// Copyright 2016 Google Inc. All rights reserved.
//
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file or at
// https://developers.google.com/open-source/licenses/bsd

#include "packager/hls/base/simple_hls_notifier.h"

#include "packager/base/base64.h"
#include "packager/base/files/file_path.h"
#include "packager/base/json/json_writer.h"
#include "packager/base/logging.h"
#include "packager/base/strings/string_number_conversions.h"
#include "packager/base/strings/stringprintf.h"
#include "packager/hls/base/media_playlist.h"
#include "packager/media/base/fixed_key_source.h"
#include "packager/media/base/widevine_key_source.h"
#include "packager/media/base/widevine_pssh_data.pb.h"

namespace shaka {
namespace hls {

namespace {
bool IsWidevineSystemId(const std::vector<uint8_t>& system_id) {
  return system_id.size() == arraysize(media::kWidevineSystemId) &&
         std::equal(system_id.begin(), system_id.end(),
                    media::kWidevineSystemId);
}

bool IsCommonSystemId(const std::vector<uint8_t>& system_id) {
  return system_id.size() == arraysize(media::kCommonSystemId) &&
         std::equal(system_id.begin(), system_id.end(), media::kCommonSystemId);
}

// TODO(rkuroiwa): Dedup these with the functions in MpdBuilder.
std::string MakePathRelative(const std::string& original_path,
                             const std::string& output_dir) {
  return (original_path.find(output_dir) == 0)
             ? original_path.substr(output_dir.size())
             : original_path;
}

void MakePathsRelativeToOutputDirectory(const std::string& output_dir,
                                        MediaInfo* media_info) {
  DCHECK(media_info);
  const std::string kFileProtocol("file://");
  std::string prefix_stripped_output_dir =
      (output_dir.find(kFileProtocol) == 0)
          ? output_dir.substr(kFileProtocol.size())
          : output_dir;

  if (prefix_stripped_output_dir.empty())
    return;

  std::string directory_with_separator(
      base::FilePath::FromUTF8Unsafe(prefix_stripped_output_dir)
      .AsEndingWithSeparator()
      .AsUTF8Unsafe());
  if (directory_with_separator.empty())
    return;

  if (media_info->has_media_file_name()) {
    media_info->set_media_file_name(MakePathRelative(
        media_info->media_file_name(), directory_with_separator));
  }
  if (media_info->has_segment_template()) {
    media_info->set_segment_template(MakePathRelative(
        media_info->segment_template(), directory_with_separator));
  }
}

bool WidevinePsshToJson(const std::vector<uint8_t>& pssh_data,
                        const std::vector<uint8_t>& key_id,
                        std::string* pssh_json) {
  media::WidevinePsshData pssh_proto;
  if (!pssh_proto.ParseFromArray(pssh_data.data(), pssh_data.size())) {
    LOG(ERROR) << "Failed to parse protection_system_specific_data.";
    return false;
  }
  if (!pssh_proto.has_provider() ||
      (!pssh_proto.has_content_id() && pssh_proto.key_id_size() == 0)) {
    LOG(ERROR) << "Missing fields to generate URI.";
    return false;
  }

  base::DictionaryValue pssh_dict;
  pssh_dict.SetString("provider", pssh_proto.provider());
  if (pssh_proto.has_content_id()) {
    std::string content_id_base64;
    base::Base64Encode(base::StringPiece(pssh_proto.content_id().data(),
                                         pssh_proto.content_id().size()),
                       &content_id_base64);
    pssh_dict.SetString("content_id", content_id_base64);
  }
  base::ListValue* key_ids = new base::ListValue();
  key_ids->AppendString(base::HexEncode(key_id.data(), key_id.size()));
  for (const std::string& id : pssh_proto.key_id()) {
    if (key_id.size() == id.size() &&
        memcmp(key_id.data(), id.data(), id.size()) == 0) {
      continue;
    }
    key_ids->AppendString(base::HexEncode(id.data(), id.size()));
  }
  pssh_dict.Set("key_ids", key_ids);

  if (!base::JSONWriter::Write(pssh_dict, pssh_json)) {
    LOG(ERROR) << "Failed to write to JSON.";
    return false;
  }
  return true;
}

}  // namespace

MediaPlaylistFactory::~MediaPlaylistFactory() {}

scoped_ptr<MediaPlaylist> MediaPlaylistFactory::Create(
    MediaPlaylist::MediaPlaylistType type,
    const std::string& file_name,
    const std::string& name,
    const std::string& group_id) {
  return scoped_ptr<MediaPlaylist>(
      new MediaPlaylist(type, file_name, name, group_id));
}

SimpleHlsNotifier::SimpleHlsNotifier(HlsProfile profile,
                                     const std::string& prefix,
                                     const std::string& output_dir,
                                     const std::string& master_playlist_name)
    : HlsNotifier(profile),
      prefix_(prefix),
      output_dir_(output_dir),
      media_playlist_factory_(new MediaPlaylistFactory()),
      master_playlist_(new MasterPlaylist(master_playlist_name)),
      media_playlist_map_deleter_(&media_playlist_map_) {}

SimpleHlsNotifier::~SimpleHlsNotifier() {}

bool SimpleHlsNotifier::Init() {
  return true;
}

bool SimpleHlsNotifier::NotifyNewStream(const MediaInfo& media_info,
                                        const std::string& playlist_name,
                                        const std::string& name,
                                        const std::string& group_id,
                                        uint32_t* stream_id) {
  DCHECK(stream_id);

  MediaPlaylist::MediaPlaylistType type;
  switch (profile()) {
    case HlsProfile::kLiveProfile:
      type = MediaPlaylist::MediaPlaylistType::kLive;
      break;
    case HlsProfile::kOnDemandProfile:
      type = MediaPlaylist::MediaPlaylistType::kVod;
      break;
    default:
      NOTREACHED();
      return false;
  }

  MediaInfo adjusted_media_info(media_info);
  MakePathsRelativeToOutputDirectory(output_dir_, &adjusted_media_info);

  scoped_ptr<MediaPlaylist> media_playlist =
      media_playlist_factory_->Create(type, playlist_name, name, group_id);
  if (!media_playlist->SetMediaInfo(adjusted_media_info)) {
    LOG(ERROR) << "Failed to set media info for playlist " << playlist_name;
    return false;
  }

  *stream_id = sequence_number_.GetNext();
  base::AutoLock auto_lock(lock_);
  master_playlist_->AddMediaPlaylist(media_playlist.get());
  media_playlist_map_.insert(
      std::make_pair(*stream_id, media_playlist.release()));
  return true;
}

bool SimpleHlsNotifier::NotifyNewSegment(uint32_t stream_id,
                                         const std::string& segment_name,
                                         uint64_t start_time,
                                         uint64_t duration,
                                         uint64_t size) {
  base::AutoLock auto_lock(lock_);
  auto result = media_playlist_map_.find(stream_id);
  if (result == media_playlist_map_.end()) {
    LOG(ERROR) << "Cannot find stream with ID: " << stream_id;
    return false;
  }
  const std::string relative_segment_name =
      MakePathRelative(segment_name, output_dir_);

  auto& media_playlist = result->second;
  media_playlist->AddSegment(prefix_ + relative_segment_name, duration, size);
  return true;
}

bool SimpleHlsNotifier::NotifyEncryptionUpdate(
    uint32_t stream_id,
    const std::vector<uint8_t>& key_id,
    const std::vector<uint8_t>& system_id,
    const std::vector<uint8_t>& iv,
    const std::vector<uint8_t>& protection_system_specific_data) {
  base::AutoLock auto_lock(lock_);
  auto result = media_playlist_map_.find(stream_id);
  if (result == media_playlist_map_.end()) {
    LOG(ERROR) << "Cannot find stream with ID: " << stream_id;
    return false;
  }

  std::string key_format;
  std::string key_uri_data;
  if (IsWidevineSystemId(system_id)) {
    key_format = "com.widevine";
    if (!WidevinePsshToJson(protection_system_specific_data, key_id,
                            &key_uri_data)) {
      return false;
    }
  } else if (IsCommonSystemId(system_id)) {
    key_format = "identity";
    // Use key_id as the key_uri. The player needs to have custom logic to
    // convert it to the actual key url.
    key_uri_data.assign(key_id.begin(), key_id.end());
  } else {
    LOG(ERROR) << "Unknown system ID: "
               << base::HexEncode(system_id.data(), system_id.size());
    return false;
  }

  auto& media_playlist = result->second;
  std::string iv_string;
  if (!iv.empty()) {
    iv_string = "0x" + base::HexEncode(iv.data(), iv.size());
  }
  std::string key_uri_data_base64;
  base::Base64Encode(key_uri_data, &key_uri_data_base64);
  media_playlist->AddEncryptionInfo(
      MediaPlaylist::EncryptionMethod::kSampleAes,
      "data:text/plain;base64," + key_uri_data_base64, iv_string, key_format,
      "" /* key_format_versions */);
  return true;
}

bool SimpleHlsNotifier::Flush() {
  base::AutoLock auto_lock(lock_);
  return master_playlist_->WriteAllPlaylists(prefix_, output_dir_);
}

}  // namespace hls
}  // namespace shaka