/*

 * Page functions

 *

 * Copyright (C) 2009-2024, 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 "libesedb_checksum.h"

#include "libesedb_debug.h"

#include "libesedb_definitions.h"

#include "libesedb_libbfio.h"

#include "libesedb_libcdata.h"

#include "libesedb_libcerror.h"

#include "libesedb_libcnotify.h"

#include "libesedb_page.h"

#include "libesedb_page_header.h"

#include "libesedb_page_value.h"

#include "esedb_page.h"

/* Creates a page

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

 * Returns 1 if successful or -1 on error

 */

int libesedb_page_initialize(

     libesedb_page_t **page,

     libcerror_error_t **error )

{

  static char *function = "libesedb_page_initialize";

  if( page == NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,

     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,

     "%s: invalid page.",

     function );

    return( -1 );

  }

  if( *page != NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_RUNTIME,

     LIBCERROR_RUNTIME_ERROR_VALUE_ALREADY_SET,

     "%s: invalid page value already set.",

     function );

    return( -1 );

  }

  *page = memory_allocate_structure(

           libesedb_page_t );

  if( *page == NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_MEMORY,

     LIBCERROR_MEMORY_ERROR_INSUFFICIENT,

     "%s: unable to create page.",

     function );

    goto on_error;

  }

  if( memory_set(

       *page,

       0,

       sizeof( libesedb_page_t ) ) == NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_MEMORY,

     LIBCERROR_MEMORY_ERROR_SET_FAILED,

     "%s: unable to clear page.",

     function );

    memory_free(

     *page );

    *page = NULL;

    return( -1 );

  }

  if( libesedb_page_header_initialize(

       &( ( *page )->header ),

       error ) != 1 )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_RUNTIME,

     LIBCERROR_RUNTIME_ERROR_INITIALIZE_FAILED,

     "%s: unable to create header.",

     function );

    goto on_error;

  }

  if( libcdata_array_initialize(

       &( ( *page )->values_array ),

       0,

       error ) != 1 )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_RUNTIME,

     LIBCERROR_RUNTIME_ERROR_INITIALIZE_FAILED,

     "%s: unable to create values array.",

     function );

    goto on_error;

  }

  return( 1 );

on_error:

  if( *page != NULL )

  {

    if( ( *page )->header != NULL )

    {

      libesedb_page_header_free(

       &( ( *page )->header ),

       NULL );

    }

    memory_free(

     *page );

    *page = NULL;

  }

  return( -1 );

}

/* Frees a page

 * Returns 1 if successful or -1 on error

 */

int libesedb_page_free(

     libesedb_page_t **page,

     libcerror_error_t **error )

{

  static char *function = "libesedb_page_free";

  int result            = 1;

  if( page == NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,

     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,

     "%s: invalid page.",

     function );

    return( -1 );

  }

  if( *page != NULL )

  {

    if( libesedb_page_header_free(

         &( ( *page )->header ),

         error ) != 1 )

    {

      libcerror_error_set(

       error,

       LIBCERROR_ERROR_DOMAIN_RUNTIME,

       LIBCERROR_RUNTIME_ERROR_FINALIZE_FAILED,

       "%s: unable to free header.",

       function );

      result = -1;

    }

    if( libcdata_array_free(

         &( ( *page )->values_array ),

         (int (*)(intptr_t **, libcerror_error_t **)) &libesedb_page_value_free,

         error ) != 1 )

    {

      libcerror_error_set(

       error,

       LIBCERROR_ERROR_DOMAIN_RUNTIME,

       LIBCERROR_RUNTIME_ERROR_FINALIZE_FAILED,

       "%s: unable to free values array.",

       function );

      result = -1;

    }

    if( ( *page )->data != NULL )

    {

      memory_free(

       ( *page )->data );

    }

    memory_free(

     *page );

    *page = NULL;

  }

  return( result );

}

/* Calculates the page checksums

 * Returns 1 if successful, 0 if page is empty or -1 on error

 */

int libesedb_page_calculate_checksums(

     libesedb_page_t *page,

     libesedb_io_handle_t *io_handle,

     const uint8_t *page_data,

     size_t page_data_size,

     uint32_t *ecc32_checksum,

     uint32_t *xor32_checksum,

     libcerror_error_t **error )

{

  static char *function = "libesedb_page_calculate_checksums";

  if( page == NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,

     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,

     "%s: invalid page.",

     function );

    return( -1 );

  }

  if( page_data == NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_RUNTIME,

     LIBCERROR_RUNTIME_ERROR_VALUE_MISSING,

     "%s: invalid page data.",

     function );

    return( -1 );

  }

  if( ( page_data_size < 4 )

   || ( page_data_size > (size_t) SSIZE_MAX ) )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_RUNTIME,

     LIBCERROR_RUNTIME_ERROR_VALUE_OUT_OF_BOUNDS,

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

     function );

    return( -1 );

  }

  if( io_handle == NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,

     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,

     "%s: invalid IO handle.",

     function );

    return( -1 );

  }

/* TODO for now don't bother calculating checksums for uninitialized pages */

  if( ( page_data[ 0 ] == 0 )

   && ( page_data[ 1 ] == 0 )

   && ( page_data[ 2 ] == 0 )

   && ( page_data[ 3 ] == 0 ) )

  {

    return( 0 );

  }

  if( ( io_handle->format_revision >= LIBESEDB_FORMAT_REVISION_EXTENDED_PAGE_HEADER )

   && ( io_handle->page_size >= 16384 ) )

  {

/* TODO calculate checksum */

  }

  else if( ( io_handle->format_revision >= LIBESEDB_FORMAT_REVISION_NEW_RECORD_FORMAT )

        && ( ( page->header->flags & LIBESEDB_PAGE_FLAG_IS_NEW_RECORD_FORMAT ) != 0 ) )

  {

    if( libesedb_checksum_calculate_little_endian_ecc32(

         ecc32_checksum,

         xor32_checksum,

         page_data,

         page_data_size,

         8,

         page->page_number,

         error ) != 1 )

    {

      libcerror_error_set(

       error,

       LIBCERROR_ERROR_DOMAIN_RUNTIME,

       LIBCERROR_RUNTIME_ERROR_UNSUPPORTED_VALUE,

       "%s: unable to calculate ECC-32 and XOR-32 checksum.",

       function );

      return( -1 );

    }

  }

  else

  {

    if( libesedb_checksum_calculate_little_endian_xor32(

         xor32_checksum,

         &( page_data[ 4 ] ),

         page_data_size - 4,

         0x89abcdef,

         error ) != 1 )

    {

      libcerror_error_set(

       error,

       LIBCERROR_ERROR_DOMAIN_RUNTIME,

       LIBCERROR_RUNTIME_ERROR_UNSUPPORTED_VALUE,

       "%s: unable to calculate XOR-32 checksum.",

       function );

      return( -1 );

    }

  }

  return( 1 );

}

/* Reads the page tags

 * Returns 1 if successful or -1 on error

 */

int libesedb_page_read_tags(

     libesedb_page_t *page,

     libesedb_io_handle_t *io_handle,

     const uint8_t *page_data,

     size_t page_data_size,

     uint16_t number_of_page_tags,

     libcerror_error_t **error )

{

  libesedb_page_value_t *page_value = NULL;

  const uint8_t *page_tags_data     = NULL;

  static char *function             = "libesedb_page_read_tags";

  size_t page_tags_data_size        = 0;

  uint16_t page_tag_offset          = 0;

  uint16_t page_tag_size            = 0;

  uint16_t page_tags_index          = 0;

  if( page == NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,

     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,

     "%s: invalid page.",

     function );

    return( -1 );

  }

  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( page_data == NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_RUNTIME,

     LIBCERROR_RUNTIME_ERROR_VALUE_MISSING,

     "%s: invalid page data.",

     function );

    return( -1 );

  }

  if( ( page_data_size < 2 )

   || ( page_data_size > (size_t) SSIZE_MAX ) )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_RUNTIME,

     LIBCERROR_RUNTIME_ERROR_VALUE_OUT_OF_BOUNDS,

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

     function );

    return( -1 );

  }

  page_tags_data_size = 4 * number_of_page_tags;

  if( page_tags_data_size > page_data_size )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_RUNTIME,

     LIBCERROR_RUNTIME_ERROR_VALUE_OUT_OF_BOUNDS,

     "%s: invalid number of page tags value out of bounds.",

     function );

    goto on_error;

  }

#if defined( HAVE_DEBUG_OUTPUT )

  if( libcnotify_verbose != 0 )

  {

    libcnotify_printf(

     "%s: page tags:\n",

     function );

    libcnotify_print_data(

     &( page_data[ page_data_size - page_tags_data_size ] ),

     page_tags_data_size,

     LIBCNOTIFY_PRINT_DATA_FLAG_GROUP_DATA );

  }

#endif

  if( libcdata_array_resize(

       page->values_array,

       number_of_page_tags,

       (int (*)(intptr_t **, libcerror_error_t **)) &libesedb_page_value_free,

       error ) != 1 )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_RUNTIME,

     LIBCERROR_RUNTIME_ERROR_RESIZE_FAILED,

     "%s: unable to resize page values array.",

     function );

    goto on_error;

  }

  /* Read the page tags back to front

   */

  page_tags_data = &( page_data[ page_data_size - 2 ] );

  for( page_tags_index = 0;

       page_tags_index < number_of_page_tags;

       page_tags_index++ )

  {

    if( libesedb_page_value_initialize(

         &page_value,

         error ) != 1 )

    {

      libcerror_error_set(

       error,

       LIBCERROR_ERROR_DOMAIN_RUNTIME,

       LIBCERROR_RUNTIME_ERROR_INITIALIZE_FAILED,

       "%s: unable to create page value.",

       function );

      goto on_error;

    }

    byte_stream_copy_to_uint16_little_endian(

     page_tags_data,

     page_tag_offset );

    page_tags_data -= 2;

    byte_stream_copy_to_uint16_little_endian(

     page_tags_data,

     page_tag_size );

    page_tags_data -= 2;

    if( ( io_handle->format_revision >= LIBESEDB_FORMAT_REVISION_EXTENDED_PAGE_HEADER )

     && ( io_handle->page_size >= 16384 ) )

    {

      page_value->flags  = 0;

      page_value->offset = page_tag_offset & 0x7fff;

      page_value->size   = page_tag_size & 0x7fff;;

    }

    else

    {

      page_value->flags  = page_tag_offset >> 13;

      page_value->offset = page_tag_offset & 0x1fff;

      page_value->size   = page_tag_size & 0x1fff;

    }

#if defined( HAVE_DEBUG_OUTPUT )

    if( libcnotify_verbose != 0 )

    {

      libcnotify_printf(

       "%s: page tag: %03" PRIu16 " offset\t\t\t\t: %" PRIu16 " (0x%04" PRIx16 ")\n",

       function,

       page_tags_index,

       page_value->offset,

       page_tag_offset );

      libcnotify_printf(

       "%s: page tag: %03" PRIu16 " size\t\t\t\t: %" PRIu16 " (0x%04" PRIx16 ")\n",

       function,

       page_tags_index,

       page_value->size,

       page_tag_size );

      if( ( io_handle->format_revision < LIBESEDB_FORMAT_REVISION_EXTENDED_PAGE_HEADER )

       && ( io_handle->page_size < 16384 ) )

      {

        libcnotify_printf(

         "%s: page tag: %03" PRIu16 " flags\t\t\t\t: 0x%02" PRIx8 "",

         function,

         page_tags_index,

         page_value->flags );

        libesedb_debug_print_page_tag_flags(

         page_value->flags );

        libcnotify_printf(

         "\n" );

      }

    }

#endif /* defined( HAVE_DEBUG_OUTPUT ) */

    if( libcdata_array_set_entry_by_index(

         page->values_array,

         (int) page_tags_index,

         (intptr_t *) page_value,

         error ) != 1 )

    {

      libcerror_error_set(

       error,

       LIBCERROR_ERROR_DOMAIN_RUNTIME,

       LIBCERROR_RUNTIME_ERROR_SET_FAILED,

       "%s: unable to set page value: %" PRIu16 ".",

       function,

       page_tags_index );

      goto on_error;

    }

    page_value = NULL;

  }

#if defined( HAVE_DEBUG_OUTPUT )

  if( libcnotify_verbose != 0 )

  {

    libcnotify_printf(

     "\n" );

  }

#endif

  return( 1 );

on_error:

  if( page_value != NULL )

  {

    libesedb_page_value_free(

     &page_value,

     NULL );

  }

  libcdata_array_empty(

   page->values_array,

   (int (*)(intptr_t **, libcerror_error_t **)) &libesedb_page_value_free,

   NULL );

  return( -1 );

}

/* Reads the page values

 * Returns 1 if successful or -1 on error

 */

int libesedb_page_read_values(

     libesedb_page_t *page,

     libesedb_io_handle_t *io_handle,

     uint8_t *page_data,

     size_t page_data_size,

     size_t page_values_data_offset,

     libcerror_error_t **error )

{

  libesedb_page_value_t *page_value = NULL;

  uint8_t *page_values_data         = NULL;

  static char *function             = "libesedb_page_read_values";

  size_t page_tags_data_size        = 0;

  size_t page_values_data_size      = 0;

  uint16_t number_of_page_tags      = 0;

  uint16_t page_tags_index          = 0;

  if( page == NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,

     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,

     "%s: invalid page.",

     function );

    return( -1 );

  }

  if( page_data == NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_RUNTIME,

     LIBCERROR_RUNTIME_ERROR_VALUE_MISSING,

     "%s: invalid page data.",

     function );

    return( -1 );

  }

  if( page_data_size > (size_t) SSIZE_MAX )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_RUNTIME,

     LIBCERROR_RUNTIME_ERROR_VALUE_OUT_OF_BOUNDS,

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

     function );

    return( -1 );

  }

  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( (size_t) page_values_data_offset >= page_data_size )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_RUNTIME,

     LIBCERROR_RUNTIME_ERROR_VALUE_OUT_OF_BOUNDS,

     "%s: invalid page values data offset value out of bounds.",

     function );

    return( -1 );

  }

  number_of_page_tags = page->header->available_page_tag;

  if( number_of_page_tags == 0 )

  {

    return( 1 );

  }

  if( libesedb_page_read_tags(

       page,

       io_handle,

       page_data,

       page_data_size,

       number_of_page_tags,

       error ) != 1 )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_IO,

     LIBCERROR_IO_ERROR_READ_FAILED,

     "%s: unable to read page tags.",

     function );

    goto on_error;

  }

  /* The offsets in the page tags are relative after the page header

   */

  page_values_data      = &( page_data[ page_values_data_offset ] );

  page_values_data_size = page_data_size - page_values_data_offset;

  page_tags_data_size   = 4 * number_of_page_tags;

  if( page_values_data_size < page_tags_data_size )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_RUNTIME,

     LIBCERROR_RUNTIME_ERROR_VALUE_OUT_OF_BOUNDS,

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

     function );

    goto on_error;

  }

  page_values_data_size -= page_tags_data_size;

#if defined( HAVE_DEBUG_OUTPUT )

  if( libcnotify_verbose != 0 )

  {

    libcnotify_printf(

     "%s: page values data:\n",

     function );

    libcnotify_print_data(

     page_values_data,

     page_values_data_size,

     LIBCNOTIFY_PRINT_DATA_FLAG_GROUP_DATA );

  }

#endif

  for( page_tags_index = 0;

       page_tags_index < number_of_page_tags;

       page_tags_index++ )

  {

    if( libcdata_array_get_entry_by_index(

         page->values_array,

         page_tags_index,

         (intptr_t **) &page_value,

         error ) != 1 )

    {

      libcerror_error_set(

       error,

       LIBCERROR_ERROR_DOMAIN_RUNTIME,

       LIBCERROR_RUNTIME_ERROR_GET_FAILED,

       "%s: unable to retrieve page value: %" PRIu16 ".",

       function,

       page_tags_index );

      goto on_error;

    }

    if( page_value == NULL )

    {

      libcerror_error_set(

       error,

       LIBCERROR_ERROR_DOMAIN_ARGUMENTS,

       LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,

       "%s: invalid page value.",

       function );

      goto on_error;

    }

    if( page_value->offset >= page_values_data_size )

    {

      libcerror_error_set(

       error,

       LIBCERROR_ERROR_DOMAIN_RUNTIME,

       LIBCERROR_RUNTIME_ERROR_VALUE_OUT_OF_BOUNDS,

       "%s: unsupported page tags value offset value out of bounds.",

       function );

#if defined( HAVE_DEBUG_OUTPUT )

      if( libcnotify_verbose != 0 )

      {

        libcnotify_printf(

         "%s: page value: %03" PRIu16 " offset: % 5" PRIu16 ", size: % 5" PRIu16 " (page value data size: %" PRIu16 ")\n",

         function,

         page_tags_index,

         page_value->offset,

         page_value->size,

         page_values_data_size );

      }

#endif

      goto on_error;

    }

    if( (size_t) page_value->size > ( page_values_data_size - page_value->offset ) )

    {

      libcerror_error_set(

       error,

       LIBCERROR_ERROR_DOMAIN_RUNTIME,

       LIBCERROR_RUNTIME_ERROR_VALUE_OUT_OF_BOUNDS,

       "%s: unsupported page tags value size value out of bounds.",

       function );

#if defined( HAVE_DEBUG_OUTPUT )

      if( libcnotify_verbose != 0 )

      {

        libcnotify_printf(

         "%s: page value: %03" PRIu16 " offset: % 5" PRIu16 ", size: % 5" PRIu16 " (page value data size: %" PRIu16 ")\n",

         function,

         page_tags_index,

         page_value->offset,

         page_value->size,

         page_values_data_size );

      }

#endif

      goto on_error;

    }

    if( ( io_handle->format_revision >= LIBESEDB_FORMAT_REVISION_EXTENDED_PAGE_HEADER )

     && ( io_handle->page_size >= 16384 ) )

    {

      if( page_value->size >= 2 )

      {

        /* The page tags flags are stored in the upper byte of the first 16-bit value

         */

        page_value->flags = page_values_data[ page_value->offset + 1 ] >> 5;

        page_values_data[ page_value->offset + 1 ] &= 0x1f;

      }

    }

#if defined( HAVE_DEBUG_OUTPUT )

    if( libcnotify_verbose != 0 )

    {

      libcnotify_printf(

       "%s: page value: %03" PRIu16 " offset: % 5" PRIu16 ", size: % 5" PRIu16 ", flags: 0x%02" PRIx8 "",

       function,

       page_tags_index,

       page_value->offset,

       page_value->size,

       page_value->flags );

      libesedb_debug_print_page_tag_flags(

       page_value->flags );

      libcnotify_printf(

       "\n" );

    }

#endif

    page_value->data    = &( page_values_data[ page_value->offset ] );

    page_value->offset += page_values_data_offset;

#if defined( HAVE_DEBUG_OUTPUT )

    if( libcnotify_verbose != 0 )

    {

      libcnotify_printf(

       "%s: page value: %" PRIu16 " data:\n",

       function,

       page_tags_index );

      libcnotify_print_data(

       page_value->data,

       page_value->size,

       LIBCNOTIFY_PRINT_DATA_FLAG_GROUP_DATA );

    }

#endif

  }

#if defined( HAVE_DEBUG_OUTPUT )

  if( libcnotify_verbose != 0 )

  {

    libcnotify_printf(

    "\n" );

  }

#endif

  return( 1 );

on_error:

  libcdata_array_empty(

   page->values_array,

   (int (*)(intptr_t **, libcerror_error_t **)) &libesedb_page_value_free,

   NULL );

  return( -1 );

}

/* Reads a page and its values

 * Returns 1 if successful or -1 on error

 */

int libesedb_page_read_file_io_handle(

     libesedb_page_t *page,

     libesedb_io_handle_t *io_handle,

     libbfio_handle_t *file_io_handle,

     off64_t file_offset,

     libcerror_error_t **error )

{

  static char *function              = "libesedb_page_read_file_io_handle";

  ssize_t read_count                 = 0;

  uint32_t calculated_ecc32_checksum = 0;

  uint32_t calculated_xor32_checksum = 0;

  int result                         = 0;

  if( page == NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,

     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,

     "%s: invalid page.",

     function );

    return( -1 );

  }

  if( page->data != NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_RUNTIME,

     LIBCERROR_RUNTIME_ERROR_VALUE_ALREADY_SET,

     "%s: invalid page data already set.",

     function );

    return( -1 );

  }

  if( io_handle == NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,

     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,

     "%s: invalid IO handle.",

     function );

    return( -1 );

  }

  page->page_number = (uint32_t) ( ( file_offset - io_handle->page_size ) / io_handle->page_size );

  page->offset      = file_offset;

#if defined( HAVE_DEBUG_OUTPUT )

  if( libcnotify_verbose != 0 )

  {

    libcnotify_printf(

     "%s: current page number\t\t\t: %" PRIu32 "\n",

     function,

     page->page_number );

    libcnotify_printf(

     "\n" );

  }

#endif

  page->data = (uint8_t *) memory_allocate(

                            (size_t) io_handle->page_size );

  if( page->data == NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_MEMORY,

     LIBCERROR_MEMORY_ERROR_INSUFFICIENT,

     "%s: unable to create page data.",

     function );

    goto on_error;

  }

  page->data_size = (size_t) io_handle->page_size;

#if defined( HAVE_DEBUG_OUTPUT )

  if( libcnotify_verbose != 0 )

  {

    libcnotify_printf(

     "%s: reading page: %" PRIu32 " at offset: %" PRIi64 " (0x%08" PRIx64 ")\n",

     function,

     page->page_number,

     page->offset,

     page->offset );

  }

#endif

  read_count = libbfio_handle_read_buffer_at_offset(

                file_io_handle,

                page->data,

                page->data_size,

                page->offset,

                error );

  if( read_count != (ssize_t) page->data_size )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_IO,

     LIBCERROR_IO_ERROR_READ_FAILED,

     "%s: unable to read page: %" PRIu32 " data at offset: %" PRIi64 " (0x%08" PRIx64 ").",

     function,

     page->page_number,

     page->offset,

     page->offset );

    goto on_error;

  }

  if( libesedb_page_header_read_data(

       page->header,

       io_handle,

       page->data,

       page->data_size,

       error ) != 1 )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_IO,

     LIBCERROR_IO_ERROR_READ_FAILED,

     "%s: unable to read page header.",

     function );

    goto on_error;

  }

  result = libesedb_page_calculate_checksums(

            page,

            io_handle,

            page->data,

            page->data_size,

            &calculated_ecc32_checksum,

            &calculated_xor32_checksum,

            error );

  if( result == -1 )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_RUNTIME,

     LIBCERROR_RUNTIME_ERROR_UNSUPPORTED_VALUE,

     "%s: unable to calculate page checksums.",

     function );

    goto on_error;

  }

  else if( result != 0 )

  {

    if( page->header->xor32_checksum != calculated_xor32_checksum )

    {

#ifdef TODO

      libcerror_error_set(

       error,

       LIBCERROR_ERROR_DOMAIN_INPUT,

       LIBCERROR_INPUT_ERROR_CRC_MISMATCH,

       "%s: mismatch in page XOR-32 checksum ( 0x%08" PRIx32 " != 0x%08" PRIx32 " ).",

       function,

       page->header->xor32_checksum,

       calculated_xor32_checksum );

      goto on_error;

#else

      if( libcnotify_verbose != 0 )

      {

        libcnotify_printf(