuid.ToString();
+		string currentDateTime = DateTime.Now.ToString("yyyyMMdd-HHmmss");
+		string backupFolderPath = Path.Combine(destinationBasePath, guid);
+		string backupFilePath = Path.Combine(backupFolderPath, currentDateTime + ".tar");
+		
+		if (File.Exists(backupFilePath)) {
+			resultBuilder.Kind = BackupCreationResultKind.BackupFileAlreadyExists;
+			logger.Warning("Skipping backup, file already exists: {File}", backupFilePath);
+			return null;
+		}
+		
+		try {
+			Directories.Create(backupFolderPath, Chmod.URWX_GRX);
+		} catch (Exception e) {
+			resultBuilder.Kind = BackupCreationResultKind.CouldNotCreateBackupFolder;
+			logger.Error(e, "Could not create backup folder: {Folder}", backupFolderPath);
+			return null;
+		}
+		
+		string temporaryFolderPath = Path.Combine(temporaryBasePath, guid + "_" + currentDateTime);
+		if (!await CopyWorldAndCreateTarArchive(temporaryFolderPath, backupFilePath, resultBuilder)) {
+			return null;
+		}
+		
+		logger.Debug("Created world backup: {FilePath}", backupFilePath);
+		return backupFilePath;
+	}
+	
+	private async Task<bool> CopyWorldAndCreateTarArchive(string temporaryFolderPath, string backupFilePath, BackupCreationResult.Builder resultBuilder) {
+		try {
+			if (!await CopyWorldToTemporaryFolder(temporaryFolderPath)) {
+				resultBuilder.Kind = BackupCreationResultKind.CouldNotCopyWorldToTemporaryFolder;
+				return false;
+			}
+			
+			if (!await CreateTarArchive(temporaryFolderPath, backupFilePath)) {
+				resultBuilder.Kind = BackupCreationResultKind.CouldNotCreateWorldArchive;
+				return false;
+			}
+			
+			return true;
+		} finally {
+			try {
+				Directory.Delete(temporaryFolderPath, recursive: true);
+			} catch (Exception e) {
+				resultBuilder.Warnings |= BackupCreationWarnings.CouldNotDeleteTemporaryFolder;
+				logger.Error(e, "Could not delete temporary world folder: {Folder}", temporaryFolderPath);
+			}
+		}
+	}
+	
+	private async Task<bool> CopyWorldToTemporaryFolder(string temporaryFolderPath) {
+		try {
+			await CopyDirectory(new DirectoryInfo(instanceProperties.InstanceFolder), temporaryFolderPath, ImmutableList<string>.Empty);
+			return true;
+		} catch (Exception e) {
+			logger.Error(e, "Could not copy world to temporary folder.");
+			return false;
+		}
+	}
+	
+	private async Task<bool> CreateTarArchive(string sourceFolderPath, string backupFilePath) {
+		try {
+			await TarFile.CreateFromDirectoryAsync(sourceFolderPath, backupFilePath, false, cancellationToken);
+			return true;
+		} catch (Exception e) {
+			logger.Error(e, "Could not create archive.");
+			DeleteBrokenArchiveFile(backupFilePath);
+			return false;
+		}
+	}
+	
+	private void DeleteBrokenArchiveFile(string filePath) {
+		if (File.Exists(filePath)) {
+			try {
+				File.Delete(filePath);
+			} catch (Exception e) {
+				logger.Error(e, "Could not delete broken archive: {File}", filePath);
+			}
+		}
+	}
+	
+	private async Task CopyDirectory(DirectoryInfo sourceFolder, string destinationFolderPath, ImmutableList<string> relativePath) {
+		cancellationToken.ThrowIfCancellationRequested();
+		
+		bool needsToCreateFolder = true;
+		
+		foreach (FileInfo file in sourceFolder.EnumerateFiles()) {
+			var filePath = relativePath.Add(file.Name);
+			if (IsFileSkipped(filePath)) {
+				logger.Debug("Skipping file: {File}", string.Join('/', filePath));
+				continue;
+			}
+			
+			if (needsToCreateFolder) {
+				needsToCreateFolder = false;
+				Directories.Create(destinationFolderPath, Chmod.URWX);
+			}
+			
+			await CopyFileWithRetries(file, destinationFolderPath);
+		}
+		
+		foreach (DirectoryInfo directory in sourceFolder.EnumerateDirectories()) {
+			var folderPath = relativePath.Add(directory.Name);
+			if (IsFolderSkipped(folderPath)) {
+				logger.Debug("Skipping folder: {Folder}", string.Join('/', folderPath));
+				continue;
+			}
+			
+			await CopyDirectory(directory, Path.Join(destinationFolderPath, directory.Name), folderPath);
+		}
+	}
+	
+	private async Task CopyFileWithRetries(FileInfo sourceFile, string destinationFolderPath) {
+		var destinationFilePath = Path.Combine(destinationFolderPath, sourceFile.Name);
+		
+		const int TotalAttempts = 10;
+		for (int attempt = 1; attempt <= TotalAttempts; attempt++) {
+			try {
+				sourceFile.CopyTo(destinationFilePath);
+				return;
+			} catch (IOException) {
+				if (attempt == TotalAttempts) {
+					throw;
+				}
+				else {
+					logger.Warning("Failed copying file {File}, retrying...", sourceFile.FullName);
+					await Task.Delay(200, cancellationToken);
+				}
+			}
+		}
+	}
+}

Agent/Phantom.Agent.Services/Backups/BackupCompressor.cs

@@ -0,0 +1,67 @@
+using Phantom.Utils.Logging;
+using Phantom.Utils.Processes;
+using Serilog;
+
+namespace Phantom.Agent.Services.Backups;
+
+static class BackupCompressor {
+	private static ILogger Logger { get; } = PhantomLogger.Create(nameof(BackupCompressor));
+	private static ILogger ZstdLogger { get; } = PhantomLogger.Create(nameof(BackupCompressor), "Zstd");
+	
+	private const string Quality = "-10";
+	private const string Memory = "--long=26";
+	private const string Threads = "-T3";
+	
+	public static async Task<string?> Compress(string sourceFilePath, CancellationToken cancellationToken) {
+		if (sourceFilePath.Contains('"')) {
+			Logger.Error("Could not compress backup, archive path contains quotes: {Path}", sourceFilePath);
+			return null;
+		}
+		
+		var destinationFilePath = sourceFilePath + ".zst";
+		
+		if (!await TryCompressFile(sourceFilePath, destinationFilePath, cancellationToken)) {
+			try {
+				File.Delete(destinationFilePath);
+			} catch (Exception e) {
+				Logger.Error(e, "Could not delete compresed archive after unsuccessful compression: {Path}", destinationFilePath);
+			}
+			
+			return null;
+		}
+		
+		return destinationFilePath;
+	}
+	
+	private static async Task<bool> TryCompressFile(string sourceFilePath, string destinationFilePath, CancellationToken cancellationToken) {
+		var workingDirectory = Path.GetDirectoryName(sourceFilePath);
+		if (string.IsNullOrEmpty(workingDirectory)) {
+			Logger.Error("Invalid destination path: {Path}", destinationFilePath);
+			return false;
+		}
+		
+		var launcher = new ProcessConfigurator {
+			FileName = "zstd",
+			WorkingDirectory = workingDirectory,
+			ArgumentList = {
+				Quality,
+				Memory,
+				Threads,
+				"--rm",
+				"--no-progress",
+				"-o", destinationFilePath,
+				"--", sourceFilePath
+			}
+		};
+		
+		static void OnZstdOutput(object? sender, Process.Output output) {
+			if (!string.IsNullOrWhiteSpace(output.Line)) {
+				ZstdLogger.Debug("[Output] {Line}", output.Line);
+			}
+		}
+		
+		var process = new OneShotProcess(ZstdLogger, launcher);
+		process.OutputReceived += OnZstdOutput;
+		return await process.Run(cancellationToken);
+	}
+}

Agent/Phantom.Agent.Services/Backups/BackupManager.cs

@@ -0,0 +1,140 @@
+using Phantom.Agent.Minecraft.Instance;
+using Phantom.Common.Data.Backups;
+using Phantom.Utils.Logging;
+using Serilog;
+
+namespace Phantom.Agent.Services.Backups;
+
+sealed class BackupManager : IDisposable {
+	private readonly string destinationBasePath;
+	private readonly string temporaryBasePath;
+	private readonly SemaphoreSlim compressionSemaphore;
+	
+	public BackupManager(AgentFolders agentFolders, int maxConcurrentCompressionTasks) {
+		this.destinationBasePath = agentFolders.BackupsFolderPath;
+		this.temporaryBasePath = Path.Combine(agentFolders.TemporaryFolderPath, "backups");
+		this.compressionSemaphore = new SemaphoreSlim(maxConcurrentCompressionTasks, maxConcurrentCompressionTasks);
+	}
+	
+	public Task<BackupCreationResult> CreateBackup(string loggerName, InstanceProcess process, CancellationToken cancellationToken) {
+		return new BackupCreator(this, loggerName, process, cancellationToken).CreateBackup();
+	}
+	
+	public void Dispose() {
+		compressionSemaphore.Dispose();
+	}
+	
+	private sealed class BackupCreator {
+		private readonly BackupManager manager;
+		private readonly string loggerName;
+		private readonly ILogger logger;
+		private readonly InstanceProcess process;
+		private readonly CancellationToken cancellationToken;
+		
+		public BackupCreator(BackupManager manager, string loggerName, InstanceProcess process, CancellationToken cancellationToken) {
+			this.manager = manager;
+			this.loggerName = loggerName;
+			this.logger = PhantomLogger.Create<BackupManager>(loggerName);
+			this.process = process;
+			this.cancellationToken = cancellationToken;
+		}
+		
+		public async Task<BackupCreationResult> CreateBackup() {
+			logger.Information("Backup started.");
+			
+			var resultBuilder = new BackupCreationResult.Builder();
+			string? backupFilePath;
+			
+			using (var dispatcher = new BackupServerCommandDispatcher(logger, process, cancellationToken)) {
+				backupFilePath = await CreateWorldArchive(dispatcher, resultBuilder);
+			}
+			
+			if (backupFilePath != null) {
+				await CompressWorldArchive(backupFilePath, resultBuilder);
+			}
+			
+			var result = resultBuilder.Build();
+			LogBackupResult(result);
+			return result;
+		}
+		
+		private async Task<string?> CreateWorldArchive(BackupServerCommandDispatcher dispatcher, BackupCreationResult.Builder resultBuilder) {
+			try {
+				await dispatcher.DisableAutomaticSaving();
+				await dispatcher.SaveAllChunks();
+				return await new BackupArchiver(manager.destinationBasePath, manager.temporaryBasePath, loggerName, process.InstanceProperties, cancellationToken).ArchiveWorld(resultBuilder);
+			} catch (OperationCanceledException) {
+				resultBuilder.Kind = BackupCreationResultKind.BackupCancelled;
+				logger.Warning("Backup creation was cancelled.");
+				return null;
+			} catch (TimeoutException) {
+				resultBuilder.Kind = BackupCreationResultKind.BackupTimedOut;
+				logger.Warning("Backup creation timed out.");
+				return null;
+			} catch (Exception e) {
+				resultBuilder.Kind = BackupCreationResultKind.UnknownError;
+				logger.Error(e, "Caught exception while creating an instance backup.");
+				return null;
+			} finally {
+				try {
+					await dispatcher.EnableAutomaticSaving();
+				} catch (OperationCanceledException) {
+					// Ignore.
+				} catch (TimeoutException) {
+					resultBuilder.Warnings |= BackupCreationWarnings.CouldNotRestoreAutomaticSaving;
+					logger.Warning("Timed out waiting for automatic saving to be re-enabled.");
+				} catch (Exception e) {
+					resultBuilder.Warnings |= BackupCreationWarnings.CouldNotRestoreAutomaticSaving;
+					logger.Error(e, "Caught exception while enabling automatic saving after creating an instance backup.");
+				}
+			}
+		}
+		
+		private async Task CompressWorldArchive(string filePath, BackupCreationResult.Builder resultBuilder) {
+			if (!await manager.compressionSemaphore.WaitAsync(TimeSpan.FromSeconds(1), cancellationToken)) {
+				logger.Information("Too many compression tasks running, waiting for one of them to complete...");
+				await manager.compressionSemaphore.WaitAsync(cancellationToken);
+			}
+			
+			logger.Information("Compressing backup...");
+			try {
+				var compressedFilePath = await BackupCompressor.Compress(filePath, cancellationToken);
+				if (compressedFilePath == null) {
+					resultBuilder.Warnings |= BackupCreationWarnings.CouldNotCompressWorldArchive;
+				}
+			} finally {
+				manager.compressionSemaphore.Release();
+			}
+		}
+		
+		private void LogBackupResult(BackupCreationResult result) {
+			if (result.Kind != BackupCreationResultKind.Success) {
+				logger.Warning("Backup failed: {Reason}", DescribeResult(result.Kind));
+				return;
+			}
+			
+			var warningCount = result.Warnings.Count();
+			if (warningCount > 0) {
+				logger.Warning("Backup finished with {Warnings} warning(s).", warningCount);
+			}
+			else {
+				logger.Information("Backup finished successfully.");
+			}
+		}
+		
+		private static string DescribeResult(BackupCreationResultKind kind) {
+			return kind switch {
+				BackupCreationResultKind.Success                            => "Backup created successfully.",
+				BackupCreationResultKind.InstanceNotRunning                 => "Instance is not running.",
+				BackupCreationResultKind.BackupCancelled                    => "Backup cancelled.",
+				BackupCreationResultKind.BackupTimedOut                     => "Backup timed out.",
+				BackupCreationResultKind.BackupAlreadyRunning               => "A backup is already being created.",
+				BackupCreationResultKind.BackupFileAlreadyExists            => "Backup with the same name already exists.",
+				BackupCreationResultKind.CouldNotCreateBackupFolder         => "Could not create backup folder.",
+				BackupCreationResultKind.CouldNotCopyWorldToTemporaryFolder => "Could not copy world to temporary folder.",
+				BackupCreationResultKind.CouldNotCreateWorldArchive         => "Could not create world archive.",
+				_                                                           => "Unknown error."
+			};
+		}
+	}
+}

Agent/Phantom.Agent.Services/Backups/BackupScheduler.cs

@@ -0,0 +1,85 @@
+using Phantom.Agent.Services.Instances;
+using Phantom.Agent.Services.Instances.State;
+using Phantom.Common.Data.Backups;
+using Phantom.Utils.Logging;
+using Phantom.Utils.Tasks;
+
+namespace Phantom.Agent.Services.Backups;
+
+sealed class BackupScheduler : CancellableBackgroundTask {
+	// TODO make configurable
+	private static readonly TimeSpan InitialDelay = TimeSpan.FromMinutes(2);
+	private static readonly TimeSpan BackupInterval = TimeSpan.FromMinutes(30);
+	private static readonly TimeSpan BackupFailureRetryDelay = TimeSpan.FromMinutes(5);
+	
+	private readonly BackupManager backupManager;
+	private readonly InstanceContext context;
+	private readonly SemaphoreSlim backupSemaphore = new (1, 1);
+	private readonly ManualResetEventSlim serverOutputWhileWaitingForOnlinePlayers = new ();
+	private readonly InstancePlayerCountTracker playerCountTracker;
+	
+	public event EventHandler<BackupCreationResult>? BackupCompleted;
+	
+	public BackupScheduler(InstanceContext context, InstancePlayerCountTracker playerCountTracker) : base(PhantomLogger.Create<BackupScheduler>(context.ShortName)) {
+		this.backupManager = context.Services.BackupManager;
+		this.context = context;
+		this.playerCountTracker = playerCountTracker;
+		Start();
+	}
+	
+	protected override async Task RunTask() {
+		await Task.Delay(InitialDelay, CancellationToken);
+		Logger.Information("Starting a new backup after server launched.");
+		
+		while (!CancellationToken.IsCancellationRequested) {
+			var result = await CreateBackup();
+			BackupCompleted?.Invoke(this, result);
+			
+			if (result.Kind.ShouldRetry()) {
+				Logger.Warning("Scheduled backup failed, retrying in {Minutes} minutes.", BackupFailureRetryDelay.TotalMinutes);
+				await Task.Delay(BackupFailureRetryDelay, CancellationToken);
+			}
+			else {
+				Logger.Information("Scheduling next backup in {Minutes} minutes.", BackupInterval.TotalMinutes);
+				await Task.Delay(BackupInterval, CancellationToken);
+				await WaitForOnlinePlayers();
+			}
+		}
+	}
+	
+	private async Task<BackupCreationResult> CreateBackup() {
+		if (!await backupSemaphore.WaitAsync(TimeSpan.FromSeconds(1))) {
+			return new BackupCreationResult(BackupCreationResultKind.BackupAlreadyRunning);
+		}
+		
+		try {
+			context.ActorCancellationToken.ThrowIfCancellationRequested();
+			return await context.Actor.Request(new InstanceActor.BackupInstanceCommand(backupManager), context.ActorCancellationToken);
+		} catch (OperationCanceledException) {
+			return new BackupCreationResult(BackupCreationResultKind.InstanceNotRunning);
+		} finally {
+			backupSemaphore.Release();
+		}
+	}
+	
+	private async Task WaitForOnlinePlayers() {
+		var task = playerCountTracker.WaitForOnlinePlayers(CancellationToken);
+		if (!task.IsCompleted) {
+			Logger.Information("Waiting for someone to join before starting a new backup.");
+		}
+		
+		try {
+			await task;
+			Logger.Information("Players are online, starting a new backup.");
+		} catch (OperationCanceledException) {
+			throw;
+		} catch (Exception) {
+			Logger.Warning("Could not detect whether any players are online, starting a new backup.");
+		}
+	}
+	
+	protected override void Dispose() {
+		backupSemaphore.Dispose();
+		serverOutputWhileWaitingForOnlinePlayers.Dispose();
+	}
+}

Agent/Phantom.Agent.Services/Backups/BackupServerCommandDispatcher.cs

@@ -0,0 +1,98 @@
+using System.Collections.Immutable;
+using System.Text.RegularExpressions;
+using Phantom.Agent.Minecraft.Command;
+using Phantom.Agent.Minecraft.Instance;
+using Phantom.Utils.Tasks;
+using Serilog;
+
+namespace Phantom.Agent.Services.Backups;
+
+sealed partial class BackupServerCommandDispatcher : IDisposable {
+	[GeneratedRegex(@"^(?:(?:\[.*?\] \[Server thread/INFO\].*?:)|(?:[\d-]+? [\d:]+? \[INFO\])) (.*?)$", RegexOptions.NonBacktracking)]
+	private static partial Regex ServerThreadInfoRegex();
+	
+	private static readonly ImmutableHashSet<string> AutomaticSavingDisabledMessages = ImmutableHashSet.Create(
+		"Automatic saving is now disabled",
+		"Turned off world auto-saving",
+		"CONSOLE: Disabling level saving.."
+	);
+	
+	private static readonly ImmutableHashSet<string> SavedTheGameMessages = ImmutableHashSet.Create(
+		"Saved the game",
+		"Saved the world",
+		"CONSOLE: Save complete."
+	);
+	
+	private static readonly ImmutableHashSet<string> AutomaticSavingEnabledMessages = ImmutableHashSet.Create(
+		"Automatic saving is now enabled",
+		"Turned on world auto-saving",
+		"CONSOLE: Enabling level saving.."
+	);
+	
+	private readonly ILogger logger;
+	private readonly InstanceProcess process;
+	private readonly CancellationToken cancellationToken;
+	
+	private readonly TaskCompletionSource automaticSavingDisabled = AsyncTasks.CreateCompletionSource();
+	private readonly TaskCompletionSource savedTheGame = AsyncTasks.CreateCompletionSource();
+	private readonly TaskCompletionSource automaticSavingEnabled = AsyncTasks.CreateCompletionSource();
+	
+	public BackupServerCommandDispatcher(ILogger logger, InstanceProcess process, CancellationToken cancellationToken) {
+		this.logger = logger;
+		this.process = process;
+		this.cancellationToken = cancellationToken;
+		
+		this.process.AddOutputListener(OnOutput, maxLinesToReadFromHistory: 0);
+	}
+	
+	void IDisposable.Dispose() {
+		process.RemoveOutputListener(OnOutput);
+	}
+	
+	public async Task DisableAutomaticSaving() {
+		await process.SendCommand(MinecraftCommand.SaveOff, cancellationToken);
+		await automaticSavingDisabled.Task.WaitAsync(TimeSpan.FromSeconds(30), cancellationToken);
+	}
+	
+	public async Task SaveAllChunks() {
+		await process.SendCommand(MinecraftCommand.SaveAll(flush: true), cancellationToken);
+		await savedTheGame.Task.WaitAsync(TimeSpan.FromMinutes(1), cancellationToken);
+	}
+	
+	public async Task EnableAutomaticSaving() {
+		await process.SendCommand(MinecraftCommand.SaveOn, cancellationToken);
+		await automaticSavingEnabled.Task.WaitAsync(TimeSpan.FromMinutes(1), cancellationToken);
+	}
+	
+	private void OnOutput(object? sender, string? line) {
+		if (line == null) {
+			return;
+		}
+		
+		var match = ServerThreadInfoRegex().Match(line);
+		if (!match.Success) {
+			return;
+		}
+		
+		string info = match.Groups[1].Value;
+		
+		if (!automaticSavingDisabled.Task.IsCompleted) {
+			if (AutomaticSavingDisabledMessages.Contains(info)) {
+				logger.Debug("Detected that automatic saving is disabled.");
+				automaticSavingDisabled.SetResult();
+			}
+		}
+		else if (!savedTheGame.Task.IsCompleted) {
+			if (SavedTheGameMessages.Contains(info)) {
+				logger.Debug("Detected that the game is saved.");
+				savedTheGame.SetResult();
+			}
+		}
+		else if (!automaticSavingEnabled.Task.IsCompleted) {
+			if (AutomaticSavingEnabledMessages.Contains(info)) {
+				logger.Debug("Detected that automatic saving is enabled.");
+				automaticSavingEnabled.SetResult();
+			}
+		}
+	}
+}

Agent/Phantom.Agent.Services/Instances/Instance.cs

@@ -1,172 +1,5 @@
-using Phantom.Agent.Minecraft.Launcher;
-using Phantom.Agent.Rpc;
-using Phantom.Agent.Services.Instances.States;
-using Phantom.Common.Data.Instance;
-using Phantom.Common.Data.Replies;
-using Phantom.Common.Logging;
-using Phantom.Common.Messages.ToServer;
-using Serilog;
+using Phantom.Common.Data.Instance;
 
 namespace Phantom.Agent.Services.Instances;
 
-sealed class Instance : IDisposable {
-	private static uint loggerSequenceId = 0;
-
-	private static string GetLoggerName(Guid guid) {
-		var prefix = guid.ToString();
-		return prefix[..prefix.IndexOf('-')] + "/" + Interlocked.Increment(ref loggerSequenceId);
-	}
-
-	public static async Task<Instance> Create(InstanceConfiguration configuration, BaseLauncher launcher, LaunchServices launchServices, PortManager portManager) {
-		var instance = new Instance(configuration, launcher, launchServices, portManager);
-		await instance.ReportLastStatus();
-		return instance;
-	}
-
-	public InstanceConfiguration Configuration { get; private set; }
-	private BaseLauncher Launcher { get; set; }
-
-	private readonly string shortName;
-	private readonly ILogger logger;
-
-	private readonly LaunchServices launchServices;
-	private readonly PortManager portManager;
-
-	private InstanceStatus currentStatus;
-	private IInstanceState currentState;
-	private readonly SemaphoreSlim stateTransitioningActionSemaphore = new (1, 1);
-
-	private Instance(InstanceConfiguration configuration, BaseLauncher launcher, LaunchServices launchServices, PortManager portManager) {
-		this.shortName = GetLoggerName(configuration.InstanceGuid);
-		this.logger = PhantomLogger.Create<Instance>(shortName);
-
-		this.Configuration = configuration;
-		this.Launcher = launcher;
-
-		this.launchServices = launchServices;
-		this.portManager = portManager;
-		this.currentState = new InstanceNotRunningState();
-		this.currentStatus = InstanceStatus.IsNotRunning;
-	}
-
-	private async Task ReportLastStatus() {
-		await ServerMessaging.SendMessage(new ReportInstanceStatusMessage(Configuration.InstanceGuid, currentStatus));
-	}
-	
-	private bool TransitionState(IInstanceState newState) {
-		if (currentState == newState) {
-			return false;
-		}
-
-		if (currentState is IDisposable disposable) {
-			disposable.Dispose();
-		}
-
-		currentState = newState;
-		return true;
-	}
-
-	public async Task Reconfigure(InstanceConfiguration configuration, BaseLauncher launcher, CancellationToken cancellationToken) {
-		await stateTransitioningActionSemaphore.WaitAsync(cancellationToken);
-		try {
-			Configuration = configuration;
-			Launcher = launcher;
-			await ReportLastStatus();
-		} finally {
-			stateTransitioningActionSemaphore.Release();
-		}
-	}
-
-	public async Task<LaunchInstanceResult> Launch(CancellationToken cancellationToken) {
-		await stateTransitioningActionSemaphore.WaitAsync(cancellationToken);
-		try {
-			if (TransitionState(currentState.Launch(new InstanceContextImpl(this)))) {
-				return LaunchInstanceResult.LaunchInitiated;
-			}
-
-			return currentState switch {
-				InstanceLaunchingState => LaunchInstanceResult.InstanceAlreadyLaunching,
-				InstanceRunningState   => LaunchInstanceResult.InstanceAlreadyRunning,
-				InstanceStoppingState  => LaunchInstanceResult.InstanceIsStopping,
-				_                      => LaunchInstanceResult.UnknownError
-			};
-		} finally {
-			stateTransitioningActionSemaphore.Release();
-		}
-	}
-
-	public async Task<StopInstanceResult> Stop() {
-		await stateTransitioningActionSemaphore.WaitAsync();
-		try {
-			if (TransitionState(currentState.Stop())) {
-				return StopInstanceResult.StopInitiated;
-			}
-
-			return currentState switch {
-				InstanceNotRunningState => StopInstanceResult.InstanceAlreadyStopped,
-				InstanceLaunchingState  => StopInstanceResult.StopInitiated,
-				InstanceStoppingState   => StopInstanceResult.InstanceAlreadyStopping,
-				_                       => StopInstanceResult.UnknownError
-			};
-		} finally {
-			stateTransitioningActionSemaphore.Release();
-		}
-	}
-
-	public async Task StopAndWait(TimeSpan waitTime) {
-		await Stop();
-
-		using var waitTokenSource = new CancellationTokenSource(waitTime);
-		var waitToken = waitTokenSource.Token;
-
-		while (currentState is not InstanceNotRunningState) {
-			await Task.Delay(TimeSpan.FromMilliseconds(250), waitToken);
-		}
-	}
-
-	public async Task<bool> SendCommand(string command, CancellationToken cancellationToken) {
-		return await currentState.SendCommand(command, cancellationToken);
-	}
-
-	private sealed class InstanceContextImpl : InstanceContext {
-		private readonly Instance instance;
-		private int statusUpdateCounter;
-
-		public InstanceContextImpl(Instance instance) : base(instance.Configuration, instance.Launcher) {
-			this.instance = instance;
-		}
-
-		public override LaunchServices LaunchServices => instance.launchServices;
-		public override PortManager PortManager => instance.portManager;
-		public override ILogger Logger => instance.logger;
-		public override string ShortName => instance.shortName;
-
-		public override void ReportStatus(InstanceStatus newStatus) {
-			int myStatusUpdateCounter = Interlocked.Increment(ref statusUpdateCounter);
-			
-			Task.Run(async () => {
-				if (myStatusUpdateCounter == statusUpdateCounter) {
-					instance.currentStatus = newStatus;
-					await ServerMessaging.SendMessage(new ReportInstanceStatusMessage(Configuration.InstanceGuid, newStatus));
-				}
-			});
-		}
-
-		public override void TransitionState(Func<IInstanceState> newState) {
-			instance.stateTransitioningActionSemaphore.Wait();
-			try {
-				instance.TransitionState(newState());
-			} finally {
-				instance.stateTransitioningActionSemaphore.Release();
-			}
-		}
-	}
-
-	public void Dispose() {
-		if (currentState is IDisposable disposable) {
-			disposable.Dispose();
-		}
-
-		stateTransitioningActionSemaphore.Dispose();
-	}
-}
+sealed record Instance(Guid InstanceGuid, IInstanceStatus Status);

Agent/Phantom.Agent.Services/Instances/InstanceActor.cs

@@ -0,0 +1,161 @@
+using Phantom.Agent.Minecraft.Launcher;
+using Phantom.Agent.Services.Backups;
+using Phantom.Agent.Services.Instances.State;
+using Phantom.Common.Data.Backups;
+using Phantom.Common.Data.Instance;
+using Phantom.Common.Data.Minecraft;
+using Phantom.Common.Data.Replies;
+using Phantom.Common.Messages.Agent.ToController;
+using Phantom.Utils.Actor;
+using Phantom.Utils.Actor.Mailbox;
+using Phantom.Utils.Logging;
+
+namespace Phantom.Agent.Services.Instances;
+
+sealed class InstanceActor : ReceiveActor<InstanceActor.ICommand> {
+	public readonly record struct Init(AgentState AgentState, Guid InstanceGuid, string ShortName, InstanceServices InstanceServices, InstanceTicketManager InstanceTicketManager, CancellationToken ShutdownCancellationToken);
+	
+	public static Props<ICommand> Factory(Init init) {
+		return Props<ICommand>.Create(() => new InstanceActor(init), new ActorConfiguration { SupervisorStrategy = SupervisorStrategies.Resume, MailboxType = UnboundedJumpAheadMailbox.Name });
+	}
+	
+	private readonly AgentState agentState;
+	private readonly CancellationToken shutdownCancellationToken;
+	
+	private readonly Guid instanceGuid;
+	private readonly InstanceServices instanceServices;
+	private readonly InstanceTicketManager instanceTicketManager;
+	private readonly InstanceContext context;
+	
+	private readonly CancellationTokenSource actorCancellationTokenSource = new ();
+	
+	private IInstanceStatus currentStatus = InstanceStatus.NotRunning;
+	private InstanceRunningState? runningState = null;
+	
+	private InstanceActor(Init init) {
+		this.agentState = init.AgentState;
+		this.instanceGuid = init.InstanceGuid;
+		this.instanceServices = init.InstanceServices;
+		this.instanceTicketManager = init.InstanceTicketManager;
+		this.shutdownCancellationToken = init.ShutdownCancellationToken;
+		
+		var logger = PhantomLogger.Create<InstanceActor>(init.ShortName);
+		this.context = new InstanceContext(instanceGuid, init.ShortName, logger, instanceServices, SelfTyped, actorCancellationTokenSource.Token);
+		
+		Receive<ReportInstanceStatusCommand>(ReportInstanceStatus);
+		ReceiveAsync<LaunchInstanceCommand>(LaunchInstance);
+		ReceiveAsync<StopInstanceCommand>(StopInstance);
+		ReceiveAsyncAndReply<SendCommandToInstanceCommand, SendCommandToInstanceResult>(SendCommandToInstance);
+		ReceiveAsyncAndReply<BackupInstanceCommand, BackupCreationResult>(BackupInstance);
+		Receive<HandleProcessEndedCommand>(HandleProcessEnded);
+		ReceiveAsync<ShutdownCommand>(Shutdown);
+	}
+	
+	private void SetAndReportStatus(IInstanceStatus status) {
+		currentStatus = status;
+		ReportCurrentStatus();
+	}
+	
+	private void ReportCurrentStatus() {
+		agentState.UpdateInstance(new Instance(instanceGuid, currentStatus));
+		instanceServices.ControllerConnection.TrySend(new ReportInstanceStatusMessage(instanceGuid, currentStatus));
+	}
+	
+	private void TransitionState(InstanceRunningState? newState) {
+		if (runningState == newState) {
+			return;
+		}
+		
+		runningState?.Dispose();
+		runningState = newState;
+		runningState?.Initialize();
+	}
+	
+	public interface ICommand {}
+	
+	public sealed record ReportInstanceStatusCommand : ICommand;
+	
+	public sealed record LaunchInstanceCommand(InstanceConfiguration Configuration, IServerLauncher Launcher, InstanceTicketManager.Ticket Ticket, bool IsRestarting) : ICommand;
+	
+	public sealed record StopInstanceCommand(MinecraftStopStrategy StopStrategy) : ICommand;
+	
+	public sealed record SendCommandToInstanceCommand(string Command) : ICommand, ICanReply<SendCommandToInstanceResult>;
+	
+	public sealed record BackupInstanceCommand(BackupManager BackupManager) : ICommand, ICanReply<BackupCreationResult>;
+	
+	public sealed record HandleProcessEndedCommand(IInstanceStatus Status) : ICommand, IJumpAhead;
+	
+	public sealed record ShutdownCommand : ICommand;
+	
+	private void ReportInstanceStatus(ReportInstanceStatusCommand command) {
+		ReportCurrentStatus();
+	}
+	
+	private async Task LaunchInstance(LaunchInstanceCommand command) {
+		if (command.IsRestarting || runningState is null) {
+			SetAndReportStatus(command.IsRestarting ? InstanceStatus.Restarting : InstanceStatus.Launching);
+			
+			var newState = await InstanceLaunchProcedure.Run(context, command.Configuration, command.Launcher, instanceTicketManager, command.Ticket, SetAndReportStatus, shutdownCancellationToken);
+			if (newState is null) {
+				instanceTicketManager.Release(command.Ticket);
+			}
+			
+			TransitionState(newState);
+		}
+	}
+	
+	private async Task StopInstance(StopInstanceCommand command) {
+		if (runningState is null) {
+			return;
+		}
+		
+		IInstanceStatus oldStatus = currentStatus;
+		SetAndReportStatus(InstanceStatus.Stopping);
+		
+		if (await InstanceStopProcedure.Run(context, command.StopStrategy, runningState, SetAndReportStatus, shutdownCancellationToken)) {
+			instanceTicketManager.Release(runningState.Ticket);
+			TransitionState(null);
+		}
+		else {
+			SetAndReportStatus(oldStatus);
+		}
+	}
+	
+	private async Task<SendCommandToInstanceResult> SendCommandToInstance(SendCommandToInstanceCommand command) {
+		if (runningState is null) {
+			return SendCommandToInstanceResult.InstanceNotRunning;
+		}
+		else {
+			return await runningState.SendCommand(command.Command, shutdownCancellationToken);
+		}
+	}
+	
+	private async Task<BackupCreationResult> BackupInstance(BackupInstanceCommand command) {
+		if (runningState is null || runningState.Process.HasEnded) {
+			return new BackupCreationResult(BackupCreationResultKind.InstanceNotRunning);
+		}
+		else {
+			SetAndReportStatus(InstanceStatus.BackingUp);
+			try {
+				return await command.BackupManager.CreateBackup(context.ShortName, runningState.Process, shutdownCancellationToken);
+			} finally {
+				SetAndReportStatus(InstanceStatus.Running);
+			}
+		}
+	}
+	
+	private void HandleProcessEnded(HandleProcessEndedCommand command) {
+		if (runningState is { Process.HasEnded: true }) {
+			SetAndReportStatus(command.Status);
+			context.ReportEvent(InstanceEvent.Stopped);
+			instanceTicketManager.Release(runningState.Ticket);
+			TransitionState(null);
+		}
+	}
+	
+	private async Task Shutdown(ShutdownCommand command) {
+		await StopInstance(new StopInstanceCommand(MinecraftStopStrategy.Instant));
+		await actorCancellationTokenSource.CancelAsync();
+		Context.Stop(Self);
+	}
+}

Agent/Phantom.Agent.Services/Instances/InstanceContext.cs

@@ -1,28 +1,12 @@
-using Phantom.Agent.Minecraft.Launcher;
-using Phantom.Agent.Services.Instances.States;
-using Phantom.Common.Data.Instance;
+using Phantom.Common.Data.Instance;
+using Phantom.Common.Messages.Agent.ToController;
+using Phantom.Utils.Actor;
 using Serilog;
 
 namespace Phantom.Agent.Services.Instances;
 
-abstract class InstanceContext {
-	public InstanceConfiguration Configuration { get; }
-	public BaseLauncher Launcher { get; }
-
-	public abstract LaunchServices LaunchServices { get; }
-	public abstract PortManager PortManager { get; }
-	public abstract ILogger Logger { get; }
-	public abstract string ShortName { get; }
-
-	protected InstanceContext(InstanceConfiguration configuration, BaseLauncher launcher) {
-		Configuration = configuration;
-		Launcher = launcher;
-	}
-
-	public abstract void ReportStatus(InstanceStatus newStatus);
-	public abstract void TransitionState(Func<IInstanceState> newState);
-
-	public void TransitionState(IInstanceState newState) {
-		TransitionState(() => newState);
+sealed record InstanceContext(Guid InstanceGuid, string ShortName, ILogger Logger, InstanceServices Services, ActorRef<InstanceActor.ICommand> Actor, CancellationToken ActorCancellationToken) {
+	public void ReportEvent(IInstanceEvent instanceEvent) {
+		Services.ControllerConnection.TrySend(new ReportInstanceEventMessage(Guid.NewGuid(), DateTime.UtcNow, InstanceGuid, instanceEvent));
 	}
 }

Agent/Phantom.Agent.Services/Instances/InstanceLogSenderThread.cs

@@ -1,84 +0,0 @@
-using System.Collections.Immutable;
-using System.Diagnostics.CodeAnalysis;
-using Phantom.Agent.Rpc;
-using Phantom.Common.Logging;
-using Phantom.Common.Messages.ToServer;
-using Phantom.Utils.Collections;
-using Serilog;
-
-namespace Phantom.Agent.Services.Instances; 
-
-sealed class InstanceLogSenderThread {
-	private readonly Guid instanceGuid;
-	private readonly ILogger logger;
-	private readonly CancellationTokenSource cancellationTokenSource;
-	private readonly CancellationToken cancellationToken;
-	
-	private readonly SemaphoreSlim semaphore = new (1, 1);
-	private readonly RingBuffer<string> buffer = new (1000);
-	
-	public InstanceLogSenderThread(Guid instanceGuid, string name) {
-		this.instanceGuid = instanceGuid;
-		this.logger = PhantomLogger.Create<InstanceLogSenderThread>(name);
-		this.cancellationTokenSource = new CancellationTokenSource();
-		this.cancellationToken = cancellationTokenSource.Token;
-		
-		var thread = new Thread(Run) {
-			IsBackground = true,
-			Name = "Instance Log Sender (" + name + ")"
-		};
-		
-		thread.Start();
-	}
-
-	[SuppressMessage("ReSharper", "LocalVariableHidesMember")]
-	private async void Run() {
-		logger.Verbose("Thread started.");
-		
-		try {
-			while (!cancellationToken.IsCancellationRequested) {
-				await semaphore.WaitAsync(cancellationToken);
-
-				ImmutableArray<string> lines;
-				
-				try {
-					lines = buffer.Count > 0 ? buffer.EnumerateLast(uint.MaxValue).ToImmutableArray() : ImmutableArray<string>.Empty;
-					buffer.Clear();
-				} finally {
-					semaphore.Release();
-				}
-
-				if (lines.Length > 0) {
-					await ServerMessaging.SendMessage(new InstanceOutputMessage(instanceGuid, lines));
-				}
-
-				await Task.Delay(TimeSpan.FromMilliseconds(200), cancellationToken);
-			}
-		} catch (OperationCanceledException) {
-			// Ignore.
-		} catch (Exception e) {
-			logger.Error(e, "Caught exception in thread.");
-		} finally {
-			cancellationTokenSource.Dispose();
-			logger.Verbose("Thread stopped.");
-		}
-	}
-
-	public void Enqueue(string line) {
-		try {
-			semaphore.Wait(cancellationToken);
-		} catch (Exception) {
-			return;
-		}
-
-		try {
-			buffer.Add(line);
-		} finally {
-			semaphore.Release();
-		}
-	}
-
-	public void Cancel() {
-		cancellationTokenSource.Cancel();
-	}
-}

Agent/Phantom.Agent.Services/Instances/InstanceManagerActor.cs

@@ -0,0 +1,208 @@
+using Phantom.Agent.Minecraft.Instance;
+using Phantom.Agent.Minecraft.Java;
+using Phantom.Agent.Minecraft.Launcher;
+using Phantom.Agent.Minecraft.Launcher.Types;
+using Phantom.Agent.Minecraft.Properties;
+using Phantom.Agent.Minecraft.Server;
+using Phantom.Agent.Services.Backups;
+using Phantom.Agent.Services.Rpc;
+using Phantom.Common.Data;
+using Phantom.Common.Data.Instance;
+using Phantom.Common.Data.Minecraft;
+using Phantom.Common.Data.Replies;
+using Phantom.Utils.Actor;
+using Phantom.Utils.IO;
+using Phantom.Utils.Logging;
+using Serilog;
+
+namespace Phantom.Agent.Services.Instances;
+
+sealed class InstanceManagerActor : ReceiveActor<InstanceManagerActor.ICommand> {
+	private static readonly ILogger Logger = PhantomLogger.Create<InstanceManagerActor>();
+	
+	public readonly record struct Init(ControllerConnection ControllerConnection, AgentFolders AgentFolders, AgentState AgentState, JavaRuntimeRepository JavaRuntimeRepository, InstanceTicketManager InstanceTicketManager, BackupManager BackupManager);
+	
+	public static Props<ICommand> Factory(Init init) {
+		return Props<ICommand>.Create(() => new InstanceManagerActor(init), new ActorConfiguration { SupervisorStrategy = SupervisorStrategies.Resume });
+	}
+	
+	private readonly AgentState agentState;
+	private readonly string basePath;
+	
+	private readonly InstanceServices instanceServices;
+	private readonly InstanceTicketManager instanceTicketManager;
+	private readonly Dictionary<Guid, InstanceInfo> instances = new ();
+	
+	private readonly CancellationTokenSource shutdownCancellationTokenSource = new ();
+	private readonly CancellationToken shutdownCancellationToken;
+	
+	private uint instanceLoggerSequenceId = 0;
+	
+	private InstanceManagerActor(Init init) {
+		this.agentState = init.AgentState;
+		this.basePath = init.AgentFolders.InstancesFolderPath;
+		this.instanceTicketManager = init.InstanceTicketManager;
+		this.shutdownCancellationToken = shutdownCancellationTokenSource.Token;
+		
+		var minecraftServerExecutables = new MinecraftServerExecutables(init.AgentFolders.ServerExecutableFolderPath);
+		var launchServices = new LaunchServices(minecraftServerExecutables, init.JavaRuntimeRepository);
+		
+		this.instanceServices = new InstanceServices(init.ControllerConnection, init.BackupManager, launchServices);
+		
+		ReceiveAndReply<ConfigureInstanceCommand, Result<ConfigureInstanceResult, InstanceActionFailure>>(ConfigureInstance);
+		ReceiveAndReply<LaunchInstanceCommand, Result<LaunchInstanceResult, InstanceActionFailure>>(LaunchInstance);
+		ReceiveAndReply<StopInstanceCommand, Result<StopInstanceResult, InstanceActionFailure>>(StopInstance);
+		ReceiveAsyncAndReply<SendCommandToInstanceCommand, Result<SendCommandToInstanceResult, InstanceActionFailure>>(SendCommandToInstance);
+		ReceiveAsync<ShutdownCommand>(Shutdown);
+	}
+	
+	private string GetInstanceLoggerName(Guid guid) {
+		var prefix = guid.ToString();
+		return prefix[..prefix.IndexOf('-')] + "/" + Interlocked.Increment(ref instanceLoggerSequenceId);
+	}
+	
+	private sealed record InstanceInfo(ActorRef<InstanceActor.ICommand> Actor, InstanceConfiguration Configuration, IServerLauncher Launcher);
+	
+	public interface ICommand {}
+	
+	public sealed record ConfigureInstanceCommand(Guid InstanceGuid, InstanceConfiguration Configuration, InstanceLaunchProperties LaunchProperties, bool LaunchNow, bool AlwaysReportStatus) : ICommand, ICanReply<Result<ConfigureInstanceResult, InstanceActionFailure>>;
+	
+	public sealed record LaunchInstanceCommand(Guid InstanceGuid) : ICommand, ICanReply<Result<LaunchInstanceResult, InstanceActionFailure>>;
+	
+	public sealed record StopInstanceCommand(Guid InstanceGuid, MinecraftStopStrategy StopStrategy) : ICommand, ICanReply<Result<StopInstanceResult, InstanceActionFailure>>;
+	
+	public sealed record SendCommandToInstanceCommand(Guid InstanceGuid, string Command) : ICommand, ICanReply<Result<SendCommandToInstanceResult, InstanceActionFailure>>;
+	
+	public sealed record ShutdownCommand : ICommand;
+	
+	private Result<ConfigureInstanceResult, InstanceActionFailure> ConfigureInstance(ConfigureInstanceCommand command) {
+		var instanceGuid = command.InstanceGuid;
+		var configuration = command.Configuration;
+		
+		var instanceFolder = Path.Combine(basePath, instanceGuid.ToString());
+		Directories.Create(instanceFolder, Chmod.URWX_GRX);
+		
+		var heapMegabytes = configuration.MemoryAllocation.InMegabytes;
+		var jvmProperties = new JvmProperties(
+			InitialHeapMegabytes: heapMegabytes / 2,
+			MaximumHeapMegabytes: heapMegabytes
+		);
+		
+		var properties = new InstanceProperties(
+			instanceGuid,
+			configuration.JavaRuntimeGuid,
+			jvmProperties,
+			configuration.JvmArguments,
+			instanceFolder,
+			configuration.MinecraftVersion,
+			new ServerProperties(configuration.ServerPort, configuration.RconPort),
+			command.LaunchProperties
+		);
+		
+		IServerLauncher launcher = configuration.MinecraftServerKind switch {
+			MinecraftServerKind.Vanilla => new VanillaLauncher(properties),
+			MinecraftServerKind.Fabric  => new FabricLauncher(properties),
+			_                           => InvalidLauncher.Instance
+		};
+		
+		if (instances.TryGetValue(instanceGuid, out var instance)) {
+			instances[instanceGuid] = instance with {
+				Configuration = configuration,
+				Launcher = launcher
+			};
+			
+			Logger.Information("Reconfigured instance \"{Name}\" (GUID {Guid}).", configuration.InstanceName, instanceGuid);
+			
+			if (command.AlwaysReportStatus) {
+				instance.Actor.Tell(new InstanceActor.ReportInstanceStatusCommand());
+			}
+		}
+		else {
+			var instanceInit = new InstanceActor.Init(agentState, instanceGuid, GetInstanceLoggerName(instanceGuid), instanceServices, instanceTicketManager, shutdownCancellationToken);
+			instances[instanceGuid] = instance = new InstanceInfo(Context.ActorOf(InstanceActor.Factory(instanceInit), "Instance-" + instanceGuid), configuration, launcher);
+			
+			Logger.Information("Created instance \"{Name}\" (GUID {Guid}).", configuration.InstanceName, instanceGuid);
+			
+			instance.Actor.Tell(new InstanceActor.ReportInstanceStatusCommand());
+		}
+		
+		if (command.LaunchNow) {
+			LaunchInstance(new LaunchInstanceCommand(instanceGuid));
+		}
+		
+		return ConfigureInstanceResult.Success;
+	}
+	
+	private Result<LaunchInstanceResult, InstanceActionFailure> LaunchInstance(LaunchInstanceCommand command) {
+		var instanceGuid = command.InstanceGuid;
+		if (!instances.TryGetValue(instanceGuid, out var instanceInfo)) {
+			return InstanceActionFailure.InstanceDoesNotExist;
+		}
+		
+		var ticket = instanceTicketManager.Reserve(instanceInfo.Configuration);
+		if (!ticket) {
+			return ticket.Error;
+		}
+		
+		if (agentState.InstancesByGuid.TryGetValue(instanceGuid, out var instance)) {
+			var status = instance.Status;
+			if (status.IsRunning()) {
+				return LaunchInstanceResult.InstanceAlreadyRunning;
+			}
+			else if (status.IsLaunching()) {
+				return LaunchInstanceResult.InstanceAlreadyLaunching;
+			}
+		}
+		
+		instanceInfo.Actor.Tell(new InstanceActor.LaunchInstanceCommand(instanceInfo.Configuration, instanceInfo.Launcher, ticket.Value, IsRestarting: false));
+		return LaunchInstanceResult.LaunchInitiated;
+	}
+	
+	private Result<StopInstanceResult, InstanceActionFailure> StopInstance(StopInstanceCommand command) {
+		var instanceGuid = command.InstanceGuid;
+		if (!instances.TryGetValue(instanceGuid, out var instanceInfo)) {
+			return InstanceActionFailure.InstanceDoesNotExist;
+		}
+		
+		if (agentState.InstancesByGuid.TryGetValue(instanceGuid, out var instance)) {
+			var status = instance.Status;
+			if (status.IsStopping()) {
+				return StopInstanceResult.InstanceAlreadyStopping;
+			}
+			else if (!status.CanStop()) {
+				return StopInstanceResult.InstanceAlreadyStopped;
+			}
+		}
+		
+		instanceInfo.Actor.Tell(new InstanceActor.StopInstanceCommand(command.StopStrategy));
+		return StopInstanceResult.StopInitiated;
+	}
+	
+	private async Task<Result<SendCommandToInstanceResult, InstanceActionFailure>> SendCommandToInstance(SendCommandToInstanceCommand command) {
+		var instanceGuid = command.InstanceGuid;
+		if (!instances.TryGetValue(instanceGuid, out var instanceInfo)) {
+			return InstanceActionFailure.InstanceDoesNotExist;
+		}
+		
+		try {
+			return await instanceInfo.Actor.Request(new InstanceActor.SendCommandToInstanceCommand(command.Command), shutdownCancellationToken);
+		} catch (OperationCanceledException) {
+			return InstanceActionFailure.AgentShuttingDown;
+		}
+	}
+	
+	private async Task Shutdown(ShutdownCommand command) {
+		Logger.Information("Stopping all instances...");
+		
+		await shutdownCancellationTokenSource.CancelAsync();
+		
+		await Task.WhenAll(instances.Values.Select(static instance => instance.Actor.Stop(new InstanceActor.ShutdownCommand())));
+		instances.Clear();
+		
+		shutdownCancellationTokenSource.Dispose();
+		
+		Logger.Information("All instances stopped.");
+		
+		Context.Stop(Self);
+	}
+}

Agent/Phantom.Agent.Services/Instances/InstanceServices.cs

@@ -0,0 +1,7 @@
+using Phantom.Agent.Minecraft.Launcher;
+using Phantom.Agent.Services.Backups;
+using Phantom.Agent.Services.Rpc;
+
+namespace Phantom.Agent.Services.Instances;
+
+sealed record InstanceServices(ControllerConnection ControllerConnection, BackupManager BackupManager, LaunchServices LaunchServices);

Agent/Phantom.Agent.Services/Instances/InstanceSessionManager.cs

@@ -1,172 +0,0 @@
-using Phantom.Agent.Minecraft.Instance;
-using Phantom.Agent.Minecraft.Java;
-using Phantom.Agent.Minecraft.Launcher;
-using Phantom.Agent.Minecraft.Launcher.Types;
-using Phantom.Agent.Minecraft.Properties;
-using Phantom.Agent.Minecraft.Server;
-using Phantom.Common.Data;
-using Phantom.Common.Data.Agent;
-using Phantom.Common.Data.Instance;
-using Phantom.Common.Data.Replies;
-using Phantom.Common.Logging;
-using Serilog;
-
-namespace Phantom.Agent.Services.Instances;
-
-sealed class InstanceSessionManager : IDisposable {
-	private static readonly ILogger Logger = PhantomLogger.Create<InstanceSessionManager>();
-	
-	private readonly AgentInfo agentInfo;
-	private readonly string basePath;
-
-	private readonly LaunchServices launchServices;
-	private readonly PortManager portManager;
-	private readonly Dictionary<Guid, Instance> instances = new ();
-
-	private readonly CancellationTokenSource shutdownCancellationTokenSource = new ();
-	private readonly CancellationToken shutdownCancellationToken;
-	private readonly SemaphoreSlim semaphore = new (1, 1);
-
-	public InstanceSessionManager(AgentInfo agentInfo, AgentFolders agentFolders, JavaRuntimeRepository javaRuntimeRepository) {
-		this.agentInfo = agentInfo;
-		this.basePath = agentFolders.InstancesFolderPath;
-		this.launchServices = new LaunchServices(new MinecraftServerExecutables(agentFolders.ServerExecutableFolderPath), javaRuntimeRepository);
-		this.portManager = new PortManager(agentInfo.AllowedServerPorts, agentInfo.AllowedRconPorts);
-		this.shutdownCancellationToken = shutdownCancellationTokenSource.Token;
-	}
-
-	public async Task<ConfigureInstanceResult> Configure(InstanceConfiguration configuration) {
-		try {
-			await semaphore.WaitAsync(shutdownCancellationToken);
-		} catch (OperationCanceledException) {
-			return ConfigureInstanceResult.AgentShuttingDown;
-		}
-
-		var instanceGuid = configuration.InstanceGuid;
-
-		try {
-			var otherInstances = instances.Values.Where(inst => inst.Configuration.InstanceGuid != instanceGuid).ToArray();
-			if (otherInstances.Length + 1 > agentInfo.MaxInstances) {
-				return ConfigureInstanceResult.InstanceLimitExceeded;
-			}
-
-			var availableMemory = agentInfo.MaxMemory - otherInstances.Aggregate(RamAllocationUnits.Zero, static (total, instance) => total + instance.Configuration.MemoryAllocation);
-			if (availableMemory < configuration.MemoryAllocation) {
-				return ConfigureInstanceResult.MemoryLimitExceeded;
-			}
-
-			var heapMegabytes = configuration.MemoryAllocation.InMegabytes;
-			var jvmProperties = new JvmProperties(
-				InitialHeapMegabytes: heapMegabytes / 2,
-				MaximumHeapMegabytes: heapMegabytes
-			);
-
-			var instanceFolder = Path.Combine(basePath, instanceGuid.ToString());
-			Directory.CreateDirectory(instanceFolder);
-
-			var properties = new InstanceProperties(
-				configuration.JavaRuntimeGuid,
-				jvmProperties,
-				instanceFolder,
-				configuration.MinecraftVersion,
-				new ServerProperties(configuration.ServerPort, configuration.RconPort)
-			);
-
-			BaseLauncher launcher = new VanillaLauncher(properties);
-
-			if (instances.TryGetValue(instanceGuid, out var instance)) {
-				await instance.Reconfigure(configuration, launcher, shutdownCancellationToken);
-				Logger.Information("Reconfigured instance \"{Name}\" (GUID {Guid}).", configuration.InstanceName, configuration.InstanceGuid);
-			}
-			else {
-				instances[instanceGuid] = instance = await Instance.Create(configuration, launcher, launchServices, portManager);
-				Logger.Information("Created instance \"{Name}\" (GUID {Guid}).", configuration.InstanceName, configuration.InstanceGuid);
-			}
-
-			if (configuration.LaunchAutomatically) {
-				await instance.Launch(shutdownCancellationToken);
-			}
-
-			return ConfigureInstanceResult.Success;
-		} finally {
-			semaphore.Release();
-		}
-	}
-
-	public async Task<LaunchInstanceResult> Launch(Guid instanceGuid) {
-		try {
-			await semaphore.WaitAsync(shutdownCancellationToken);
-		} catch (OperationCanceledException) {
-			return LaunchInstanceResult.AgentShuttingDown;
-		}
-
-		try {
-			if (!instances.TryGetValue(instanceGuid, out var instance)) {
-				return LaunchInstanceResult.InstanceDoesNotExist;
-			}
-			else {
-				return await instance.Launch(shutdownCancellationToken);
-			}
-		} finally {
-			semaphore.Release();
-		}
-	}
-
-	public async Task<StopInstanceResult> Stop(Guid instanceGuid) {
-		try {
-			await semaphore.WaitAsync(shutdownCancellationToken);
-		} catch (OperationCanceledException) {
-			return StopInstanceResult.AgentShuttingDown;
-		}
-
-		try {
-			if (!instances.TryGetValue(instanceGuid, out var instance)) {
-				return StopInstanceResult.InstanceDoesNotExist;
-			}
-			else {
-				return await instance.Stop();
-			}
-		} finally {
-			semaphore.Release();
-		}
-	}
-
-	public async Task<SendCommandToInstanceResult> SendCommand(Guid instanceGuid, string command) {
-		try {
-			await semaphore.WaitAsync(shutdownCancellationToken);
-		} catch (OperationCanceledException) {
-			return SendCommandToInstanceResult.AgentShuttingDown;
-		}
-
-		try {
-			if (!instances.TryGetValue(instanceGuid, out var instance)) {
-				return SendCommandToInstanceResult.InstanceDoesNotExist;
-			}
-
-			if (!await instance.SendCommand(command, shutdownCancellationToken)) {
-				return SendCommandToInstanceResult.UnknownError;
-			}
-
-			return SendCommandToInstanceResult.Success;
-		} finally {
-			semaphore.Release();
-		}
-	}
-
-	public async Task StopAll() {
-		shutdownCancellationTokenSource.Cancel();
-
-		await semaphore.WaitAsync(CancellationToken.None);
-		try {
-			await Task.WhenAll(instances.Values.Select(static instance => instance.StopAndWait(TimeSpan.FromSeconds(30))));
-			instances.Clear();
-		} finally {
-			semaphore.Release();
-		}
-	}
-
-	public void Dispose() {
-		shutdownCancellationTokenSource.Dispose();
-		semaphore.Dispose();
-	}
-}

Agent/Phantom.Agent.Services/Instances/InstanceTicketManager.cs

@@ -0,0 +1,99 @@
+using Phantom.Agent.Services.Rpc;
+using Phantom.Common.Data;
+using Phantom.Common.Data.Agent;
+using Phantom.Common.Data.Instance;
+using Phantom.Common.Data.Replies;
+using Phantom.Common.Messages.Agent.ToController;
+using Phantom.Utils.Logging;
+using Serilog;
+
+namespace Phantom.Agent.Services.Instances;
+
+sealed class InstanceTicketManager {
+	private static readonly ILogger Logger = PhantomLogger.Create<InstanceTicketManager>();
+	
+	private readonly AgentInfo agentInfo;
+	private readonly ControllerConnection controllerConnection;
+	
+	private readonly HashSet<Guid> activeTicketGuids = new ();
+	private readonly HashSet<ushort> usedPorts = new ();
+	private RamAllocationUnits usedMemory = new ();
+	
+	public InstanceTicketManager(AgentInfo agentInfo, ControllerConnection controllerConnection) {
+		this.agentInfo = agentInfo;
+		this.controllerConnection = controllerConnection;
+	}
+	
+	public Result<Ticket, LaunchInstanceResult> Reserve(InstanceConfiguration configuration) {
+		var memoryAllocation = configuration.MemoryAllocation;
+		var serverPort = configuration.ServerPort;
+		var rconPort = configuration.RconPort;
+		
+		if (!agentInfo.AllowedServerPorts.Contains(serverPort)) {
+			return LaunchInstanceResult.ServerPortNotAllowed;
+		}
+		
+		if (!agentInfo.AllowedRconPorts.Contains(rconPort)) {
+			return LaunchInstanceResult.RconPortNotAllowed;
+		}
+		
+		lock (this) {
+			if (activeTicketGuids.Count + 1 > agentInfo.MaxInstances) {
+				return LaunchInstanceResult.InstanceLimitExceeded;
+			}
+			
+			if (usedMemory + memoryAllocation > agentInfo.MaxMemory) {
+				return LaunchInstanceResult.MemoryLimitExceeded;
+			}
+			
+			if (usedPorts.Contains(serverPort)) {
+				return LaunchInstanceResult.ServerPortAlreadyInUse;
+			}
+			
+			if (usedPorts.Contains(rconPort)) {
+				return LaunchInstanceResult.RconPortAlreadyInUse;
+			}
+			
+			var ticket = new Ticket(Guid.NewGuid(), memoryAllocation, serverPort, rconPort);
+			
+			activeTicketGuids.Add(ticket.TicketGuid);
+			usedMemory += memoryAllocation;
+			usedPorts.Add(serverPort);
+			usedPorts.Add(rconPort);
+			
+			RefreshAgentStatus();
+			Logger.Debug("Reserved ticket {TicketGuid} (server port {ServerPort}, rcon port {RconPort}, memory allocation {MemoryAllocation} MB).", ticket.TicketGuid, ticket.ServerPort, ticket.RconPort, ticket.MemoryAllocation.InMegabytes);
+			
+			return ticket;
+		}
+	}
+	
+	public bool IsValid(Ticket ticket) {
+		lock (this) {
+			return activeTicketGuids.Contains(ticket.TicketGuid);
+		}
+	}
+	
+	public void Release(Ticket ticket) {
+		lock (this) {
+			if (!activeTicketGuids.Remove(ticket.TicketGuid)) {
+				return;
+			}
+			
+			usedMemory -= ticket.MemoryAllocation;
+			usedPorts.Remove(ticket.ServerPort);
+			usedPorts.Remove(ticket.RconPort);
+			
+			RefreshAgentStatus();
+			Logger.Debug("Released ticket {TicketGuid} (server port {ServerPort}, rcon port {RconPort}, memory allocation {MemoryAllocation} MB).", ticket.TicketGuid, ticket.ServerPort, ticket.RconPort, ticket.MemoryAllocation.InMegabytes);
+		}
+	}
+	
+	public void RefreshAgentStatus() {
+		lock (this) {
+			controllerConnection.TrySend(new ReportAgentStatusMessage(activeTicketGuids.Count, usedMemory));
+		}
+	}
+	
+	public sealed record Ticket(Guid TicketGuid, RamAllocationUnits MemoryAllocation, ushort ServerPort, ushort RconPort);
+}

Agent/Phantom.Agent.Services/Instances/PortManager.cs

@@ -1,47 +0,0 @@
-using Phantom.Common.Data;
-using Phantom.Common.Data.Instance;
-
-namespace Phantom.Agent.Services.Instances;
-
-sealed class PortManager {
-	private readonly AllowedPorts allowedServerPorts;
-	private readonly AllowedPorts allowedRconPorts;
-	private readonly HashSet<ushort> usedPorts = new ();
-
-	public PortManager(AllowedPorts allowedServerPorts, AllowedPorts allowedRconPorts) {
-		this.allowedServerPorts = allowedServerPorts;
-		this.allowedRconPorts = allowedRconPorts;
-	}
-
-	public Result Reserve(InstanceConfiguration configuration) {
-		lock (usedPorts) {
-			if (usedPorts.Contains(configuration.ServerPort)) {
-				return Result.ServerPortAlreadyInUse;
-			}
-
-			if (usedPorts.Contains(configuration.RconPort)) {
-				return Result.RconPortAlreadyInUse;
-			}
-
-			usedPorts.Add(configuration.ServerPort);
-			usedPorts.Add(configuration.RconPort);
-		}
-
-		return Result.Success;
-	}
-	
-	public void Release(InstanceConfiguration configuration) {
-		lock (usedPorts) {
-			usedPorts.Remove(configuration.ServerPort);
-			usedPorts.Remove(configuration.RconPort);
-		}
-	}
-
-	public enum Result {
-		Success,
-		ServerPortNotAllowed,
-		ServerPortAlreadyInUse,
-		RconPortNotAllowed,
-		RconPortAlreadyInUse,
-	}
-}

Agent/Phantom.Agent.Services/Instances/State/InstanceLaunchProcedure.cs

@@ -0,0 +1,86 @@
+using Phantom.Agent.Minecraft.Instance;
+using Phantom.Agent.Minecraft.Launcher;
+using Phantom.Agent.Minecraft.Server;
+using Phantom.Common.Data;
+using Phantom.Common.Data.Instance;
+
+namespace Phantom.Agent.Services.Instances.State;
+
+static class InstanceLaunchProcedure {
+	public static async Task<InstanceRunningState?> Run(InstanceContext context, InstanceConfiguration configuration, IServerLauncher launcher, InstanceTicketManager ticketManager, InstanceTicketManager.Ticket ticket, Action<IInstanceStatus> reportStatus, CancellationToken cancellationToken) {
+		context.Logger.Information("Session starting...");
+		
+		Result<InstanceProcess, InstanceLaunchFailReason> result;
+		
+		if (ticketManager.IsValid(ticket)) {
+			try {
+				result = await LaunchInstance(context, launcher, reportStatus, cancellationToken);
+			} catch (OperationCanceledException) {
+				reportStatus(InstanceStatus.NotRunning);
+				return null;
+			} catch (Exception e) {
+				context.Logger.Error(e, "Caught exception while launching instance.");
+				result = InstanceLaunchFailReason.UnknownError;
+			}
+		}
+		else {
+			context.Logger.Error("Attempted to launch instance with an invalid ticket!");
+			result = InstanceLaunchFailReason.UnknownError;
+		}
+		
+		if (result) {
+			reportStatus(InstanceStatus.Running);
+			context.ReportEvent(InstanceEvent.LaunchSucceeded);
+			return new InstanceRunningState(context, configuration, launcher, ticket, result.Value, cancellationToken);
+		}
+		else {
+			reportStatus(InstanceStatus.Failed(result.Error));
+			context.ReportEvent(new InstanceLaunchFailedEvent(result.Error));
+			return null;
+		}
+	}
+	
+	private static async Task<Result<InstanceProcess, InstanceLaunchFailReason>> LaunchInstance(InstanceContext context, IServerLauncher launcher, Action<IInstanceStatus> reportStatus, CancellationToken cancellationToken) {
+		cancellationToken.ThrowIfCancellationRequested();
+		
+		byte lastDownloadProgress = byte.MaxValue;
+		
+		void OnDownloadProgress(object? sender, DownloadProgressEventArgs args) {
+			byte progress = (byte) Math.Min(args.DownloadedBytes * 100 / args.TotalBytes, 100);
+			
+			if (lastDownloadProgress != progress) {
+				lastDownloadProgress = progress;
+				reportStatus(InstanceStatus.Downloading(progress));
+			}
+		}
+		
+		switch (await launcher.Launch(context.Logger, context.Services.LaunchServices, OnDownloadProgress, cancellationToken)) {
+			case LaunchResult.Success launchSuccess:
+				return launchSuccess.Process;
+			
+			case LaunchResult.InvalidJavaRuntime:
+				context.Logger.Error("Session failed to launch, invalid Java runtime.");
+				return InstanceLaunchFailReason.JavaRuntimeNotFound;
+			
+			case LaunchResult.CouldNotDownloadMinecraftServer:
+				context.Logger.Error("Session failed to launch, could not download Minecraft server.");
+				return InstanceLaunchFailReason.CouldNotDownloadMinecraftServer;
+			
+			case LaunchResult.CouldNotPrepareMinecraftServerLauncher:
+				context.Logger.Error("Session failed to launch, could not prepare Minecraft server launcher.");
+				return InstanceLaunchFailReason.CouldNotPrepareMinecraftServerLauncher;
+			
+			case LaunchResult.CouldNotConfigureMinecraftServer:
+				context.Logger.Error("Session failed to launch, could not configure Minecraft server.");
+				return InstanceLaunchFailReason.CouldNotConfigureMinecraftServer;
+			
+			case LaunchResult.CouldNotStartMinecraftServer:
+				context.Logger.Error("Session failed to launch, could not start Minecraft server.");
+				return InstanceLaunchFailReason.CouldNotStartMinecraftServer;
+			
+			default:
+				context.Logger.Error("Session failed to launch.");
+				return InstanceLaunchFailReason.UnknownError;
+		}
+	}
+}

Agent/Phantom.Agent.Services/Instances/State/InstanceLogSender.cs

@@ -0,0 +1,84 @@
+using System.Collections.Immutable;
+using System.Threading.Channels;
+using Phantom.Agent.Services.Rpc;
+using Phantom.Common.Messages.Agent.ToController;
+using Phantom.Utils.Logging;
+using Phantom.Utils.Tasks;
+
+namespace Phantom.Agent.Services.Instances.State;
+
+sealed class InstanceLogSender : CancellableBackgroundTask {
+	private static readonly BoundedChannelOptions BufferOptions = new (capacity: 100) {
+		SingleReader = true,
+		SingleWriter = true,
+		FullMode = BoundedChannelFullMode.DropNewest
+	};
+	
+	private static readonly TimeSpan SendDelay = TimeSpan.FromMilliseconds(200);
+	
+	private readonly ControllerConnection controllerConnection;
+	private readonly Guid instanceGuid;
+	private readonly Channel<string> outputChannel;
+	
+	private int droppedLinesSinceLastSend;
+	
+	public InstanceLogSender(ControllerConnection controllerConnection, Guid instanceGuid, string loggerName) : base(PhantomLogger.Create<InstanceLogSender>(loggerName)) {
+		this.controllerConnection = controllerConnection;
+		this.instanceGuid = instanceGuid;
+		this.outputChannel = Channel.CreateBounded<string>(BufferOptions, OnLineDropped);
+		Start();
+	}
+	
+	protected override async Task RunTask() {
+		var lineReader = outputChannel.Reader;
+		var lineBuilder = ImmutableArray.CreateBuilder<string>();
+		
+		try {
+			while (await lineReader.WaitToReadAsync(CancellationToken)) {
+				await Task.Delay(SendDelay, CancellationToken);
+				SendOutputToServer(ReadLinesFromChannel(lineReader, lineBuilder));
+			}
+		} catch (OperationCanceledException) {
+			// Ignore.
+		}
+		
+		// Flush remaining lines.
+		SendOutputToServer(ReadLinesFromChannel(lineReader, lineBuilder));
+	}
+	
+	private ImmutableArray<string> ReadLinesFromChannel(ChannelReader<string> reader, ImmutableArray<string>.Builder builder) {
+		builder.Clear();
+		
+		while (reader.TryRead(out string? line)) {
+			builder.Add(line);
+		}
+		
+		int droppedLines = Interlocked.Exchange(ref droppedLinesSinceLastSend, 0);
+		if (droppedLines > 0) {
+			builder.Add($"Dropped {droppedLines} {(droppedLines == 1 ? "line" : "lines")} due to buffer overflow.");
+		}
+		
+		return builder.ToImmutable();
+	}
+	
+	private void SendOutputToServer(ImmutableArray<string> lines) {
+		if (!lines.IsEmpty) {
+			controllerConnection.TrySend(new InstanceOutputMessage(instanceGuid, lines));
+		}
+	}
+	
+	private void OnLineDropped(string line) {
+		Logger.Warning("Buffer is full, dropped line: {Line}", line);
+		Interlocked.Increment(ref droppedLinesSinceLastSend);
+	}
+	
+	public void Enqueue(string line) {
+		outputChannel.Writer.TryWrite(line);
+	}
+	
+	protected override void Dispose() {
+		if (!outputChannel.Writer.TryComplete()) {
+			Logger.Error("Could not mark channel as completed.");
+		}
+	}
+}

Agent/Phantom.Agent.Services/Instances/State/InstancePlayerCountTracker.cs

@@ -0,0 +1,140 @@
+using Phantom.Agent.Minecraft.Instance;
+using Phantom.Agent.Minecraft.Server;
+using Phantom.Agent.Services.Rpc;
+using Phantom.Common.Data.Instance;
+using Phantom.Common.Messages.Agent.ToController;
+using Phantom.Utils.Logging;
+using Phantom.Utils.Tasks;
+using Phantom.Utils.Threading;
+
+namespace Phantom.Agent.Services.Instances.State;
+
+sealed class InstancePlayerCountTracker : CancellableBackgroundTask {
+	private readonly ControllerConnection controllerConnection;
+	private readonly Guid instanceGuid;
+	private readonly ushort serverPort;
+	private readonly InstanceProcess process;
+	
+	private readonly TaskCompletionSource firstDetection = AsyncTasks.CreateCompletionSource();
+	private readonly ManualResetEventSlim serverOutputEvent = new ();
+	
+	private InstancePlayerCounts? playerCounts;
+	
+	public InstancePlayerCounts? PlayerCounts {
+		get {
+			lock (this) {
+				return playerCounts;
+			}
+		}
+		private set {
+			EventHandler<int?>? onlinePlayerCountChanged;
+			lock (this) {
+				if (playerCounts == value) {
+					return;
+				}
+				
+				playerCounts = value;
+				onlinePlayerCountChanged = OnlinePlayerCountChanged;
+			}
+			
+			onlinePlayerCountChanged?.Invoke(this, value?.Online);
+			controllerConnection.TrySend(new ReportInstancePlayerCountsMessage(instanceGuid, value));
+		}
+	}
+	
+	private event EventHandler<int?>? OnlinePlayerCountChanged;
+	
+	private bool isDisposed = false;
+	
+	public InstancePlayerCountTracker(InstanceContext context, InstanceProcess process, ushort serverPort) : base(PhantomLogger.Create<InstancePlayerCountTracker>(context.ShortName)) {
+		this.controllerConnection = context.Services.ControllerConnection;
+		this.instanceGuid = context.InstanceGuid;
+		this.process = process;
+		this.serverPort = serverPort;
+		Start();
+	}
+	
+	protected override async Task RunTask() {
+		// Give the server time to start accepting connections.
+		await Task.Delay(TimeSpan.FromSeconds(10), CancellationToken);
+		
+		serverOutputEvent.Set();
+		process.AddOutputListener(OnOutput, maxLinesToReadFromHistory: 0);
+		
+		while (!CancellationToken.IsCancellationRequested) {
+			serverOutputEvent.Reset();
+			
+			PlayerCounts = await TryGetPlayerCounts();
+			
+			if (!firstDetection.Task.IsCompleted) {
+				firstDetection.SetResult();
+			}
+			
+			await Task.Delay(TimeSpan.FromSeconds(10), CancellationToken);
+			await serverOutputEvent.WaitHandle.WaitOneAsync(CancellationToken);
+			await Task.Delay(TimeSpan.FromSeconds(1), CancellationToken);
+		}
+	}
+	
+	private async Task<InstancePlayerCounts?> TryGetPlayerCounts() {
+		try {
+			var result = await ServerStatusProtocol.GetPlayerCounts(serverPort, CancellationToken);
+			Logger.Debug("Detected {OnlinePlayerCount} / {MaximumPlayerCount} online player(s).", result.Online, result.Maximum);
+			return result;
+		} catch (ServerStatusProtocol.ProtocolException e) {
+			Logger.Error(e.Message);
+			return null;
+		} catch (Exception e) {
+			Logger.Error(e, "Caught exception while checking online player count.");
+			return null;
+		}
+	}
+	
+	public async Task WaitForOnlinePlayers(CancellationToken cancellationToken) {
+		await firstDetection.Task.WaitAsync(cancellationToken);
+		
+		var onlinePlayersDetected = AsyncTasks.CreateCompletionSource();
+		
+		lock (this) {
+			if (playerCounts is { Online: > 0 }) {
+				return;
+			}
+			else if (playerCounts == null) {
+				throw new InvalidOperationException();
+			}
+			
+			OnlinePlayerCountChanged += OnOnlinePlayerCountChanged;
+			
+			void OnOnlinePlayerCountChanged(object? sender, int? newPlayerCount) {
+				if (newPlayerCount == null) {
+					onlinePlayersDetected.TrySetException(new InvalidOperationException());
+					OnlinePlayerCountChanged -= OnOnlinePlayerCountChanged;
+				}
+				else if (newPlayerCount > 0) {
+					onlinePlayersDetected.TrySetResult();
+					OnlinePlayerCountChanged -= OnOnlinePlayerCountChanged;
+				}
+			}
+		}
+		
+		await onlinePlayersDetected.Task;
+	}
+	
+	private void OnOutput(object? sender, string? line) {
+		lock (this) {
+			if (!isDisposed) {
+				serverOutputEvent.Set();
+			}
+		}
+	}
+	
+	protected override void Dispose() {
+		lock (this) {
+			isDisposed = true;
+			playerCounts = null;
+		}
+		
+		process.RemoveOutputListener(OnOutput);
+		serverOutputEvent.Dispose();
+	}
+}

Agent/Phantom.Agent.Services/Instances/State/InstanceRunningState.cs

@@ -0,0 +1,123 @@
+using Phantom.Agent.Minecraft.Instance;
+using Phantom.Agent.Minecraft.Launcher;
+using Phantom.Agent.Services.Backups;
+using Phantom.Common.Data.Backups;
+using Phantom.Common.Data.Instance;
+using Phantom.Common.Data.Replies;
+
+namespace Phantom.Agent.Services.Instances.State;
+
+sealed class InstanceRunningState : IDisposable {
+	public InstanceTicketManager.Ticket Ticket { get; }
+	public InstanceProcess Process { get; }
+	
+	internal bool IsStopping { get; set; }
+	
+	private readonly InstanceContext context;
+	private readonly InstanceConfiguration configuration;
+	private readonly IServerLauncher launcher;
+	private readonly CancellationToken cancellationToken;
+	
+	private readonly InstanceLogSender logSender;
+	private readonly InstancePlayerCountTracker playerCountTracker;
+	private readonly BackupScheduler backupScheduler;
+	
+	private bool isDisposed;
+	
+	public InstanceRunningState(InstanceContext context, InstanceConfiguration configuration, IServerLauncher launcher, InstanceTicketManager.Ticket ticket, InstanceProcess process, CancellationToken cancellationToken) {
+		this.context = context;
+		this.configuration = configuration;
+		this.launcher = launcher;
+		this.Ticket = ticket;
+		this.Process = process;
+		this.cancellationToken = cancellationToken;
+		
+		this.logSender = new InstanceLogSender(context.Services.ControllerConnection, context.InstanceGuid, context.ShortName);
+		this.playerCountTracker = new InstancePlayerCountTracker(context, process, configuration.ServerPort);
+		
+		this.backupScheduler = new BackupScheduler(context, playerCountTracker);
+		this.backupScheduler.BackupCompleted += OnScheduledBackupCompleted;
+	}
+	
+	public void Initialize() {
+		Process.Ended += ProcessEnded;
+		
+		if (Process.HasEnded) {
+			if (TryDispose()) {
+				context.Logger.Warning("Session ended immediately after it was started.");
+				context.Actor.Tell(new InstanceActor.HandleProcessEndedCommand(InstanceStatus.Failed(InstanceLaunchFailReason.UnknownError)));
+			}
+		}
+		else {
+			context.Logger.Information("Session started.");
+			Process.AddOutputListener(SessionOutput);
+		}
+	}
+	
+	private void SessionOutput(object? sender, string line) {
+		context.Logger.Debug("[Server] {Line}", line);
+		logSender.Enqueue(line);
+	}
+	
+	private void ProcessEnded(object? sender, EventArgs e) {
+		if (!TryDispose()) {
+			return;
+		}
+		
+		if (cancellationToken.IsCancellationRequested) {
+			return;
+		}
+		
+		if (IsStopping) {
+			context.Actor.Tell(new InstanceActor.HandleProcessEndedCommand(InstanceStatus.NotRunning));
+		}
+		else {
+			context.Logger.Information("Session ended unexpectedly, restarting...");
+			context.ReportEvent(InstanceEvent.Crashed);
+			context.Actor.Tell(new InstanceActor.LaunchInstanceCommand(configuration, launcher, Ticket, IsRestarting: true));
+		}
+	}
+	
+	private void OnScheduledBackupCompleted(object? sender, BackupCreationResult e) {
+		context.ReportEvent(new InstanceBackupCompletedEvent(e.Kind, e.Warnings));
+	}
+	
+	public async Task<SendCommandToInstanceResult> SendCommand(string command, CancellationToken cancellationToken) {
+		try {
+			context.Logger.Information("Sending command: {Command}", command);
+			await Process.SendCommand(command, cancellationToken);
+			return SendCommandToInstanceResult.Success;
+		} catch (OperationCanceledException) {
+			return SendCommandToInstanceResult.UnknownError;
+		} catch (Exception e) {
+			context.Logger.Warning(e, "Caught exception while sending command.");
+			return SendCommandToInstanceResult.UnknownError;
+		}
+	}
+	
+	public void OnStopInitiated() {
+		backupScheduler.Stop();
+		playerCountTracker.Stop();
+	}
+	
+	private bool TryDispose() {
+		lock (this) {
+			if (isDisposed) {
+				return false;
+			}
+			
+			isDisposed = true;
+		}
+		
+		OnStopInitiated();
+		logSender.Stop();
+		
+		Process.Dispose();
+		
+		return true;
+	}
+	
+	public void Dispose() {
+		TryDispose();
+	}
+}

Agent/Phantom.Agent.Services/Instances/State/InstanceStopProcedure.cs

@@ -0,0 +1,99 @@
+using System.Diagnostics;
+using Phantom.Agent.Minecraft.Command;
+using Phantom.Agent.Minecraft.Instance;
+using Phantom.Common.Data.Instance;
+using Phantom.Common.Data.Minecraft;
+
+namespace Phantom.Agent.Services.Instances.State;
+
+static class InstanceStopProcedure {
+	private static readonly ushort[] Stops = { 60, 30, 10, 5, 4, 3, 2, 1, 0 };
+	
+	public static async Task<bool> Run(InstanceContext context, MinecraftStopStrategy stopStrategy, InstanceRunningState runningState, Action<IInstanceStatus> reportStatus, CancellationToken cancellationToken) {
+		var process = runningState.Process;
+		runningState.IsStopping = true;
+		
+		var seconds = stopStrategy.Seconds;
+		if (seconds > 0) {
+			try {
+				await CountDownWithAnnouncements(context, process, seconds, cancellationToken);
+			} catch (OperationCanceledException) {
+				runningState.IsStopping = false;
+				return false;
+			}
+		}
+		
+		try {
+			// Too late to cancel the stop procedure now.
+			runningState.OnStopInitiated();
+			
+			if (!process.HasEnded) {
+				context.Logger.Information("Session stopping now.");
+				await DoStop(context, process);
+			}
+		} finally {
+			context.Logger.Information("Session stopped.");
+			reportStatus(InstanceStatus.NotRunning);
+			context.ReportEvent(InstanceEvent.Stopped);
+		}
+		
+		return true;
+	}
+	
+	private static async Task CountDownWithAnnouncements(InstanceContext context, InstanceProcess process, ushort seconds, CancellationToken cancellationToken) {
+		context.Logger.Information("Session stopping in {Seconds} seconds.", seconds);
+		
+		foreach (var stop in Stops) {
+			// TODO change to event-based cancellation
+			if (process.HasEnded) {
+				return;
+			}
+			
+			if (seconds > stop) {
+				await process.SendCommand(GetCountDownAnnouncementCommand(seconds), cancellationToken);
+				await Task.Delay(TimeSpan.FromSeconds(seconds - stop), cancellationToken);
+				seconds = stop;
+			}
+		}
+	}
+	
+	private static string GetCountDownAnnouncementCommand(ushort seconds) {
+		return MinecraftCommand.Say("Server shutting down in " + seconds + (seconds == 1 ? " second." : " seconds."));
+	}
+	
+	private static async Task DoStop(InstanceContext context, InstanceProcess process) {
+		context.Logger.Information("Sending stop command...");
+		await TrySendStopCommand(context, process);
+		
+		context.Logger.Information("Waiting for session to end...");
+		await WaitForSessionToEnd(context, process);
+	}
+	
+	private static async Task TrySendStopCommand(InstanceContext context, InstanceProcess process) {
+		using var timeout = new CancellationTokenSource(TimeSpan.FromSeconds(5));
+		try {
+			await process.SendCommand(MinecraftCommand.Stop, timeout.Token);
+		} catch (OperationCanceledException) {
+			// Ignore.
+		} catch (ObjectDisposedException e) when (e.ObjectName == typeof(Process).FullName && process.HasEnded) {
+			// Ignore.
+		} catch (IOException e) when (e.HResult == -2147024664 /* The pipe is being closed */) {
+			// Ignore.
+		} catch (Exception e) {
+			context.Logger.Warning(e, "Caught exception while sending stop command.");
+		}
+	}
+	
+	private static async Task WaitForSessionToEnd(InstanceContext context, InstanceProcess process) {
+		try {
+			await process.WaitForExit(TimeSpan.FromSeconds(55));
+		} catch (TimeoutException) {
+			try {
+				context.Logger.Warning("Waiting timed out, killing session...");
+				process.Kill();
+			} catch (Exception e) {
+				context.Logger.Error(e, "Caught exception while killing session.");
+			}
+		}
+	}
+}

Agent/Phantom.Agent.Services/Instances/States/IInstanceState.cs

@@ -1,7 +0,0 @@
-namespace Phantom.Agent.Services.Instances.States; 
-
-interface IInstanceState {
-	IInstanceState Launch(InstanceContext context);
-	IInstanceState Stop();
-	Task<bool> SendCommand(string command, CancellationToken cancellationToken);
-}

Agent/Phantom.Agent.Services/Instances/States/InstanceLaunchingState.cs

@@ -1,104 +0,0 @@
-using Phantom.Agent.Minecraft.Instance;
-using Phantom.Agent.Minecraft.Launcher;
-using Phantom.Agent.Minecraft.Server;
-using Phantom.Common.Data.Instance;
-
-namespace Phantom.Agent.Services.Instances.States;
-
-sealed class InstanceLaunchingState : IInstanceState, IDisposable {
-	private readonly InstanceContext context;
-	private readonly CancellationTokenSource cancellationTokenSource = new ();
-	private byte lastDownloadProgress = byte.MaxValue;
-
-	public InstanceLaunchingState(InstanceContext context) {
-		this.context = context;
-		this.context.Logger.Information("Session starting...");
-		this.context.ReportStatus(InstanceStatus.IsLaunching);
-		
-		var launchTask = Task.Run(DoLaunch);
-		launchTask.ContinueWith(OnLaunchSuccess, CancellationToken.None, TaskContinuationOptions.OnlyOnRanToCompletion, TaskScheduler.Default);
-		launchTask.ContinueWith(OnLaunchFailure, CancellationToken.None, TaskContinuationOptions.NotOnRanToCompletion, TaskScheduler.Default);
-	}
-
-	private async Task<InstanceSession> DoLaunch() {
-		var cancellationToken = cancellationTokenSource.Token;
-		cancellationToken.ThrowIfCancellationRequested();
-		
-		void OnDownloadProgress(object? sender, DownloadProgressEventArgs args) {
-			byte progress = (byte) Math.Min(args.DownloadedBytes * 100 / args.TotalBytes, 100);
-			
-			if (lastDownloadProgress != progress) {
-				lastDownloadProgress = progress;
-				context.ReportStatus(new InstanceStatus.Downloading(progress));
-			}
-		}
-
-		var launchResult = await context.Launcher.Launch(context.LaunchServices, OnDownloadProgress, cancellationToken);
-		if (launchResult is LaunchResult.CouldNotDownloadMinecraftServer) {
-			throw new LaunchFailureException(InstanceLaunchFailReason.CouldNotDownloadMinecraftServer, "Session failed to launch, could not download Minecraft server.");
-		}
-		else if (launchResult is LaunchResult.InvalidJavaRuntime) {
-			throw new LaunchFailureException(InstanceLaunchFailReason.JavaRuntimeNotFound, "Session failed to launch, invalid Java runtime.");
-		}
-
-		if (launchResult is not LaunchResult.Success launchSuccess) {
-			throw new LaunchFailureException(InstanceLaunchFailReason.UnknownError, "Session failed to launch.");
-		}
-
-		context.ReportStatus(InstanceStatus.IsLaunching);
-		return launchSuccess.Session;
-	}
-
-	private void OnLaunchSuccess(Task<InstanceSession> task) {
-		context.TransitionState(() => {
-			if (cancellationTokenSource.IsCancellationRequested) {
-				context.PortManager.Release(context.Configuration);
-				context.ReportStatus(InstanceStatus.IsNotRunning);
-				return new InstanceNotRunningState();
-			}
-			else {
-				return new InstanceRunningState(context, task.Result);
-			}
-		});
-	}
-
-	private void OnLaunchFailure(Task task) {
-		if (task.Exception is { InnerException: LaunchFailureException e }) {
-			context.Logger.Error(e.LogMessage);
-			context.ReportStatus(new InstanceStatus.Failed(e.Reason));
-		}
-		else {
-			context.ReportStatus(new InstanceStatus.Failed(InstanceLaunchFailReason.UnknownError));
-		}
-		
-		context.PortManager.Release(context.Configuration);
-		context.TransitionState(new InstanceNotRunningState());
-	}
-
-	private sealed class LaunchFailureException : Exception {
-		public InstanceLaunchFailReason Reason { get; }
-		public string LogMessage { get; }
-		
-		public LaunchFailureException(InstanceLaunchFailReason reason, string logMessage) {
-			this.Reason = reason;
-			this.LogMessage = logMessage;
-		}
-	}
-
-	public IInstanceState Launch(InstanceContext context) {
-		return this;
-	}
-
-	public IInstanceState Stop() {
-		cancellationTokenSource.Cancel();
-		return this;
-	}
-
-	public Task<bool> SendCommand(string command, CancellationToken cancellationToken) {
-		return Task.FromResult(false);
-	}
-
-	public void Dispose() {
-		cancellationTokenSource.Dispose();
-	}
-}

Agent/Phantom.Agent.Services/Instances/States/InstanceNotRunningState.cs

@@ -1,30 +0,0 @@
-using Phantom.Common.Data.Instance;
-
-namespace Phantom.Agent.Services.Instances.States; 
-
-sealed class InstanceNotRunningState : IInstanceState {
-	public IInstanceState Launch(InstanceContext context) {
-		InstanceLaunchFailReason? failReason = context.PortManager.Reserve(context.Configuration) switch {
-			PortManager.Result.ServerPortNotAllowed   => InstanceLaunchFailReason.ServerPortNotAllowed,
-			PortManager.Result.ServerPortAlreadyInUse => InstanceLaunchFailReason.ServerPortAlreadyInUse,
-			PortManager.Result.RconPortNotAllowed     => InstanceLaunchFailReason.RconPortNotAllowed,
-			PortManager.Result.RconPortAlreadyInUse   => InstanceLaunchFailReason.RconPortAlreadyInUse,
-			_                                         => null
-		};
-
-		if (failReason != null) {
-			context.ReportStatus(new InstanceStatus.Failed(failReason.Value));
-			return this;
-		}
-		
-		return new InstanceLaunchingState(context);
-	}
-
-	public IInstanceState Stop() {
-		return this;
-	}
-
-	public Task<bool> SendCommand(string command, CancellationToken cancellationToken) {
-		return Task.FromResult(false);
-	}
-}

Agent/Phantom.Agent.Services/Instances/States/InstanceRunningState.cs

@@ -1,96 +0,0 @@
-using Phantom.Agent.Minecraft.Instance;
-using Phantom.Common.Data.Instance;
-
-namespace Phantom.Agent.Services.Instances.States;
-
-sealed class InstanceRunningState : IInstanceState {
-	private readonly InstanceContext context;
-	private readonly InstanceSession session;
-	private readonly InstanceLogSenderThread logSenderThread;
-	private readonly SessionObjects sessionObjects;
-
-	public InstanceRunningState(InstanceContext context, InstanceSession session) {
-		this.context = context;
-		this.session = session;
-		this.logSenderThread = new InstanceLogSenderThread(context.Configuration.InstanceGuid, context.ShortName);
-		this.sessionObjects = new SessionObjects(context, session, logSenderThread);
-
-		this.session.AddOutputListener(SessionOutput);
-		this.session.SessionEnded += SessionEnded;
-
-		if (session.HasEnded) {
-			if (sessionObjects.Dispose()) {
-				context.Logger.Warning("Session ended immediately after it was started.");
-				context.ReportStatus(new InstanceStatus.Failed(InstanceLaunchFailReason.UnknownError));
-				Task.Run(() => context.TransitionState(new InstanceNotRunningState()));
-			}
-		}
-		else {
-			context.ReportStatus(InstanceStatus.IsRunning);
-			context.Logger.Information("Session started.");
-		}
-	}
-
-	private void SessionOutput(object? sender, string e) {
-		context.Logger.Verbose("[Server] {Line}", e);
-		logSenderThread.Enqueue(e);
-	}
-
-	private void SessionEnded(object? sender, EventArgs e) {
-		if (sessionObjects.Dispose()) {
-			context.Logger.Information("Session ended.");
-			context.ReportStatus(InstanceStatus.IsNotRunning);
-			context.TransitionState(new InstanceNotRunningState());
-		}
-	}
-
-	public IInstanceState Launch(InstanceContext context) {
-		return this;
-	}
-
-	public IInstanceState Stop() {
-		session.SessionEnded -= SessionEnded;
-		return new InstanceStoppingState(context, session, sessionObjects);
-	}
-
-	public async Task<bool> SendCommand(string command, CancellationToken cancellationToken) {
-		try {
-			context.Logger.Information("Sending command: {Command}", command);
-			await session.SendCommand(command, cancellationToken);
-			return true;
-		} catch (OperationCanceledException) {
-			return false;
-		} catch (Exception e) {
-			context.Logger.Warning(e, "Caught exception while sending command.");
-			return false;
-		}
-	}
-
-	public sealed class SessionObjects {
-		private readonly InstanceContext context;
-		private readonly InstanceSession session;
-		private readonly InstanceLogSenderThread logSenderThread;
-		private bool isDisposed;
-
-		public SessionObjects(InstanceContext context, InstanceSession session, InstanceLogSenderThread logSenderThread) {
-			this.context = context;
-			this.session = session;
-			this.logSenderThread = logSenderThread;
-		}
-
-		public bool Dispose() {
-			lock (this) {
-				if (isDisposed) {
-					return false;
-				}
-
-				isDisposed = true;
-			}
-
-			logSenderThread.Cancel();
-			session.Dispose();
-			context.PortManager.Release(context.Configuration);
-			return true;
-		}
-	}
-}

Agent/Phantom.Agent.Services/Instances/States/InstanceStoppingState.cs

@@ -1,75 +0,0 @@
-using Phantom.Agent.Minecraft.Instance;
-using Phantom.Common.Data.Instance;
-
-namespace Phantom.Agent.Services.Instances.States; 
-
-sealed class InstanceStoppingState : IInstanceState, IDisposable {
-	private readonly InstanceContext context;
-	private readonly InstanceSession session;
-	private readonly InstanceRunningState.SessionObjects sessionObjects;
-
-	public InstanceStoppingState(InstanceContext context, InstanceSession session, InstanceRunningState.SessionObjects sessionObjects) {
-		this.sessionObjects = sessionObjects;
-		this.session = session;
-		this.context = context;
-		this.context.Logger.Information("Session stopping.");
-		this.context.ReportStatus(InstanceStatus.IsStopping);
-		
-		Task.Run(DoStop);
-	}
-
-	private async Task DoStop() {
-		try {
-			context.Logger.Information("Sending stop command...");
-			await DoSendStopCommand();
-
-			context.Logger.Information("Waiting for session to end...");
-			await DoWaitForSessionToEnd();
-		} finally {
-			context.Logger.Information("Session stopped.");
-			context.ReportStatus(InstanceStatus.IsNotRunning);
-			context.TransitionState(new InstanceNotRunningState());
-		}
-	}
-
-	private async Task DoSendStopCommand() {
-		using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(5));
-		try {
-			await session.SendCommand("stop", cts.Token);
-		} catch (OperationCanceledException) {
-			// ignore
-		} catch (Exception e) {
-			context.Logger.Warning(e, "Caught exception while sending stop command.");
-		}
-	}
-
-	private async Task DoWaitForSessionToEnd() {
-		using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(55));
-		try {
-			await session.WaitForExit(cts.Token);
-		} catch (OperationCanceledException) {
-			try {
-				context.Logger.Warning("Waiting timed out, killing session...");
-				session.Kill();
-			} catch (Exception e) {
-				context.Logger.Error(e, "Caught exception while killing session.");
-			}
-		}
-	}
-
-	public IInstanceState Launch(InstanceContext context) {
-		return this;
-	}
-
-	public IInstanceState Stop() {
-		return this; // TODO maybe provide a way to kill?
-	}
-
-	public Task<bool> SendCommand(string command, CancellationToken cancellationToken) {
-		return Task.FromResult(false);
-	}
-
-	public void Dispose() {
-		sessionObjects.Dispose();
-	}
-}

Agent/Phantom.Agent.Services/Phantom.Agent.Services.csproj

@@ -1,15 +1,13 @@
 <Project Sdk="Microsoft.NET.Sdk">
   
   <PropertyGroup>
-    <TargetFramework>net7.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   
   <ItemGroup>
-    <ProjectReference Include="..\..\Common\Phantom.Common.Messages\Phantom.Common.Messages.csproj" />
+    <ProjectReference Include="..\..\Common\Phantom.Common.Messages.Agent\Phantom.Common.Messages.Agent.csproj" />
     <ProjectReference Include="..\Phantom.Agent.Minecraft\Phantom.Agent.Minecraft.csproj" />
-    <ProjectReference Include="..\Phantom.Agent.Rpc\Phantom.Agent.Rpc.csproj" />
   </ItemGroup>
 
 </Project>

Agent/Phantom.Agent.Services/Rpc/ControllerConnection.cs

@@ -0,0 +1,20 @@
+using Phantom.Common.Messages.Agent;
+using Phantom.Utils.Actor;
+using Phantom.Utils.Rpc.Runtime;
+
+namespace Phantom.Agent.Services.Rpc;
+
+public sealed class ControllerConnection(RpcSendChannel<IMessageToController> sendChannel) {
+	public ValueTask Send<TMessage>(TMessage message, CancellationToken cancellationToken) where TMessage : IMessageToController {
+		return sendChannel.SendMessage(message, cancellationToken);
+	}
+	
+	// TODO handle properly
+	public bool TrySend<TMessage>(TMessage message) where TMessage : IMessageToController {
+		return sendChannel.TrySendMessage(message);
+	}
+	
+	public Task<TReply> Send<TMessage, TReply>(TMessage message, TimeSpan waitForReplyTime, CancellationToken cancellationToken) where TMessage : IMessageToController, ICanReply<TReply> {
+		return sendChannel.SendMessage<TMessage, TReply>(message, waitForReplyTime, cancellationToken);
+	}
+}

Agent/Phantom.Agent.Services/Rpc/ControllerMessageHandlerActor.cs

@@ -0,0 +1,43 @@
+using Phantom.Agent.Services.Instances;
+using Phantom.Common.Data;
+using Phantom.Common.Data.Replies;
+using Phantom.Common.Messages.Agent;
+using Phantom.Common.Messages.Agent.ToAgent;
+using Phantom.Utils.Actor;
+
+namespace Phantom.Agent.Services.Rpc;
+
+public sealed class ControllerMessageHandlerActor : ReceiveActor<IMessageToAgent> {
+	public readonly record struct Init(AgentServices Agent);
+	
+	public static Props<IMessageToAgent> Factory(Init init) {
+		return Props<IMessageToAgent>.Create(() => new ControllerMessageHandlerActor(init), new ActorConfiguration { SupervisorStrategy = SupervisorStrategies.Resume });
+	}
+	
+	private readonly AgentServices agent;
+	
+	private ControllerMessageHandlerActor(Init init) {
+		this.agent = init.Agent;
+		
+		ReceiveAndReplyLater<ConfigureInstanceMessage, Result<ConfigureInstanceResult, InstanceActionFailure>>(HandleConfigureInstance);
+		ReceiveAndReplyLater<LaunchInstanceMessage, Result<LaunchInstanceResult, InstanceActionFailure>>(HandleLaunchInstance);
+		ReceiveAndReplyLater<StopInstanceMessage, Result<StopInstanceResult, InstanceActionFailure>>(HandleStopInstance);
+		ReceiveAndReplyLater<SendCommandToInstanceMessage, Result<SendCommandToInstanceResult, InstanceActionFailure>>(HandleSendCommandToInstance);
+	}
+	
+	private async Task<Result<ConfigureInstanceResult, InstanceActionFailure>> HandleConfigureInstance(ConfigureInstanceMessage message) {
+		return await agent.InstanceManager.Request(new InstanceManagerActor.ConfigureInstanceCommand(message.InstanceGuid, message.Configuration, message.LaunchProperties, message.LaunchNow, AlwaysReportStatus: false));
+	}
+	
+	private async Task<Result<LaunchInstanceResult, InstanceActionFailure>> HandleLaunchInstance(LaunchInstanceMessage message) {
+		return await agent.InstanceManager.Request(new InstanceManagerActor.LaunchInstanceCommand(message.InstanceGuid));
+	}
+	
+	private async Task<Result<StopInstanceResult, InstanceActionFailure>> HandleStopInstance(StopInstanceMessage message) {
+		return await agent.InstanceManager.Request(new InstanceManagerActor.StopInstanceCommand(message.InstanceGuid, message.StopStrategy));
+	}
+	
+	private async Task<Result<SendCommandToInstanceResult, InstanceActionFailure>> HandleSendCommandToInstance(SendCommandToInstanceMessage message) {
+		return await agent.InstanceManager.Request(new InstanceManagerActor.SendCommandToInstanceCommand(message.InstanceGuid, message.Command));
+	}
+}

Agent/Phantom.Agent.Services/Rpc/MessageListener.cs

@@ -1,72 +0,0 @@
-using NetMQ.Sockets;
-using Phantom.Agent.Rpc;
-using Phantom.Common.Data.Replies;
-using Phantom.Common.Messages;
-using Phantom.Common.Messages.ToAgent;
-using Phantom.Common.Messages.ToServer;
-using Serilog;
-
-namespace Phantom.Agent.Services.Rpc;
-
-public sealed class MessageListener : IMessageToAgentListener {
-	private static ILogger Logger { get; } = PhantomLogger.Create<MessageListener>();
-
-	private readonly ClientSocket socket;
-	private readonly AgentServices agent;
-	private readonly CancellationTokenSource shutdownTokenSource;
-
-	public MessageListener(ClientSocket socket, AgentServices agent, CancellationTokenSource shutdownTokenSource) {
-		this.socket = socket;
-		this.agent = agent;
-		this.shutdownTokenSource = shutdownTokenSource;
-	}
-
-	public async Task HandleRegisterAgentSuccessResult(RegisterAgentSuccessMessage message) {
-		Logger.Information("Agent authentication successful.");
-
-		foreach (var instanceInfo in message.InitialInstances) {
-			if (await agent.InstanceSessionManager.Configure(instanceInfo) != ConfigureInstanceResult.Success) {
-				Logger.Fatal("Unable to configure instance \"{Name}\" (GUID {Guid}), shutting down.", instanceInfo.InstanceName, instanceInfo.InstanceGuid);
-
-				shutdownTokenSource.Cancel();
-				return;
-			}
-		}
-
-		await ServerMessaging.SendMessage(new AdvertiseJavaRuntimesMessage(agent.JavaRuntimeRepository.All));
-	}
-
-	public Task HandleRegisterAgentFailureResult(RegisterAgentFailureMessage message) {
-		string errorMessage = message.FailureKind switch {
-			RegisterAgentFailure.ConnectionAlreadyHasAnAgent => "This connection already has an associated agent.",
-			RegisterAgentFailure.InvalidToken                => "Invalid token.",
-			_                                                => "Unknown error " + (byte) message.FailureKind + "."
-		};
-
-		Logger.Fatal("Agent authentication failed: {Error}", errorMessage);
-		Environment.Exit(1);
-
-		return Task.CompletedTask;
-	}
-	
-	public Task HandleShutdownAgent(ShutdownAgentMessage message) {
-		shutdownTokenSource.Cancel();
-		return Task.CompletedTask;
-	}
-
-	public async Task HandleConfigureInstance(ConfigureInstanceMessage message) {
-		await socket.SendSimpleReply(message, await agent.InstanceSessionManager.Configure(message.Configuration));
-	}
-
-	public async Task HandleLaunchInstance(LaunchInstanceMessage message) {
-		await socket.SendSimpleReply(message, await agent.InstanceSessionManager.Launch(message.InstanceGuid));
-	}
-
-	public async Task HandleStopInstance(StopInstanceMessage message) {
-		await socket.SendSimpleReply(message, await agent.InstanceSessionManager.Stop(message.InstanceGuid));
-	}
-
-	public async Task HandleSendCommandToInstance(SendCommandToInstanceMessage message) {
-		await socket.SendSimpleReply(message, await agent.InstanceSessionManager.SendCommand(message.InstanceGuid, message.Command));
-	}
-}

Agent/Phantom.Agent/AgentKey.cs

@@ -0,0 +1,59 @@
+using System.Text;
+using Phantom.Common.Data;
+using Phantom.Utils.Cryptography;
+using Phantom.Utils.IO;
+using Phantom.Utils.Logging;
+using Serilog;
+
+namespace Phantom.Agent;
+
+static class AgentKey {
+	private static ILogger Logger { get; } = PhantomLogger.Create(nameof(AgentKey));
+	
+	public static Task<ConnectionKey?> Load(string? agentKeyToken, string? agentKeyFilePath) {
+		if (agentKeyFilePath != null) {
+			return LoadFromFile(agentKeyFilePath);
+		}
+		else if (agentKeyToken != null) {
+			return Task.FromResult(LoadFromToken(agentKeyToken));
+		}
+		else {
+			throw new InvalidOperationException();
+		}
+	}
+	
+	private static async Task<ConnectionKey?> LoadFromFile(string agentKeyFilePath) {
+		if (!File.Exists(agentKeyFilePath)) {
+			Logger.Fatal("Missing agent key file: {AgentKeyFilePath}", agentKeyFilePath);
+			return null;
+		}
+		
+		try {
+			Files.RequireMaximumFileSize(agentKeyFilePath, maximumBytes: 64);
+			string[] lines = await File.ReadAllLinesAsync(agentKeyFilePath, Encoding.UTF8);
+			return LoadFromToken(lines[0]);
+		} catch (IOException e) {
+			Logger.Fatal("Error loading agent key from file: {AgentKeyFilePath}", agentKeyFilePath);
+			Logger.Fatal("{}", e.Message);
+			return null;
+		} catch (Exception) {
+			Logger.Fatal("File does not contain a valid agent key: {AgentKeyFilePath}", agentKeyFilePath);
+			return null;
+		}
+	}
+	
+	private static ConnectionKey? LoadFromToken(string agentKey) {
+		try {
+			return LoadFromBytes(TokenGenerator.DecodeBytes(agentKey));
+		} catch (Exception) {
+			Logger.Fatal("Invalid agent key: {AgentKey}", agentKey);
+			return null;
+		}
+	}
+	
+	private static ConnectionKey? LoadFromBytes(byte[] agentKey) {
+		var connectionKey = ConnectionKey.FromBytes(agentKey);
+		Logger.Information("Loaded agent key.");
+		return connectionKey;
+	}
+}

Agent/Phantom.Agent/CertificateFile.cs

@@ -1,32 +0,0 @@
-using NetMQ;
-using Phantom.Common.Logging;
-using Phantom.Utils.IO;
-using Serilog;
-
-namespace Phantom.Agent;
-
-static class CertificateFile {
-	private static ILogger Logger { get; } = PhantomLogger.Create(typeof(CertificateFile));
-
-	public static async Task<NetMQCertificate?> LoadPublicKey(string publicKeyFilePath) {
-		if (!File.Exists(publicKeyFilePath)) {
-			Logger.Fatal("Cannot load server certificate, missing key file: {PublicKeyFilePath}", publicKeyFilePath);
-			return null;
-		}
-
-		try {
-			var publicKey = await LoadPublicKeyFromFile(publicKeyFilePath);
-			Logger.Information("Loaded server certificate.");
-			return publicKey;
-		} catch (Exception e) {
-			Logger.Fatal(e, "Error loading server certificate from key file: {PublicKeyFilePath}", publicKeyFilePath);
-			return null;
-		}
-	}
-
-	private static async Task<NetMQCertificate> LoadPublicKeyFromFile(string filePath) {
-		Files.RequireMaximumFileSize(filePath, 1024);
-		byte[] publicKey = await File.ReadAllBytesAsync(filePath);
-		return NetMQCertificate.FromPublicKey(publicKey);
-	}
-}

Agent/Phantom.Agent/GuidFile.cs

@@ -1,18 +1,18 @@
 using System.Text;
-using Phantom.Common.Logging;
 using Phantom.Utils.IO;
+using Phantom.Utils.Logging;
 using Serilog;
 
-namespace Phantom.Agent; 
+namespace Phantom.Agent;
 
 static class GuidFile {
-	private static ILogger Logger { get; } = PhantomLogger.Create(typeof(GuidFile));
-
+	private static ILogger Logger { get; } = PhantomLogger.Create(nameof(GuidFile));
+	
 	private const string GuidFileName = "agent.guid";
 	
 	public static async Task<Guid?> CreateOrLoad(string folderPath) {
 		string filePath = Path.Combine(folderPath, GuidFileName);
-
+		
 		if (File.Exists(filePath)) {
 			try {
 				var guid = await LoadGuidFromFile(filePath);
@@ -25,7 +25,7 @@ static class GuidFile {
 		}
 		
 		Logger.Information("Creating agent GUID file: {FilePath}", filePath);
-
+		
 		try {
 			var guid = Guid.NewGuid();
 			await File.WriteAllTextAsync(filePath, guid.ToString(), Encoding.ASCII);

Agent/Phantom.Agent/Phantom.Agent.csproj

@@ -1,18 +1,17 @@
 <Project Sdk="Microsoft.NET.Sdk">
   
   <PropertyGroup>
-    <TargetFramework>net7.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   
   <PropertyGroup>
     <OutputType>Exe</OutputType>
+    <SatelliteResourceLanguages>en</SatelliteResourceLanguages>
   </PropertyGroup>
   
   <ItemGroup>
-    <ProjectReference Include="..\..\Utils\Phantom.Utils.IO\Phantom.Utils.IO.csproj" />
-    <ProjectReference Include="..\..\Utils\Phantom.Utils.Runtime\Phantom.Utils.Runtime.csproj" />
+    <ProjectReference Include="..\..\Utils\Phantom.Utils\Phantom.Utils.csproj" />
     <ProjectReference Include="..\Phantom.Agent.Minecraft\Phantom.Agent.Minecraft.csproj" />
     <ProjectReference Include="..\Phantom.Agent.Services\Phantom.Agent.Services.csproj" />
   </ItemGroup>

Agent/Phantom.Agent/Program.cs

@@ -1,63 +1,113 @@
-using Phantom.Agent;
-using Phantom.Agent.Rpc;
+using System.Reflection;
+using Phantom.Agent;
 using Phantom.Agent.Services;
 using Phantom.Agent.Services.Rpc;
 using Phantom.Common.Data.Agent;
-using Phantom.Common.Logging;
-using Phantom.Utils.Rpc;
+using Phantom.Common.Messages.Agent;
+using Phantom.Common.Messages.Agent.ToController;
+using Phantom.Utils.Actor;
+using Phantom.Utils.Logging;
+using Phantom.Utils.Rpc.Runtime.Client;
 using Phantom.Utils.Runtime;
+using Phantom.Utils.Threading;
 
-const int AgentVersion = 1;
+const int ProtocolVersion = 1;
 
-var cancellationTokenSource = new CancellationTokenSource();
+var shutdownCancellationTokenSource = new CancellationTokenSource();
+var shutdownCancellationToken = shutdownCancellationTokenSource.Token;
 
-PosixSignals.RegisterCancellation(cancellationTokenSource, static () => {
+ProgramCulture.UseInvariantCulture();
+ThreadPool.SetMinThreads(workerThreads: 2, completionPortThreads: 1);
+
+PosixSignals.RegisterCancellation(shutdownCancellationTokenSource, static () => {
 	PhantomLogger.Root.InformationHeading("Stopping Phantom Panel agent...");
 });
 
 try {
-	PhantomLogger.Root.InformationHeading("Initializing Phantom Panel agent...");
-
-	var (serverHost, serverPort, javaSearchPath, authToken, authTokenFilePath, agentName, maxInstances, maxMemory, allowedServerPorts, allowedRconPorts) = Variables.LoadOrExit();
+	var fullVersion = AssemblyAttributes.GetFullVersion(Assembly.GetExecutingAssembly());
 	
-	AgentAuthToken agentAuthToken;
-	try {
-		agentAuthToken = authTokenFilePath == null ? new AgentAuthToken(authToken) : await AgentAuthToken.ReadFromFile(authTokenFilePath);
-	} catch (Exception e) {
-		PhantomLogger.Root.Fatal(e, "Error reading auth token.");
-		Environment.Exit(1);
-		return;
+	PhantomLogger.Root.InformationHeading("Initializing Phantom Panel agent...");
+	PhantomLogger.Root.Information("Agent version: {Version}", fullVersion);
+	
+	var (controllerHost, controllerPort, javaSearchPath, agentKeyToken, agentKeyFilePath, agentName, maxInstances, maxMemory, allowedServerPorts, allowedRconPorts, maxConcurrentBackupCompressionTasks) = Variables.LoadOrStop();
+	
+	var agentKey = await AgentKey.Load(agentKeyToken, agentKeyFilePath);
+	if (agentKey == null) {
+		return 1;
 	}
-
-	string serverPublicKeyPath = Path.GetFullPath("./secrets/agent.key");
-	var serverCertificate = await CertificateFile.LoadPublicKey(serverPublicKeyPath);
-	if (serverCertificate == null) {
-		Environment.Exit(1);
-	}
-
+	
 	var folders = new AgentFolders("./data", "./temp", javaSearchPath);
 	if (!folders.TryCreate()) {
-		Environment.Exit(1);
+		return 1;
 	}
-
+	
 	var agentGuid = await GuidFile.CreateOrLoad(folders.DataFolderPath);
 	if (agentGuid == null) {
-		Environment.Exit(1);
-		return;
+		return 1;
 	}
-
-	var agentInfo = new AgentInfo(agentGuid.Value, agentName, AgentVersion, maxInstances, maxMemory, allowedServerPorts, allowedRconPorts);
-	var agentServices = new AgentServices(agentInfo, folders);
-
-	PhantomLogger.Root.InformationHeading("Launching Phantom Panel agent...");
 	
-	await agentServices.Initialize();
-	await RpcLauncher.Launch(new RpcConfiguration(PhantomLogger.Create("Rpc"), serverHost, serverPort, serverCertificate, cancellationTokenSource.Token), agentAuthToken, agentInfo, socket => new MessageListener(socket, agentServices, cancellationTokenSource));
-	await agentServices.Shutdown();
+	var rpcClientConnectionParameters = new RpcClientConnectionParameters(
+		Host: controllerHost,
+		Port: controllerPort,
+		DistinguishedName: "phantom-controller",
+		CertificateThumbprint: agentKey.Value.CertificateThumbprint,
+		AuthToken: agentKey.Value.AuthToken,
+		SendQueueCapacity: 500,
+		PingInterval: TimeSpan.FromSeconds(10)
+	);
+	
+	using var rpcClient = await RpcClient<IMessageToController, IMessageToAgent>.Connect("Controller", rpcClientConnectionParameters, AgentMessageRegistries.Definitions, shutdownCancellationToken);
+	if (rpcClient == null) {
+		return 1;
+	}
+	
+	var controllerConnection = new ControllerConnection(rpcClient.SendChannel);
+	
+	Task? rpcClientListener = null;
+	try {
+		PhantomLogger.Root.InformationHeading("Launching Phantom Panel agent...");
+		
+		var agentInfo = new AgentInfo(agentGuid.Value, agentName, ProtocolVersion, fullVersion, maxInstances, maxMemory, allowedServerPorts, allowedRconPorts);
+		var agentServices = new AgentServices(agentInfo, folders, new AgentServiceConfiguration(maxConcurrentBackupCompressionTasks), controllerConnection);
+		await agentServices.Initialize();
+		
+		var rpcMessageHandlerInit = new ControllerMessageHandlerActor.Init(agentServices);
+		var rpcMessageHandlerActor = agentServices.ActorSystem.ActorOf(ControllerMessageHandlerActor.Factory(rpcMessageHandlerInit), "ControllerMessageHandler");
+		
+		rpcClientListener = rpcClient.Listen(rpcMessageHandlerActor);
+		
+		if (await agentServices.Register(controllerConnection, shutdownCancellationToken)) {
+			PhantomLogger.Root.Information("Phantom Panel agent is ready.");
+			await shutdownCancellationToken.WaitHandle.WaitOneAsync();
+		}
+		
+		await agentServices.Shutdown();
+	} finally {
+		try {
+			await controllerConnection.Send(new UnregisterAgentMessage(), CancellationToken.None);
+			// TODO wait for acknowledgment
+		} catch (Exception e) {
+			PhantomLogger.Root.Warning(e, "Could not unregister agent after shutdown.");
+		} finally {
+			await rpcClient.Shutdown();
+			
+			if (rpcClientListener != null) {
+				await rpcClientListener;
+			}
+		}
+	}
+	
+	return 0;
 } catch (OperationCanceledException) {
-	// Ignore.
+	return 0;
+} catch (StopProcedureException) {
+	return 1;
+} catch (Exception e) {
+	PhantomLogger.Root.Fatal(e, "Caught exception in entry point.");
+	return 1;
 } finally {
-	cancellationTokenSource.Dispose();
+	shutdownCancellationTokenSource.Dispose();
+	
 	PhantomLogger.Root.Information("Bye!");
 	PhantomLogger.Dispose();
 }