// Copyright 2013 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef THIRD_PARTY_BLINK_RENDERER_PLATFORM_P2P_SOCKET_CLIENT_IMPL_H_
#define THIRD_PARTY_BLINK_RENDERER_PLATFORM_P2P_SOCKET_CLIENT_IMPL_H_

#include <stdint.h>

#include "base/memory/raw_ptr.h"
#include "base/threading/thread_checker.h"
#include "mojo/public/cpp/bindings/pending_receiver.h"
#include "mojo/public/cpp/bindings/pending_remote.h"
#include "mojo/public/cpp/bindings/receiver.h"
#include "mojo/public/cpp/bindings/remote.h"
#include "net/base/ip_endpoint.h"
#include "net/traffic_annotation/network_traffic_annotation.h"
#include "services/network/public/cpp/p2p_socket_type.h"
#include "services/network/public/mojom/p2p.mojom-blink.h"
#include "third_party/blink/renderer/platform/heap/cross_thread_persistent.h"
#include "third_party/blink/renderer/platform/p2p/socket_client.h"
#include "third_party/blink/renderer/platform/platform_export.h"
#include "third_party/blink/renderer/platform/wtf/vector.h"

namespace blink {

using network::mojom::blink::P2PReceivedPacketPtr;

class P2PSocketDispatcher;

// P2P socket that routes all calls over Mojo.
//
// The object is created and runs on the WebRTC worker thread.
class PLATFORM_EXPORT P2PSocketClientImpl
    : public blink::P2PSocketClient,
      public network::mojom::blink::P2PSocketClient {
 public:
  explicit P2PSocketClientImpl(bool batch_packets);
  P2PSocketClientImpl(const P2PSocketClientImpl&) = delete;
  P2PSocketClientImpl& operator=(const P2PSocketClientImpl&) = delete;
  ~P2PSocketClientImpl() override;

  // Initialize socket of the specified |type| and connected to the
  // specified |address|. |address| matters only when |type| is set to
  // P2P_SOCKET_TCP_CLIENT.
  virtual void Init(blink::P2PSocketClientDelegate* delegate);

  // Send the |data| to the |address| using Differentiated Services Code Point
  // |dscp|. Return value is the unique packet_id for this packet.
  uint64_t Send(const net::IPEndPoint& address,
                base::span<const uint8_t> data,
                const webrtc::AsyncSocketPacketOptions& options) override;
  void FlushBatch() override;

  // Setting socket options.
  void SetOption(network::P2PSocketOption option, int value) override;

  // Must be called before the socket is destroyed. The delegate may
  // not be called after |closed_task| is executed.
  void Close() override;

  int GetSocketID() const override;

  void SetDelegate(blink::P2PSocketClientDelegate* delegate) override;

  mojo::PendingReceiver<network::mojom::blink::P2PSocket>
  CreatePendingReceiver() {
    return socket_.BindNewPipeAndPassReceiver();
  }
  mojo::PendingRemote<network::mojom::blink::P2PSocketClient>
  CreatePendingRemote() {
    return receiver_.BindNewPipeAndPassRemote();
  }

 private:
  enum State {
    kStateUninitialized,
    kStateOpening,
    kStateOpen,
    kStateClosed,
    kStateError,
  };

  friend class P2PSocketDispatcher;

  // Helper function to be called by Send to handle different threading
  // condition.
  void SendWithPacketId(const net::IPEndPoint& address,
                        base::span<const uint8_t> data,
                        const webrtc::AsyncSocketPacketOptions& options,
                        uint64_t packet_id);

  // network::mojom::blink::P2PSocketClient interface.
  void SocketCreated(const net::IPEndPoint& local_address,
                     const net::IPEndPoint& remote_address) override;
  void SendComplete(const network::P2PSendPacketMetrics& send_metrics) override;
  void SendBatchComplete(const Vector<::network::P2PSendPacketMetrics>&
                             in_send_metrics_batch) override;
  void DataReceived(Vector<P2PReceivedPacketPtr> packets) override;
  void DoSendBatch();

  void OnConnectionError();

  THREAD_CHECKER(thread_checker_);
  const bool batch_packets_;
  int socket_id_;
  raw_ptr<blink::P2PSocketClientDelegate> delegate_;
  State state_;

  // Packets sent with webrtc::AsyncSocketPacketOptions::batchable being true
  // are collected here until a packet with
  // webrtc::AsyncSocketPacketOptions::last_packet_in_batch is signalled.
  Vector<network::mojom::blink::P2PSendPacketPtr> batched_send_packets_;
  Vector<Vector<uint8_t>> batched_packets_storage_;
  // Attribute recording if we're currently awaiting OnSendWatchComplete.
  bool awaiting_batch_complete_ = false;

  // These two fields are used to identify packets for tracing.
  uint32_t random_socket_id_;
  uint32_t next_packet_id_;

  mojo::Remote<network::mojom::blink::P2PSocket> socket_;
  mojo::Receiver<network::mojom::blink::P2PSocketClient> receiver_{this};
};

}  // namespace blink

#endif  // THIRD_PARTY_BLINK_RENDERER_PLATFORM_P2P_SOCKET_CLIENT_IMPL_H_