// Copyright 2020 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "platform/public/wifi_lan.h"

#include "platform/public/mutex_lock.h"

namespace location {
namespace nearby {

bool WifiLanMedium::StartAdvertising(const NsdServiceInfo& nsd_service_info) {
  return impl_->StartAdvertising(nsd_service_info);
}

bool WifiLanMedium::StopAdvertising(const NsdServiceInfo& nsd_service_info) {
  return impl_->StopAdvertising(nsd_service_info);
}

bool WifiLanMedium::StartDiscovery(const std::string& service_id,
                                   const std::string& service_type,
                                   DiscoveredServiceCallback callback) {
  {
    MutexLock lock(&mutex_);
    if (discovery_callbacks_.contains(service_type)) {
      NEARBY_LOGS(INFO) << "WifiLan Discovery already start with service_type="
                        << service_type << "; impl=" << &GetImpl();
      return false;
    }
  }
  api::WifiLanMedium::DiscoveredServiceCallback api_callback = {
      .service_discovered_cb =
          [this](NsdServiceInfo service_info) {
            MutexLock lock(&mutex_);
            std::string service_type = service_info.GetServiceType();
            auto pair = discovery_services_.insert(service_type);
            if (!pair.second) {
              NEARBY_LOGS(INFO)
                  << "Discovering (again) service_info=" << &service_info
                  << ", service_type=" << service_type
                  << ", service_name=" << service_info.GetServiceName();
              return;
            }
            NEARBY_LOGS(INFO)
                << "Adding service_info=" << &service_info
                << ", service_type=" << service_type
                << ", service_name=" << service_info.GetServiceName();
            // Callback service found.
            const auto& it = discovery_callbacks_.find(service_type);
            if (it != discovery_callbacks_.end()) {
              std::string service_id = it->second->service_id;
              DiscoveredServiceCallback medium_callback =
                  it->second->medium_callback;
              medium_callback.service_discovered_cb(service_info, service_id);
            } else {
              NEARBY_LOGS(ERROR)
                  << "There is no callback found for service_type="
                  << service_type;
            }
          },
      .service_lost_cb =
          [this](NsdServiceInfo service_info) {
            MutexLock lock(&mutex_);
            std::string service_type = service_info.GetServiceType();
            auto item = discovery_services_.extract(service_type);
            if (item.empty()) return;
            NEARBY_LOGS(INFO)
                << "Removing service_info=" << &service_info
                << ", service_type=" << service_type
                << ", service_info_name=" << service_info.GetServiceName();
            // Callback service lost.
            const auto& it = discovery_callbacks_.find(service_type);
            if (it != discovery_callbacks_.end()) {
              std::string service_id = it->second->service_id;
              DiscoveredServiceCallback medium_callback =
                  it->second->medium_callback;
              medium_callback.service_lost_cb(service_info, service_id);
            }
          },
  };
  {
    // Insert callback to the map first no matter it succeeds or not.
    MutexLock lock(&mutex_);
    auto pair = discovery_callbacks_.insert(
        {service_type, absl::make_unique<DiscoveryCallbackInfo>()});
    auto& context = *pair.first->second;
    context.medium_callback = std::move(callback);
    context.service_id = service_id;
  }

  bool success = impl_->StartDiscovery(service_type, std::move(api_callback));
  if (!success) {
    // If failed, then revert back the insertion.
    MutexLock lock(&mutex_);
    discovery_callbacks_.erase(service_type);
  }
  NEARBY_LOGS(INFO) << "WifiLan Discovery started for service_type="
                    << service_type << ", impl=" << &GetImpl()
                    << ", success=" << success;
  return success;
}

bool WifiLanMedium::StopDiscovery(const std::string& service_type) {
  MutexLock lock(&mutex_);
  if (!discovery_callbacks_.contains(service_type)) {
    return false;
  }
  discovery_callbacks_.erase(service_type);
  if (discovery_services_.contains(service_type)) {
    discovery_services_.erase(service_type);
  }
  NEARBY_LOGS(INFO) << "WifiLan Discovery disabled for service_type="
                    << service_type << ", impl=" << &GetImpl();
  return impl_->StopDiscovery(service_type);
}

WifiLanSocket WifiLanMedium::ConnectToService(
    const NsdServiceInfo& remote_service_info,
    CancellationFlag* cancellation_flag) {
  NEARBY_LOGS(INFO) << "WifiLanMedium::ConnectToService: remote_service_name="
                    << remote_service_info.GetServiceName();
  return WifiLanSocket(
      impl_->ConnectToService(remote_service_info, cancellation_flag));
}

WifiLanSocket WifiLanMedium::ConnectToService(
    const std::string& ip_address, int port,
    CancellationFlag* cancellation_flag) {
  NEARBY_LOGS(INFO) << "WifiLanMedium::ConnectToService: ip address="
                    << ip_address << ", port=" << port;
  return WifiLanSocket(
      impl_->ConnectToService(ip_address, port, cancellation_flag));
}

}  // namespace nearby
}  // namespace location