From e4ab7cc8647fc2b05d48a5b3a5fd20d3101e5576 Mon Sep 17 00:00:00 2001
From: lars-berger <lars.berger@yahoo.com>
Date: Thu, 2 Feb 2023 19:22:04 +0800
Subject: [PATCH] feat: add command history to error logs (#237)

---
 GlazeWM.Bootstrapper/Program.cs                        | 10 +++++++++-
 GlazeWM.Infrastructure/Bussing/Bus.cs                  |  7 +++++++
 .../CommandHandlers/HandleFatalExceptionHandler.cs     |  1 +
 3 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/GlazeWM.Bootstrapper/Program.cs b/GlazeWM.Bootstrapper/Program.cs
index 45020cb7e..b9db405d4 100644
--- a/GlazeWM.Bootstrapper/Program.cs
+++ b/GlazeWM.Bootstrapper/Program.cs
@@ -2,12 +2,14 @@
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.IO;
+using System.Linq;
 using System.Text.Json.Serialization;
 using System.Threading;
 using GlazeWM.Bar;
 using GlazeWM.Domain;
 using GlazeWM.Domain.Containers;
 using GlazeWM.Infrastructure;
+using GlazeWM.Infrastructure.Bussing;
 using GlazeWM.Infrastructure.Exceptions;
 using GlazeWM.Infrastructure.Logging;
 using GlazeWM.Infrastructure.Serialization;
@@ -69,7 +71,7 @@ private static IHost CreateHost(string[] args)
           // Configure exception handler.
           services
             .AddOptions<ExceptionHandlingOptions>()
-            .Configure<ContainerService, JsonService>((options, containerService, jsonService) =>
+            .Configure<Bus, ContainerService, JsonService>((options, bus, containerService, jsonService) =>
             {
               options.ErrorLogPath = Path.Combine(
                 Environment.GetFolderPath(Environment.SpecialFolder.UserProfile),
@@ -83,8 +85,14 @@ private static IHost CreateHost(string[] args)
                   new List<JsonConverter> { new JsonContainerConverter() }
                 );
 
+                // History of latest command invocations. Most recent is first.
+                var commandHistory = bus.CommandHistory
+                  .Select(command => command.Name)
+                  .Reverse();
+
                 return $"{DateTime.Now}\n"
                   + $"{exception}\n"
+                  + $"Command history: {string.Join(", ", commandHistory)} \n"
                   + $"State dump: {stateDump}\n\n";
               };
             });
diff --git a/GlazeWM.Infrastructure/Bussing/Bus.cs b/GlazeWM.Infrastructure/Bussing/Bus.cs
index 3ebffad71..46eba7135 100644
--- a/GlazeWM.Infrastructure/Bussing/Bus.cs
+++ b/GlazeWM.Infrastructure/Bussing/Bus.cs
@@ -13,6 +13,7 @@ namespace GlazeWM.Infrastructure.Bussing
   public sealed class Bus
   {
     public readonly Subject<Event> Events = new();
+    public readonly Queue<Command> CommandHistory = new();
     public readonly object LockObj = new();
     private readonly ILogger<Bus> _logger;
 
@@ -30,6 +31,12 @@ public CommandResponse Invoke<T>(T command) where T : Command
       {
         _logger.LogDebug("Command {CommandName} invoked.", command.Name);
 
+        CommandHistory.Enqueue(command);
+
+        // Maintain a history of the last 15 command invocations for debugging.
+        if (CommandHistory.Count > 15)
+          CommandHistory.Dequeue();
+
         // Create a `Type` object representing the constructed `ICommandHandler` generic.
         var handlerType = typeof(ICommandHandler<>).MakeGenericType(command.GetType());
 
diff --git a/GlazeWM.Infrastructure/Common/CommandHandlers/HandleFatalExceptionHandler.cs b/GlazeWM.Infrastructure/Common/CommandHandlers/HandleFatalExceptionHandler.cs
index 4587a565b..8afe4d999 100644
--- a/GlazeWM.Infrastructure/Common/CommandHandlers/HandleFatalExceptionHandler.cs
+++ b/GlazeWM.Infrastructure/Common/CommandHandlers/HandleFatalExceptionHandler.cs
@@ -23,6 +23,7 @@ public CommandResponse Handle(HandleFatalExceptionCommand command)
     {
       // Alert the user of the error.
       var exception = command.Exception;
+      // TODO: Show foreground window.
       MessageBox.Show($"Unhandled exception: {exception.Message}");
 
       WriteToErrorLog(exception);