/* The file is based of zpipe.c + minor rename and minor adaptation
 *
 * zpipe.c: example of proper use of zlib's inflate() and deflate()
 * Not copyrighted -- provided to the public domain
 * Version 1.4  11 December 2005  Mark Adler 
 */

#include <iostream>

#include <stdio.h>
#include <string.h>
#include <assert.h>

//#define ZLIB_WINAPI
#include "zlib.h"

int def(char *src, char *dst, int bytes_to_compress, int *bytes_after_compressed)
{
	z_stream strm;

	int ret;
	unsigned have;

	/* allocate deflate state */
	strm.zalloc = Z_NULL;
	strm.zfree = Z_NULL;
	strm.opaque = Z_NULL;
	ret = deflateInit(&strm, Z_DEFAULT_COMPRESSION) ;

	if (ret != Z_OK)
		return ret;

	/* compress */
	strm.avail_in = bytes_to_compress ;
	strm.avail_out = bytes_to_compress ;

	strm.next_in = (Bytef *)src ;
	strm.next_out = (Bytef *)dst ;

	ret = deflate(&strm, Z_FINISH) ;

	have = bytes_to_compress - strm.avail_out ;

	*bytes_after_compressed = have ;

	assert(ret == Z_STREAM_END);		/* stream will be complete */

	/* clean up and return */
	(void)deflateEnd(&strm);

	return Z_OK;
}

int inf(char *src, char *dst, int bytes_to_decompress, int maximum_after_decompress, int* outbytes)
{
	z_stream strm;

	int ret;

	/* allocate inflate state */
	strm.zalloc = Z_NULL;
	strm.zfree = Z_NULL;
	strm.opaque = Z_NULL;
	strm.avail_in = 0;
	strm.next_in = Z_NULL;
	ret = inflateInit(&strm);

	if (ret != Z_OK) return ret;

	/* decompress */
	strm.avail_in = bytes_to_decompress ;
	strm.next_in = (Bytef *)src ;
	strm.next_out = (Bytef *)dst ;
	strm.avail_out = maximum_after_decompress ;

	ret = inflate(&strm, Z_NO_FLUSH) ;

	assert(ret != Z_STREAM_ERROR);  /* state not clobbered */

	switch (ret)
	{

		case Z_NEED_DICT:
			ret = Z_DATA_ERROR;	 /* and fall through */

		case Z_DATA_ERROR:

		case Z_MEM_ERROR:
			(void)inflateEnd(&strm);
			return ret;
	}

	assert(strm.avail_in == 0);	 /* all input will be used */

	if (outbytes != NULL) *outbytes = strm.total_out;

	/* clean up and return */
	(void)inflateEnd(&strm);

	return ret == Z_STREAM_END ? Z_OK : Z_DATA_ERROR;
}

/* report a zlib or i/o error */
void zerr(int ret)
{
	fputs("zpipe: ", stderr);

	switch (ret)
	{

		case Z_ERRNO:
			if (ferror(stdin)) fputs("error reading stdin\n", stderr);
			if (ferror(stdout)) fputs("error writing stdout\n", stderr);
			break;

		case Z_STREAM_ERROR:
			fputs("invalid compression level\n", stderr);
			break;

		case Z_DATA_ERROR:
			fputs("invalid or incomplete deflate data\n", stderr);
			break;

		case Z_MEM_ERROR:
			fputs("out of memory\n", stderr);
			break;

		case Z_VERSION_ERROR:
			fputs("zlib version mismatch!\n", stderr);
	}
}
