/*

 * LZFSE bit-stream functions

 *

 * Copyright (C) 2019-2024, 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 "libfmos_libcerror.h"

#include "libfmos_libcnotify.h"

#include "libfmos_lzfse_bit_stream.h"

/* Creates a bit stream

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

 * Returns 1 if successful or -1 on error

 */

int libfmos_lzfse_bit_stream_initialize(

     libfmos_lzfse_bit_stream_t **bit_stream,

     const uint8_t *byte_stream,

     size_t byte_stream_size,

     libcerror_error_t **error )

{

  static char *function = "libfmos_lzfse_bit_stream_initialize";

  if( bit_stream == NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,

     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,

     "%s: invalid bit stream.",

     function );

    return( -1 );

  }

  if( *bit_stream != NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_RUNTIME,

     LIBCERROR_RUNTIME_ERROR_VALUE_ALREADY_SET,

     "%s: invalid bit stream value already set.",

     function );

    return( -1 );

  }

  if( byte_stream == NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,

     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,

     "%s: invalid byte stream.",

     function );

    return( -1 );

  }

  if( byte_stream_size > (size_t) SSIZE_MAX )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,

     LIBCERROR_ARGUMENT_ERROR_VALUE_EXCEEDS_MAXIMUM,

     "%s: invalid byte stream size value exceeds maximum.",

     function );

    return( -1 );

  }

  *bit_stream = memory_allocate_structure(

                 libfmos_lzfse_bit_stream_t );

  if( *bit_stream == NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_MEMORY,

     LIBCERROR_MEMORY_ERROR_INSUFFICIENT,

     "%s: unable to create bit stream.",

     function );

    goto on_error;

  }

  if( memory_set(

       *bit_stream,

       0,

       sizeof( libfmos_lzfse_bit_stream_t ) ) == NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_MEMORY,

     LIBCERROR_MEMORY_ERROR_SET_FAILED,

     "%s: unable to clear bit stream.",

     function );

    goto on_error;

  }

  ( *bit_stream )->byte_stream        = byte_stream;

  ( *bit_stream )->byte_stream_size   = byte_stream_size;

  ( *bit_stream )->byte_stream_offset = byte_stream_size;

  return( 1 );

on_error:

  if( *bit_stream != NULL )

  {

    memory_free(

     *bit_stream );

    *bit_stream = NULL;

  }

  return( -1 );

}

/* Frees a bit stream

 * Returns 1 if successful or -1 on error

 */

int libfmos_lzfse_bit_stream_free(

     libfmos_lzfse_bit_stream_t **bit_stream,

     libcerror_error_t **error )

{

  static char *function = "libfmos_lzfse_bit_stream_free";

  if( bit_stream == NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,

     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,

     "%s: invalid bit stream.",

     function );

    return( -1 );

  }

  if( *bit_stream != NULL )

  {

    memory_free(

     *bit_stream );

    *bit_stream = NULL;

  }

  return( 1 );

}

/* Retrieves a value from the bit stream

 * Returns 1 on success or -1 on error

 */

int libfmos_lzfse_bit_stream_get_value(

     libfmos_lzfse_bit_stream_t *bit_stream,

     uint8_t number_of_bits,

     uint32_t *value_32bit,

     libcerror_error_t **error )

{

  static char *function            = "libfmos_lzfse_bit_stream_get_value";

  uint32_t read_value_32bit        = 0;

  uint32_t safe_value_32bit        = 0;

  uint8_t read_number_of_bits      = 0;

  uint8_t remaining_number_of_bits = 0;

  if( bit_stream == NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,

     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,

     "%s: invalid bit stream.",

     function );

    return( -1 );

  }

  if( number_of_bits > (uint8_t) 32 )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,

     LIBCERROR_ARGUMENT_ERROR_VALUE_EXCEEDS_MAXIMUM,

     "%s: invalid number of bits value exceeds maximum.",

     function );

    return( -1 );

  }

  if( value_32bit == NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,

     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,

     "%s: invalid 32-bit value.",

     function );

    return( -1 );

  }

  remaining_number_of_bits = number_of_bits;

  while( remaining_number_of_bits > 0 )

  {

    while( ( remaining_number_of_bits > bit_stream->bit_buffer_size )

        && ( bit_stream->bit_buffer_size <= 24 ) )

    {

      if( bit_stream->byte_stream_offset == 0 )

      {

        libcerror_error_set(

         error,

         LIBCERROR_ERROR_DOMAIN_RUNTIME,

         LIBCERROR_RUNTIME_ERROR_VALUE_OUT_OF_BOUNDS,

         "%s: invalid byte stream offset value out of bounds.",

         function );

        return( -1 );

      }

      bit_stream->byte_stream_offset -= 1;

      bit_stream->bit_buffer     <<= 8;

      bit_stream->bit_buffer      |= bit_stream->byte_stream[ bit_stream->byte_stream_offset ];

      bit_stream->bit_buffer_size += 8;

    }

    if( remaining_number_of_bits < bit_stream->bit_buffer_size )

    {

      read_number_of_bits = remaining_number_of_bits;

    }

    else

    {

      read_number_of_bits = bit_stream->bit_buffer_size;

    }

    read_value_32bit = bit_stream->bit_buffer;

    if( remaining_number_of_bits < number_of_bits )

    {

      safe_value_32bit <<= remaining_number_of_bits;

    }

    bit_stream->bit_buffer_size -= read_number_of_bits;

    read_value_32bit           >>= bit_stream->bit_buffer_size;

    if( bit_stream->bit_buffer_size > 0 )

    {

      bit_stream->bit_buffer &= 0xffffffffUL >> ( 32 - bit_stream->bit_buffer_size );

    }

    else

    {

      bit_stream->bit_buffer = 0;

    }

    safe_value_32bit         |= read_value_32bit;

    remaining_number_of_bits -= read_number_of_bits;

  }

  *value_32bit = safe_value_32bit;

  return( 1 );

}