#include <webrtc/api/peer_connection_interface.h>
#include <memory>

namespace rtcutil {

class ConductorObserver {
public:
	enum class ErrorType {
		WARNING,
		RECEIVE_OFFER,
		RECEIVE_ICE_CANDIDATE,
		CREATE_ANSWER,
	};

	virtual void onError(ErrorType type, std::string err);

	virtual void onIceCandidate(std::string mid, int index, std::string sdp) = 0;
	virtual void onAnswer(std::string sdp) = 0;
	virtual void onRemoteTrack(rtc::scoped_refptr<webrtc::MediaStreamTrackInterface> track) = 0;
	virtual void removeRemoteTrack(rtc::scoped_refptr<webrtc::MediaStreamTrackInterface> track) = 0;
};

class Conductor:
		public webrtc::PeerConnectionObserver,
		public webrtc::CreateSessionDescriptionObserver {
public:
	Conductor(ConductorObserver &observer): observer_(observer) {}

	void receiveOffer(const std::string &sdp);
	void receiveOffer(std::unique_ptr<webrtc::SessionDescriptionInterface> offer);
	void receiveIceCandidate(std::string mid, int index, std::string sdp);

	void ensurePeerConnection();

protected:
	// PeerConnectionObserver
	void OnAddTrack(
			rtc::scoped_refptr<webrtc::RtpReceiverInterface> receiver,
			const std::vector<rtc::scoped_refptr<webrtc::MediaStreamInterface>> &streams) override;
	void OnRemoveTrack(
			rtc::scoped_refptr<webrtc::RtpReceiverInterface> receiver) override;
	void OnIceCandidate(const webrtc::IceCandidateInterface *candidate) override;

	void OnSignalingChange(
			webrtc::PeerConnectionInterface::SignalingState new_state) override {}
	void OnDataChannel(
			rtc::scoped_refptr<webrtc::DataChannelInterface> channel) override {}
	void OnRenegotiationNeeded() override {}
	void OnIceConnectionChange(
			webrtc::PeerConnectionInterface::IceConnectionState new_state) override {}
	void OnIceGatheringChange(
			webrtc::PeerConnectionInterface::IceGatheringState new_state) override {}
	void OnIceConnectionReceivingChange(bool receiving) override {}

	// CreateSessionDescriptionObserver
	void OnSuccess(webrtc::SessionDescriptionInterface* desc) override;
	void OnFailure(webrtc::RTCError error) override;

	// Overridables for consumers
	virtual rtc::scoped_refptr<webrtc::PeerConnectionFactoryInterface>
	doCreatePeerConnectionFactory();
	virtual rtc::scoped_refptr<webrtc::PeerConnectionInterface>
	doCreatePeerConnection(webrtc::PeerConnectionFactoryInterface &factory);
	virtual void doAddTracks(webrtc::PeerConnectionInterface &conn) {};

	ConductorObserver &observer_;
	rtc::scoped_refptr<webrtc::PeerConnectionFactoryInterface> peer_conn_factory_;
	rtc::scoped_refptr<webrtc::PeerConnectionInterface> peer_conn_;
};

}