var localVideo;
var remoteVideo;
var peerConnection;
var peerConnectionConfig = {'iceServers': [{'url': 'stun:stun.services.mozilla.com'}, {'url': 'stun:stun.l.google.com:19302'}]};

navigator.getUserMedia = navigator.getUserMedia || navigator.mozGetUserMedia || navigator.webkitGetUserMedia;
window.RTCPeerConnection = window.RTCPeerConnection || window.mozRTCPeerConnection || window.webkitRTCPeerConnection;
window.RTCIceCandidate = window.RTCIceCandidate || window.mozRTCIceCandidate || window.webkitRTCIceCandidate;
window.RTCSessionDescription = window.RTCSessionDescription || window.mozRTCSessionDescription || window.webkitRTCSessionDescription;

function pageReady() {
    localVideo = document.getElementById('localVideo');
    remoteVideo = document.getElementById('remoteVideo');

    serverConnection = new WebSocket('ws://127.0.0.1:3434');
    serverConnection.onmessage = gotMessageFromServer;

    var constraints = {
        video: true,
        audio: true,
    };

    if(navigator.getUserMedia) {
        navigator.getUserMedia(constraints, getUserMediaSuccess, errorHandler);
    } else {
        alert('Your browser does not support getUserMedia API');
    }
}

function getUserMediaSuccess(stream) {
	console.log('['+(new Date().toLocaleString())+'] ' + '[getUserMediaSuccess] ' + stream);

    localStream = stream;
    localVideo.src = window.URL.createObjectURL(stream);
}

function start(isCaller) {
	console.log('['+(new Date().toLocaleString())+'] ' + "[start] caller? " + isCaller);
    peerConnection = new RTCPeerConnection(peerConnectionConfig);
    peerConnection.onicecandidate = gotIceCandidate;
    peerConnection.onaddstream = gotRemoteStream;
    peerConnection.addStream(localStream);

	if(isCaller)
        peerConnection.createOffer(gotDescription, errorHandler);
}

function gotMessageFromServer(message) {
    if(!peerConnection) start(false);

    var signal = JSON.parse(message.data);
    if(signal.sdp) {
        peerConnection.setRemoteDescription(new RTCSessionDescription(signal.sdp), function() {
            peerConnection.createAnswer(gotDescription, errorHandler);
        }, errorHandler);
    } else if(signal.ice) {
        peerConnection.addIceCandidate(new RTCIceCandidate(signal.ice));
    }
}

function gotIceCandidate(event) {
	console.log('['+(new Date().toLocaleString())+'] ' + '[gotIceCandidate] ' + event);
    if(event.candidate != null) {
		console.log('['+(new Date().toLocaleString())+'] ' + '[gotIceCandidate] ' + event.candidate);
        serverConnection.send(JSON.stringify({'ice': event.candidate}));
    }
}

function gotDescription(description) {
	console.log('['+(new Date().toLocaleString())+'] ' + '[gotDescription] got description');
    peerConnection.setLocalDescription(description, function () {
        serverConnection.send(JSON.stringify({'sdp': description}));
	}, function() {console.log('['+(new Date().toLocaleString())+'] ' + '[gotDescription] set description error')});
}

function gotRemoteStream(event) {
	console.log('['+(new Date().toLocaleString())+'] ' + '[gotRemoteStream] got remote stream');
    remoteVideo.src = window.URL.createObjectURL(event.stream);
}

function errorHandler(error) {
	console.log('['+(new Date().toLocaleString())+'] ' + "[errorHandler] " + error);
}