/* This file is (c) 2008-2011 Konstantin Isakov <ikm@goldendict.org>
 * Part of GoldenDict. Licensed under GPLv3 or later, see the LICENSE file */

#include "indexedzip.hh"
#include "zipfile.hh"
#include <zlib.h>
#include "dprintf.hh"

using namespace BtreeIndexing;
using std::vector;

bool IndexedZip::openZipFile( QString const & name )
{
  zip.setFileName( name );

  zipIsOpen = zip.open( QFile::ReadOnly );

  return zipIsOpen;
}

bool IndexedZip::hasFile( gd::wstring const & name )
{
  if ( !zipIsOpen )
    return false;

  vector< WordArticleLink > links = findArticles( name );

  return !links.empty();
}

bool IndexedZip::loadFile( gd::wstring const & name, vector< char > & data )
{
  if ( !zipIsOpen )
    return false;

  vector< WordArticleLink > links = findArticles( name );

  if ( links.empty() )
    return false;

  // Now seek into the zip file and read its header

  if ( !zip.seek( links[ 0 ].articleOffset ) )
    return false;

  ZipFile::LocalFileHeader header;

  if ( !ZipFile::readLocalHeader( zip, header ) )
  {
    DPRINTF( "Failed to load header\n" );
    return false;
  }

  // Which algorithm was used?

  switch( header.compressionMethod )
  {
    case ZipFile::Uncompressed:
      DPRINTF( "Uncompressed\n" );
      data.resize( header.uncompressedSize );
      return zip.read( &data.front(), data.size() ) == data.size();

    case ZipFile::Deflated:
    {
      DPRINTF( "Deflated\n" );

      // Now do the deflation

      QByteArray compressedData = zip.read( header.compressedSize );

      if ( compressedData.size() != (int)header.compressedSize )
        return false;

      data.resize( header.uncompressedSize );

      z_stream stream;

      memset( &stream, 0, sizeof( stream ) );

      stream.next_in = ( Bytef * ) compressedData.data();
      stream.avail_in = compressedData.size();
      stream.next_out = ( Bytef * ) &data.front();
      stream.avail_out = data.size();

      if ( inflateInit2( &stream, -MAX_WBITS ) != Z_OK )
      {
        data.clear();        
        return false;
      }

      if ( inflate( &stream, Z_FINISH ) != Z_STREAM_END )
      {
        DPRINTF( "Not zstream end!" );

        data.clear();

        inflateEnd( &stream );

        return false;
      }

      inflateEnd( &stream );

      return true;
    }

    default:

      return false;
  }
}