/*

 * Compression functions

 *

 * Copyright (C) 2018-2026, Joachim Metz <joachim.metz@gmail.com>

 *

 * Refer to AUTHORS for acknowledgements.

 *

 * This program is free software: you can redistribute it and/or modify

 * it under the terms of the GNU Lesser General Public License as published by

 * the Free Software Foundation, either version 3 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public License

 * along with this program.  If not, see <https://www.gnu.org/licenses/>.

 */

#include <common.h>

#include <memory.h>

#include <types.h>

#if defined( HAVE_STDLIB_H ) || defined( WINAPI )

#include <stdlib.h>

#endif

#if defined( HAVE_ZLIB ) || defined( ZLIB_DLL )

#include <zlib.h>

#endif

#include "libfsapfs_compression.h"

#include "libfsapfs_definitions.h"

#include "libfsapfs_deflate.h"

#include "libfsapfs_libcerror.h"

#include "libfsapfs_libcnotify.h"

#include "libfsapfs_libfmos.h"

/* Decompresses data using the compression method

 * Returns 1 on success, 0 on failure or -1 on error

 */

int libfsapfs_decompress_data(

     const uint8_t *compressed_data,

     size_t compressed_data_size,

     int compression_method,

     uint8_t *uncompressed_data,

     size_t *uncompressed_data_size,

     libcerror_error_t **error )

{

  static char *function              = "libfsapfs_decompress_data";

  int result                         = 0;

  uint8_t uncompressed_data_marker   = 0;

#if ( defined( HAVE_ZLIB ) && defined( HAVE_ZLIB_UNCOMPRESS ) ) || defined( ZLIB_DLL )

  uLongf zlib_uncompressed_data_size = 0;

#endif

  if( compressed_data == NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,

     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,

     "%s: invalid compressed data buffer.",

     function );

    return( -1 );

  }

  if( uncompressed_data == NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,

     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,

     "%s: invalid uncompressed data buffer.",

     function );

    return( -1 );

  }

  if( uncompressed_data == compressed_data )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,

     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,

     "%s: invalid compressed data buffer equals uncompressed data buffer.",

     function );

    return( -1 );

  }

  if( uncompressed_data_size == NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,

     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,

     "%s: invalid uncompressed data size.",

     function );

    return( -1 );

  }

  if( ( compression_method == LIBFSAPFS_COMPRESSION_METHOD_DEFLATE )

   || ( compression_method == LIBFSAPFS_COMPRESSION_METHOD_LZFSE ) )

  {

    uncompressed_data_marker = 0xff;

  }

  else if( compression_method == LIBFSAPFS_COMPRESSION_METHOD_LZVN )

  {

    uncompressed_data_marker = 0x06;

  }

  else if( compression_method == LIBFSAPFS_COMPRESSION_METHOD_RAW )

  {

    uncompressed_data_marker = 0xcc;

  }

  if( ( uncompressed_data_marker != 0 )

   && ( compressed_data_size >= 1 )

   && ( compressed_data[ 0 ] == uncompressed_data_marker ) )

  {

    if( compressed_data_size > (size_t) SSIZE_MAX )

    {

      libcerror_error_set(

       error,

       LIBCERROR_ERROR_DOMAIN_ARGUMENTS,

       LIBCERROR_ARGUMENT_ERROR_VALUE_EXCEEDS_MAXIMUM,

       "%s: invalid compressed data size value exceeds maximum.",

       function );

      return( -1 );

    }

    if( *uncompressed_data_size > (size_t) SSIZE_MAX )

    {

      libcerror_error_set(

       error,

       LIBCERROR_ERROR_DOMAIN_ARGUMENTS,

       LIBCERROR_ARGUMENT_ERROR_VALUE_EXCEEDS_MAXIMUM,

       "%s: invalid uncompressed data size value exceeds maximum.",

       function );

      return( -1 );

    }

    if( ( compressed_data_size - 1 ) > *uncompressed_data_size )

    {

      libcerror_error_set(

       error,

       LIBCERROR_ERROR_DOMAIN_RUNTIME,

       LIBCERROR_RUNTIME_ERROR_VALUE_OUT_OF_BOUNDS,

       "%s: compressed data size value exceeds uncompressed data size.",

       function );

      return( -1 );

    }

    *uncompressed_data_size = compressed_data_size - 1;

    if( memory_copy(

         uncompressed_data,

         &( compressed_data[ 1 ] ),

         *uncompressed_data_size ) == NULL )

    {

      libcerror_error_set(

       error,

       LIBCERROR_ERROR_DOMAIN_MEMORY,

       LIBCERROR_MEMORY_ERROR_COPY_FAILED,

       "%s: unable to copy compressed to uncompressed data.",

       function );

      return( -1 );

    }

    return( 1 );

  }

  if( compression_method == LIBFSAPFS_COMPRESSION_METHOD_DEFLATE )

  {

#if ( defined( HAVE_ZLIB ) && defined( HAVE_ZLIB_UNCOMPRESS ) ) || defined( ZLIB_DLL )

    if( compressed_data_size > (size_t) ULONG_MAX )

    {

      libcerror_error_set(

       error,

       LIBCERROR_ERROR_DOMAIN_ARGUMENTS,

       LIBCERROR_ARGUMENT_ERROR_VALUE_EXCEEDS_MAXIMUM,

       "%s: invalid compressed data size value exceeds maximum.",

       function );

      return( -1 );

    }

    if( *uncompressed_data_size > (size_t) ULONG_MAX )

    {

      libcerror_error_set(

       error,

       LIBCERROR_ERROR_DOMAIN_ARGUMENTS,

       LIBCERROR_ARGUMENT_ERROR_VALUE_EXCEEDS_MAXIMUM,

       "%s: invalid uncompressed data size value exceeds maximum.",

       function );

      return( -1 );

    }

    zlib_uncompressed_data_size = (uLongf) *uncompressed_data_size;

    result = uncompress(

        (Bytef *) uncompressed_data,

        &zlib_uncompressed_data_size,

        (Bytef *) compressed_data,

        (uLong) compressed_data_size );

    if( result == Z_OK )

    {

      *uncompressed_data_size = (size_t) zlib_uncompressed_data_size;

      result = 1;

    }

    else if( result == Z_DATA_ERROR )

    {

#if defined( HAVE_DEBUG_OUTPUT )

      if( libcnotify_verbose != 0 )

      {

        libcnotify_printf(

         "%s: unable to read compressed data: data error.\n",

         function );

      }

#endif

      *uncompressed_data_size = 0;

      result = -1;

    }

    else if( result == Z_BUF_ERROR )

    {

#if defined( HAVE_DEBUG_OUTPUT )

      if( libcnotify_verbose != 0 )

      {

        libcnotify_printf(

        "%s: unable to read compressed data: target buffer too small.\n",

         function );

      }

#endif

      /* Estimate that a factor 2 enlargement should suffice

       */

      *uncompressed_data_size *= 2;

      result = 0;

    }

    else if( result == Z_MEM_ERROR )

    {

      libcerror_error_set(

       error,

       LIBCERROR_ERROR_DOMAIN_MEMORY,

       LIBCERROR_MEMORY_ERROR_INSUFFICIENT,

       "%s: unable to read compressed data: insufficient memory.",

       function );

      *uncompressed_data_size = 0;

      result = -1;

    }

    else

    {

      libcerror_error_set(

       error,

       LIBCERROR_ERROR_DOMAIN_COMPRESSION,

       LIBCERROR_COMPRESSION_ERROR_DECOMPRESS_FAILED,

       "%s: zlib returned undefined error: %d.",

       function,

       result );

      *uncompressed_data_size = 0;

      result = -1;

    }

#else

    result = libfsapfs_deflate_decompress_zlib(

        compressed_data,

        compressed_data_size,

        uncompressed_data,

        uncompressed_data_size,

        error );

    if( result != 1 )

    {

      libcerror_error_set(

       error,

       LIBCERROR_ERROR_DOMAIN_ENCRYPTION,

       LIBCERROR_ENCRYPTION_ERROR_GENERIC,

       "%s: unable to decompress DEFLATE compressed data.",

       function );

      return( -1 );

    }

#endif /* ( defined( HAVE_ZLIB ) && defined( HAVE_ZLIB_UNCOMPRESS ) ) || defined( ZLIB_DLL ) */

  }

  else if( compression_method == LIBFSAPFS_COMPRESSION_METHOD_LZFSE )

  {

    result = libfmos_lzfse_decompress(

              compressed_data,

              compressed_data_size,

              uncompressed_data,

              uncompressed_data_size,

              error );

    if( result != 1 )

    {

      libcerror_error_set(

       error,

       LIBCERROR_ERROR_DOMAIN_ENCRYPTION,

       LIBCERROR_ENCRYPTION_ERROR_GENERIC,

       "%s: unable to decompress LZFSE compressed data.",

       function );

      return( -1 );

    }

  }

  else if( compression_method == LIBFSAPFS_COMPRESSION_METHOD_LZVN )

  {

    result = libfmos_lzvn_decompress(

        compressed_data,

        compressed_data_size,

        uncompressed_data,

        uncompressed_data_size,

        error );

    if( result != 1 )

    {

      libcerror_error_set(

       error,

       LIBCERROR_ERROR_DOMAIN_ENCRYPTION,

       LIBCERROR_ENCRYPTION_ERROR_GENERIC,

       "%s: unable to decompress LZVN compressed data.",

       function );

      return( -1 );

    }

  }

  else if( compression_method == LIBFSAPFS_COMPRESSION_METHOD_RAW )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_RUNTIME,

     LIBCERROR_RUNTIME_ERROR_UNSUPPORTED_VALUE,

     "%s: invalid raw compressed data - unsupported marker byte.",

     function );

    return( -1 );

  }

  else

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_RUNTIME,

     LIBCERROR_RUNTIME_ERROR_UNSUPPORTED_VALUE,

     "%s: unsupported compression method.",

     function );

    return( -1 );

  }

  return( result );

}