/*

 * Input/Output (IO) handle functions

 *

 * Copyright (C) 2014-2026, 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 <byte_stream.h>

#include <memory.h>

#include <types.h>

#include "libagdb_debug.h"

#include "libagdb_definitions.h"

#include "libagdb_io_handle.h"

#include "libagdb_libbfio.h"

#include "libagdb_libcerror.h"

#include "libagdb_libcnotify.h"

#include "libagdb_libfcache.h"

#include "libagdb_libfdata.h"

#include "libagdb_unused.h"

const char *agdb_mem_file_signature_vista  = "MEMO";

const char *agdb_mem_file_signature_win7   = "MEM0";

const char *agdb_mem_file_signature_win8_0 = "MEM\xb0";

const char *agdb_mam_file_signature_win8_1 = "MAM\x84";

/* Creates an IO handle

 * Make sure the value io_handle is referencing, is set to NULL

 * Returns 1 if successful or -1 on error

 */

int libagdb_io_handle_initialize(

     libagdb_io_handle_t **io_handle,

     libcerror_error_t **error )

{

  static char *function = "libagdb_io_handle_initialize";

  if( io_handle == NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,

     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,

     "%s: invalid IO handle.",

     function );

    return( -1 );

  }

  if( *io_handle != NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_RUNTIME,

     LIBCERROR_RUNTIME_ERROR_VALUE_ALREADY_SET,

     "%s: invalid IO handle value already set.",

     function );

    return( -1 );

  }

  *io_handle = memory_allocate_structure(

                libagdb_io_handle_t );

  if( *io_handle == NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_MEMORY,

     LIBCERROR_MEMORY_ERROR_INSUFFICIENT,

     "%s: unable to create IO handle.",

     function );

    goto on_error;

  }

  if( memory_set(

       *io_handle,

       0,

       sizeof( libagdb_io_handle_t ) ) == NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_MEMORY,

     LIBCERROR_MEMORY_ERROR_SET_FAILED,

     "%s: unable to clear file.",

     function );

    goto on_error;

  }

  return( 1 );

on_error:

  if( *io_handle != NULL )

  {

    memory_free(

     *io_handle );

    *io_handle = NULL;

  }

  return( -1 );

}

/* Frees a IO handle

 * Returns 1 if successful or -1 on error

 */

int libagdb_io_handle_free(

     libagdb_io_handle_t **io_handle,

     libcerror_error_t **error )

{

  static char *function = "libagdb_io_handle_free";

  if( io_handle == NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,

     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,

     "%s: invalid IO handle.",

     function );

    return( -1 );

  }

  if( *io_handle != NULL )

  {

    memory_free(

     *io_handle );

    *io_handle = NULL;

  }

  return( 1 );

}

/* Clears the IO handle

 * Returns 1 if successful or -1 on error

 */

int libagdb_io_handle_clear(

     libagdb_io_handle_t *io_handle,

     libcerror_error_t **error )

{

  static char *function = "libagdb_io_handle_clear";

  if( io_handle == NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,

     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,

     "%s: invalid IO handle.",

     function );

    return( -1 );

  }

  if( memory_set(

       io_handle,

       0,

       sizeof( libagdb_io_handle_t ) ) == NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_MEMORY,

     LIBCERROR_MEMORY_ERROR_SET_FAILED,

     "%s: unable to clear IO handle.",

     function );

    return( -1 );

  }

  return( 1 );

}

/* Reads the compressed blocks

 * Returns 1 if successful or -1 on error

 */

int libagdb_io_handle_read_compressed_blocks(

     libagdb_io_handle_t *io_handle,

     libbfio_handle_t *file_io_handle,

     libfdata_list_t *compressed_blocks_list,

     libcerror_error_t **error )

{

  uint8_t compressed_block_data[ 4 ];

  static char *function            = "libagdb_io_handle_read_compressed_blocks";

  off64_t file_offset              = 0;

  size_t read_size                 = 0;

  ssize_t read_count               = 0;

  uint32_t compressed_block_size   = 0;

  uint32_t uncompressed_data_size  = 0;

  uint32_t uncompressed_block_size = 0;

  int compressed_block_index       = 0;

  int element_index                = 0;

  if( io_handle == NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,

     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,

     "%s: invalid IO handle.",

     function );

    return( -1 );

  }

  if( ( io_handle->file_type != LIBAGDB_FILE_TYPE_COMPRESSED_VISTA )

   && ( io_handle->file_type != LIBAGDB_FILE_TYPE_COMPRESSED_WINDOWS7 )

   && ( io_handle->file_type != LIBAGDB_FILE_TYPE_COMPRESSED_WINDOWS8_0 )

   && ( io_handle->file_type != LIBAGDB_FILE_TYPE_COMPRESSED_WINDOWS8_1 ) )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_RUNTIME,

     LIBCERROR_RUNTIME_ERROR_UNSUPPORTED_VALUE,

     "%s: invalid IO handle - unsupported file type.",

     function );

    return( -1 );

  }

  if( io_handle->file_type == LIBAGDB_FILE_TYPE_COMPRESSED_VISTA )

  {

    file_offset = 8;

    read_size   = 2;

  }

  else if( io_handle->file_type == LIBAGDB_FILE_TYPE_COMPRESSED_WINDOWS7 )

  {

    file_offset = 8;

    read_size   = 4;

  }

  else if( io_handle->file_type == LIBAGDB_FILE_TYPE_COMPRESSED_WINDOWS8_0 )

  {

    file_offset = 12;

    read_size   = 4;

  }

  else if( io_handle->file_type == LIBAGDB_FILE_TYPE_COMPRESSED_WINDOWS8_1 )

  {

    file_offset = 12;

    read_size   = 4;

  }

  uncompressed_data_size = io_handle->uncompressed_data_size;

  while( (size64_t) file_offset < io_handle->file_size )

  {

#if defined( HAVE_DEBUG_OUTPUT )

    if( libcnotify_verbose != 0 )

    {

      libcnotify_printf(

       "%s: reading compressed data block at offset: %" PRIi64 " (0x%08" PRIx64 ")\n",

       function,

       file_offset,

       file_offset );

    }

#endif

    read_count = libbfio_handle_read_buffer_at_offset(

                  file_io_handle,

                  compressed_block_data,

                  read_size,

                  file_offset,

                  error );

    if( read_count != (ssize_t) read_size )

    {

      libcerror_error_set(

       error,

       LIBCERROR_ERROR_DOMAIN_IO,

       LIBCERROR_IO_ERROR_READ_FAILED,

       "%s: unable to read compressed block data at offset: %" PRIi64 " (0x%08" PRIx64 ").",

       function,

       file_offset,

       file_offset );

      return( -1 );

    }

    if( io_handle->file_type == LIBAGDB_FILE_TYPE_COMPRESSED_VISTA )

    {

      byte_stream_copy_to_uint16_little_endian(

       compressed_block_data,

       compressed_block_size );

      compressed_block_size &= 0x0fff;

      if( compressed_block_size == 0 )

      {

        libcerror_error_set(

         error,

         LIBCERROR_ERROR_DOMAIN_RUNTIME,

         LIBCERROR_RUNTIME_ERROR_VALUE_OUT_OF_BOUNDS,

         "%s: invalid compressed block size value out of bounds.",

         function );

        return( -1 );

      }

      compressed_block_size += 3;

      uncompressed_block_size = io_handle->uncompressed_block_size;

    }

    else if( ( io_handle->file_type == LIBAGDB_FILE_TYPE_COMPRESSED_WINDOWS7 )

          || ( io_handle->file_type == LIBAGDB_FILE_TYPE_COMPRESSED_WINDOWS8_0 ) )

    {

      byte_stream_copy_to_uint32_little_endian(

       compressed_block_data,

       compressed_block_size );

      file_offset += 4;

      uncompressed_block_size = io_handle->uncompressed_block_size;

    }

    else if( io_handle->file_type == LIBAGDB_FILE_TYPE_COMPRESSED_WINDOWS8_1 )

    {

      if( io_handle->file_size > (size64_t) UINT32_MAX )

      {

        libcerror_error_set(

         error,

         LIBCERROR_ERROR_DOMAIN_RUNTIME,

         LIBCERROR_RUNTIME_ERROR_VALUE_OUT_OF_BOUNDS,

         "%s: invalid compressed block size value out of bounds.",

         function );

        return( -1 );

      }

      compressed_block_size = (uint32_t) io_handle->file_size - 12;

      if( ( uncompressed_data_size % io_handle->uncompressed_block_size ) != 0 )

      {

        uncompressed_data_size /= io_handle->uncompressed_block_size;

        uncompressed_data_size += 1;

        uncompressed_data_size *= io_handle->uncompressed_block_size;

      }

      uncompressed_block_size = uncompressed_data_size;

    }

    if( uncompressed_data_size < uncompressed_block_size )

    {

      uncompressed_block_size = uncompressed_data_size;

    }

    else

    {

      uncompressed_block_size = uncompressed_block_size;

    }

#if defined( HAVE_DEBUG_OUTPUT )

    if( libcnotify_verbose != 0 )

    {

      libcnotify_printf(

       "%s: compressed block: %d size\t: %" PRIu32 "\n",

       function,

       compressed_block_index,

       compressed_block_size );

    }

#endif

    if( compressed_block_size == 0 )

    {

      libcerror_error_set(

       error,

       LIBCERROR_ERROR_DOMAIN_RUNTIME,

       LIBCERROR_RUNTIME_ERROR_VALUE_OUT_OF_BOUNDS,

       "%s: invalid compressed block size value out of bounds.",

       function );

      return( -1 );

    }

    if( libfdata_list_append_element_with_mapped_size(

         compressed_blocks_list,

         &element_index,

         0,

         file_offset,

         (size64_t) compressed_block_size,

         LIBFDATA_RANGE_FLAG_IS_COMPRESSED,

         uncompressed_block_size,

         error ) != 1 )

    {

      libcerror_error_set(

       error,

       LIBCERROR_ERROR_DOMAIN_RUNTIME,

       LIBCERROR_RUNTIME_ERROR_APPEND_FAILED,

       "%s: unable to append compressed block: %d to list.",

       function,

       compressed_block_index );

      return( -1 );

    }

    file_offset            += compressed_block_size;

    uncompressed_data_size -= uncompressed_block_size;

    if( uncompressed_data_size == 0 )

    {

      break;

    }

    compressed_block_index++;

  }

#if defined( HAVE_DEBUG_OUTPUT )

  if( libcnotify_verbose != 0 )

  {

    if( (size64_t) file_offset < io_handle->file_size )

    {

      libcnotify_printf(

       "%s: trailing data size\t: %" PRIu64 "\n",

       function,

       io_handle->file_size - (size64_t) file_offset );

    }

  }

#endif /* defined( HAVE_DEBUG_OUTPUT ) */

  return( 1 );

}

/* Reads data from the current offset into a buffer

 * Callback for the uncompressed block stream

 * Returns the number of bytes read or -1 on error

 */

ssize_t libagdb_io_handle_read_segment_data(

         intptr_t *data_handle LIBAGDB_ATTRIBUTE_UNUSED,

         intptr_t *file_io_handle,

         int segment_index,

         int segment_file_index LIBAGDB_ATTRIBUTE_UNUSED,

         uint8_t *segment_data,

         size_t segment_data_size,

         uint32_t segment_flags LIBAGDB_ATTRIBUTE_UNUSED,

         uint8_t read_flags LIBAGDB_ATTRIBUTE_UNUSED,

         libcerror_error_t **error )

{

  static char *function = "libagdb_io_handle_read_segment_data";

  ssize_t read_count    = 0;

  LIBAGDB_UNREFERENCED_PARAMETER( data_handle )

  LIBAGDB_UNREFERENCED_PARAMETER( segment_file_index )

  LIBAGDB_UNREFERENCED_PARAMETER( segment_flags )

  LIBAGDB_UNREFERENCED_PARAMETER( read_flags )

  if( segment_data_size > (size64_t) SSIZE_MAX )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,

     LIBCERROR_ARGUMENT_ERROR_VALUE_OUT_OF_BOUNDS,

     "%s: invalid segment data size value out of bounds.",

     function );

    return( -1 );

  }

  read_count = libbfio_handle_read_buffer(

                (libbfio_handle_t *) file_io_handle,

                segment_data,

                segment_data_size,

                error );

  if( read_count != (ssize_t) segment_data_size )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_IO,

     LIBCERROR_IO_ERROR_READ_FAILED,

     "%s: unable to read segment: %d data.",

     function,

     segment_index );

    return( -1 );

  }

  return( read_count );

}

/* Seeks a certain offset of the data

 * Callback for the uncompressed block stream

 * Returns the offset if seek is successful or -1 on error

 */

off64_t libagdb_io_handle_seek_segment_offset(

         intptr_t *data_handle LIBAGDB_ATTRIBUTE_UNUSED,

         intptr_t *file_io_handle,

         int segment_index,

         int segment_file_index LIBAGDB_ATTRIBUTE_UNUSED,

         off64_t segment_offset,

         libcerror_error_t **error )

{

  static char *function = "libagdb_io_handle_seek_segment_offset";

  LIBAGDB_UNREFERENCED_PARAMETER( data_handle )

  LIBAGDB_UNREFERENCED_PARAMETER( segment_file_index )

  if( libbfio_handle_seek_offset(

       (libbfio_handle_t *) file_io_handle,

       segment_offset,

       SEEK_SET,

       error ) == -1 )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_IO,

     LIBCERROR_IO_ERROR_SEEK_FAILED,

     "%s: unable to seek segment: %d offset: %" PRIi64 ".",

     function,

     segment_index,

     segment_offset );

    return( -1 );

  }

  return( segment_offset );

}