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

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(ch) {
	localVideo = document.getElementById('localVideo');
	remoteVideo = document.getElementById('remoteVideo');
	channel = ch;

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

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

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

function onConnection(data) {
	// console.log('['+(new Date().toLocaleString())+'] ' + '[onConnect]' + data.toString());
	serverConnection.send( JSON.stringify({ 'channel': channel }) );
}

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;
	if(typeof localStream !== 'undefined')
		peerConnection.addStream(localStream);

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

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

	// console.log('message : ' + message.data);

	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);
}