/*
   orxonox - the future of 3D-vertical-scrollers

   Copyright (C) 2004 orx

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2, or (at your option)
   any later version.

### File Specific:
   main-programmer: Christoph Renner
   co-programmer: ...
*/

#include "zip.h"
#include "loading/new_resource_manager.h"
#include "debug.h"

/**
 *  the singleton reference to this class
 */
Zip* Zip::singletonRef = NULL;


/**
 * standard constructor
 */
Zip::Zip()
{

}


/**
 * @brief standard deconstructor
 */
Zip::~Zip()
{
  Zip::singletonRef = NULL;
}

/**
 * load a dictionary to unzip. you can load more than one dictionary
 * if you call unzip with data from zip without loading the same dictionary
 * used with zip unzip will fail
 * @param name name of dictionary
 * @return true on success
 */
int Zip::loadDictionary( std::string name )
{
  std::string fileName = Resources::NewResourceManager::getInstance()->mainGlobalPath().name();
  //PRINTF(0)("datadir: %s\n", fileName.c_str());
  fileName = fileName + "/dicts/" + name;
  //PRINTF(0)("filename: %s\n", fileName.c_str());

  FILE * f = fopen( fileName.c_str(), "r" );

  if ( !f )
  {
    PRINTF(1)("Could not open %d\n", fileName.c_str());
    return -1;
  }

  byte buf[1024];

  int nBytesRead = 0;

  while ( !feof( f ) )
  {
    nBytesRead += fread( buf, 1, sizeof(buf), f );
  }

  DictionaryEntry entry;

  entry.dictLen = nBytesRead;
  entry.dict = new Byte[nBytesRead];

  fseek( f, 0, SEEK_SET );

  assert( fread( entry.dict, 1, nBytesRead, f ) == nBytesRead );

  entry.adler = adler32( adler32( 0L, Z_NULL, 0 ), entry.dict, nBytesRead );

  dicts.push_back( entry );

  PRINTF(3)("Loaded dictionary '%s' with adler = %d\n", name.c_str(), entry.adler );

  return dicts.size()-1;
}

/**
 * zip data. you must call loadDictionary before
 * @param from data to compress
 * @param fromLength length of data to compress
 * @param to pointer to compressed data
 * @param maxLength max bytes to compress
 * @param dict dictionary to use. default is 0
 * @return num bytes writen to to
 */
int Zip::zip( byte * from, int fromLength, byte * to, int maxLength, int dict )
{
  if ( dicts.size() < dict+1 )
  {
    PRINTF(1)("you cannot use dict nr %d. num dicts: %d\n", dict, dicts.size() );
    return -1;
  }

  int res;

  z_stream strm;

  strm.zalloc = Z_NULL;
  strm.zfree = Z_NULL;
  strm.opaque = Z_NULL;

  res = deflateInit( &strm, 9 );

  if ( res != Z_OK )
  {
    PRINTF(1)("deflateInit error: %s\n", strm.msg);
    return -1;
  }

  res = deflateSetDictionary( &strm, (Bytef*)(dicts[dict].dict), dicts[dict].dictLen );

  if ( res != Z_OK )
  {
    PRINTF(1)("deflateSetDictionary error: %s\n", strm.msg);
    return -1;
  }

  strm.next_out = (Bytef*)to;
  strm.avail_out = maxLength;
  assert( strm.total_out == 0 );
  strm.next_in = (Bytef*)from;
  strm.avail_in = fromLength;
  assert( strm.total_in == 0 );

  res = deflate( &strm, Z_FINISH );

  if ( res != Z_STREAM_END )
  {
    PRINTF(1)("buffer to small or deflate error: %s\n", strm.msg);
    return -1;
  }

  assert( strm.avail_out != 0 );
  assert( strm.avail_in == 0 );

  int zippedlen = strm.total_out;

  res = deflateEnd( &strm );

  if ( res != Z_OK )
  {
    if ( res == Z_STREAM_ERROR )
      PRINTF(1)("deflateEnd error: Z_STREAM_ERROR\n");
    else if ( res == Z_DATA_ERROR )
      PRINTF(1)("deflateEnd error: Z_DATA_ERROR %s\n", strm.msg);
    else
      PRINTF(1)("deflateEnd error: dont know\n");

    return -1;
  }

  return zippedlen;

}

/**
 * uncompress data. same dict as used in zip must be loaded
 * @param from compressed data
 * @param fromLength length of compressed data
 * @param to buffer to copy uncompressed data to
 * @param maxLength max bytes to copy to to
 * @return num bytes writen to to
 */
int Zip::unZip( byte * from, int fromLength, byte * to, int maxLength )
{
  z_stream strm;
  int res = 0;

  strm.zalloc = Z_NULL;
  strm.zfree = Z_NULL;
  strm.opaque = Z_NULL;

  res = inflateInit( &strm );

  if ( res != Z_OK )
  {
    PRINTF(1)("inflateInit error: %s\n", strm.msg);
    return -1;
  }

  strm.next_out = (Bytef*)to;
  strm.avail_out = maxLength;
  assert( strm.total_out == 0 );
  strm.next_in = (Bytef*)from;
  strm.avail_in = fromLength;
  assert( strm.total_in == 0 );

  assert( inflate( &strm, Z_NO_FLUSH ) == Z_NEED_DICT );

  int dictId = -1;

  for ( int i = 0; i < dicts.size(); i++ )
  {
    if ( dicts[i].adler == strm.adler )
    {
      dictId = i;
      break;
    }
  }

  if ( dictId == -1 )
  {
    PRINTF(1)("Could not find dict used to compress this packet! ( adler = %d )\n", strm.adler);
    return -1;
  }

  res = inflateSetDictionary( &strm, (Bytef*)dicts[dictId].dict, dicts[dictId].dictLen );

  if ( res != Z_OK )
  {
    PRINTF(1)("inflateSetDictionary error: %s\n", strm.msg);
    return -1;
  }


  res = inflate( &strm, Z_FINISH );

  if ( res != Z_STREAM_END )
  {
    PRINTF(1)("inflate error: %s\n", strm.msg);
    return -1;
  }

  assert( strm.avail_out != 0 );
  assert( strm.avail_in == 0 );

  int unzippedlen = strm.total_out;

  res = inflateEnd( &strm );

  if ( res != Z_OK )
  {
    PRINTF(1)("inflateEnd error: %s\n", strm.msg);
    return -1;
  }

  return unzippedlen;
}