using System;
using System.Linq;
using System.IO;
using System.Net;
using System.Text;
using System.Net.Sockets;
using System.Threading;
using System.Collections;
using System.Collections.Generic;
using System.Security.Cryptography;
using System.Runtime.Serialization.Formatters.Binary;
using System.Text.RegularExpressions;

namespace _olbaid_websockets
{
	
	class UnPack {
		
		byte [] buffer;
		public int position;
		
		public UnPack(byte[] b){
			buffer = b;
			position = 0;
		}
		
		public uint w (){
			uint num = 0;
            byte bite = 0;
            do {
                num*=128;
                bite = buffer[position++];
                num+=(uint)(bite&0x7f);
            }while ((bite&0x80)>0);
            return num;
		}
	}
	class Client
	{
		private Socket client;
		private Thread thread;
		private Socket deliantraClient = null;
		private bool upgraded = false;
		private bool mask = true;
		private bool useHixie = false;
		
		Random r = new Random();
		
		System.Text.UTF8Encoding encodingUTF8 = new System.Text.UTF8Encoding();
	
		
		private byte[] buffer = new byte[4096*16];
		private byte[] mergedBuffer = new byte[4096*32];
		private int mergedBufferLength = 0;
		
		public bool IsBitSet(byte b, int pos) {
			return (b & (int)Math.Pow(2, pos)) > 0 ? true : false;
		}
		
		public static int getNSpaces (string s){			
			return (new String(s.Where( c=> c==' ').ToArray())).Length;			
		}
		
		public static Int64 numbers(string s){
			char[] nums = s.Where( c => Char.IsNumber(c)).ToArray();	        
			Int64 ret = Int64.Parse(new String(nums));
			return ret;
		}
		
		public static void setBytes(byte [] buffer,UInt16 val,int index){
			for (int i=0;i<2;++i){
				byte b = (byte)((val >> (3-i)*8)&0xff);
				buffer[index+i] = b;				
			}
		}
		
		public static void setBytes(byte [] buffer,UInt32 val,int index){
			for (int i=0;i<4;++i){
				byte b = (byte)((val >> (3-i)*8)&0xff);
				buffer[index+i] = b;				
			}
		}
		
		public static void setBytesR(byte [] buffer,UInt16 val,int index){
			for (int i=1;i>=0;--i){
				byte b = (byte)((val >> (3-i)*8)&0xff);
				buffer[index+i] = b;				
			}
		}
		
		public static byte [] calcHixieResponse (string key1,string key2,byte [] l8b){
			UInt64 numbers1 = (UInt64) numbers(key1);
			UInt64 numbers2 = (UInt64) numbers(key2);
			UInt64  spaces1 = (ulong)getNSpaces(key1);
			UInt64 spaces2 = (ulong)getNSpaces(key2);
			byte [] key = new byte [16];
			
			Array.Clear(key,0,16);
			
			setBytes(key,(UInt32)(((numbers1/spaces1))),0);
			setBytes(key,(UInt32)(((numbers2/spaces2))),4);
		
			Array.Copy(l8b,0,key,8,8);			
			MD5 md5Hash = MD5.Create();
			return md5Hash.ComputeHash(key);			
		}
		
		public static void setBytesR(byte [] buffer,UInt32 val,int index){
			for (int i=3;i>=0;--i){
				byte b = (byte)((val >> (3-i)*8)&0xff);
				buffer[index+i] = b;				
			}
		}
		public void onReceivedClientData (IAsyncResult asyn){
			
			Socket mySocket = (Socket)asyn.AsyncState;
			
			int bytesRead = mySocket.EndReceive(asyn);
			if (bytesRead==0){
				Console.WriteLine ("Connection closed by socket {0}" , mySocket==client?" client " : " deliantra ");
				
				mySocket.Close();
				
				if ((mySocket==client)&&(deliantraClient!=null)){
					client = null;
					Console.WriteLine ("trying to close deliantraClient");
					try {
						deliantraClient.Close();
						deliantraClient = null;
					}catch (Exception ex){
					
					}
				}
				return;
			}
			
			
			if (mySocket == client){
				//deliantraClient.Send(buffer,bytesRead,0);
				Hashtable request = new Hashtable();
									
				if (upgraded == false){
					dump(buffer,bytesRead);
					string incoming = encodingUTF8.GetString(buffer,0,bytesRead);
					
					Console.WriteLine (incoming);
					
					string [] lines = incoming.Split(new string [] {"\n"},StringSplitOptions.RemoveEmptyEntries);
					
					for (int i = 1;i<lines.Length;++i){
						string [] line = lines[i].Split(new string [] {": "},StringSplitOptions.RemoveEmptyEntries);
						if (line.Length>=3)
							request.Add(line[0].ToString().ToLower().Trim(),line[1] + ":" + line[2]);
						else if (line.Length>=2)
							request.Add(line[0].ToString().ToLower().Trim(),line[1]);
							         
					}
					foreach (DictionaryEntry e in request){
						Console.WriteLine(e.Key.ToString() + " : '" + e.Value.ToString() + "'");
					}
					
					
					if (request["sec-websocket-key1"]!=null){
						string key1 = "357184 636 L0";
						key1 = request["sec-websocket-key1"].ToString().Trim();
						
						string key2 = "U 4=> 9&6=  52OeA[8 #880";
						key2 = request["sec-websocket-key2"].ToString().Trim();
						byte [] l8b = new byte[8];
						Array.Copy (buffer,bytesRead-8,l8b,0,8);
						
						dump(l8b,8);
						
						byte [] hixiResp = calcHixieResponse(key1,key2,l8b);
						
						string origin = (string) (request["origin"] != null ? request["origin"].ToString().Trim(): "");
						//origin="http://localhost";
						string host = (string) (request["host"] != null ? request["host"].ToString().Trim (): "");
						string location = Regex.Match(incoming,@"(/[a-z]+)",RegexOptions.IgnoreCase).Value.ToString();
						
						StringBuilder bResponse = new StringBuilder();
						bResponse.Append("HTTP/1.1 101 WebSocket Protocol Handshake\r\n");
						bResponse.Append( "Upgrade: WebSocket\r\n");
						bResponse.Append("Connection: Upgrade\r\n");
						bResponse.AppendFormat("Sec-WebSocket-Origin: {0}\r\n",origin);
						bResponse.Append( "Sec-WebSocket-Protocol: chat\r\n");
						bResponse.AppendFormat("Sec-WebSocket-Location: ws://{0}{1}\r\n\r\n",host,location);
						byte [] data = encodingUTF8.GetBytes(bResponse.ToString());
						byte [] result = new byte[data.Length+hixiResp.Length];
						Array.Copy(data,0,result,0,data.Length);
						Array.Copy(hixiResp,0,result,data.Length,hixiResp.Length);
						client.Send(result,result.Length,SocketFlags.None);
						useHixie = true;
						upgraded = true;
					}else{
						string key = "";
						if (request["sec-websocket-key"]!=null){
							Console.WriteLine("Key: "  + request["sec-websocket-key"].ToString());
							key = request["sec-websocket-key"].ToString().Trim();
						}else{
							key = "";
						}
						if (request["sec-websocket-extensions"]!=null){
							mask = false;
						}
						Console.WriteLine(key);
						//key+=Guid.NewGuid().ToString();
						key+="258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
						Console.WriteLine(key);
						SHA1 sha = new SHA1CryptoServiceProvider(); 
						byte [] hash = sha.ComputeHash(encoding.GetBytes(key));
						
						key = EncodeTo64(hash);
						Console.WriteLine(key);
						string response = "HTTP/1.1 101 Switching Protocols\n" 
										+ "Upgrade: websocket\n" 										
	        							+ "Connection: Upgrade\n"
										//+ "Sec-WebSocket-Protocol: chat\r\n"
										+ "Sec-WebSocket-Accept: " + key +"\n\n";
						response = "HTTP/1.1 101 WebSocket Protocol Handshake\r\n" 
										+ "Upgrade: WebSocket\r\n" 										
	        							+ "Connection: Upgrade\r\n"
										+ "Sec-WebSocket-Accept: " +key + "\r\n\r\n";
						client.Send(encoding.GetBytes(response));
						upgraded = true;											
					}
					
					deliantraClient = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
					deliantraClient.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, true);
					IPEndPoint ipLocal = new IPEndPoint(IPAddress.Parse("194.126.175.156"), 13327);
	                		deliantraClient.Connect(ipLocal);
					deliantraClient.BeginReceive(buffer, 0, 4096, 0, new AsyncCallback(onReceivedClientData),deliantraClient);			
					
				}else{
					//dump (buffer,bytesRead);
					
					String msg = receiveMessage(buffer,bytesRead);
					Console.WriteLine(msg);
					Array.Copy(encodingUTF8.GetBytes(msg),0,buffer,2,bytesRead = encodingUTF8.GetBytes(msg).Length);
					buffer [0] = (byte)(bytesRead/256);
					buffer [1] = (byte)(bytesRead%256);
					deliantraClient.Send(buffer,0,bytesRead+2,0);
					//Console.WriteLine(encoding.GetString(unmaskedData,0,payloadLen));
					
					//sendMessage("HELLO CRUEL WORLD"); 
					
				}
				
			}else{
				//client.Send(buffer,bytesRead,0);
				//dump (buffer,bytesRead);
				if (client == null){
					    deliantraClient.Close();
					    deliantraClient = null;
					    return;
				}
				Array.Copy ( buffer,0,mergedBuffer,mergedBufferLength,bytesRead);
				mergedBufferLength += bytesRead;
				
				int index = 0;
				int len;
				byte [] tmpBuffer;
				while (index<mergedBufferLength){
					try {
						len = mergedBuffer[index++]*256 + mergedBuffer[index++];
						//Console.WriteLine("Index : {0}, len : {1}, mergedBufferLength {2}",index,len,mergedBufferLength);
						
						if ((len+index)<=mergedBufferLength){
						    //Console.WriteLine("Sending {0}",encodingUTF8.GetString(mergedBuffer,index,len));
						    //sendMessage(encodingUTF8.GetString(mergedBuffer,index,len));
							tmpBuffer = new byte [len];
							Array.Copy(mergedBuffer,index,tmpBuffer,0,len);
							if (encoding.GetString(tmpBuffer,0,2).Equals("ix")){
								StringBuilder sb = new StringBuilder();
								UnPack up = new UnPack(tmpBuffer);
								up.position = 3;
								uint id = up.w();
								up.w();
								sb.Append(id);
								sb.Append(".png");
								
								if (!File.Exists("/var/www/olbaid/faces/" + sb.ToString())){
									BinaryWriter bw = new BinaryWriter(File.OpenWrite("/var/www/olbaid/faces/" + sb.ToString()));
									bw.Write(tmpBuffer,up.position,len-up.position);
									bw.Close();
								}
								tmpBuffer = new byte [up.position+3];
								Array.Copy(mergedBuffer,index,tmpBuffer,0,3+up.position);
								
							}
							sendMessage(EncodeTo64(tmpBuffer));
							           
							Array.Copy(mergedBuffer,index+len,mergedBuffer,0,mergedBufferLength-len-2);
							mergedBufferLength -= len + 2;
							index = 0;
						}else{
							break;
						}
					}catch (Exception ex){
					}
					
				}
				
			}
			mySocket.BeginReceive(buffer, 0, 4096, 0, new AsyncCallback(onReceivedClientData),mySocket);		
		}
		
			
		public string receiveMessage(byte[] buffer,int bytesRead){
			
					
					if (useHixie){
						string ret = encodingUTF8.GetString(buffer,1,bytesRead-2);
						Console.WriteLine(ret);
						return ret;
					}
					UInt64 payloadLen = 0;
					
					//int opcode = buffer[0]&0xf;
					
					
					bool mask = IsBitSet(buffer[1],7);
					if (!mask){
						//Console.WriteLine("Ignoring non masked message");
						//return;
					}
					
					
					payloadLen = (ulong)(buffer[1]& ~128);
					
					if (payloadLen==125){
						
					}else if (payloadLen==126){
						payloadLen = (ulong)(buffer[2]*256 + buffer[3]);
						Array.Copy(buffer,4,buffer,2,bytesRead-2);
					}else if (payloadLen==127){
						payloadLen = (ulong)(buffer[2]*256*256*256 + buffer[3]*256*256 + buffer[4]*256 + buffer[5]);
						Array.Copy(buffer,6,buffer,2,bytesRead-2);
					}
					
					byte [] maskKey = new byte[]{0,0,0,0};
					
					if (mask){
						Array.Copy(buffer,2,maskKey,0,4);
					}
					
					byte [] unmaskedData = new byte[payloadLen];
					
					
					Array.Copy(buffer,6,unmaskedData,0,(int)payloadLen);
					
					for (int i =0;i<(int)payloadLen;++i){
						unmaskedData[i]=(byte)(unmaskedData[i]^maskKey[i%4]);
					}
					return encodingUTF8.GetString(unmaskedData);
		}
		public void sendMessage(byte[] message){
			
			if (useHixie){
				byte [] data = new byte[message.Length+2];
				data[0] = 0;
				data[message.Length+1] = 255;
				Array.Copy((message),0,data,1,message.Length);
				client.Send(data,data.Length,SocketFlags.None);
				return;
			}
			//System.Text.UTF8Encoding encoding = new System.Text.UTF8Encoding();
			byte [] unmaskedData = (message);
			int len = unmaskedData.Length;
			bool big = false;
			bool bigger = false;
			
			if (len>256*256+256){
				bigger = true;
			}else if (len>125){
				big = true;
			}
			
			byte [] buffer;
			
			if (bigger){
				buffer = new byte[len+6+(mask?4:0)];
				Array.Clear(buffer,0,len+6+(mask?4:0));
			}else if (big){
				buffer = new byte[len+4+(mask?4:0)];
				Array.Clear(buffer,0,len+4+(mask?4:0));
			}else{
				buffer = new byte[len+2+(mask?4:0)];
				Array.Clear(buffer,0,len+2+(mask?4:0));
			}
			int optcode = 1;
			buffer[0] = (byte)(128 + optcode);			

			int maskVal = 0;
			
			if (mask){
				maskVal = 128;
			}
			
			if (bigger){
				buffer[1] = (byte)(maskVal + 127);
				buffer[5] = (byte)(len%256);
				len/=256;
				buffer[4] = (byte)(len%256);
				len/=256;
				buffer[3] = (byte)(len%256);
				len/=256;
				buffer[2] = (byte)(len%256);								
			}else if (big){
				buffer[1] = (byte)(maskVal  + 126);
				buffer[2] = (byte)(len/256);
				buffer[3] = (byte)(len%256);
			}else{
				buffer[1] = (byte)(maskVal + len	);
			}
			
			if (mask){
				byte [] maskKey = new byte[4];
				r.NextBytes(maskKey);
				if (bigger){
					Array.Copy(maskKey,0,buffer,6,4);
				}else if (big){
					Array.Copy(maskKey,0,buffer,4,4);
				}else{
					Array.Copy(maskKey,0,buffer,2,4);
				}
				if (bigger){
					for (int i = 0 ; i<unmaskedData.Length;++i){
						buffer[10+i] = (byte)(unmaskedData[i]^maskKey[i%4]);
					}
				}else if (big){
					for (int i = 0 ; i<unmaskedData.Length;++i){
						buffer[8+i] = (byte)(unmaskedData[i]^maskKey[i%4]);
					}
				}else{
					for (int i = 0 ; i<unmaskedData.Length;++i){
						buffer[6+i] = (byte)(unmaskedData[i]^maskKey[i%4]);
					}
				}
			}else{
				int offset = 0;
				if (bigger){
					offset=6;
				}else if (big){
					offset=4;
				}else{
					offset=2;
				}
				for (int i = 0 ; i<unmaskedData.Length;++i){
						buffer[offset+i] = (byte)(unmaskedData[i]);
				}
			}
			
			client.Send(buffer);
			
			
		}
		public void sendMessage(string message){
			
			if (useHixie){
				byte [] data = new byte[message.Length+2];
				data[0] = 0;
				data[message.Length+1] = 255;
				Array.Copy(encodingUTF8.GetBytes(message),0,data,1,message.Length);
				client.Send(data,data.Length,SocketFlags.None);
				return;
			}
			//System.Text.UTF8Encoding encoding = new System.Text.UTF8Encoding();
			byte [] unmaskedData = encoding.GetBytes(message);
			int len = unmaskedData.Length;
			bool big = false;
			bool bigger = false;
			
			if (len>256*256+256){
				bigger = true;
			}else if (len>125){
				big = true;
			}
			
			byte [] buffer;
			
			if (bigger){
				buffer = new byte[len+6+(mask?4:0)];
				Array.Clear(buffer,0,len+6+(mask?4:0));
			}else if (big){
				buffer = new byte[len+4+(mask?4:0)];
				Array.Clear(buffer,0,len+4+(mask?4:0));
			}else{
				buffer = new byte[len+2+(mask?4:0)];
				Array.Clear(buffer,0,len+2+(mask?4:0));
			}
			int optcode = 1;
			buffer[0] = (byte)(128 + optcode);			

			int maskVal = 0;
			
			if (mask){
				maskVal = 128;
			}
			
			if (bigger){
				buffer[1] = (byte)(maskVal + 127);
				buffer[5] = (byte)(len%256);
				len/=256;
				buffer[4] = (byte)(len%256);
				len/=256;
				buffer[3] = (byte)(len%256);
				len/=256;
				buffer[2] = (byte)(len%256);								
			}else if (big){
				buffer[1] = (byte)(maskVal  + 126);
				buffer[2] = (byte)(len/256);
				buffer[3] = (byte)(len%256);
			}else{
				buffer[1] = (byte)(maskVal + len	);
			}
			
			if (mask){
				byte [] maskKey = new byte[4];
				r.NextBytes(maskKey);
				if (bigger){
					Array.Copy(maskKey,0,buffer,6,4);
				}else if (big){
					Array.Copy(maskKey,0,buffer,4,4);
				}else{
					Array.Copy(maskKey,0,buffer,2,4);
				}
				if (bigger){
					for (int i = 0 ; i<unmaskedData.Length;++i){
						buffer[10+i] = (byte)(unmaskedData[i]^maskKey[i%4]);
					}
				}else if (big){
					for (int i = 0 ; i<unmaskedData.Length;++i){
						buffer[8+i] = (byte)(unmaskedData[i]^maskKey[i%4]);
					}
				}else{
					for (int i = 0 ; i<unmaskedData.Length;++i){
						buffer[6+i] = (byte)(unmaskedData[i]^maskKey[i%4]);
					}
				}
			}else{
				int offset = 0;
				if (bigger){
					offset=6;
				}else if (big){
					offset=4;
				}else{
					offset=2;
				}
				for (int i = 0 ; i<unmaskedData.Length;++i){
						buffer[offset+i] = (byte)(unmaskedData[i]);
				}
			}
			
			client.Send(buffer);
			
			
		}
		public string EncodeTo64(byte[] toEncode) {
		    byte[] toEncodeAsBytes = toEncode;
		    string returnValue = System.Convert.ToBase64String(toEncodeAsBytes);
		    return returnValue;
		}
		public string EncodeTo64(string toEncode) {
		    byte[] toEncodeAsBytes = encoding.GetBytes(toEncode);
		    string returnValue = System.Convert.ToBase64String(toEncodeAsBytes);
		    return returnValue;
		}

		public Client(Socket client){
			this.client = client;
			client.BeginReceive(buffer, 0, 4096, 0, new AsyncCallback(onReceivedClientData),client);
			
			
		}
		public void close(){
			this.client.Close();
		}
		
		public void threadfunc (){
			
		}
		
				
		public Thread createThread(){
			thread = new Thread(new ThreadStart(this.threadfunc));
			return thread;
		}
		
		System.Text.ASCIIEncoding encoding = new System.Text.ASCIIEncoding();
		
		public void dumpBinary (BitArray b,int length){
			Console.WriteLine("");
			int counter = 0;
			for (int i = 0;i<length;++i){
				if (b[i]){
					Console.Write(1);
				}else{
					Console.Write(0);
				}
				if (counter==0){
					Console.Write(" ");
				}
				counter = (counter+1)%4;
			}
			Console.WriteLine("");
		}
		
		public void dump (byte [] b,int size){
			Console.WriteLine("{0} bytes received",size);
			int offset = 0;
			
			while (offset<size){
				Console.Write ("{0:X2} ",b[offset]);
				
				if (offset>0&&offset%16==0){
					
					Console.Write(encoding.GetString(b,offset-16,16));
					
					Console.WriteLine();
				}
				offset+=1;
			}
			
			Console.WriteLine();
			                   
		}
	}
}