TweetDuck/Resources/ScriptLoader.cs

using CefSharp;
using System;
using System.IO;
using System.Text;
using System.Windows.Forms;
using TweetDuck.Core.Controls;
using TweetDuck.Core.Other;
#if DEBUG
using System.Diagnostics;
using System.Reflection;
using TweetDuck.Core;
using TweetDuck.Plugins;
#endif

namespace TweetDuck.Resources{
    static class ScriptLoader{
        public static string LoadResource(string name, bool silent = false, Control sync = null){
            try{
                string path = Program.ScriptPath;

                #if DEBUG
                if (Directory.Exists(HotSwapTargetDir)){
                    path = Path.Combine(HotSwapTargetDir, "scripts");
                    Debug.WriteLine("Hot swap active, redirecting "+name);
                }
                #endif

                string contents = File.ReadAllText(Path.Combine(path, name), Encoding.UTF8);
                int separator;

                // first line can be either:
                // #<version>\r\n
                // #<version>\n

                if (contents[0] != '#'){
                    ShowLoadError(silent, sync, $"File {name} appears to be corrupted, please try reinstalling the app.");
                    separator = 0;
                }
                else{
                    separator = contents.IndexOf('\n');
                    string fileVersion = contents.Substring(1, separator-1).TrimEnd();

                    if (fileVersion != Program.VersionTag){
                        ShowLoadError(silent, sync, $"File {name} is made for a different version of TweetDuck ({fileVersion}) and may not function correctly in this version, please try reinstalling the app.");
                    }
                }

                return contents.Substring(separator).TrimStart();
            }catch(Exception ex){
                ShowLoadError(silent, sync, $"Could not load {name}. The program will continue running with limited functionality.\n\n{ex.Message}");
                return null;
            }
        }

        public static bool ExecuteFile(IFrame frame, string file, Control sync = null){
            string script = LoadResource(file, sync == null, sync);
            ExecuteScript(frame, script, GetRootIdentifier(file));
            return script != null;
        }

        public static void ExecuteScript(IFrame frame, string script, string identifier){
            if (script != null){
                frame.ExecuteJavaScriptAsync(script, "td:"+identifier, 1);
            }
        }

        public static string GetRootIdentifier(string file){
            return "root:"+Path.GetFileNameWithoutExtension(file);
        }

        private static void ShowLoadError(bool silent, Control sync, string message){
            if (silent){
                return;
            }

            if (sync == null){
                FormMessage.Error("Resource Error", message, FormMessage.OK);
            }
            else{
                sync.InvokeSafe(() => FormMessage.Error("Resource Error", message, FormMessage.OK));
            }
        }
        
        #if DEBUG
        private static readonly string HotSwapProjectRoot = FixPathSlash(Path.GetFullPath(Path.Combine(Program.ProgramPath, "../../../")));
        private static readonly string HotSwapTargetDir = FixPathSlash(Path.Combine(HotSwapProjectRoot, "bin", "tmp"));
        private static readonly string HotSwapRebuildScript = Path.Combine(HotSwapProjectRoot, "Resources", "PostBuild.ps1");

        static ScriptLoader(){
            if (File.Exists(HotSwapRebuildScript)){
                Debug.WriteLine("Activating resource hot swap");

                ResetHotSwap();
                Application.ApplicationExit += (sender, args) => ResetHotSwap();
            }
        }

        public static void HotSwap(){
            if (!File.Exists(HotSwapRebuildScript)){
                Debug.WriteLine("Failed resource hot swap, missing rebuild script: "+HotSwapRebuildScript);
                return;
            }
            
            ResetHotSwap();
            Directory.CreateDirectory(HotSwapTargetDir);

            using(Process process = Process.Start(new ProcessStartInfo{
                FileName = "powershell",
                Arguments = $"-ExecutionPolicy Unrestricted -File \"{HotSwapRebuildScript}\" \"{HotSwapTargetDir}\\\" \"{HotSwapProjectRoot}\\\" \"Debug\" \"{Program.VersionTag}\"",
                WindowStyle = ProcessWindowStyle.Hidden
            })){
                // ReSharper disable once PossibleNullReferenceException
                if (!process.WaitForExit(8000)){
                    Debug.WriteLine("Failed resource hot swap, script did not finish in time");
                    return;
                }
                else if (process.ExitCode != 0){
                    Debug.WriteLine("Failed resource hot swap, script exited with code "+process.ExitCode);
                    return;
                }
            }

            // Force update plugin manager setup scripts

            string newPluginRoot = Path.Combine(HotSwapTargetDir, "plugins");
            
            const BindingFlags flagsInstance = BindingFlags.Instance | BindingFlags.NonPublic;
            const BindingFlags flagsStatic = BindingFlags.Static | BindingFlags.NonPublic;

            Type typePluginManager = typeof(PluginManager);
            Type typeFormBrowser = typeof(FormBrowser);

            // ReSharper disable PossibleNullReferenceException
            object pluginSetupScripts = typePluginManager.GetMethod("LoadSetupScripts", flagsStatic).Invoke(null, new object[0]);
            typePluginManager.GetField("PluginSetupScripts", flagsStatic).SetValue(null, pluginSetupScripts);
            
            object instPluginManager = typeFormBrowser.GetField("plugins", flagsInstance).GetValue(FormManager.TryFind<FormBrowser>());
            typePluginManager.GetField("rootPath", flagsInstance).SetValue(instPluginManager, newPluginRoot);

            Debug.WriteLine("Reloading hot swapped plugins...");
            ((PluginManager)instPluginManager).Reload();
            // ReSharper restore PossibleNullReferenceException
        }

        private static void ResetHotSwap(){
            try{
                Directory.Delete(HotSwapTargetDir, true);
            }catch(DirectoryNotFoundException){}
        }

        private static string FixPathSlash(string path){
            return path.TrimEnd(Path.DirectorySeparatorChar, Path.AltDirectorySeparatorChar)+'\\';
        }
        #endif
    }
}