Add /mute command (timeouts only) (#44)

Co-authored-by: Octol1ttle <l1ttleofficial@outlook.com>

Commands/ErrorLoggingEvents.cs

@@ -0,0 +1,62 @@
+using Microsoft.Extensions.Logging;
+using Remora.Discord.Commands.Contexts;
+using Remora.Discord.Commands.Services;
+using Remora.Results;
+
+// ReSharper disable ClassNeverInstantiated.Global
+
+namespace Boyfriend.Commands;
+
+/// <summary>
+///     Handles error logging for slash commands that couldn't be successfully prepared.
+/// </summary>
+public class ErrorLoggingPreparationErrorEvent : IPreparationErrorEvent {
+    private readonly ILogger<ErrorLoggingPreparationErrorEvent> _logger;
+
+    public ErrorLoggingPreparationErrorEvent(ILogger<ErrorLoggingPreparationErrorEvent> logger) {
+        _logger = logger;
+    }
+
+    /// <summary>
+    ///     Logs a warning using the injected <see cref="ILogger" /> if the <paramref name="preparationResult" /> has not
+    ///     succeeded.
+    /// </summary>
+    /// <param name="context">The context of the slash command. Unused.</param>
+    /// <param name="preparationResult">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> PreparationFailed(
+        IOperationContext context, IResult preparationResult, CancellationToken ct = default) {
+        if (!preparationResult.IsSuccess)
+            _logger.LogWarning("Error in slash command preparation.\n{ErrorMessage}", preparationResult.Error.Message);
+
+        return Task.FromResult(Result.FromSuccess());
+    }
+}
+
+/// <summary>
+///     Handles error logging for slash command groups.
+/// </summary>
+public class ErrorLoggingPostExecutionEvent : IPostExecutionEvent {
+    private readonly ILogger<ErrorLoggingPostExecutionEvent> _logger;
+
+    public ErrorLoggingPostExecutionEvent(ILogger<ErrorLoggingPostExecutionEvent> logger) {
+        _logger = logger;
+    }
+
+    /// <summary>
+    ///     Logs a warning using the injected <see cref="ILogger" /> if the <paramref name="commandResult" /> has not
+    ///     succeeded.
+    /// </summary>
+    /// <param name="context">The context of the slash command. Unused.</param>
+    /// <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(
+        ICommandContext context, IResult commandResult, CancellationToken ct = default) {
+        if (!commandResult.IsSuccess)
+            _logger.LogWarning("Error in slash command execution.\n{ErrorMessage}", commandResult.Error.Message);
+
+        return Task.FromResult(Result.FromSuccess());
+    }
+}