let peerConnection;
let streamPath = window.location.href;
let stream = streamPath;
let quality = "source";


const startPeerConnection = () => {
    // Init peer connection
    peerConnection = new RTCPeerConnection({
        iceServers: [{ urls: stunServers }]
    });

    // On connection change, change indicator color
    // if connection failed, restart peer connection
    peerConnection.oniceconnectionstatechange = e => {
        console.log("ICE connection state changed, " + peerConnection.iceConnectionState);
        switch (peerConnection.iceConnectionState) {
        case "disconnected":
            document.getElementById("connectionIndicator").style.fill = "#dc3545";
            break;
        case "checking":
            document.getElementById("connectionIndicator").style.fill = "#ffc107";
            break;
        case "connected":
            document.getElementById("connectionIndicator").style.fill = "#28a745";
            break;
        case "closed":
        case "failed":
            console.log("Connection failed, restarting...");
            peerConnection.close();
            peerConnection = null;
            setTimeout(startPeerConnection, 1000);
            break;
        }
    };

    // We want to receive audio and video
    peerConnection.addTransceiver("video", { "direction": "sendrecv" });
    peerConnection.addTransceiver("audio", { "direction": "sendrecv" });

    // Create offer and set local description
    peerConnection.createOffer().then(offer => {
        // After setLocalDescription, the browser will fire onicecandidate events
        peerConnection.setLocalDescription(offer);
    }).catch(console.log);

    // When candidate is null, ICE layer has run out of potential configurations to suggest
    // so let's send the offer to the server
    peerConnection.onicecandidate = event => {
        if (event.candidate === null) {
            // Send offer to server
            // The server replies with its description
            // After setRemoteDescription, the browser will fire ontrack events
            console.log("Sending session description to server");
            fetch(streamPath, {
                method: "POST",
                headers: {
                    "Accept": "application/json",
                    "Content-Type": "application/json"
                },
                body: JSON.stringify({
                    "webRtcSdp": peerConnection.localDescription,
                    "stream": stream,
                    "quality": quality
                })
            })
                .then(response => response.json())
                .then((data) => peerConnection.setRemoteDescription(new RTCSessionDescription(data)))
                .catch(console.log);
        }
    };

    // When video track is received, configure player
    peerConnection.ontrack = function (event) {
        console.log(`New ${event.track.kind} track`);
        if (event.track.kind === "video") {
            const viewer = document.getElementById("viewer");
            viewer.srcObject = event.streams[0];
        }
    };
};