/*
 *  Copyright (c) 2020 The WebRTC project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */

#include "test/pc/e2e/peer_configurer.h"

#include <set>

#include "absl/strings/string_view.h"
#include "rtc_base/arraysize.h"
#include "test/testsupport/file_utils.h"

namespace webrtc {
namespace webrtc_pc_e2e {
namespace {

using AudioConfig = PeerConnectionE2EQualityTestFixture::AudioConfig;
using VideoConfig = PeerConnectionE2EQualityTestFixture::VideoConfig;
using RunParams = PeerConnectionE2EQualityTestFixture::RunParams;
using VideoGeneratorType =
    PeerConnectionE2EQualityTestFixture::VideoGeneratorType;
using VideoCodecConfig = PeerConnectionE2EQualityTestFixture::VideoCodecConfig;

// List of default names of generic participants according to
// https://en.wikipedia.org/wiki/Alice_and_Bob
constexpr absl::string_view kDefaultNames[] = {"alice", "bob",  "charlie",
                                               "david", "erin", "frank"};

class DefaultNamesProvider {
 public:
  // Caller have to ensure that default names array will outlive names provider
  // instance.
  explicit DefaultNamesProvider(
      absl::string_view prefix,
      rtc::ArrayView<const absl::string_view> default_names = {})
      : prefix_(prefix), default_names_(default_names) {}

  void MaybeSetName(absl::optional<std::string>* name) {
    if (name->has_value()) {
      known_names_.insert(name->value());
    } else {
      *name = GenerateName();
    }
  }

 private:
  std::string GenerateName() {
    std::string name;
    do {
      name = GenerateNameInternal();
    } while (!known_names_.insert(name).second);
    return name;
  }

  std::string GenerateNameInternal() {
    if (counter_ < default_names_.size()) {
      return std::string(default_names_[counter_++]);
    }
    return prefix_ + std::to_string(counter_++);
  }

  const std::string prefix_;
  const rtc::ArrayView<const absl::string_view> default_names_;

  std::set<std::string> known_names_;
  size_t counter_ = 0;
};

}  // namespace

void SetDefaultValuesForMissingParams(
    RunParams* run_params,
    std::vector<std::unique_ptr<PeerConfigurerImpl>>* peers) {
  DefaultNamesProvider peer_names_provider("peer_", kDefaultNames);
  for (size_t i = 0; i < peers->size(); ++i) {
    auto* peer = peers->at(i).get();
    auto* p = peer->params();
    peer_names_provider.MaybeSetName(&p->name);
    DefaultNamesProvider video_stream_names_provider(
        *p->name + "_auto_video_stream_label_");
    for (VideoConfig& video_config : p->video_configs) {
      video_stream_names_provider.MaybeSetName(&video_config.stream_label);
    }
    if (p->audio_config) {
      DefaultNamesProvider audio_stream_names_provider(
          *p->name + "_auto_audio_stream_label_");
      audio_stream_names_provider.MaybeSetName(&p->audio_config->stream_label);
    }
  }

  if (run_params->video_codecs.empty()) {
    run_params->video_codecs.push_back(
        VideoCodecConfig(cricket::kVp8CodecName));
  }
}

void ValidateParams(
    const RunParams& run_params,
    const std::vector<std::unique_ptr<PeerConfigurerImpl>>& peers) {
  RTC_CHECK_GT(run_params.video_encoder_bitrate_multiplier, 0.0);

  std::set<std::string> peer_names;
  std::set<std::string> video_labels;
  std::set<std::string> audio_labels;
  int media_streams_count = 0;

  bool has_simulcast = false;
  for (size_t i = 0; i < peers.size(); ++i) {
    Params* p = peers[i]->params();

    {
      RTC_CHECK(p->name);
      bool inserted = peer_names.insert(p->name.value()).second;
      RTC_CHECK(inserted) << "Duplicate name=" << p->name.value();
    }

    if (p->audio_config) {
      media_streams_count++;
    }
    media_streams_count += p->video_configs.size();

    // Validate that all video stream labels are unique.
    for (const VideoConfig& video_config : p->video_configs) {
      RTC_CHECK(video_config.stream_label);
      bool inserted =
          video_labels.insert(video_config.stream_label.value()).second;
      RTC_CHECK(inserted) << "Duplicate video_config.stream_label="
                          << video_config.stream_label.value();

      if (video_config.simulcast_config) {
        has_simulcast = true;
        if (video_config.simulcast_config->target_spatial_index) {
          RTC_CHECK_GE(*video_config.simulcast_config->target_spatial_index, 0);
          RTC_CHECK_LT(*video_config.simulcast_config->target_spatial_index,
                       video_config.simulcast_config->simulcast_streams_count);
        }
        RTC_CHECK(!video_config.max_encode_bitrate_bps)
            << "Setting max encode bitrate is not implemented for simulcast.";
        RTC_CHECK(!video_config.min_encode_bitrate_bps)
            << "Setting min encode bitrate is not implemented for simulcast.";
      }
    }
    if (p->audio_config) {
      bool inserted =
          audio_labels.insert(p->audio_config->stream_label.value()).second;
      RTC_CHECK(inserted) << "Duplicate audio_config.stream_label="
                          << p->audio_config->stream_label.value();
      // Check that if mode input file name specified only if mode is kFile.
      if (p->audio_config.value().mode == AudioConfig::Mode::kGenerated) {
        RTC_CHECK(!p->audio_config.value().input_file_name);
      }
      if (p->audio_config.value().mode == AudioConfig::Mode::kFile) {
        RTC_CHECK(p->audio_config.value().input_file_name);
        RTC_CHECK(
            test::FileExists(p->audio_config.value().input_file_name.value()))
            << p->audio_config.value().input_file_name.value()
            << " doesn't exist";
      }
    }
  }
  if (has_simulcast) {
    RTC_CHECK_EQ(run_params.video_codecs.size(), 1)
        << "Only 1 video codec is supported when simulcast is enabled in at "
        << "least 1 video config";
  }

  RTC_CHECK_GT(media_streams_count, 0) << "No media in the call.";
}

}  // namespace webrtc_pc_e2e
}  // namespace webrtc