/*
 *  Copyright 2017 The WebRTC project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */

#include "pc/rtp_transceiver.h"

#include <algorithm>
#include <string>

#include "pc/rtp_media_utils.h"
#include "rtc_base/checks.h"
#include "rtc_base/logging.h"

namespace webrtc {

RtpTransceiver::RtpTransceiver(cricket::MediaType media_type)
    : unified_plan_(false), media_type_(media_type) {
  RTC_DCHECK(media_type == cricket::MEDIA_TYPE_AUDIO ||
             media_type == cricket::MEDIA_TYPE_VIDEO);
}

RtpTransceiver::RtpTransceiver(
    rtc::scoped_refptr<RtpSenderProxyWithInternal<RtpSenderInternal>> sender,
    rtc::scoped_refptr<RtpReceiverProxyWithInternal<RtpReceiverInternal>>
        receiver)
    : unified_plan_(true), media_type_(sender->media_type()) {
  RTC_DCHECK(media_type_ == cricket::MEDIA_TYPE_AUDIO ||
             media_type_ == cricket::MEDIA_TYPE_VIDEO);
  RTC_DCHECK_EQ(sender->media_type(), receiver->media_type());
  senders_.push_back(sender);
  receivers_.push_back(receiver);
}

RtpTransceiver::~RtpTransceiver() {
  Stop();
}

void RtpTransceiver::SetChannel(cricket::ChannelInterface* channel) {
  // Cannot set a non-null channel on a stopped transceiver.
  if (stopped_ && channel) {
    return;
  }

  if (channel) {
    RTC_DCHECK_EQ(media_type(), channel->media_type());
  }

  if (channel_) {
    channel_->SignalFirstPacketReceived().disconnect(this);
  }

  channel_ = channel;

  if (channel_) {
    channel_->SignalFirstPacketReceived().connect(
        this, &RtpTransceiver::OnFirstPacketReceived);
  }

  for (auto sender : senders_) {
    sender->internal()->SetMediaChannel(channel_ ? channel_->media_channel()
                                                 : nullptr);
  }

  for (auto receiver : receivers_) {
    if (!channel_) {
      receiver->internal()->Stop();
    }

    receiver->internal()->SetMediaChannel(channel_ ? channel_->media_channel()
                                                   : nullptr);
  }
}

void RtpTransceiver::AddSender(
    rtc::scoped_refptr<RtpSenderProxyWithInternal<RtpSenderInternal>> sender) {
  RTC_DCHECK(!stopped_);
  RTC_DCHECK(!unified_plan_);
  RTC_DCHECK(sender);
  RTC_DCHECK_EQ(media_type(), sender->media_type());
  RTC_DCHECK(std::find(senders_.begin(), senders_.end(), sender) ==
             senders_.end());
  senders_.push_back(sender);
}

bool RtpTransceiver::RemoveSender(RtpSenderInterface* sender) {
  RTC_DCHECK(!unified_plan_);
  if (sender) {
    RTC_DCHECK_EQ(media_type(), sender->media_type());
  }
  auto it = std::find(senders_.begin(), senders_.end(), sender);
  if (it == senders_.end()) {
    return false;
  }
  (*it)->internal()->Stop();
  senders_.erase(it);
  return true;
}

void RtpTransceiver::AddReceiver(
    rtc::scoped_refptr<RtpReceiverProxyWithInternal<RtpReceiverInternal>>
        receiver) {
  RTC_DCHECK(!stopped_);
  RTC_DCHECK(!unified_plan_);
  RTC_DCHECK(receiver);
  RTC_DCHECK_EQ(media_type(), receiver->media_type());
  RTC_DCHECK(std::find(receivers_.begin(), receivers_.end(), receiver) ==
             receivers_.end());
  receivers_.push_back(receiver);
}

bool RtpTransceiver::RemoveReceiver(RtpReceiverInterface* receiver) {
  RTC_DCHECK(!unified_plan_);
  if (receiver) {
    RTC_DCHECK_EQ(media_type(), receiver->media_type());
  }
  auto it = std::find(receivers_.begin(), receivers_.end(), receiver);
  if (it == receivers_.end()) {
    return false;
  }
  (*it)->internal()->Stop();
  receivers_.erase(it);
  return true;
}

rtc::scoped_refptr<RtpSenderInternal> RtpTransceiver::sender_internal() const {
  RTC_DCHECK(unified_plan_);
  RTC_CHECK_EQ(1u, senders_.size());
  return senders_[0]->internal();
}

rtc::scoped_refptr<RtpReceiverInternal> RtpTransceiver::receiver_internal()
    const {
  RTC_DCHECK(unified_plan_);
  RTC_CHECK_EQ(1u, receivers_.size());
  return receivers_[0]->internal();
}

cricket::MediaType RtpTransceiver::media_type() const {
  return media_type_;
}

absl::optional<std::string> RtpTransceiver::mid() const {
  return mid_;
}

void RtpTransceiver::OnFirstPacketReceived(cricket::ChannelInterface*) {
  for (auto receiver : receivers_) {
    receiver->internal()->NotifyFirstPacketReceived();
  }
}

rtc::scoped_refptr<RtpSenderInterface> RtpTransceiver::sender() const {
  RTC_DCHECK(unified_plan_);
  RTC_CHECK_EQ(1u, senders_.size());
  return senders_[0];
}

rtc::scoped_refptr<RtpReceiverInterface> RtpTransceiver::receiver() const {
  RTC_DCHECK(unified_plan_);
  RTC_CHECK_EQ(1u, receivers_.size());
  return receivers_[0];
}

void RtpTransceiver::set_current_direction(RtpTransceiverDirection direction) {
  RTC_LOG(LS_INFO) << "Changing transceiver (MID=" << mid_.value_or("<not set>")
                   << ") current direction from "
                   << (current_direction_ ? RtpTransceiverDirectionToString(
                                                *current_direction_)
                                          : "<not set>")
                   << " to " << RtpTransceiverDirectionToString(direction)
                   << ".";
  current_direction_ = direction;
  if (RtpTransceiverDirectionHasSend(*current_direction_)) {
    has_ever_been_used_to_send_ = true;
  }
}

void RtpTransceiver::set_fired_direction(RtpTransceiverDirection direction) {
  fired_direction_ = direction;
}

bool RtpTransceiver::stopped() const {
  return stopped_;
}

RtpTransceiverDirection RtpTransceiver::direction() const {
  return direction_;
}

void RtpTransceiver::SetDirection(RtpTransceiverDirection new_direction) {
  if (stopped()) {
    return;
  }
  if (new_direction == direction_) {
    return;
  }
  direction_ = new_direction;
  SignalNegotiationNeeded();
}

absl::optional<RtpTransceiverDirection> RtpTransceiver::current_direction()
    const {
  return current_direction_;
}

absl::optional<RtpTransceiverDirection> RtpTransceiver::fired_direction()
    const {
  return fired_direction_;
}

void RtpTransceiver::Stop() {
  for (auto sender : senders_) {
    sender->internal()->Stop();
  }
  for (auto receiver : receivers_) {
    receiver->internal()->Stop();
  }
  stopped_ = true;
  current_direction_ = absl::nullopt;
}

void RtpTransceiver::SetCodecPreferences(
    rtc::ArrayView<RtpCodecCapability> codecs) {
  // TODO(steveanton): Implement this.
  RTC_NOTREACHED() << "Not implemented";
}

}  // namespace webrtc