[WIP] Add command support

build.bat

@@ -0,0 +1,6 @@
+@echo off
+cd src
+dotnet restore
+dotnet build
+
+pause

src/MineCase.Core/Minecase.Core.csproj

@@ -9,10 +9,6 @@
     <AssemblyName>MineCase.Core</AssemblyName>
   </PropertyGroup>
 
-  <ItemGroup>
-    <ProjectReference Include="..\MineCase.Nbt\MineCase.Nbt.csproj" />
-  </ItemGroup>
-
   <ItemGroup>
     <PackageReference Include="StyleCop.Analyzers" Version="1.1.0-beta004" PrivateAssets="All" />
     <PackageReference Include="Newtonsoft.Json" Version="10.0.3" />
@@ -25,4 +21,8 @@
     <AdditionalFiles Include="..\..\build\stylecop.json" />
   </ItemGroup>
 
+  <ItemGroup>
+    <ProjectReference Include="..\MineCase.Nbt\MineCase.Nbt.csproj" />
+  </ItemGroup>
+
 </Project>

src/MineCase.Nbt/Tags/NbtCompound.cs

@@ -111,7 +111,7 @@ public void Add(NbtTag tag)
 
             if (_childTags.ContainsKey(tag.Name))
             {
-                throw new ArgumentException($"试图加入具有名称{tag.Name}的 Tag，但因已有重名的子 Tag 而失败", nameof(tag));
+                throw new ArgumentException($"试图加入具有名称 \"{tag.Name}\" 的 Tag，但因已有重名的子 Tag 而失败", nameof(tag));
             }
 
             Contract.EndContractBlock();

src/MineCase.Server.Commands/MineCase.Server.Commands.csproj

@@ -0,0 +1,12 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>netcoreapp2.0</TargetFramework>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\MineCase.Server.Grains\MineCase.Server.Grains.csproj" />
+    <ProjectReference Include="..\MineCase.Server.Interfaces\MineCase.Server.Interfaces.csproj" />
+  </ItemGroup>
+
+</Project>

src/MineCase.Server.Commands/Vanilla/GameModeCommand.cs

@@ -0,0 +1,110 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using MineCase.Server.Game;
+using MineCase.Server.Game.Entities;
+using MineCase.Server.Game.Commands;
+
+namespace MineCase.Server.Commands.Vanilla
+{
+    public class GameModeCommand
+        : SimpleCommand
+    {
+        public GameModeCommand()
+            : base("gamemode", "Changes the player to a specific game mode")
+        {
+        }
+
+        public override async Task<bool> Execute(ICommandSender commandSender, IReadOnlyList<ICommandArgument> args)
+        {
+            var player = (IPlayer)commandSender;
+
+            if (args.Count < 1)
+            {
+                throw new CommandWrongUsageException(this, "Invalid arguments");
+            }
+
+            GameMode.Class gameModeClass;
+
+            switch (((UnresolvedArgument)args[0]).RawContent)
+            {
+                case "survival":
+                case "s":
+                case "0":
+                    gameModeClass = GameMode.Class.Survival;
+                    break;
+                case "creative":
+                case "c":
+                case "1":
+                    gameModeClass = GameMode.Class.Creative;
+                    break;
+                case "adventure":
+                case "ad":
+                case "2":
+                    gameModeClass = GameMode.Class.Adventure;
+                    break;
+                case "spectator":
+                case "sp":
+                case "3":
+                    gameModeClass = GameMode.Class.Spectator;
+                    break;
+                default:
+                    throw new CommandWrongUsageException(this);
+            }
+
+            var targets = new List<IPlayer>();
+
+            if (args.Count == 2)
+            {
+                var rawArg = (UnresolvedArgument)args[1];
+
+                if (rawArg is TargetSelectorArgument targetSelector)
+                {
+                    switch (targetSelector.Type)
+                    {
+                        case TargetSelectorType.NearestPlayer:
+                            break;
+                        case TargetSelectorType.RandomPlayer:
+                            break;
+                        case TargetSelectorType.AllPlayers:
+                            break;
+                        case TargetSelectorType.AllEntites:
+                            break;
+                        case TargetSelectorType.Executor:
+                            break;
+                        default:
+                            throw new CommandException(this);
+                    }
+
+                    throw new CommandException(this, "Sorry, this feature has not been implemented.");
+                }
+                else
+                {
+                    var user = await player.GetUser();
+                    var session = await user.GetGameSession();
+
+                    var targetPlayer = await (await session.FindUserByName(rawArg.RawContent)).GetPlayer();
+
+                    if (targetPlayer == null)
+                    {
+                        throw new CommandException(this, $"Player \"{rawArg.RawContent}\" not found, may be offline or not existing.");
+                    }
+
+                    targets.Add(targetPlayer);
+                }
+            }
+
+            foreach (var target in targets)
+            {
+                var targetDesc = await target.GetDescription();
+                var mode = targetDesc.GameMode;
+                mode.ModeClass = gameModeClass;
+                targetDesc.GameMode = mode;
+            }
+
+            return true;
+        }
+    }
+}

src/MineCase.Server.Grains/Game/Entities/PlayerGrain.cs

@@ -336,5 +336,17 @@ private class WindowContext
             public IWindow Window;
             public short ActionNumber;
         }
+
+        public Task<bool> HasPermission(Permission permission)
+        {
+            // TODO: 临时提供所有权限，需要实现权限管理
+            return Task.FromResult(true);
+        }
+
+        public Task SendMessage(string msg)
+        {
+            // TODO: 向玩家发送信息
+            return Task.CompletedTask;
+        }
     }
 }

src/MineCase.Server.Grains/Game/GameSession.cs

@@ -23,6 +23,8 @@ internal class GameSession : Grain, IGameSession
 
         private HashSet<ITickable> _tickables;
 
+        private readonly Commands.CommandMap _commandMap = new Commands.CommandMap();
+
         public override async Task OnActivateAsync()
         {
             _world = await GrainFactory.GetGrain<IWorldAccessor>(0).GetWorld(this.GetPrimaryKeyString());
@@ -32,6 +34,24 @@ public override async Task OnActivateAsync()
             _gameTick = RegisterTimer(OnGameTick, null, TimeSpan.Zero, TimeSpan.FromMilliseconds(50));
         }
 
+        public Task<IEnumerable<IUser>> GetUsers()
+        {
+            return Task.FromResult((IEnumerable<IUser>)_users.Keys);
+        }
+
+        public async Task<IUser> FindUserByName(string name)
+        {
+            foreach (var user in _users)
+            {
+                if (await user.Key.GetName() == name)
+                {
+                    return user.Key;
+                }
+            }
+
+            return null;
+        }
+
         public async Task JoinGame(IUser user)
         {
             var sink = await user.GetClientPacketSink();
@@ -64,10 +84,23 @@ public async Task SendChatMessage(IUser sender, string message)
         {
             var senderName = await sender.GetName();
 
-            // TODO command parser
+            if (!string.IsNullOrWhiteSpace(message))
+            {
+                var command = message.Trim();
+                if (command[0] == '/')
+                {
+                    if (!await _commandMap.Dispatch(await sender.GetPlayer(), message))
+                    {
+                        await SendSystemMessage(sender, $"试图执行指令 \"{command}\" 时被拒绝，请检查是否具有足够的权限以及指令语法是否正确");
+                    }
+
+                    return;
+                }
+            }
+
             // construct name
-            Chat jsonData = await CreateStandardChatMessage(senderName, message);
-            byte position = 0; // It represents user message in chat box
+            var jsonData = await CreateStandardChatMessage(senderName, message);
+            const byte position = 0; // It represents user message in chat box
             foreach (var item in _users.Keys)
             {
                 await item.SendChatMessage(jsonData, position);
@@ -79,8 +112,8 @@ public async Task SendChatMessage(IUser sender, IUser receiver, string message)
             var senderName = await sender.GetName();
             var receiverName = await receiver.GetName();
 
-            Chat jsonData = await CreateStandardChatMessage(senderName, message);
-            byte position = 0; // It represents user message in chat box
+            var jsonData = await CreateStandardChatMessage(senderName, message);
+            const byte position = 0; // It represents user message in chat box
             foreach (var item in _users.Keys)
             {
                 if (await item.GetName() == receiverName ||
@@ -89,6 +122,24 @@ await item.GetName() == senderName)
             }
         }
 
+        public async Task SendSystemMessage(IUser receiver, string message)
+        {
+            var receiverName = await receiver.GetName();
+
+            var jsonData = await CreateStandardSystemMessage(message);
+            const byte position = 1; // It represents user message as system message
+            await receiver.SendChatMessage(jsonData, position);
+        }
+
+        public async Task SendGameInfoMessage(IUser receiver, string message)
+        {
+            var receiverName = await receiver.GetName();
+
+            var jsonData = await CreateStandardGameInfoMessage(message);
+            const byte position = 2; // It represents user message as system message
+            await receiver.SendChatMessage(jsonData, position);
+        }
+
         private async Task OnGameTick(object state)
         {
             var now = DateTime.UtcNow;
@@ -105,20 +156,35 @@ await Task.WhenAll(from u in _tickables
 
         private Task<Chat> CreateStandardChatMessage(string name, string message)
         {
-            StringComponent nameComponent = new StringComponent(name);
-            nameComponent.ClickEvent = new ChatClickEvent(ClickEventType.SuggestCommand, "/msg " + name);
-            nameComponent.HoverEvent = new ChatHoverEvent(HoverEventType.ShowEntity, name);
-            nameComponent.Insertion = name;
+            var nameComponent = new StringComponent(name)
+            {
+                ClickEvent = new ChatClickEvent(ClickEventType.SuggestCommand, "/msg " + name),
+                HoverEvent = new ChatHoverEvent(HoverEventType.ShowEntity, name),
+                Insertion = name
+            };
 
             // construct message
-            StringComponent messageComponent = new StringComponent(message);
+            var messageComponent = new StringComponent(message);
 
             // list
-            List<ChatComponent> list = new List<ChatComponent>();
-            list.Add(nameComponent);
-            list.Add(messageComponent);
+            var list = new List<ChatComponent>
+            {
+                nameComponent, messageComponent
+            };
 
-            Chat jsonData = new Chat(new TranslationComponent("chat.type.text", list));
+            var jsonData = new Chat(new TranslationComponent("chat.type.text", list));
+            return Task.FromResult(jsonData);
+        }
+
+        private Task<Chat> CreateStandardSystemMessage(string message)
+        {
+            var jsonData = new Chat(new StringComponent(message));
+            return Task.FromResult(jsonData);
+        }
+
+        private Task<Chat> CreateStandardGameInfoMessage(string message)
+        {
+            var jsonData = new Chat(new StringComponent(message));
             return Task.FromResult(jsonData);
         }
 

src/MineCase.Server.Grains/World/WorldGrain.cs

@@ -43,6 +43,11 @@ public Task<IEntity> FindEntity(uint eid)
             return Task.FromException<IEntity>(new EntityNotFoundException());
         }
 
+        public Task<IEnumerable<IEntity>> GetEntities()
+        {
+            return Task.FromResult((IEnumerable<IEntity>)_entities.Values);
+        }
+
         public Task<(long age, long timeOfDay)> GetTime()
         {
             return Task.FromResult((_worldAge, _worldAge % 24000));

src/MineCase.Server.Interfaces/Game/Commands/CommandMap.cs

@@ -0,0 +1,60 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics.Contracts;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace MineCase.Server.Game.Commands
+{
+    /// <summary>
+    /// 命令 Map
+    /// </summary>
+    public class CommandMap
+    {
+        private readonly Dictionary<string, ICommand> _commandMap = new Dictionary<string, ICommand>();
+
+        /// <summary>
+        /// 注册一个命令
+        /// </summary>
+        /// <param name="command">要注册的命令</param>
+        /// <exception cref="ArgumentNullException"><paramref name="command"/> 为 null</exception>
+        /// <exception cref="ArgumentException">已有重名的 command 被注册</exception>
+        public void RegisterCommand(ICommand command)
+        {
+            if (command == null)
+            {
+                throw new ArgumentNullException(nameof(command));
+            }
+
+            Contract.EndContractBlock();
+
+            _commandMap.Add(command.Name, command);
+        }
+
+        /// <summary>
+        /// 分派命令
+        /// </summary>
+        /// <param name="sender">命令的发送者</param>
+        /// <param name="commandContent">命令的内容</param>
+        public Task<bool> Dispatch(ICommandSender sender, string commandContent)
+        {
+            var (commandName, args) = CommandParser.ParseCommand(commandContent);
+
+            try
+            {
+                if (_commandMap.TryGetValue(commandName, out var command) &&
+                    (command.NeededPermission == null || sender.HasPermission(command.NeededPermission).Result))
+                {
+                    return command.Execute(sender, args);
+                }
+
+                return Task.FromResult(false);
+            }
+            catch (CommandException e)
+            {
+                sender.SendMessage($"在执行命令 {commandName} 之时发生命令相关的异常 {e}");
+                return Task.FromResult(false);
+            }
+        }
+    }
+}