// ClassicalSharp copyright 2014-2016 UnknownShadow200 | Licensed under MIT
// This class was partially based on information from http://files.worldofminecraft.com/texturing/
// NOTE: http://files.worldofminecraft.com/ has been down for quite a while, so support was removed on Oct 10, 2015
using System;
using ClassicalSharp.Map;

namespace ClassicalSharp.Network.Protocols {

	/// <summary> Implements the WoM http environment protocol. </summary>
	public sealed class WoMProtocol : IProtocol {
		
		public WoMProtocol( Game game ) : base( game ) { }
		
		string womEnvIdentifier = "womenv_0";
		int womCounter = 0;
		internal bool sendWomId = false, sentWomId = false;

		public override void Tick() {
			DownloadedItem item;
			game.AsyncDownloader.TryGetItem( womEnvIdentifier, out item );
			if( item != null && item.Data != null ) {
				ParseWomConfig( (string)item.Data );
			}
		}
		
		internal void CheckMotd() {
			int index = net.ServerMotd.IndexOf( "cfg=" );
			if( game.PureClassic || index == -1 ) return;
			
			string host = net.ServerMotd.Substring( index + 4 ); // "cfg=".Length
			string url = "http://" + host;
			url = url.Replace( "$U", game.Username );
			
			// NOTE: this (should, I did test this) ensure that if the user quickly changes to a
			// different world, the environment settings from the last world are not loaded in the
			// new world if the async 'get request' didn't complete before the new world was loaded.
			womCounter++;
			womEnvIdentifier = "womenv_" + womCounter;
			game.AsyncDownloader.DownloadPage( url, true, womEnvIdentifier );
			sendWomId = true;
		}
		
		internal void CheckSendWomID() {
			if( sendWomId && !sentWomId ) {
				net.SendChat( "/womid WoMClient-2.0.7", false );
				sentWomId = true;
			}
		}
		
		void ParseWomConfig( string page ) {
			string line;
			int start = 0;
			while( (line = ReadLine( ref start, page )) != null ) {
				Utils.LogDebug( line );
				int sepIndex = line.IndexOf('=');
				if( sepIndex == -1 ) continue;
				string key = line.Substring(0, sepIndex).TrimEnd();
				string value = line.Substring(sepIndex + 1).TrimStart();
				
				if( key == "environment.cloud" ) {
					FastColour col = ParseWomColour( value, WorldEnv.DefaultCloudsColour );
					game.World.Env.SetCloudsColour( col );
				} else if( key == "environment.sky" ) {
					FastColour col = ParseWomColour( value, WorldEnv.DefaultSkyColour );
					game.World.Env.SetSkyColour( col );
				} else if( key == "environment.fog" ) {
					FastColour col = ParseWomColour( value, WorldEnv.DefaultFogColour );
					game.World.Env.SetFogColour( col );
				} else if( key == "environment.level" ) {
					int waterLevel = 0;
					if( Int32.TryParse( value, out waterLevel ) )
						game.World.Env.SetEdgeLevel( waterLevel );
				} else if( key == "user.detail" && !net.cpeData.useMessageTypes ) {
					game.Chat.Add( value, MessageType.Status2 );
				}
			}
		}
		
		const int fullAlpha = 0xFF << 24;
		static FastColour ParseWomColour( string value, FastColour defaultCol ) {
			int argb;
			return Int32.TryParse( value, out argb ) ? new FastColour( argb | fullAlpha ) : defaultCol;
		}
		
		static string ReadLine(ref int start, string value) {
			if (start == -1) return null;
			for (int i = start; i < value.Length; i++) {
				char c = value[i];
				if (c != '\r' && c != '\n') continue;
				
				string line = value.Substring(start, i - start);
				start = i + 1;
				if (c == '\r' && start < value.Length && value[start] == '\n')
					start++; // we stop at the \r, so make sure to skip following \n
				return line;
			}
			
			string last = value.Substring(start);
			start = -1;
			return last;
		}
	}
}