// Copyright 2017 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "chrome/browser/media/router/discovery/dial/dial_media_sink_service_impl.h"

#include <algorithm>
#include <memory>

#include "base/containers/contains.h"
#include "base/functional/bind.h"
#include "base/strings/strcat.h"
#include "base/strings/string_util.h"
#include "base/strings/stringprintf.h"
#include "base/task/sequenced_task_runner.h"
#include "chrome/browser/media/router/discovery/dial/dial_device_data.h"
#include "chrome/browser/media/router/media_router_feature.h"
#include "components/media_router/common/mojom/media_router.mojom.h"

namespace media_router {

using SinkAppStatus = DialMediaSinkServiceImpl::SinkAppStatus;

namespace {

constexpr char kLoggerComponent[] = "DialMediaSinkServiceImpl";

static constexpr const char* kDiscoveryOnlyModelNames[3] = {
    "eureka dongle", "chromecast audio", "chromecast ultra"};

std::string EnumToString(DialRegistry::DialErrorCode code) {
  switch (code) {
    case DialRegistry::DialErrorCode::DIAL_NO_LISTENERS:
      return "DIAL_NO_LISTENERS";
    case DialRegistry::DialErrorCode::DIAL_NO_INTERFACES:
      return "DIAL_NO_INTERFACES";
    case DialRegistry::DialErrorCode::DIAL_NETWORK_DISCONNECTED:
      return "DIAL_NETWORK_DISCONNECTED";
    case DialRegistry::DialErrorCode::DIAL_CELLULAR_NETWORK:
      return "DIAL_CELLULAR_NETWORK";
    case DialRegistry::DialErrorCode::DIAL_SOCKET_ERROR:
      return "DIAL_SOCKET_ERROR";
    case DialRegistry::DialErrorCode::DIAL_UNKNOWN:
      return "DIAL_UNKNOWN";
  }
}

// Returns true if DIAL (SSDP) was only used to discover this sink, and it is
// not expected to support other DIAL features (app discovery, activity
// discovery, etc.)
// |model_name|: device model name.
bool IsDiscoveryOnly(const std::string& model_name) {
  std::string lower_model_name = base::ToLowerASCII(model_name);
  return base::Contains(kDiscoveryOnlyModelNames, lower_model_name);
}

SinkAppStatus GetSinkAppStatusFromResponse(const DialAppInfoResult& result) {
  if (!result.app_info) {
    if (result.result_code == DialAppInfoResultCode::kParsingError ||
        result.result_code == DialAppInfoResultCode::kHttpError) {
      return SinkAppStatus::kUnavailable;
    } else {
      return SinkAppStatus::kUnknown;
    }
  }

  return (result.app_info->state == DialAppState::kRunning ||
          result.app_info->state == DialAppState::kStopped)
             ? SinkAppStatus::kAvailable
             : SinkAppStatus::kUnavailable;
}

}  // namespace

DialMediaSinkServiceImpl::DialMediaSinkServiceImpl(
    const OnSinksDiscoveredCallback& on_sinks_discovered_cb,
    const scoped_refptr<base::SequencedTaskRunner>& task_runner)
    : MediaSinkServiceBase(on_sinks_discovered_cb), task_runner_(task_runner) {
  DETACH_FROM_SEQUENCE(sequence_checker_);
}

DialMediaSinkServiceImpl::~DialMediaSinkServiceImpl() {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
}

void DialMediaSinkServiceImpl::Initialize() {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  if (description_service_) {
    return;
  }

  description_service_ = std::make_unique<DeviceDescriptionService>(
      base::BindRepeating(
          &DialMediaSinkServiceImpl::OnDeviceDescriptionAvailable,
          base::Unretained(this)),
      base::BindRepeating(&DialMediaSinkServiceImpl::OnDeviceDescriptionError,
                          base::Unretained(this)));

  app_discovery_service_ = std::make_unique<DialAppDiscoveryService>();

  if (base::FeatureList::IsEnabled(media_router::kDelayMediaSinkDiscovery)) {
    LoggerList::GetInstance()->Log(
        LoggerImpl::Severity::kInfo, mojom::LogCategory::kDiscovery,
        kLoggerComponent,
        "The sink service is initialized. Device discovery will start "
        "after user interaction.",
        "", "", "");
  } else {
    LoggerList::GetInstance()->Log(
        LoggerImpl::Severity::kInfo, mojom::LogCategory::kDiscovery,
        kLoggerComponent, "The sink service is initialized.", "", "", "");
    StartDiscovery();
  }
}

void DialMediaSinkServiceImpl::StartDiscovery() {
  DCHECK(description_service_);
  DCHECK(app_discovery_service_);
  if (dial_registry_) {
    return;
  }

  StartTimer();

  dial_registry_ = std::make_unique<DialRegistry>(*this, task_runner_);
  dial_registry_->Start();

  LoggerList::GetInstance()->Log(
      LoggerImpl::Severity::kInfo, mojom::LogCategory::kDiscovery,
      kLoggerComponent, "DialMediaSinkService has started.", "", "", "");
}

void DialMediaSinkServiceImpl::DiscoverSinksNow() {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  if (!dial_registry_) {
    LoggerList::GetInstance()->Log(
        LoggerImpl::Severity::kError, mojom::LogCategory::kDiscovery,
        kLoggerComponent,
        "Failed to discover sinks. Device discovery hasn't started.", "", "",
        "");
    return;
  }

  dial_registry_->DiscoverNow();
  RescanAppInfo();
}

DialAppDiscoveryService* DialMediaSinkServiceImpl::app_discovery_service() {
  return app_discovery_service_.get();
}

base::CallbackListSubscription
DialMediaSinkServiceImpl::StartMonitoringAvailableSinksForApp(
    const std::string& app_name,
    const SinkQueryByAppCallback& callback) {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);

  auto& callback_list = sink_queries_[app_name];
  if (!callback_list) {
    callback_list = std::make_unique<SinkQueryByAppCallbackList>();
    callback_list->set_removal_callback(base::BindRepeating(
        &DialMediaSinkServiceImpl::MaybeRemoveSinkQueryCallbackList,
        base::Unretained(this), app_name, callback_list.get()));

    // Start checking if |app_name| is available on existing sinks.
    for (const auto& sink : GetSinks()) {
      FetchAppInfoForSink(sink.second, app_name);
    }
  }

  return callback_list->Add(callback);
}

void DialMediaSinkServiceImpl::SetDescriptionServiceForTest(
    std::unique_ptr<DeviceDescriptionService> description_service) {
  description_service_ = std::move(description_service);
}

void DialMediaSinkServiceImpl::SetAppDiscoveryServiceForTest(
    std::unique_ptr<DialAppDiscoveryService> app_discovery_service) {
  app_discovery_service_ = std::move(app_discovery_service);
}

void DialMediaSinkServiceImpl::OnDiscoveryComplete() {
  std::vector<MediaSinkInternal> sinks_to_update;
  std::vector<MediaSinkInternal> sinks_to_remove;
  for (const auto& sink : GetSinks()) {
    if (!base::Contains(latest_sinks_, sink.first)) {
      sinks_to_remove.push_back(sink.second);
    }
  }

  for (const auto& latest_sink : latest_sinks_) {
    // Sink is added or updated.
    const MediaSinkInternal* sink = GetSinkById(latest_sink.first);
    if (!sink || *sink != latest_sink.second) {
      sinks_to_update.push_back(latest_sink.second);
    }
  }

  // Note: calling |AddOrUpdateSink()| or |RemoveSink()| here won't cause the
  // discovery timer to fire again, since it is considered to be still running.
  for (const auto& sink : sinks_to_update) {
    AddOrUpdateSink(sink);
  }

  for (const auto& sink : sinks_to_remove) {
    RemoveSink(sink);
  }

  // If discovered sinks are updated, then query results might have changed.
  for (const auto& query : sink_queries_) {
    query.second->Notify(query.first);
  }

  MediaSinkServiceBase::OnDiscoveryComplete();
}

void DialMediaSinkServiceImpl::OnDialDeviceList(
    const DialRegistry::DeviceList& devices) {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  current_devices_ = devices;
  latest_sinks_.clear();

  description_service_->GetDeviceDescriptions(devices);

  // Makes sure the timer fires even if there is no device.
  StartTimer();
}

void DialMediaSinkServiceImpl::OnDialError(DialRegistry::DialErrorCode type) {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  LoggerList::GetInstance()->Log(
      LoggerImpl::Severity::kError, mojom::LogCategory::kDiscovery,
      kLoggerComponent, base::StrCat({"Dial Error: ", EnumToString(type)}), "",
      "", "");
}

void DialMediaSinkServiceImpl::OnDeviceDescriptionAvailable(
    const DialDeviceData& device_data,
    const ParsedDialDeviceDescription& description_data) {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  if (!base::Contains(current_devices_, device_data)) {
    return;
  }

  std::string processed_uuid =
      MediaSinkInternal::ProcessDeviceUUID(description_data.unique_id);
  MediaSink::Id sink_id = base::StringPrintf("dial:%s", processed_uuid.c_str());
  MediaSink sink(sink_id, description_data.friendly_name, SinkIconType::GENERIC,
                 mojom::MediaRouteProviderId::DIAL);
  DialSinkExtraData extra_data;
  extra_data.app_url = description_data.app_url;
  extra_data.model_name = description_data.model_name;
  extra_data.ip_address = device_data.ip_address();

  MediaSinkInternal dial_sink(sink, extra_data);
  latest_sinks_.insert_or_assign(sink_id, dial_sink);
  StartTimer();

  if (!IsDiscoveryOnly(description_data.model_name)) {
    // Start checking if all registered apps are available on |dial_sink|.
    for (const auto& query : sink_queries_) {
      FetchAppInfoForSink(dial_sink, query.first);
    }
  }
}

void DialMediaSinkServiceImpl::OnDeviceDescriptionError(
    const DialDeviceData& device,
    const std::string& error_message) {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  LoggerList::GetInstance()->Log(
      LoggerImpl::Severity::kError, mojom::LogCategory::kDiscovery,
      kLoggerComponent,
      base::StrCat({"Device description error. Device id: ", device.device_id(),
                    ", error message: ", error_message}),
      "", "", "");
}

void DialMediaSinkServiceImpl::OnAppInfoParseCompleted(
    const std::string& sink_id,
    const std::string& app_name,
    DialAppInfoResult result) {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);

  SinkAppStatus app_status = GetSinkAppStatusFromResponse(result);
  if (app_status == SinkAppStatus::kUnknown) {
    return;
  }

  SinkAppStatus old_status = GetAppStatus(sink_id, app_name);
  SetAppStatus(sink_id, app_name, app_status);

  if (old_status == app_status) {
    return;
  }

  if (!result.app_info) {
    LoggerList::GetInstance()->Log(
        LoggerImpl::Severity::kError, mojom::LogCategory::kDiscovery,
        kLoggerComponent,
        base::StringPrintf(
            "App info parsing error. DialAppInfoResultCode: %d. app name: %s",
            static_cast<int>(result.result_code), app_name.c_str()),
        sink_id, "", "");
  }

  // The sink might've been removed before the parse was complete. In that case
  // the callbacks won't be notified, but the app status will be saved for later
  // use.
  if (!GetSinkById(sink_id)) {
    return;
  }

  auto query_it = sink_queries_.find(app_name);
  if (query_it != sink_queries_.end()) {
    query_it->second->Notify(app_name);
  }
}

void DialMediaSinkServiceImpl::FetchAppInfoForSink(
    const MediaSinkInternal& dial_sink,
    const std::string& app_name) {
  std::string model_name = dial_sink.dial_data().model_name;
  if (IsDiscoveryOnly(model_name)) {
    return;
  }

  std::string sink_id = dial_sink.sink().id();
  SinkAppStatus app_status = GetAppStatus(sink_id, app_name);
  if (app_status != SinkAppStatus::kUnknown) {
    return;
  }

  app_discovery_service_->FetchDialAppInfo(
      dial_sink, app_name,
      base::BindOnce(&DialMediaSinkServiceImpl::OnAppInfoParseCompleted,
                     base::Unretained(this)));
}

void DialMediaSinkServiceImpl::RescanAppInfo() {
  for (const auto& sink : GetSinks()) {
    std::string model_name = sink.second.dial_data().model_name;
    if (IsDiscoveryOnly(model_name)) {
      continue;
    }

    for (const auto& query : sink_queries_) {
      FetchAppInfoForSink(sink.second, query.first);
    }
  }
}

SinkAppStatus DialMediaSinkServiceImpl::GetAppStatus(
    const std::string& sink_id,
    const std::string& app_name) const {
  std::string key = sink_id + ':' + app_name;
  auto status_it = app_statuses_.find(key);
  return status_it == app_statuses_.end() ? SinkAppStatus::kUnknown
                                          : status_it->second;
}

void DialMediaSinkServiceImpl::SetAppStatus(const std::string& sink_id,
                                            const std::string& app_name,
                                            SinkAppStatus app_status) {
  std::string key = sink_id + ':' + app_name;
  app_statuses_[key] = app_status;
}

void DialMediaSinkServiceImpl::RecordDeviceCounts() {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  metrics_.RecordDeviceCountsIfNeeded(GetSinks().size(),
                                      current_devices_.size());
}

void DialMediaSinkServiceImpl::MaybeRemoveSinkQueryCallbackList(
    const std::string& app_name,
    SinkQueryByAppCallbackList* callback_list) {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);

  // There are no more profiles monitoring |app_name|.
  if (callback_list->empty()) {
    sink_queries_.erase(app_name);
  }
}

std::vector<MediaSinkInternal> DialMediaSinkServiceImpl::GetAvailableSinks(
    const std::string& app_name) const {
  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
  std::vector<MediaSinkInternal> sinks;
  for (const auto& sink : GetSinks()) {
    if (GetAppStatus(sink.first, app_name) == SinkAppStatus::kAvailable) {
      sinks.push_back(sink.second);
    }
  }
  return sinks;
}

}  // namespace media_router