using System;

namespace Project1
{
	/// <summary>
	/// Summary description for BNLSChecksumCls 1.03.
	///
	/// Copyright(c) 2004 - l)ragon
	///
	/// My representation of the CRC32 in C#
	/// this is horible get a real language.
	///
	/// 1.03 { Removed CRCTables and added a conversion of Yoni's VB InitCRC.,
	///		   Added HexValues table. }
	/// 1.02 { N/A }
	/// 1.01 { N/A }
	/// 1.00 { N/A }
	/// </summary>
	public class BNLSChecksumCls
	{
		public BNLSChecksumCls()
		{
			//
			// TODO: Add constructor logic here
			//
		}
		static string[] HexValues = {   "00" ,"01" ,"02" ,"03" ,"04" ,"05" ,"06" ,"07" ,"08" ,"09" ,"0A" ,"0B" ,"0C" ,"0D" ,
										"0E" ,"0F" ,"10" ,"11" ,"12" ,"13" ,"14" ,"15" ,"16" ,"17" ,"18" ,"19" ,"1A" ,"1B" ,
										"1C" ,"1D" ,"1E" ,"1F" ,"20" ,"21" ,"22" ,"23" ,"24" ,"25" ,"26" ,"27" ,"28" ,"29" ,
										"2A" ,"2B" ,"2C" ,"2D" ,"2E" ,"2F" ,"30" ,"31" ,"32" ,"33" ,"34" ,"35" ,"36" ,"37" ,
										"38" ,"39" ,"3A" ,"3B" ,"3C" ,"3D" ,"3E" ,"3F" ,"40" ,"41" ,"42" ,"43" ,"44" ,"45" ,
										"46" ,"47" ,"48" ,"49" ,"4A" ,"4B" ,"4C" ,"4D" ,"4E" ,"4F" ,"50" ,"51" ,"52" ,"53" ,
										"54" ,"55" ,"56" ,"57" ,"58" ,"59" ,"5A" ,"5B" ,"5C" ,"5D" ,"5E" ,"5F" ,"60" ,"61" ,
										"62" ,"63" ,"64" ,"65" ,"66" ,"67" ,"68" ,"69" ,"6A" ,"6B" ,"6C" ,"6D" ,"6E" ,"6F" ,
										"70" ,"71" ,"72" ,"73" ,"74" ,"75" ,"76" ,"77" ,"78" ,"79" ,"7A" ,"7B" ,"7C" ,"7D" ,
										"7E" ,"7F" ,"80" ,"81" ,"82" ,"83" ,"84" ,"85" ,"86" ,"87" ,"88" ,"89" ,"8A" ,"8B" ,
										"8C" ,"8D" ,"8E" ,"8F" ,"90" ,"91" ,"92" ,"93" ,"94" ,"95" ,"96" ,"97" ,"98" ,"99" ,
										"9A" ,"9B" ,"9C" ,"9D" ,"9E" ,"9F" ,"A0" ,"A1" ,"A2" ,"A3" ,"A4" ,"A5" ,"A6" ,"A7" ,
										"A8" ,"A9" ,"AA" ,"AB" ,"AC" ,"AD" ,"AE" ,"AF" ,"B0" ,"B1" ,"B2" ,"B3" ,"B4" ,"B5" ,
										"B6" ,"B7" ,"B8" ,"B9" ,"BA" ,"BB" ,"BC" ,"BD" ,"BE" ,"BF" ,"C0" ,"C1" ,"C2" ,"C3" ,
										"C4" ,"C5" ,"C6" ,"C7" ,"C8" ,"C9" ,"CA" ,"CB" ,"CC" ,"CD" ,"CE" ,"CF" ,"D0" ,"D1" ,
										"D2" ,"D3" ,"D4" ,"D5" ,"D6" ,"D7" ,"D8" ,"D9" ,"DA" ,"DB" ,"DC" ,"DD" ,"DE" ,"DF" ,
										"E0" ,"E1" ,"E2" ,"E3" ,"E4" ,"E5" ,"E6" ,"E7" ,"E8" ,"E9" ,"EA" ,"EB" ,"EC" ,"ED" ,
										"EE" ,"EF" ,"F0" ,"F1" ,"F2" ,"F3" ,"F4" ,"F5" ,"F6" ,"F7" ,"F8" ,"F9" ,"FA" ,"FB" ,
										"FC" ,"FD" ,"FE" ,"FF" };

		public long CRC32_POLYNOMIAL = 0xEDB88320;
		public long[] CRC32Table;

		private void InitCRC32()
		{
			long I, J, K, X, XorVal;

			CRC32Table = new long[256];

			for(I = 0; I < 256; I++) 
			{
				K = I;
        
				for(J = 0; J < 8; J++)
				{  
					X = (K & ((long)1));

					if(X > 0) 
					{	
						XorVal = CRC32_POLYNOMIAL; 
					} 
					else 
					{	
						XorVal = 0;	
					}
					if(K < 0) 
					{	
						K = ((K & 0x7FFFFFFF) / 2) | 0x40000000; 
					} 
					else	
					{
						K = K / 2; 
					}
					K ^= XorVal;
				}
				CRC32Table[I] = K;
			}
		}
		private long CRC32(string txt) 
		{
			long c=-1;
			int I = 0, J = 0, L = 0, U = 0, U2 = 0;
			InitCRC32();

			for(I = 0; I < txt.Length; I++)
			{
				L = (int)txt[I];
				U2 = 0xFF;
				U = (int)(c & U2);
				J = (L ^ U);
				if(c < 0) 
				{ 
					c = (((c & 0x7FFFFFFF) / 0x100) | 0x800000); 
				} 
				else 
				{ 
					c = (c / 0x100); 
				}
				c ^= CRC32Table[J];
				c = ConvertLong(c);
			}
			c = ((c * -1) - 1);
			return c; 
		}
		private long ConvertLong(long Value)
		{
			if(Value < 0xFFFFFFFF)
			{
				Value -= 0xFFFFFFFF;
				Value -= 1;
			}
			if(Value > (0xFFFFFFFF * -1))
			{
				Value += 0xFFFFFFFF;
				Value += 1;
			}
			return Value;
		}
		public string BNLSChecksum(string Password, long ServerCode)
		{
			string strSCode = "", strTm = "";
			char[] scChC;
			
			scChC = ServerCode.ToString().ToCharArray();
			strSCode = MakeDW(ConvertLong(ServerCode));
			strTm = reverse(strSCode);
			strTm = tohex(strTm);

			return MakeDW(CRC32(Password+strTm));
		}
		private string tohex(string inBuf)
		{
			int x, numVal;
			string outBuf="";

			for(x = 0; x < inBuf.Length; x++)
			{
				numVal = inBuf[x];
				outBuf = outBuf+HexValues[numVal];
			}
			return outBuf;
		}
		private string reverse(string inBuf)
		{
			int x;
			string outBuf = "";
			for(x = inBuf.Length - 1; x > -1; x--)
			{
				outBuf = outBuf+inBuf[x];
			}
			return outBuf;
		}

		private string MakeDW(long lngInt)
		{
			char a, b, c, d;
			long tmpLng;
			int tmpint;
			string outBuf;

			if(lngInt < -1) { lngInt += 0xFFFFFFFF; lngInt += 1; }
				
			tmpLng = lngInt;
			
			tmpint = (int)(((tmpLng / 256) / 256) / 256);
			a = (char)(tmpint);
			tmpLng -= (((tmpint* 256)* 256)* 256);
			
			tmpint = (int)((tmpLng / 256) / 256);
			b = (char)(tmpint);
			tmpLng -= ((tmpint*256)*256);
			
			tmpint = (int)(tmpLng / 256);
			c = (char)(tmpint);
			tmpLng -= (tmpint*256);
			
			tmpint = (int)(tmpLng);
			d = (char)(tmpint);

			outBuf = d.ToString()+c.ToString()+b.ToString()+a.ToString();
			
			return outBuf;
		}
	}
}