// SPDX-License-Identifier: 0BSD

///////////////////////////////////////////////////////////////////////////////

//

/// \file       stream_flags_encoder.c

/// \brief      Encodes Stream Header and Stream Footer for .xz files

//

//  Author:     Lasse Collin

//

///////////////////////////////////////////////////////////////////////////////

#include "stream_flags_common.h"

static bool

stream_flags_encode(const lzma_stream_flags *options, uint8_t *out)

{

  if ((unsigned int)(options->check) > LZMA_CHECK_ID_MAX)

    return true;

  out[0] = 0x00;

  out[1] = options->check;

  return false;

}

extern LZMA_API(lzma_ret)

lzma_stream_header_encode(const lzma_stream_flags *options, uint8_t *out)

{

  assert(sizeof(lzma_header_magic) + LZMA_STREAM_FLAGS_SIZE

      + 4 == LZMA_STREAM_HEADER_SIZE);

  if (options->version != 0)

    return LZMA_OPTIONS_ERROR;

  // Magic

  memcpy(out, lzma_header_magic, sizeof(lzma_header_magic));

  // Stream Flags

  if (stream_flags_encode(options, out + sizeof(lzma_header_magic)))

    return LZMA_PROG_ERROR;

  // CRC32 of the Stream Header

  const uint32_t crc = lzma_crc32(out + sizeof(lzma_header_magic),

      LZMA_STREAM_FLAGS_SIZE, 0);

  write32le(out + sizeof(lzma_header_magic) + LZMA_STREAM_FLAGS_SIZE,

      crc);

  return LZMA_OK;

}

extern LZMA_API(lzma_ret)

lzma_stream_footer_encode(const lzma_stream_flags *options, uint8_t *out)

{

  assert(2 * 4 + LZMA_STREAM_FLAGS_SIZE + sizeof(lzma_footer_magic)

      == LZMA_STREAM_HEADER_SIZE);

  if (options->version != 0)

    return LZMA_OPTIONS_ERROR;

  // Backward Size

  if (!is_backward_size_valid(options))

    return LZMA_PROG_ERROR;

  write32le(out + 4, options->backward_size / 4 - 1);

  // Stream Flags

  if (stream_flags_encode(options, out + 2 * 4))

    return LZMA_PROG_ERROR;

  // CRC32

  const uint32_t crc = lzma_crc32(

      out + 4, 4 + LZMA_STREAM_FLAGS_SIZE, 0);

  write32le(out, crc);

  // Magic

  memcpy(out + 2 * 4 + LZMA_STREAM_FLAGS_SIZE,

      lzma_footer_magic, sizeof(lzma_footer_magic));

  return LZMA_OK;

}