#include <rtcutil/Conductor.h>

#include <webrtc/api/create_peerconnection_factory.h>
#include <webrtc/api/audio_codecs/builtin_audio_encoder_factory.h>
#include <webrtc/api/audio_codecs/builtin_audio_decoder_factory.h>
#include <webrtc/api/video_codecs/builtin_video_encoder_factory.h>
#include <webrtc/api/video_codecs/builtin_video_decoder_factory.h>
#include <webrtc/pc/video_track_source.h>
#include <stdio.h>
#include <stdlib.h>

namespace rtcutil {

void ConductorObserver::onError(ErrorType type, std::string err) {
	if (type == ErrorType::WARNING) {
		fprintf(stderr, "Warning: %s\n", err.c_str());
	} else {
		fprintf(stderr, "Error: %s\n", err.c_str());
		abort();
	}
}

class SetSessionDescriptionObserver: public webrtc::SetSessionDescriptionObserver {
public:
	SetSessionDescriptionObserver(ConductorObserver &observer): observer_(observer) {}

	static SetSessionDescriptionObserver* Create(ConductorObserver &observer) {
		return new rtc::RefCountedObject<SetSessionDescriptionObserver>(observer);
	}

	virtual void OnSuccess() {}
	virtual void OnFailure(webrtc::RTCError error) {
		observer_.onError(ConductorObserver::ErrorType::RECEIVE_OFFER,
				error.message());
	}

private:
	ConductorObserver &observer_;
};

void Conductor::receiveOffer(const std::string &sdp) {
	printf("receive offer 1\n");
	webrtc::SdpParseError error;
	std::unique_ptr<webrtc::SessionDescriptionInterface> desc =
		webrtc::CreateSessionDescription(webrtc::SdpType::kOffer, sdp, &error);
	if (!desc.get()) {
		observer_.onError(ConductorObserver::ErrorType::RECEIVE_OFFER,
				std::move(error.description));
		return;
	}

	receiveOffer(std::move(desc));
}

void Conductor::receiveOffer(std::unique_ptr<webrtc::SessionDescriptionInterface> offer) {
	printf("receive offer 2\n");
	ensurePeerConnection();

	peer_conn_->SetRemoteDescription(
			SetSessionDescriptionObserver::Create(observer_),
			offer.release());

	peer_conn_->CreateAnswer(
			this, webrtc::PeerConnectionInterface::RTCOfferAnswerOptions());
}

void Conductor::receiveIceCandidate(std::string mid, int index, std::string sdp) {
	printf("receive ice candidate\n");
	webrtc::SdpParseError error;
	std::unique_ptr<webrtc::IceCandidateInterface> candidate(
			webrtc::CreateIceCandidate(mid, index, sdp, &error));
	if (!candidate.get()) {
		observer_.onError(ConductorObserver::ErrorType::WARNING,
				std::move(error.description));
		return;
	}

	if (!peer_conn_->AddIceCandidate(candidate.get())) {
		observer_.onError(ConductorObserver::ErrorType::WARNING,
				"Failed to apply the received candidate");
		return;
	}
}

void Conductor::ensurePeerConnection() {
	if (peer_conn_factory_.get())
		return;

	peer_conn_factory_ = doCreatePeerConnectionFactory();
	peer_conn_ = doCreatePeerConnection(*peer_conn_factory_);
}

void Conductor::OnAddTrack(
		rtc::scoped_refptr<webrtc::RtpReceiverInterface> receiver,
		const std::vector<rtc::scoped_refptr<webrtc::MediaStreamInterface>> &streams) {
	observer_.onRemoteTrack(std::move(receiver->track()));
}

void Conductor::OnRemoveTrack(
		rtc::scoped_refptr<webrtc::RtpReceiverInterface> receiver) {
	observer_.removeRemoteTrack(std::move(receiver->track()));
}

void Conductor::OnIceCandidate(const webrtc::IceCandidateInterface* candidate) {
	std::string sdp;
	if (!candidate->ToString(&sdp)) {
		observer_.onError(ConductorObserver::ErrorType::WARNING,
				"Failed to serialize candidate");
		return;
	}

	observer_.onIceCandidate(
			std::move(candidate->sdp_mid()),
			candidate->sdp_mline_index(),
			std::move(sdp));
}

rtc::scoped_refptr<webrtc::PeerConnectionFactoryInterface>
Conductor::doCreatePeerConnectionFactory() {
	return webrtc::CreatePeerConnectionFactory(
			nullptr /* network_thread */, nullptr /* worker_thread */,
			nullptr /* signaling_thread */, nullptr /* default_adm */,
			webrtc::CreateBuiltinAudioEncoderFactory(),
			webrtc::CreateBuiltinAudioDecoderFactory(),
			webrtc::CreateBuiltinVideoEncoderFactory(),
			webrtc::CreateBuiltinVideoDecoderFactory(), nullptr /* audio_mixer */,
			nullptr /* audio_processing */);
}

rtc::scoped_refptr<webrtc::PeerConnectionInterface>
Conductor::doCreatePeerConnection(webrtc::PeerConnectionFactoryInterface &factory) {
	webrtc::PeerConnectionInterface::RTCConfiguration config;
	config.sdp_semantics = webrtc::SdpSemantics::kUnifiedPlan;

	webrtc::PeerConnectionInterface::IceServer server;
	const char *uri = getenv("WEBRTC_CONNECT");
	if (uri) {
		server.uri = uri;
	} else {
		server.uri = "stun:stun.l.google.com:19302";
	}
	config.servers.push_back(server);

	rtc::scoped_refptr<webrtc::PeerConnectionInterface> conn =
		factory.CreatePeerConnection(
				config, nullptr, nullptr, this);

	doAddTracks(*conn);

	return conn;
}

void Conductor::OnSuccess(webrtc::SessionDescriptionInterface *desc) {
	fprintf(stderr, "on success; got answer\n");
	peer_conn_->SetLocalDescription(
			SetSessionDescriptionObserver::Create(observer_), desc);

	std::string sdp;
	desc->ToString(&sdp);
	observer_.onAnswer(std::move(sdp));
}

void Conductor::OnFailure(webrtc::RTCError error) {
	observer_.onError(ConductorObserver::ErrorType::WARNING,
			error.message());
}

}