// zpipe.cpp : Defines the entry point for the console application.
//

#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) ;
int inf(char *src, char *dst, int bytes_to_decompress, int maximum_after_decompress) ;

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

    int ret;//, flush;
    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;
    //unsigned have;

    /* 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);
    }
}
