Add IAppErrorHandler w/ implementation

Program.cs

@@ -58,6 +58,7 @@ static Program(){
             Config = new ConfigManager();
 
             Lib.Initialize(new App.Builder{
+                ErrorHandler = Reporter
             });
         }
 

Reporter.cs

@@ -7,9 +7,10 @@
 using TweetDuck.Configuration;
 using TweetDuck.Core.Other;
 using TweetLib.Core;
+using TweetLib.Core.Application;
 
 namespace TweetDuck{
-    sealed class Reporter{
+    sealed class Reporter : IAppErrorHandler{
         private readonly string logFile;
 
         public Reporter(string logFile){
@@ -29,8 +30,12 @@ public bool LogVerbose(string data){
         }
 
         public bool LogImportant(string data){
+            return ((IAppErrorHandler)this).Log(data);
+        }
+
+        bool IAppErrorHandler.Log(string text){
             #if DEBUG
-            Debug.WriteLine(data);
+            Debug.WriteLine(text);
             #endif
 
             StringBuilder build = new StringBuilder();
@@ -40,7 +45,7 @@ public bool LogImportant(string data){
             }
 
             build.Append("[").Append(DateTime.Now.ToString("G", Lib.Culture)).Append("]\r\n");
-            build.Append(data).Append("\r\n\r\n");
+            build.Append(text).Append("\r\n\r\n");
 
             try{
                 File.AppendAllText(logFile, build.ToString(), Encoding.UTF8);

lib/TweetLib.Core/App.cs

@@ -3,14 +3,17 @@
 
 namespace TweetLib.Core{
     public sealed class App{
+        public static IAppErrorHandler ErrorHandler { get; private set; }
 
         // Builder
 
         public sealed class Builder{
+            public IAppErrorHandler? ErrorHandler { get; set; }
 
             // Validation
 
             internal void Initialize(){
+                App.ErrorHandler = Validate(ErrorHandler, nameof(ErrorHandler))!;
             }
 
             private T Validate<T>(T obj, string name){

lib/TweetLib.Core/Application/IAppErrorHandler.cs

@@ -0,0 +1,8 @@
+using System;
+
+namespace TweetLib.Core.Application{
+    public interface IAppErrorHandler{
+        bool Log(string text);
+        void HandleException(string caption, string message, bool canIgnore, Exception e);
+    }
+}