/*
Copyright (C) 2012-13 Miranda NG team (http://miranda-ng.org)

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, see <http://www.gnu.org/licenses/>.
*/

#include "commonheaders.h"

/////////////////////////////////////////////////////////////////////////////////////////

static const char szHexDigits[] = "0123456789ABCDEF";

MIR_CORE_DLL(char*) mir_urlEncode(const char *szUrl)
{
	if (szUrl == NULL)
		return NULL;

	const BYTE *s;
	int outputLen;
	for (outputLen = 0, s = (const BYTE*)szUrl; *s; s++) {
		if (('0' <= *s && *s <= '9')  || //0-9
			 ('A' <= *s && *s <= 'Z')  || //ABC...XYZ
			 ('a' <= *s && *s <= 'z')  || //abc...xyz
			*s == '-' || *s == '_' || *s == '.' || *s == ' ') outputLen++;
		else outputLen += 3;
	}

	char *szOutput = (char*)mir_alloc(outputLen+1);
	if (szOutput == NULL)
		return NULL;

	char *d = szOutput;
	for (s = (const BYTE*)szUrl; *s; s++) {
		if (('0' <= *s && *s <= '9')  || //0-9
			 ('A' <= *s && *s <= 'Z')  || //ABC...XYZ
			 ('a' <= *s && *s <= 'z')  || //abc...xyz
			*s == '-' || *s == '_' || *s == '.') *d++ = *s;
		else if (*s == ' ') *d++='+';
		else {
			*d++ = '%';
			*d++ = szHexDigits[*s >> 4];
			*d++ = szHexDigits[*s & 0xF];
		}
	}
	*d = '\0';
	return szOutput;
}

/////////////////////////////////////////////////////////////////////////////////////////

static char cb64[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

MIR_CORE_DLL(char*) mir_base64_encode(const BYTE *input, unsigned inputLen)
{
	if (input == NULL)
		return NULL;

	BYTE chr[3];

	size_t length = inputLen;
	size_t nLength = 4 * ((length + 2) / 3) + 1;

	char *output = (char *)mir_alloc(nLength);
	char *p = output;

	for (size_t i=0; i < length; )
	{
		chr[0] = input[i++];
		chr[1] = input[i++];
		chr[2] = input[i++];

		*p++ = cb64[ chr[0] >> 2 ];
		*p++ = cb64[ ((chr[0] & 0x03) << 4) | (chr[1] >> 4) ];
		BYTE b2 = ((chr[1] & 0x0F) << 2) | (chr[2] >> 6),
		     b3 = chr[2] & 0x3F;

		if (i - 2 >= length) { *p++ = '='; *p++ = '='; }
		else if (i - 1 >= length) { *p++ = cb64[b2]; *p++ = '='; }
		else { *p++ = cb64[b2]; *p++ = cb64[b3]; }
	}

	*p = 0;

	return output;
}

/////////////////////////////////////////////////////////////////////////////////////////

static int Base64DecodeTable[] =
{
	-1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1,
	-1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1,
	-1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,62, -1,-1,-1,63,
	52,53,54,55, 56,57,58,59, 60,61,-1,-1, -1,-1,-1,-1,
	-1, 0, 1, 2,  3, 4, 5, 6,  7, 8, 9,10, 11,12,13,14,
	15,16,17,18, 19,20,21,22, 23,24,25,-1, -1,-1,-1,-1,
	-1,26,27,28, 29,30,31,32, 33,34,35,36, 37,38,39,40,
	41,42,43,44, 45,46,47,48, 49,50,51,-1, -1,-1,-1,-1,
	-1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1,
	-1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1,
	-1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1,
	-1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1,
	-1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1,
	-1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1,
	-1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1,
	-1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1
};

MIR_CORE_DLL(void*) mir_base64_decode(const char *input, unsigned *outputLen)
{
	if (input == NULL)
		return NULL;

	size_t i = 0;
	BYTE chr[3], enc[4];

	size_t length = strlen(input);
	size_t nLength = (length / 4) * 3;

	char *output = (char *)mir_alloc(nLength+1);
	char *p = output;

	while (i < length)
	{
		enc[0] = Base64DecodeTable[input[i++]];
		enc[1] = Base64DecodeTable[input[i++]];
		enc[2] = Base64DecodeTable[input[i++]];
		enc[3] = Base64DecodeTable[input[i++]];

		if (enc[0] == -1 || enc[1] == -1) break;

		chr[0] = (enc[0] << 2) | (enc[1] >> 4);
		chr[1] = ((enc[1] & 15) << 4) | (enc[2] >> 2);
		chr[2] = ((enc[2] & 3) << 6) | enc[3];

		*p++ = chr[0];

		if (enc[2] != -1) *p++ = chr[1];
		if (enc[3] != -1) *p++ = chr[2];
	}

	*p = 0;

	if (outputLen != NULL)
		*outputLen = (unsigned)nLength;

	return output;
}