conversations-classic/src/main/java/eu/siacs/conversations/xmpp/jingle/JingleRtpConnection.java

package eu.siacs.conversations.xmpp.jingle;

import android.util.Log;

import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;

import org.webrtc.AudioSource;
import org.webrtc.AudioTrack;
import org.webrtc.DataChannel;
import org.webrtc.IceCandidate;
import org.webrtc.MediaConstraints;
import org.webrtc.MediaStream;
import org.webrtc.PeerConnection;
import org.webrtc.PeerConnectionFactory;
import org.webrtc.RtpReceiver;
import org.webrtc.SdpObserver;

import java.util.ArrayDeque;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.Map;

import eu.siacs.conversations.Config;
import eu.siacs.conversations.xml.Element;
import eu.siacs.conversations.xml.Namespace;
import eu.siacs.conversations.xmpp.jingle.stanzas.Group;
import eu.siacs.conversations.xmpp.jingle.stanzas.IceUdpTransportInfo;
import eu.siacs.conversations.xmpp.jingle.stanzas.JinglePacket;
import eu.siacs.conversations.xmpp.stanzas.MessagePacket;
import rocks.xmpp.addr.Jid;

public class JingleRtpConnection extends AbstractJingleConnection {

    private static final Map<State, Collection<State>> VALID_TRANSITIONS;

    static {
        final ImmutableMap.Builder<State, Collection<State>> transitionBuilder = new ImmutableMap.Builder<>();
        transitionBuilder.put(State.NULL, ImmutableList.of(State.PROPOSED, State.SESSION_INITIALIZED));
        transitionBuilder.put(State.PROPOSED, ImmutableList.of(State.ACCEPTED, State.PROCEED));
        transitionBuilder.put(State.PROCEED, ImmutableList.of(State.SESSION_INITIALIZED));
        VALID_TRANSITIONS = transitionBuilder.build();
    }

    private State state = State.NULL;
    private RtpContentMap initialRtpContentMap;
    private PeerConnection peerConnection;

    private final ArrayDeque<IceCandidate> pendingIceCandidates = new ArrayDeque<>();


    public JingleRtpConnection(JingleConnectionManager jingleConnectionManager, Id id, Jid initiator) {
        super(jingleConnectionManager, id, initiator);
    }

    @Override
    void deliverPacket(final JinglePacket jinglePacket) {
        Log.d(Config.LOGTAG, id.account.getJid().asBareJid() + ": packet delivered to JingleRtpConnection");
        switch (jinglePacket.getAction()) {
            case SESSION_INITIATE:
                receiveSessionInitiate(jinglePacket);
                break;
            case TRANSPORT_INFO:
                receiveTransportInfo(jinglePacket);
                break;
            default:
                Log.d(Config.LOGTAG, String.format("%s: received unhandled jingle action %s", id.account.getJid().asBareJid(), jinglePacket.getAction()));
                break;
        }
    }

    private void receiveTransportInfo(final JinglePacket jinglePacket) {
        if (isInState(State.SESSION_INITIALIZED, State.SESSION_ACCEPTED)) {
            final RtpContentMap contentMap;
            try {
                contentMap = RtpContentMap.of(jinglePacket);
            } catch (IllegalArgumentException | NullPointerException e) {
                Log.d(Config.LOGTAG, id.account.getJid().asBareJid() + ": improperly formatted contents", e);
                return;
            }
            final Group originalGroup = this.initialRtpContentMap != null ? this.initialRtpContentMap.group : null;
            final List<String> identificationTags = originalGroup == null ? Collections.emptyList() : originalGroup.getIdentificationTags();
            if (identificationTags.size() == 0) {
                Log.w(Config.LOGTAG,id.account.getJid().asBareJid()+": no identification tags found in initial offer. we won't be able to calculate mLineIndices");
            }
            for(final Map.Entry<String, RtpContentMap.DescriptionTransport> content : contentMap.contents.entrySet()) {
                final String ufrag = content.getValue().transport.getAttribute("ufrag");
                for(final IceUdpTransportInfo.Candidate candidate : content.getValue().transport.getCandidates()) {
                    final String sdp = candidate.toSdpAttribute(ufrag);
                    final String sdpMid = content.getKey();
                    final int mLineIndex = identificationTags.indexOf(sdpMid);
                    final IceCandidate iceCandidate = new IceCandidate(sdpMid, mLineIndex, sdp);
                    Log.d(Config.LOGTAG,"received candidate: "+iceCandidate);
                    if (isInState(State.SESSION_ACCEPTED)) {
                        this.peerConnection.addIceCandidate(iceCandidate);
                    } else {
                        this.pendingIceCandidates.push(iceCandidate);
                    }
                }
            }
        } else {
            Log.d(Config.LOGTAG, id.account.getJid().asBareJid() + ": received transport info while in state=" + this.state);
        }
    }

    private void receiveSessionInitiate(final JinglePacket jinglePacket) {
        Log.d(Config.LOGTAG, jinglePacket.toString());
        if (isInitiator()) {
            Log.d(Config.LOGTAG, String.format("%s: received session-initiate even though we were initiating", id.account.getJid().asBareJid()));
            //TODO respond with out-of-order
            return;
        }
        final RtpContentMap contentMap;
        try {
            contentMap = RtpContentMap.of(jinglePacket);
            contentMap.requireContentDescriptions();
        } catch (IllegalArgumentException | IllegalStateException | NullPointerException e) {
            Log.d(Config.LOGTAG, id.account.getJid().asBareJid() + ": improperly formatted contents", e);
            return;
        }
        Log.d(Config.LOGTAG, "processing session-init with " + contentMap.contents.size() + " contents");
        final State oldState = this.state;
        if (transition(State.SESSION_INITIALIZED)) {
            this.initialRtpContentMap = contentMap;
            if (oldState == State.PROCEED) {
                processContents(contentMap);
                sendSessionAccept();
            } else {
                //TODO start ringing
            }
        } else {
            Log.d(Config.LOGTAG, String.format("%s: received session-initiate while in state %s", id.account.getJid().asBareJid(), state));
        }
    }

    private void processContents(final RtpContentMap contentMap) {
        setupWebRTC();
        org.webrtc.SessionDescription sessionDescription = new org.webrtc.SessionDescription(org.webrtc.SessionDescription.Type.OFFER, SessionDescription.of(contentMap).toString());
        Log.d(Config.LOGTAG, "debug print for sessionDescription:" + sessionDescription.description);
        this.peerConnection.setRemoteDescription(new SdpObserver() {
            @Override
            public void onCreateSuccess(org.webrtc.SessionDescription sessionDescription) {

            }

            @Override
            public void onSetSuccess() {
                Log.d(Config.LOGTAG, "onSetSuccess() for setRemoteDescription");
            }

            @Override
            public void onCreateFailure(String s) {

            }

            @Override
            public void onSetFailure(String s) {
                Log.d(Config.LOGTAG, "onSetFailure() for setRemoteDescription. " + s);

            }
        }, sessionDescription);
    }

    void deliveryMessage(final Jid from, final Element message) {
        Log.d(Config.LOGTAG, id.account.getJid().asBareJid() + ": delivered message to JingleRtpConnection " + message);
        switch (message.getName()) {
            case "propose":
                receivePropose(from, message);
                break;
            case "proceed":
                receiveProceed(from, message);
            default:
                break;
        }
    }

    private void receivePropose(final Jid from, final Element propose) {
        final boolean originatedFromMyself = from.asBareJid().equals(id.account.getJid().asBareJid());
        if (originatedFromMyself) {
            Log.d(Config.LOGTAG, id.account.getJid().asBareJid() + ": saw proposal from mysql. ignoring");
        } else if (transition(State.PROPOSED)) {
            //TODO start ringing or something
            pickUpCall();
        } else {
            Log.d(Config.LOGTAG, id.account.getJid() + ": ignoring session proposal because already in " + state);
        }
    }

    private void receiveProceed(final Jid from, final Element proceed) {
        if (from.equals(id.with)) {
            if (isInitiator()) {
                if (transition(State.PROCEED)) {
                    this.sendSessionInitiate();
                } else {
                    Log.d(Config.LOGTAG, String.format("%s: ignoring proceed because already in %s", id.account.getJid().asBareJid(), this.state));
                }
            } else {
                Log.d(Config.LOGTAG, String.format("%s: ignoring proceed because we were not initializing", id.account.getJid().asBareJid()));
            }
        } else {
            Log.d(Config.LOGTAG, String.format("%s: ignoring proceed from %s. was expected from %s", id.account.getJid().asBareJid(), from, id.with));
        }
    }

    private void sendSessionInitiate() {
        Log.d(Config.LOGTAG, id.account.getJid().asBareJid() + ": prepare session-initiate");
        setupWebRTC();
        createOffer();
    }

    private void sendSessionInitiate(RtpContentMap rtpContentMap) {
        this.initialRtpContentMap = rtpContentMap;
        final JinglePacket sessionInitiate = rtpContentMap.toJinglePacket(JinglePacket.Action.SESSION_INITIATE, id.sessionId);
        Log.d(Config.LOGTAG, sessionInitiate.toString());
        Log.d(Config.LOGTAG, "here is what we think the sdp looks like" + SessionDescription.of(rtpContentMap).toString());
        send(sessionInitiate);
    }

    private void sendTransportInfo(final String contentName, IceUdpTransportInfo.Candidate candidate) {
        final RtpContentMap transportInfo;
        try {
            transportInfo = this.initialRtpContentMap.transportInfo(contentName, candidate);
        } catch (Exception e) {
            Log.d(Config.LOGTAG, id.account.getJid().asBareJid() + ": unable to prepare transport-info from candidate for content=" + contentName);
            return;
        }
        final JinglePacket jinglePacket = transportInfo.toJinglePacket(JinglePacket.Action.TRANSPORT_INFO, id.sessionId);
        Log.d(Config.LOGTAG, jinglePacket.toString());
        send(jinglePacket);
    }

    private void send(final JinglePacket jinglePacket) {
        jinglePacket.setTo(id.with);
        //TODO track errors
        xmppConnectionService.sendIqPacket(id.account, jinglePacket, null);
    }


    private void sendSessionAccept() {
        Log.d(Config.LOGTAG, "sending session-accept");
    }

    public void pickUpCall() {
        switch (this.state) {
            case PROPOSED:
                pickupCallFromProposed();
                break;
            case SESSION_INITIALIZED:
                pickupCallFromSessionInitialized();
                break;
            default:
                throw new IllegalStateException("Can not pick up call from " + this.state);
        }
    }

    private void setupWebRTC() {
        PeerConnectionFactory.initialize(
                PeerConnectionFactory.InitializationOptions.builder(xmppConnectionService).createInitializationOptions()
        );
        final PeerConnectionFactory.Options options = new PeerConnectionFactory.Options();
        PeerConnectionFactory peerConnectionFactory = PeerConnectionFactory.builder().createPeerConnectionFactory();

        final AudioSource audioSource = peerConnectionFactory.createAudioSource(new MediaConstraints());

        final AudioTrack audioTrack = peerConnectionFactory.createAudioTrack("my-audio-track", audioSource);
        final MediaStream stream = peerConnectionFactory.createLocalMediaStream("my-media-stream");
        stream.addTrack(audioTrack);


        final List<PeerConnection.IceServer> iceServers = ImmutableList.of(
                PeerConnection.IceServer.builder("stun:xmpp.conversations.im:3478").createIceServer()
        );
        this.peerConnection = peerConnectionFactory.createPeerConnection(iceServers, new PeerConnection.Observer() {
            @Override
            public void onSignalingChange(PeerConnection.SignalingState signalingState) {

            }

            @Override
            public void onIceConnectionChange(PeerConnection.IceConnectionState iceConnectionState) {

            }

            @Override
            public void onIceConnectionReceivingChange(boolean b) {

            }

            @Override
            public void onIceGatheringChange(PeerConnection.IceGatheringState iceGatheringState) {
                Log.d(Config.LOGTAG, "onIceGatheringChange() " + iceGatheringState);
            }

            @Override
            public void onIceCandidate(IceCandidate iceCandidate) {
                IceUdpTransportInfo.Candidate candidate = IceUdpTransportInfo.Candidate.fromSdpAttribute(iceCandidate.sdp);
                Log.d(Config.LOGTAG, "onIceCandidate: " + iceCandidate.sdp + " mLineIndex=" + iceCandidate.sdpMLineIndex);
                sendTransportInfo(iceCandidate.sdpMid, candidate);

            }

            @Override
            public void onIceCandidatesRemoved(IceCandidate[] iceCandidates) {

            }

            @Override
            public void onAddStream(MediaStream mediaStream) {

            }

            @Override
            public void onRemoveStream(MediaStream mediaStream) {

            }

            @Override
            public void onDataChannel(DataChannel dataChannel) {

            }

            @Override
            public void onRenegotiationNeeded() {

            }

            @Override
            public void onAddTrack(RtpReceiver rtpReceiver, MediaStream[] mediaStreams) {

            }
        });

        peerConnection.addStream(stream);
    }

    private void createOffer() {
        Log.d(Config.LOGTAG, "createOffer()");
        peerConnection.createOffer(new SdpObserver() {

            @Override
            public void onCreateSuccess(org.webrtc.SessionDescription description) {
                final SessionDescription sessionDescription = SessionDescription.parse(description.description);
                Log.d(Config.LOGTAG, "description: " + description.description);
                final RtpContentMap rtpContentMap = RtpContentMap.of(sessionDescription);
                sendSessionInitiate(rtpContentMap);
                peerConnection.setLocalDescription(new SdpObserver() {
                    @Override
                    public void onCreateSuccess(org.webrtc.SessionDescription sessionDescription) {

                    }

                    @Override
                    public void onSetSuccess() {
                        Log.d(Config.LOGTAG, "onSetSuccess()");
                    }

                    @Override
                    public void onCreateFailure(String s) {

                    }

                    @Override
                    public void onSetFailure(String s) {

                    }
                }, description);
            }

            @Override
            public void onSetSuccess() {

            }

            @Override
            public void onCreateFailure(String s) {

            }

            @Override
            public void onSetFailure(String s) {

            }
        }, new MediaConstraints());
    }

    private void pickupCallFromProposed() {
        transitionOrThrow(State.PROCEED);
        final MessagePacket messagePacket = new MessagePacket();
        messagePacket.setTo(id.with);
        //Note that Movim needs 'accept', correct is 'proceed' https://github.com/movim/movim/issues/916
        messagePacket.addChild("proceed", Namespace.JINGLE_MESSAGE).setAttribute("id", id.sessionId);
        Log.d(Config.LOGTAG, messagePacket.toString());
        xmppConnectionService.sendMessagePacket(id.account, messagePacket);
    }

    private void pickupCallFromSessionInitialized() {

    }

    private synchronized boolean isInState(State... state) {
        return Arrays.asList(state).contains(this.state);
    }

    private synchronized boolean transition(final State target) {
        final Collection<State> validTransitions = VALID_TRANSITIONS.get(this.state);
        if (validTransitions != null && validTransitions.contains(target)) {
            this.state = target;
            Log.d(Config.LOGTAG, id.account.getJid().asBareJid() + ": transitioned into " + target);
            return true;
        } else {
            return false;
        }
    }

    public void transitionOrThrow(final State target) {
        if (!transition(target)) {
            throw new IllegalStateException(String.format("Unable to transition from %s to %s", this.state, target));
        }
    }
}