Notify user when a command execution error occurs (#171)

With this PR, whenever command execution fails, the user will get an
error message with details of the error that can be passed on to
developers

An unrelated minor change: errors caused by task cancellations will no
longer be logged

---------

Signed-off-by: Octol1ttle <l1ttleofficial@outlook.com>
Signed-off-by: mctaylors <mctaylxrs@outlook.com>

locale/Messages.resx

@@ -570,4 +570,10 @@
   <data name="MessagesClearedFiltered" xml:space="preserve">
       <value>Cleared {0} messages from {1}</value>
   </data>
+  <data name="CommandExecutionFailed" xml:space="preserve">
+      <value>An error occurred during command execution, try again later.</value>
+  </data>
+  <data name="ContactDevelopers" xml:space="preserve">
+      <value>Contact the developers if the problem occurs again.</value>
+  </data>
 </root>

locale/Messages.ru.resx

@@ -570,4 +570,10 @@
   <data name="MessagesClearedFiltered" xml:space="preserve">
       <value>Очищено {0} сообщений от {1}</value>
   </data>
+  <data name="CommandExecutionFailed" xml:space="preserve">
+      <value>Произошла ошибка при выполнении команды, повтори попытку позже.</value>
+  </data>
+  <data name="ContactDevelopers" xml:space="preserve">
+      <value>Обратись к разработчикам, если проблема возникнет снова.</value>
+  </data>
 </root>

locale/Messages.tt-ru.resx

@@ -570,4 +570,10 @@
   <data name="MessagesClearedFiltered" xml:space="preserve">
       <value>вырезано {0} забавных сообщений от {1}</value>
   </data>
+  <data name="CommandExecutionFailed" xml:space="preserve">
+      <value>произошёл тотальный разнос в команде, удачи.</value>
+  </data>
+  <data name="ContactDevelopers" xml:space="preserve">
+      <value>если ты это читаешь второй раз за сегодня, пиши разрабам</value>
+  </data>
 </root>

src/Commands/Events/ErrorLoggingPostExecutionEvent.cs

@@ -1,8 +1,12 @@
 using JetBrains.Annotations;
 using Microsoft.Extensions.Logging;
 using Octobot.Extensions;
+using Remora.Discord.API.Abstractions.Rest;
 using Remora.Discord.Commands.Contexts;
+using Remora.Discord.Commands.Feedback.Services;
 using Remora.Discord.Commands.Services;
+using Remora.Discord.Extensions.Embeds;
+using Remora.Discord.Extensions.Formatting;
 using Remora.Results;
 
 namespace Octobot.Commands.Events;
@@ -14,10 +18,15 @@ namespace Octobot.Commands.Events;
 public class ErrorLoggingPostExecutionEvent : IPostExecutionEvent
 {
     private readonly ILogger<ErrorLoggingPostExecutionEvent> _logger;
+    private readonly FeedbackService _feedback;
+    private readonly IDiscordRestUserAPI _userApi;
 
-    public ErrorLoggingPostExecutionEvent(ILogger<ErrorLoggingPostExecutionEvent> logger)
+    public ErrorLoggingPostExecutionEvent(ILogger<ErrorLoggingPostExecutionEvent> logger, FeedbackService feedback,
+        IDiscordRestUserAPI userApi)
     {
         _logger = logger;
+        _feedback = feedback;
+        _userApi = userApi;
     }
 
     /// <summary>
@@ -28,11 +37,34 @@ public class ErrorLoggingPostExecutionEvent : IPostExecutionEvent
     /// <param name="commandResult">The result whose success is checked.</param>
     /// <param name="ct">The cancellation token for this operation. Unused.</param>
     /// <returns>A result which has succeeded.</returns>
-    public Task<Result> AfterExecutionAsync(
+    public async Task<Result> AfterExecutionAsync(
         ICommandContext context, IResult commandResult, CancellationToken ct = default)
     {
         _logger.LogResult(commandResult, $"Error in slash command execution for /{context.Command.Command.Node.Key}.");
 
-        return Task.FromResult(Result.FromSuccess());
+        var result = commandResult;
+        while (result.Inner is not null)
+        {
+            result = result.Inner;
+        }
+
+        if (result.IsSuccess)
+        {
+            return Result.FromSuccess();
+        }
+
+        var botResult = await _userApi.GetCurrentUserAsync(ct);
+        if (!botResult.IsDefined(out var bot))
+        {
+            return Result.FromError(botResult);
+        }
+
+        var embed = new EmbedBuilder().WithSmallTitle(Messages.CommandExecutionFailed, bot)
+            .WithDescription(Markdown.InlineCode(result.Error.Message))
+            .WithFooter(Messages.ContactDevelopers)
+            .WithColour(ColorsList.Red)
+            .Build();
+
+        return await _feedback.SendContextualEmbedResultAsync(embed, ct);
     }
 }

src/Extensions/LoggerExtensions.cs

@@ -26,6 +26,11 @@ public static class LoggerExtensions
 
         if (result.Error is ExceptionError exe)
         {
+            if (exe.Exception is TaskCanceledException)
+            {
+                return;
+            }
+
             logger.LogError(exe.Exception, "{ErrorMessage}", message);
             return;
         }

src/Messages.Designer.cs

@@ -996,5 +996,21 @@ namespace Octobot {
                 return ResourceManager.GetString("MessagesClearedFiltered", resourceCulture);
             }
         }
+
+        internal static string CommandExecutionFailed
+        {
+            get
+            {
+                return ResourceManager.GetString("CommandExecutionFailed", resourceCulture);
+            }
+        }
+
+        internal static string ContactDevelopers
+        {
+            get
+            {
+                return ResourceManager.GetString("ContactDevelopers", resourceCulture);
+            }
+        }
     }
 }