/**

  * vim: set ts=4 sw=4 tw=99 et :

  * =============================================================================

  * SourceMod

  * Copyright (C) 2004-2009 AlliedModders LLC.  All rights reserved.

  * =============================================================================

  *

  * This program is free software; you can redistribute it and/or modify it under

  * the terms of the GNU General Public License, version 3.0, as published by the

  * Free Software Foundation.

  * 

  * 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/>.

  *

  * As a special exception, AlliedModders LLC gives you permission to link the

  * code of this program (as well as its derivative works) to "Half-Life 2," the

  * "Source Engine," the "SourcePawn JIT," and any Game MODs that run on software

  * by the Valve Corporation.  You must obey the GNU General Public License in

  * all respects for all other code used.  Additionally, AlliedModders LLC grants

  * this exception to all derivative works.  AlliedModders LLC defines further

  * exceptions, found in LICENSE.txt (as of this writing, version JULY-31-2007),

  * or <http://www.sourcemod.net/license.php>.

  *

  * Version: $Id$

  */

 #include <string.h>

 #include <ctype.h>

 #include "stringutil.h"

 const char *stristr(const char *str, const char *substr)

 {

 	if (!*substr)

 	{

 		return ((char *)str);

 	}

 	char *needle = (char *)substr;

 	char *prevloc = (char *)str;

 	char *haystack = (char *)str;

 	while (*haystack)

 	{

 		if (tolower(*haystack) == tolower(*needle))

 		{

 			haystack++;

 			if (!*++needle)

 			{

 				return prevloc;

 			}

 		}

 		else

 		{

 			haystack = ++prevloc;

 			needle = (char *)substr;

 		}

 	}

 	return NULL;

 }

 unsigned int strncopy(char *dest, const char *src, size_t count)

 {

 	if (!count)

 	{

 		return 0;

 	}

 	char *start = dest;

 	while ((*src) && (--count))

 	{

 		*dest++ = *src++;

 	}

 	*dest = '\0';

 	return (dest - start);

 }

 unsigned int UTIL_ReplaceAll(char *subject, size_t maxlength, const char *search, const char *replace, bool caseSensitive)

 {

 	size_t searchLen = strlen(search);

 	size_t replaceLen = strlen(replace);

 	char *ptr = subject;

 	unsigned int total = 0;

 	while ((ptr = UTIL_ReplaceEx(ptr, maxlength, search, searchLen, replace, replaceLen, caseSensitive)) != NULL)

 	{

 		total++;

 		if (*ptr == '\0')

 		{

 			break;

 		}

 	}

 	return total;

 }

 /**

  * NOTE: Do not edit this for the love of god unless you have 

  * read the test cases and understand the code behind each one.

  * While I don't guarantee there aren't mistakes, I do guarantee

  * that plugins will end up relying on tiny idiosyncrasies of this

  * function, just like they did with AMX Mod X.

  *

  * There are explicitly more cases than the AMX Mod X version because

  * we're not doing a blind copy.  Each case is specifically optimized

  * for what needs to be done.  Even better, we don't have to error on

  * bad buffer sizes.  Instead, this function will smartly cut off the 

  * string in a way that pushes old data out.

  */

 char *UTIL_ReplaceEx(char *subject, size_t maxLen, const char *search, size_t searchLen, const char *replace, size_t replaceLen, bool caseSensitive)

 {

 	char *ptr = subject;

 	size_t browsed = 0;

 	size_t textLen = strlen(subject);

 	/* It's not possible to search or replace */

 	if (searchLen > textLen)

 	{

 		return NULL;

 	}

 	/* Handle the case of one byte replacement.

 	 * It's only valid in one case.

 	 */

 	if (maxLen == 1)

 	{

 		/* If the search matches and the replace length is 0, 

 		 * we can just terminate the string and be done.

 		 */

 		if ((caseSensitive ? strcmp(subject, search) : strcasecmp(subject, search)) == 0 && replaceLen == 0)

 		{

 			*subject = '\0';

 			return subject;

 		}

 		else

 		{

 			return NULL;

 		}

 	}

 	/* Subtract one off the maxlength so we can include the null terminator */

 	maxLen--;

 	while (*ptr != '\0' && (browsed <= textLen - searchLen))

 	{

 		/* See if we get a comparison */

 		if ((caseSensitive ? strncmp(ptr, search, searchLen) : strncasecmp(ptr, search, searchLen)) == 0)

 		{

 			if (replaceLen > searchLen)

 			{

 				/* First, see if we have enough space to do this operation */

 				if (maxLen - textLen < replaceLen - searchLen)

 				{

 					/* First, see if the replacement length goes out of bounds. */

 					if (browsed + replaceLen >= maxLen)

 					{

 						/* EXAMPLE CASE:

 						 * Subject: AABBBCCC

 						 * Buffer : 12 bytes

 						 * Search : BBB

 						 * Replace: DDDDDDDDDD

 						 * OUTPUT : AADDDDDDDDD

 						 * POSITION:           ^

 						 */

 						/* If it does, we'll just bound the length and do a strcpy. */

 						replaceLen = maxLen - browsed;

 						/* Note, we add one to the final result for the null terminator */

 						strncopy(ptr, replace, replaceLen+1);

 					}

 					else

 					{

 						/* EXAMPLE CASE:

 						 * Subject: AABBBCCC

 						 * Buffer : 12 bytes

 						 * Search : BBB

 						 * Replace: DDDDDDD

 						 * OUTPUT : AADDDDDDDCC

 						 * POSITION:         ^

 						 */

 						/* We're going to have some bytes left over... */

 						size_t origBytesToCopy = (textLen - (browsed + searchLen)) + 1;

 						size_t realBytesToCopy = (maxLen - (browsed + replaceLen)) + 1;

 						char *moveFrom = ptr + searchLen + (origBytesToCopy - realBytesToCopy);

 						char *moveTo = ptr + replaceLen;

 						/* First, move our old data out of the way. */

 						memmove(moveTo, moveFrom, realBytesToCopy);

 						/* Now, do our replacement. */

 						memcpy(ptr, replace, replaceLen);

 					}

 				}

 				else

 				{

 					/* EXAMPLE CASE:

 					 * Subject: AABBBCCC

 					 * Buffer : 12 bytes

 					 * Search : BBB

 					 * Replace: DDDD

 					 * OUTPUT : AADDDDCCC

 					 * POSITION:      ^

 					 */

 					/* Yes, we have enough space.  Do a normal move operation. */

 					char *moveFrom = ptr + searchLen;

 					char *moveTo = ptr + replaceLen;

 					/* First move our old data out of the way. */

 					size_t bytesToCopy = (textLen - (browsed + searchLen)) + 1;

 					memmove(moveTo, moveFrom, bytesToCopy);

 					/* Now do our replacement. */

 					memcpy(ptr, replace, replaceLen);

 				}

 			}

 			else if (replaceLen < searchLen)

 			{

 				/* EXAMPLE CASE:

 				 * Subject: AABBBCCC

 				 * Buffer : 12 bytes

 				 * Search : BBB

 				 * Replace: D

 				 * OUTPUT : AADCCC

 				 * POSITION:   ^

 				 */

 				/* If the replacement does not grow the string length, we do not

 				 * need to do any fancy checking at all.  Yay!

 				 */

 				char *moveFrom = ptr + searchLen;		/* Start after the search pointer */

 				char *moveTo = ptr + replaceLen;		/* Copy to where the replacement ends */

 				/* Copy our replacement in, if any */

 				if (replaceLen)

 				{

 					memcpy(ptr, replace, replaceLen);

 				}

 				/* Figure out how many bytes to move down, including null terminator */

 				size_t bytesToCopy = (textLen - (browsed + searchLen)) + 1;

 				/* Move the rest of the string down */

 				memmove(moveTo, moveFrom, bytesToCopy);

 			}

 			else

 			{

 				/* EXAMPLE CASE:

 				 * Subject: AABBBCCC

 				 * Buffer : 12 bytes

 				 * Search : BBB

 				 * Replace: DDD

 				 * OUTPUT : AADDDCCC

 				 * POSITION:     ^

 				 */

 				/* We don't have to move anything around, just do a straight copy */

 				memcpy(ptr, replace, replaceLen);

 			}

 			return ptr + replaceLen;

 		}

 		ptr++;

 		browsed++;

 	}

 	return NULL;

 }