/* libFLAC - Free Lossless Audio Codec

 * Copyright (C) 2004-2009  Josh Coalson

 * Copyright (C) 2011-2025  Xiph.Org Foundation

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * - Redistributions of source code must retain the above copyright

 * notice, this list of conditions and the following disclaimer.

 *

 * - Redistributions in binary form must reproduce the above copyright

 * notice, this list of conditions and the following disclaimer in the

 * documentation and/or other materials provided with the distribution.

 *

 * - Neither the name of the Xiph.org Foundation nor the names of its

 * contributors may be used to endorse or promote products derived from

 * this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

 * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR

 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF

 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING

 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS

 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

#ifdef HAVE_CONFIG_H

#  include <config.h>

#endif

#include <stdlib.h> /* for malloc() */

#include <string.h> /* for memcmp(), memcpy() */

#include "FLAC/assert.h"

#include "share/alloc.h"

#include "private/ogg_helper.h"

#include "protected/stream_encoder.h"

static FLAC__bool full_read_(FLAC__StreamEncoder *encoder, FLAC__byte *buffer, size_t bytes, FLAC__StreamEncoderReadCallback read_callback, void *client_data)

{

  while(bytes > 0) {

    size_t bytes_read = bytes;

    switch(read_callback(encoder, buffer, &bytes_read, client_data)) {

      case FLAC__STREAM_ENCODER_READ_STATUS_CONTINUE:

        bytes -= bytes_read;

        buffer += bytes_read;

        break;

      case FLAC__STREAM_ENCODER_READ_STATUS_END_OF_STREAM:

        if(bytes_read == 0) {

          encoder->protected_->state = FLAC__STREAM_ENCODER_OGG_ERROR;

          return false;

        }

        bytes -= bytes_read;

        buffer += bytes_read;

        break;

      case FLAC__STREAM_ENCODER_READ_STATUS_ABORT:

        encoder->protected_->state = FLAC__STREAM_ENCODER_CLIENT_ERROR;

        return false;

      case FLAC__STREAM_ENCODER_READ_STATUS_UNSUPPORTED:

        return false;

      default:

        /* double protection: */

        FLAC__ASSERT(0);

        encoder->protected_->state = FLAC__STREAM_ENCODER_CLIENT_ERROR;

        return false;

    }

  }

  return true;

}

void simple_ogg_page__init(ogg_page *page)

{

  page->header = 0;

  page->header_len = 0;

  page->body = 0;

  page->body_len = 0;

}

void simple_ogg_page__clear(ogg_page *page)

{

  if(page->header)

    free(page->header);

  if(page->body)

    free(page->body);

  simple_ogg_page__init(page);

}

FLAC__bool simple_ogg_page__get_at(FLAC__StreamEncoder *encoder, FLAC__uint64 position, ogg_page *page, FLAC__StreamEncoderSeekCallback seek_callback, FLAC__StreamEncoderReadCallback read_callback, void *client_data)

{

  static const uint32_t OGG_HEADER_FIXED_PORTION_LEN = 27;

  static const uint32_t OGG_MAX_HEADER_LEN = 27/*OGG_HEADER_FIXED_PORTION_LEN*/ + 255;

  FLAC__byte crc[4];

  FLAC__StreamEncoderSeekStatus seek_status;

  FLAC__ASSERT(page->header == 0);

  FLAC__ASSERT(page->header_len == 0);

  FLAC__ASSERT(page->body == 0);

  FLAC__ASSERT(page->body_len == 0);

  /* move the stream pointer to the supposed beginning of the page */

  if(0 == seek_callback)

    return false;

  if((seek_status = seek_callback((FLAC__StreamEncoder*)encoder, position, client_data)) != FLAC__STREAM_ENCODER_SEEK_STATUS_OK) {

    if(seek_status == FLAC__STREAM_ENCODER_SEEK_STATUS_ERROR)

      encoder->protected_->state = FLAC__STREAM_ENCODER_CLIENT_ERROR;

    return false;

  }

  /* allocate space for the page header */

  if(0 == (page->header = safe_malloc_(OGG_MAX_HEADER_LEN))) {

    encoder->protected_->state = FLAC__STREAM_ENCODER_MEMORY_ALLOCATION_ERROR;

    return false;

  }

  /* read in the fixed part of the page header (up to but not including

   * the segment table */

  if(!full_read_(encoder, page->header, OGG_HEADER_FIXED_PORTION_LEN, read_callback, client_data))

    return false;

  page->header_len = OGG_HEADER_FIXED_PORTION_LEN + page->header[26];

  /* check to see if it's a correct, "simple" page (one packet only) */

  if(

    memcmp(page->header, "OggS", 4) ||               /* doesn't start with OggS */

    (page->header[5] & 0x01) ||                      /* continued packet */

    memcmp(page->header+6, "\0\0\0\0\0\0\0\0", 8) || /* granulepos is non-zero */

    page->header[26] == 0                            /* packet is 0-size */

  ) {

    encoder->protected_->state = FLAC__STREAM_ENCODER_OGG_ERROR;

    return false;

  }

  /* read in the segment table */

  if(!full_read_(encoder, page->header + OGG_HEADER_FIXED_PORTION_LEN, page->header[26], read_callback, client_data))

    return false;

  {

    uint32_t i;

    /* check to see that it specifies a single packet */

    for(i = 0; i < (uint32_t)page->header[26] - 1; i++) {

      if(page->header[i + OGG_HEADER_FIXED_PORTION_LEN] != 255) {

        encoder->protected_->state = FLAC__STREAM_ENCODER_OGG_ERROR;

        return false;

      }

    }

    page->body_len = 255 * i + page->header[i + OGG_HEADER_FIXED_PORTION_LEN];

  }

  /* allocate space for the page body */

  if(0 == (page->body = safe_malloc_(page->body_len))) {

    encoder->protected_->state = FLAC__STREAM_ENCODER_MEMORY_ALLOCATION_ERROR;

    return false;

  }

  /* read in the page body */

  if(!full_read_(encoder, page->body, page->body_len, read_callback, client_data))

    return false;

  /* check the CRC */

  memcpy(crc, page->header+22, 4);

  ogg_page_checksum_set(page);

  if(memcmp(crc, page->header+22, 4)) {

    encoder->protected_->state = FLAC__STREAM_ENCODER_OGG_ERROR;

    return false;

  }

  return true;

}

FLAC__bool simple_ogg_page__set_at(FLAC__StreamEncoder *encoder, FLAC__uint64 position, ogg_page *page, FLAC__StreamEncoderSeekCallback seek_callback, FLAC__StreamEncoderWriteCallback write_callback, void *client_data)

{

  FLAC__StreamEncoderSeekStatus seek_status;

  FLAC__ASSERT(page->header != 0);

  FLAC__ASSERT(page->header_len != 0);

  FLAC__ASSERT(page->body != 0);

  FLAC__ASSERT(page->body_len != 0);

  /* move the stream pointer to the supposed beginning of the page */

  if(0 == seek_callback)

    return false;

  if((seek_status = seek_callback((FLAC__StreamEncoder*)encoder, position, client_data)) != FLAC__STREAM_ENCODER_SEEK_STATUS_OK) {

    if(seek_status == FLAC__STREAM_ENCODER_SEEK_STATUS_ERROR)

      encoder->protected_->state = FLAC__STREAM_ENCODER_CLIENT_ERROR;

    return false;

  }

  ogg_page_checksum_set(page);

  /* re-write the page */

  if(write_callback((FLAC__StreamEncoder*)encoder, page->header, page->header_len, 0, 0, client_data) != FLAC__STREAM_ENCODER_WRITE_STATUS_OK) {

    encoder->protected_->state = FLAC__STREAM_ENCODER_CLIENT_ERROR;

    return false;

  }

  if(write_callback((FLAC__StreamEncoder*)encoder, page->body, page->body_len, 0, 0, client_data) != FLAC__STREAM_ENCODER_WRITE_STATUS_OK) {

    encoder->protected_->state = FLAC__STREAM_ENCODER_CLIENT_ERROR;

    return false;

  }

  return true;

}