// Copyright 2015 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "third_party/blink/renderer/platform/p2p/empty_network_manager.h"

#include "base/check_op.h"
#include "base/functional/bind.h"
#include "base/location.h"
#include "third_party/blink/renderer/platform/p2p/ipc_network_manager.h"

namespace blink {

EmptyNetworkManager::EmptyNetworkManager(IpcNetworkManager* network_manager)
    : EmptyNetworkManager(network_manager,
                          network_manager->AsWeakPtrForSignalingThread()) {}

// DO NOT dereference/check `network_manager_for_signaling_thread_` in the ctor!
// Doing so would bind its WeakFactory to the constructing thread (main thread)
// instead of the thread `this` lives in (signaling thread).
EmptyNetworkManager::EmptyNetworkManager(
    webrtc::NetworkManager* network_manager,
    base::WeakPtr<webrtc::NetworkManager> network_manager_for_signaling_thread)
    : network_manager_for_signaling_thread_(
          network_manager_for_signaling_thread) {
  DCHECK(network_manager);
  DETACH_FROM_THREAD(thread_checker_);
  set_enumeration_permission(ENUMERATION_BLOCKED);
}

EmptyNetworkManager::~EmptyNetworkManager() {
  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
  if (network_manager_for_signaling_thread_) {
    network_manager_for_signaling_thread_->UnsubscribeNetworksChanged(this);
  }
}

void EmptyNetworkManager::StartUpdating() {
  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
  DCHECK(network_manager_for_signaling_thread_);

  if (!subscribe_networks_changed_called_) {
    subscribe_networks_changed_called_ = true;
    network_manager_for_signaling_thread_->SubscribeNetworksChanged(
        this, [this]() { OnNetworksChanged(); });
  }

  ++start_count_;
  network_manager_for_signaling_thread_->StartUpdating();
}

void EmptyNetworkManager::StopUpdating() {
  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);

  if (network_manager_for_signaling_thread_)
    network_manager_for_signaling_thread_->StopUpdating();

  --start_count_;
  DCHECK_GE(start_count_, 0);
}

std::vector<const webrtc::Network*> EmptyNetworkManager::GetNetworks() const {
  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
  return {};
}

bool EmptyNetworkManager::GetDefaultLocalAddress(
    int family,
    webrtc::IPAddress* ipaddress) const {
  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
  DCHECK(network_manager_for_signaling_thread_);
  return network_manager_for_signaling_thread_->GetDefaultLocalAddress(
      family, ipaddress);
}

void EmptyNetworkManager::OnNetworksChanged() {
  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);

  if (!start_count_)
    return;

  NotifyNetworksChanged();
}

}  // namespace blink