/*
 * Hedgewars, a free turn based strategy game
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
 */

#include "misc.h"

#define F1(x, y, z)	(z ^ (x & (y ^ z)))
#define F2(x, y, z)	F1(z, x, y)
#define F3(x, y, z)	(x ^ y ^ z)
#define F4(x, y, z)	(y ^ (x | ~z))

#define MD5STEP(f, w, x, y, z, in, s) \
	(w += f(x, y, z) + in, w = (w<<s | w>>(32-s)) + x)

Hash::Hash()
{

}

QString Hash::md5(QByteArray buf)
{
// prepare
	quint32 size = buf.size();

	if (size > 55)
		return QString("md5 hash value :D");
	
	buf += '\x80';
	buf += QByteArray(55 - size, '\x00');

	size *= 8;
	
	quint8 tb1 = size & 0xff;
	quint8 tb2 = (size >> 8) & 0xff;
	
	buf += QByteArray::fromRawData((char *)&tb1, 1);
	buf += QByteArray::fromRawData((char *)&tb2, 1);
	buf += QByteArray(6, '\x00');

	const char * message = buf.data();
	
// start hashing
	
	quint32 w[16], i, a, b, c, d, f, g, t;

	quint32 h0 = 0x67452301;
	quint32 h1 = 0xEFCDAB89;
	quint32 h2 = 0x98BADCFE;
	quint32 h3 = 0x10325476;
	int j;
	
	for(i = 0; i < 16; i++)
	{
		w[i] = 0;
		
		for(j = 3; j >= 0; j--)
		{
			w[i] <<= 8;
			w[i] += message[(i << 2) + j] & 0xFF;
		}
	}
	a = h0; b = h1; c = h2; d = h3;

	MD5STEP(F1, a, b, c, d, w[0]  + 0xd76aa478, 7);
	MD5STEP(F1, d, a, b, c, w[1]  + 0xe8c7b756, 12);
	MD5STEP(F1, c, d, a, b, w[2]  + 0x242070db, 17);
	MD5STEP(F1, b, c, d, a, w[3]  + 0xc1bdceee, 22);
	MD5STEP(F1, a, b, c, d, w[4]  + 0xf57c0faf, 7);
	MD5STEP(F1, d, a, b, c, w[5]  + 0x4787c62a, 12);
	MD5STEP(F1, c, d, a, b, w[6]  + 0xa8304613, 17);
	MD5STEP(F1, b, c, d, a, w[7]  + 0xfd469501, 22);
	MD5STEP(F1, a, b, c, d, w[8]  + 0x698098d8, 7);
	MD5STEP(F1, d, a, b, c, w[9]  + 0x8b44f7af, 12);
	MD5STEP(F1, c, d, a, b, w[10] + 0xffff5bb1, 17);
	MD5STEP(F1, b, c, d, a, w[11] + 0x895cd7be, 22);
	MD5STEP(F1, a, b, c, d, w[12] + 0x6b901122, 7);
	MD5STEP(F1, d, a, b, c, w[13] + 0xfd987193, 12);
	MD5STEP(F1, c, d, a, b, w[14] + 0xa679438e, 17);
	MD5STEP(F1, b, c, d, a, w[15] + 0x49b40821, 22);

	MD5STEP(F2, a, b, c, d, w[1]  + 0xf61e2562, 5);
	MD5STEP(F2, d, a, b, c, w[6]  + 0xc040b340, 9);
	MD5STEP(F2, c, d, a, b, w[11] + 0x265e5a51, 14);
	MD5STEP(F2, b, c, d, a, w[0]  + 0xe9b6c7aa, 20);
	MD5STEP(F2, a, b, c, d, w[5]  + 0xd62f105d, 5);
	MD5STEP(F2, d, a, b, c, w[10] + 0x02441453, 9);
	MD5STEP(F2, c, d, a, b, w[15] + 0xd8a1e681, 14);
	MD5STEP(F2, b, c, d, a, w[4]  + 0xe7d3fbc8, 20);
	MD5STEP(F2, a, b, c, d, w[9]  + 0x21e1cde6, 5);
	MD5STEP(F2, d, a, b, c, w[14] + 0xc33707d6, 9);
	MD5STEP(F2, c, d, a, b, w[3]  + 0xf4d50d87, 14);
	MD5STEP(F2, b, c, d, a, w[8]  + 0x455a14ed, 20);
	MD5STEP(F2, a, b, c, d, w[13] + 0xa9e3e905, 5);
	MD5STEP(F2, d, a, b, c, w[2]  + 0xfcefa3f8, 9);
	MD5STEP(F2, c, d, a, b, w[7]  + 0x676f02d9, 14);
	MD5STEP(F2, b, c, d, a, w[12] + 0x8d2a4c8a, 20);

	MD5STEP(F3, a, b, c, d, w[5]  + 0xfffa3942, 4);
	MD5STEP(F3, d, a, b, c, w[8]  + 0x8771f681, 11);
	MD5STEP(F3, c, d, a, b, w[11] + 0x6d9d6122, 16);
	MD5STEP(F3, b, c, d, a, w[14] + 0xfde5380c, 23);
	MD5STEP(F3, a, b, c, d, w[1]  + 0xa4beea44, 4);
	MD5STEP(F3, d, a, b, c, w[4]  + 0x4bdecfa9, 11);
	MD5STEP(F3, c, d, a, b, w[7]  + 0xf6bb4b60, 16);
	MD5STEP(F3, b, c, d, a, w[10] + 0xbebfbc70, 23);
	MD5STEP(F3, a, b, c, d, w[13] + 0x289b7ec6, 4);
	MD5STEP(F3, d, a, b, c, w[0]  + 0xeaa127fa, 11);
	MD5STEP(F3, c, d, a, b, w[3]  + 0xd4ef3085, 16);
	MD5STEP(F3, b, c, d, a, w[6]  + 0x04881d05, 23);
	MD5STEP(F3, a, b, c, d, w[9]  + 0xd9d4d039, 4);
	MD5STEP(F3, d, a, b, c, w[12] + 0xe6db99e5, 11);
	MD5STEP(F3, c, d, a, b, w[15] + 0x1fa27cf8, 16);
	MD5STEP(F3, b, c, d, a, w[2]  + 0xc4ac5665, 23);

	MD5STEP(F4, a, b, c, d, w[0]  + 0xf4292244, 6);
	MD5STEP(F4, d, a, b, c, w[7]  + 0x432aff97, 10);
	MD5STEP(F4, c, d, a, b, w[14] + 0xab9423a7, 15);
	MD5STEP(F4, b, c, d, a, w[5]  + 0xfc93a039, 21);
	MD5STEP(F4, a, b, c, d, w[12] + 0x655b59c3, 6);
	MD5STEP(F4, d, a, b, c, w[3]  + 0x8f0ccc92, 10);
	MD5STEP(F4, c, d, a, b, w[10] + 0xffeff47d, 15);
	MD5STEP(F4, b, c, d, a, w[1]  + 0x85845dd1, 21);
	MD5STEP(F4, a, b, c, d, w[8]  + 0x6fa87e4f, 6);
	MD5STEP(F4, d, a, b, c, w[15] + 0xfe2ce6e0, 10);
	MD5STEP(F4, c, d, a, b, w[6]  + 0xa3014314, 15);
	MD5STEP(F4, b, c, d, a, w[13] + 0x4e0811a1, 21);
	MD5STEP(F4, a, b, c, d, w[4]  + 0xf7537e82, 6);
	MD5STEP(F4, d, a, b, c, w[11] + 0xbd3af235, 10);
	MD5STEP(F4, c, d, a, b, w[2]  + 0x2ad7d2bb, 15);
	MD5STEP(F4, b, c, d, a, w[9]  + 0xeb86d391, 21);

	h0 = h0 + a;
	h1 = h1 + b;
	h2 = h2 + c;
	h3 = h3 + d;

	QString result;

	result.sprintf("%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x",
			h0 & 0xFF, h0 >> 8 & 0xFF, h0 >> 16 & 0xFF, h0 >> 24 & 0xFF,
			h1 & 0xFF, h1 >> 8 & 0xFF, h1 >> 16 & 0xFF, h1 >> 24 & 0xFF,
			h2 & 0xFF, h2 >> 8 & 0xFF, h2 >> 16 & 0xFF, h2 >> 24 & 0xFF,
			h3 & 0xFF, h3 >> 8 & 0xFF, h3 >> 16 & 0xFF, h3 >> 24 & 0xFF
		);

	return result;
}