/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this file,
 * You can obtain one at http://mozilla.org/MPL/2.0/. */

// Original author: ekr@rtfm.com

#ifndef transportlayerloopback_h_
#define transportlayerloopback_h_

#include <queue>

#include "m_cpp_utils.h"
#include "nsCOMPtr.h"
#include "nsINamed.h"
#include "nsITimer.h"
#include "prlock.h"
#include "transportlayer.h"

// A simple loopback transport layer that is used for testing.
namespace mozilla {

class TransportLayerLoopback : public TransportLayer {
 public:
  TransportLayerLoopback()
      : peer_(nullptr),
        timer_(nullptr),
        packets_lock_(nullptr),
        deliverer_(nullptr),
        combinePackets_(false) {}

  ~TransportLayerLoopback() {
    while (!packets_.empty()) {
      MediaPacket* packet = packets_.front();
      packets_.pop();
      delete packet;
    }
    if (packets_lock_) {
      PR_DestroyLock(packets_lock_);
    }
    timer_->Cancel();
    deliverer_->Detach();
  }

  // Init
  nsresult Init();

  // Connect to the other side
  void Connect(TransportLayerLoopback* peer);

  // Disconnect
  void Disconnect() {
    TransportLayerLoopback* peer = peer_;

    peer_ = nullptr;
    if (peer) {
      peer->Disconnect();
    }
  }

  void CombinePackets(bool combine) { combinePackets_ = combine; }

  // Overrides for TransportLayer
  TransportResult SendPacket(MediaPacket& packet) override;

  // Deliver queued packets
  void DeliverPackets();

  TRANSPORT_LAYER_ID("loopback")

 private:
  DISALLOW_COPY_ASSIGN(TransportLayerLoopback);

  // A timer to deliver packets if some are available
  // Fires every 100 ms
  class Deliverer : public nsITimerCallback, public nsINamed {
   public:
    explicit Deliverer(TransportLayerLoopback* layer) : layer_(layer) {}
    void Detach() { layer_ = nullptr; }

    NS_DECL_THREADSAFE_ISUPPORTS
    NS_DECL_NSITIMERCALLBACK
    NS_DECL_NSINAMED

   private:
    virtual ~Deliverer() = default;

    DISALLOW_COPY_ASSIGN(Deliverer);

    TransportLayerLoopback* layer_;
  };

  // Queue a packet for delivery
  nsresult QueuePacket(MediaPacket& packet);

  TransportLayerLoopback* peer_;
  nsCOMPtr<nsITimer> timer_;
  std::queue<MediaPacket*> packets_;
  PRLock* packets_lock_;
  RefPtr<Deliverer> deliverer_;
  bool combinePackets_;
};

}  // namespace mozilla
#endif