/* poppler-cached-file-loader.h: glib interface to poppler
 *
 * Copyright (C) 2012 Carlos Garcia Campos <carlosgc@gnome.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, 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 General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.
 */

#include "config.h"
#include "poppler-cached-file-loader.h"

PopplerCachedFileLoader::PopplerCachedFileLoader(GInputStream *inputStreamA, GCancellable *cancellableA, goffset lengthA)
{
  inputStream = (GInputStream *)g_object_ref(inputStreamA);
  cancellable = cancellableA ? (GCancellable *)g_object_ref(cancellableA) : nullptr;
  length = lengthA;
  url = nullptr;
  cachedFile = nullptr;
}

PopplerCachedFileLoader::~PopplerCachedFileLoader()
{
  g_object_unref(inputStream);
  if (cancellable)
    g_object_unref(cancellable);
}

size_t PopplerCachedFileLoader::init(GooString *urlA, CachedFile *cachedFileA)
{
  size_t size;
  gssize bytesRead;
  char buf[CachedFileChunkSize];

  url = urlA;
  cachedFile = cachedFileA;

  if (length != (goffset)-1)
    return length;

  if (G_IS_FILE_INPUT_STREAM(inputStream)) {
    GFileInfo *info;

    info = g_file_input_stream_query_info(G_FILE_INPUT_STREAM (inputStream), G_FILE_ATTRIBUTE_STANDARD_SIZE, cancellable, nullptr);
    if (!info) {
      error(errInternal, -1, "Failed to get size of '{0:t}'.", urlA);
      return (size_t)-1;
    }

    length = g_file_info_get_size(info);
    g_object_unref(info);

    return length;
  }

  // Unknown stream length, read the whole stream and return the size.
  CachedFileWriter writer = CachedFileWriter(cachedFile, nullptr);
  size = 0;
  do {
    bytesRead = g_input_stream_read(inputStream, buf, CachedFileChunkSize, cancellable, nullptr);
    if (bytesRead == -1)
      break;

    writer.write(buf, bytesRead);
    size += bytesRead;
  } while (bytesRead > 0);

  return size;
}

int PopplerCachedFileLoader::load(const std::vector<ByteRange> &ranges, CachedFileWriter *writer)
{
  char buf[CachedFileChunkSize];
  gssize bytesRead;
  size_t rangeBytesRead, bytesToRead, size;

  if (length == (goffset)-1)
    return 0;

  size = 0;
  for (const ByteRange &range : ranges) {
    bytesToRead = MIN(CachedFileChunkSize, range.length);
    rangeBytesRead = 0;
    g_seekable_seek(G_SEEKABLE(inputStream), range.offset, G_SEEK_SET, cancellable, nullptr);
    do {
      bytesRead = g_input_stream_read(inputStream, buf, bytesToRead, cancellable, nullptr);
      if (bytesRead == -1)
        return -1;

      writer->write(buf, bytesRead);
      size += bytesRead;
      rangeBytesRead += bytesRead;
      bytesToRead = range.length - rangeBytesRead;
    } while (bytesRead > 0 && bytesToRead > 0);
  }

  return 0;
}
