/*
  Copyright (c) 2023 Alex Diener
  
  This software is provided 'as-is', without any express or implied
  warranty. In no event will the authors be held liable for any damages
  arising from the use of this software.
  
  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:
  
  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.
  
  Alex Diener alex@ludobloom.com
*/

#ifndef __StringDiff_H__
#define __StringDiff_H__

#include <stddef.h>
#include <stdint.h>

typedef struct StringDiff {
	char * bytes;
	size_t length;
	int lengthChange;
	uint8_t isNull;
} StringDiff;

#define StringDiff_empty ((StringDiff) {NULL, 0, 0, 1 << 2})

// NULL strings are legal, and are distinguished from empty strings and set appropriately after apply() or revert().
StringDiff StringDiff_create(const char * oldString, const char * newString);
void StringDiff_dispose(StringDiff * stringDiff);
// Transforms target from old to new. *target must be heap-allocated, and may be realloced or freed by this function.
void StringDiff_apply(StringDiff * stringDiff, char ** target);
// Transforms target from new to old. *target must be heap-allocated, and may be realloced or freed by this function.
void StringDiff_revert(StringDiff * stringDiff, char ** target);

#endif