/**
*******************************************************************************

  @file /net/compress.cpp
  @brief Nastroje na kompresi a dekompresi
  
  @author Vta
  @version 1.0
 
******************************************************************************/

#include <stdio.h>
#include <string.h>
#include <assert.h>
#include "net/compress.h"
#include "common/xml/strda.h"
#include "common/Log.h"
#include "common/exc.h"
#include "zlib/zlib.h"

char bu_outC[COMPRESS_BUFFER];
int MyCompress(char * source, DA<char> * dest, int level)
{
  int ret, flush;
  unsigned have;
  z_stream strm;
  // pouziti defautlnich funkci, inicializace strm
  strm.zalloc = Z_NULL;
  strm.zfree = Z_NULL;
  strm.opaque = Z_NULL;
  ret = deflateInit(&strm, level);
  if (ret != Z_OK)
    return ret;

  strm.avail_in = strlen(source);
  flush = Z_FINISH;
  strm.next_in = (unsigned char*)source;
  // pousti se deflate() na vstup dokud neni vystupni buffer plny
  do 
  {
    strm.avail_out = COMPRESS_BUFFER;
    strm.next_out = (unsigned char*)bu_outC;

    ret = deflate(&strm, flush);  
    if (ret==Z_STREAM_ERROR)
    {
      GLOBALLOGID(PRIORITY_COMPRESSION,"Chyba pri kompresi");
      THROW(E_8K_COMPRESSION,"Chyba pri kompresi"); 
    }
    have = COMPRESS_BUFFER - strm.avail_out;
    addtodanum(dest,bu_outC,0,have);
  } 
  while (strm.avail_out == 0);
  // konci, kdyz uz vsechny vstupni data byla prectena

  // ukoncit strm
  (void)deflateEnd(&strm);
  return Z_OK;
}

char bu_outD[COMPRESS_BUFFER];
int MyDecompress(char * source, int size, DA<char> * dest)
{
  int ret;
  unsigned have;
  z_stream strm;
  // inicializace strm
  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;
  strm.avail_in = size;
  strm.next_in = (unsigned char*)source;
  // vlastni cteni vstupu
  do 
  {
    strm.avail_out = COMPRESS_BUFFER;
    strm.next_out = (unsigned char*)bu_outD;

    ret = inflate(&strm, Z_NO_FLUSH);
    if (ret==Z_STREAM_ERROR)
    {
      GLOBALLOGID(PRIORITY_COMPRESSION,"Compression error");
      THROW(E_8K_COMPRESSION,"Compression error"); 
    }
    switch (ret) 
    {
      case Z_NEED_DICT:
        ret = Z_DATA_ERROR;     // a ukonci
      case Z_DATA_ERROR:
      case Z_MEM_ERROR:
        (void)inflateEnd(&strm);
        return ret;
    }

    have = COMPRESS_BUFFER - strm.avail_out;
    addtodanum(dest,bu_outD,0,have);

  } 
  while (strm.avail_out == 0);
  // konec, kdyz uz na vstupu nic neni

  // ukonceni strm
  (void)inflateEnd(&strm);
  return ret == Z_STREAM_END ? Z_OK : Z_DATA_ERROR;
}