1 files changed, 64 insertions, 0 deletions
diff --git a/src/SMAPI/Framework/Commands/HelpCommand.cs b/src/SMAPI/Framework/Commands/HelpCommand.cs
new file mode 100644
index 00000000..b8730a00
--- /dev/null
+++ b/src/SMAPI/Framework/Commands/HelpCommand.cs
@@ -0,0 +1,64 @@
+using System.Linq;
+
+namespace StardewModdingAPI.Framework.Commands
+{
+    /// <summary>The 'help' SMAPI console command.</summary>
+    internal class HelpCommand : IInternalCommand
+    {
+        /*********
+        ** Fields
+        *********/
+        /// <summary>Manages console commands.</summary>
+        private readonly CommandManager CommandManager;
+
+
+        /*********
+        ** Accessors
+        *********/
+        /// <summary>The command name, which the user must type to trigger it.</summary>
+        public string Name { get; } = "help";
+
+        /// <summary>The human-readable documentation shown when the player runs the built-in 'help' command.</summary>
+        public string Description { get; } = "Lists command documentation.\n\nUsage: help\nLists all available commands.\n\nUsage: help <cmd>\n- cmd: The name of a command whose documentation to display.";
+
+
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Construct an instance.</summary>
+        /// <param name="commandManager">Manages console commands.</param>
+        public HelpCommand(CommandManager commandManager)
+        {
+            this.CommandManager = commandManager;
+        }
+
+        /// <summary>Handle the console command when it's entered by the user.</summary>
+        /// <param name="args">The command arguments.</param>
+        /// <param name="monitor">Writes messages to the console.</param>
+        public void HandleCommand(string[] args, IMonitor monitor)
+        {
+            if (args.Any())
+            {
+                Command result = this.CommandManager.Get(args[0]);
+                if (result == null)
+                    monitor.Log("There's no command with that name.", LogLevel.Error);
+                else
+                    monitor.Log($"{result.Name}: {result.Documentation}{(result.Mod != null ? $"\n(Added by {result.Mod.DisplayName}.)" : "")}", LogLevel.Info);
+            }
+            else
+            {
+                string message = "The following commands are registered:\n";
+                IGrouping<string, string>[] groups = (from command in this.CommandManager.GetAll() orderby command.Mod?.DisplayName, command.Name group command.Name by command.Mod?.DisplayName).ToArray();
+                foreach (var group in groups)
+                {
+                    string modName = group.Key ?? "SMAPI";
+                    string[] commandNames = group.ToArray();
+                    message += $"{modName}:\n  {string.Join("\n  ", commandNames)}\n\n";
+                }
+                message += "For more information about a command, type 'help command_name'.";
+
+                monitor.Log(message, LogLevel.Info);
+            }
+        }
+    }
+}