Added CommandService logging

src/Discord.Net.Commands/CommandException.cs

@@ -0,0 +1,15 @@
+using System;
+
+namespace Discord.Commands
+{
+    public class CommandException : Exception
+    {
+        public CommandInfo Command { get; }
+        public ICommandContext Content { get; }
+
+        public CommandException(CommandInfo command, ICommandContext context, Exception ex)
+            : base($"Error occurred executing {command.GetLogText(context)}.", ex)
+        {
+        }
+    }
+}

src/Discord.Net.Commands/CommandService.cs

@@ -1,4 +1,6 @@
-using System;
+using Discord.Commands.Builders;
+using Discord.Logging;
+using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Collections.Immutable;
@@ -7,12 +9,13 @@ using System.Reflection;
 using System.Threading;
 using System.Threading.Tasks;
 
-using Discord.Commands.Builders;
-
 namespace Discord.Commands
 {
     public class CommandService
     {
+        public event Func<LogMessage, Task> Log { add { _logEvent.Add(value); } remove { _logEvent.Remove(value); } }
+        internal readonly AsyncEvent<Func<LogMessage, Task>> _logEvent = new AsyncEvent<Func<LogMessage, Task>>();
+
         private readonly SemaphoreSlim _moduleLock;
         private readonly ConcurrentDictionary<Type, ModuleInfo> _typedModuleDefs;
         private readonly ConcurrentDictionary<Type, ConcurrentDictionary<Type, TypeReader>> _typeReaders;
@@ -24,6 +27,8 @@ namespace Discord.Commands
         internal readonly bool _caseSensitive;
         internal readonly char _separatorChar;
         internal readonly RunMode _defaultRunMode;
+        internal readonly Logger _cmdLogger;
+        internal readonly LogManager _logManager;
 
         public IEnumerable<ModuleInfo> Modules => _moduleDefs.Select(x => x);
         public IEnumerable<CommandInfo> Commands => _moduleDefs.SelectMany(x => x.Commands);
@@ -36,7 +41,11 @@ namespace Discord.Commands
             _separatorChar = config.SeparatorChar;
             _defaultRunMode = config.DefaultRunMode;
             if (_defaultRunMode == RunMode.Default)
-                throw new InvalidOperationException("The default run mode cannot be set to Default, it must be one of Sync, Mixed, or Async");
+                throw new InvalidOperationException("The default run mode cannot be set to Default.");
+
+            _logManager = new LogManager(config.LogLevel);
+            _logManager.Message += async msg => await _logEvent.InvokeAsync(msg).ConfigureAwait(false);
+            _cmdLogger = _logManager.CreateLogger("Command");
 
             _moduleLock = new SemaphoreSlim(1, 1);
             _typedModuleDefs = new ConcurrentDictionary<Type, ModuleInfo>();

src/Discord.Net.Commands/CommandServiceConfig.cs

@@ -8,5 +8,8 @@
         public char SeparatorChar { get; set; } = ' ';
         /// <summary> Should commands be case-sensitive? </summary>
         public bool CaseSensitiveCommands { get; set; } = false;
+
+        /// <summary> Gets or sets the minimum log level severity that will be sent to the Log event. </summary>
+        public LogSeverity LogLevel { get; set; } = LogSeverity.Info;
     }
 }

src/Discord.Net.Commands/Info/CommandInfo.cs

@@ -137,16 +137,48 @@ namespace Discord.Commands
                         return ExecuteResult.FromError(result);
                 }
 
+                await Module.Service._cmdLogger.DebugAsync($"Executing {GetLogText(context)}").ConfigureAwait(false);
                 switch (RunMode)
                 {
                     case RunMode.Sync: //Always sync
-                        await _action(context, args, map).ConfigureAwait(false);
+                        try
+                        {
+                            await _action(context, args, map).ConfigureAwait(false);
+                        }
+                        catch (Exception ex)
+                        {
+                            ex = new CommandException(this, context, ex);
+                            await Module.Service._cmdLogger.ErrorAsync(ex).ConfigureAwait(false);
+                            throw;
+                        }
+                        await Module.Service._cmdLogger.VerboseAsync($"Executed {GetLogText(context)}").ConfigureAwait(false);
                         break;
                     case RunMode.Mixed: //Sync until first await statement
-                        var t1 = _action(context, args, map);
+                        var t1 = _action(context, args, map).ContinueWith(async t =>
+                        {
+                            if (t.IsFaulted)
+                            {
+                                var ex = new CommandException(this, context, t.Exception);
+                                await Module.Service._cmdLogger.ErrorAsync(ex).ConfigureAwait(false);
+                            }
+                            else
+                                await Module.Service._cmdLogger.VerboseAsync($"Executed {GetLogText(context)}").ConfigureAwait(false);
+                        });
                         break;
                     case RunMode.Async: //Always async
-                        var t2 = Task.Run(() => _action(context, args, map));
+                        var t2 = Task.Run(() => 
+                        {
+                            var _ = _action(context, args, map).ContinueWith(async t =>
+                            {
+                                if (t.IsFaulted)
+                                {
+                                    var ex = new CommandException(this, context, t.Exception);
+                                    await Module.Service._cmdLogger.ErrorAsync(ex).ConfigureAwait(false);
+                                }
+                                else
+                                    await Module.Service._cmdLogger.VerboseAsync($"Executed {GetLogText(context)}").ConfigureAwait(false);
+                            });
+                        });
                         break;
                 }
                 return ExecuteResult.FromSuccess();
@@ -189,5 +221,13 @@ namespace Discord.Commands
 
         private static T[] ConvertParamsList<T>(IEnumerable<object> paramsList)
             => paramsList.Cast<T>().ToArray();
+
+        internal string GetLogText(ICommandContext context)
+        {            
+            if (context.Guild != null)
+                return $"\"{Name}\" for {context.User} in {context.Guild}/{context.Channel}";
+            else
+                return $"\"{Name}\" for {context.User} in {context.Channel}";
+        }
     }
 }

src/Discord.Net.Commands/Info/ParameterInfo.cs

@@ -1,11 +1,9 @@
+using Discord.Commands.Builders;
 using System;
 using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.Threading.Tasks;
 
-using Discord.Commands.Builders;
-using System.Reflection;
-
 namespace Discord.Commands
 {
     public class ParameterInfo

src/Discord.Net.Core/DiscordConfig.cs

@@ -22,7 +22,7 @@ namespace Discord
         /// <summary> Gets or sets how a request should act in the case of an error, by default. </summary>
         public RetryMode DefaultRetryMode { get; set; } = RetryMode.AlwaysRetry;
         
-        /// <summary> Gets or sets the minimum log level severity that will be sent to the LogMessage event. </summary>
+        /// <summary> Gets or sets the minimum log level severity that will be sent to the Log event. </summary>
         public LogSeverity LogLevel { get; set; } = LogSeverity.Info;
 
         /// <summary> Gets or sets whether the initial log entry should be printed. </summary>