// ClassicalSharp copyright 2014-2016 UnknownShadow200 | Licensed under MIT
using System;
using System.Collections.Generic;

namespace ClassicalSharp.Commands {
	
	public class CommandList : IGameComponent {
		
		const string prefix = "/client";
		public bool IsCommandPrefix( string input ) {
			if( game.Server.IsSinglePlayer && Utils.CaselessStarts( input, "/" ) )
				return true;
			
			return Utils.CaselessStarts( input, prefix + " " )
				|| Utils.CaselessEquals( input, prefix );
		}
		
		protected Game game;
		public List<Command> RegisteredCommands = new List<Command>();
		public void Init( Game game ) {
			this.game = game;
			Register( new CommandsCommand() );
			Register( new GpuInfoCommand() );
			Register( new HelpCommand() );
			Register( new RenderTypeCommand() );
			
			if( !game.Server.IsSinglePlayer ) return;
			Register( new ModelCommand() );
			Register( new CuboidCommand() );
		}

		public void Ready( Game game ) { }
		public void Reset( Game game ) { }
		public void OnNewMap( Game game ) { }
		public void OnNewMapLoaded( Game game ) { }
		
		public void Register( Command command ) {
			command.game = game;
			for( int i = 0; i < RegisteredCommands.Count; i++ ) {
				Command cmd = RegisteredCommands[i];
				if( Utils.CaselessEquals( cmd.Name, command.Name ) )
					throw new InvalidOperationException( "Another command already has name : " + command.Name );
			}
			RegisteredCommands.Add( command );
		}
		
		public Command GetMatch( string cmdName ) {
			Command match = null;
			for( int i = 0; i < RegisteredCommands.Count; i++ ) {
				Command cmd = RegisteredCommands[i];
				if( !Utils.CaselessStarts( cmd.Name, cmdName ) ) continue;
				
				if( match != null ) {
					game.Chat.Add( "&e/client: Multiple commands found that start with: \"&f" + cmdName + "&e\"." );
					return null;
				}
				match = cmd;
			}
			
			if( match == null )
				game.Chat.Add( "&e/client: Unrecognised command: \"&f" + cmdName + "&e\"." );
			return match;
		}
		
		static char[] splitChar = { ' ' };
		public void Execute( string text ) {
			if( Utils.CaselessStarts( text, prefix ) ) { // /client command args
				text = text.Substring( prefix.Length ).TrimStart( splitChar );
			} else { // /command args
				text = text.Substring( 1 );
			}
			
			if( text.Length == 0 ) { // only / or /client
				game.Chat.Add( "&eList of client commands:" );
				PrintDefinedCommands( game );
				game.Chat.Add( "&eTo see a particular command's help, type /client help [cmd name]" );
				return;
			}
			
			string[] args = text.Split( splitChar );
			Command cmd = GetMatch( args[0] );
			if( cmd == null ) return;
			cmd.Execute( args );
		}
		
		public void PrintDefinedCommands( Game game ) {
			StringBuffer sb = new StringBuffer( Utils.StringLength );
			int index = 0;
			
			for( int i = 0; i < RegisteredCommands.Count; i++ ) {
				Command cmd = RegisteredCommands[i];
				string name = cmd.Name;
				
				if( (sb.Length + name.Length + 2) > sb.Capacity ) {
					game.Chat.Add( sb.ToString() );
					sb.Clear();
					index = 0;
				}
				sb.Append( ref index, name );
				sb.Append( ref index, ", " );
			}
			
			if( sb.Length > 0 )
				game.Chat.Add( sb.ToString() );
		}
		
		public void Dispose() {
			RegisteredCommands.Clear();
		}
	}
}