<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML//EN">

<html>

<head>
<title>WebRTC Autocaller</title>
<script type="text/javascript">

var local_name;
var server;
var my_id = -1;
var other_peers = {};
var request = null;
var hanging_get = null;
var pc = null;
var local_stream = null;
var call_state = 0;
// 0 - Not started
// 1 - Call ongoing
// 2 - We have initiated closing the call
// 3 - Other side has initiated closing the call

// General
function toggleExtraButtons() {
  document.getElementById("createPcBtn").hidden = 
    !document.getElementById("createPcBtn").hidden;
  document.getElementById("addStreamBtn").hidden = 
    !document.getElementById("addStreamBtn").hidden;
}

function trace(txt) {
  var elem = document.getElementById("debug");
  elem.innerHTML += txt + "<br>";
}

function trace_warning(txt) {
  var wtxt = "<b>" + txt + "</b>";
  trace(wtxt);
}

function setCallState(state) {
  trace("Changing call state: " + call_state + " -> " + state);
  call_state = state;
}

function checkPeerConnection() {
  if (!pc) {
    trace_warning("No PeerConnection object exists.");
    return 0;
  }
  return 1;
}

// Local stream generation
function gotStream(s) {
  var url = webkitURL.createObjectURL(s);
  document.getElementById("localView").src = url;
  trace("User has granted access to webcam. url = " + url);
  local_stream = s;
}

function gotStreamFailed(error) {
  alert("Failed to get access to webcam. Error code was " + error.code);
  trace("Failed to get access to webcam. Error code was " + error.code);
}

// Call control
function createPeerConnection() {
  if (pc) {
    trace_warning("PeerConnection object already exists.");
  }
  trace("Creating PeerConnection object.");
  // CRASH TEST
  pc = new webkitPeerConnection("STUN 1.2.3.4:43", onSignalingMessage); 
  pc.onaddstream = onAddStream;
  pc.onremovestream = onRemoveStream;
}

function startCall() {
  document.getElementById("startcall").disabled = true;
  createPeerConnection();
  addStream();
}

function addStream() {
  trace("Starting call. [pc.addStream(local_stream)]");
  pc.addStream(local_stream);
  document.getElementById("stopcall").disabled = false;
}

function stopCall() {
  document.getElementById("stopcall").disabled = true;
  trace("Stopping call [pc.close()]");
  setCallState(2);
  pc.close();
}

function test1() {
  addStream();
}

function callHasStarted() {
  setCallState(1);
}

// PeerConnection callbacks
function onAddStream(e) {
  var stream = pc.remoteStreams[0];
  var url = webkitURL.createObjectURL(stream);
  document.getElementById("remoteView").src = url;
  trace("Started showing remote stream. url = " + url);
  setTimeout(callHasStarted, 5000);  // TODO(hta): workaround, to be removed
}

function onRemoveStream(e) {
  // Currently if we get this callback, call has ended.
  document.getElementById("remoteView").src = "";
  trace("Stopped showing remote stream.");
  if (call_state == 2) {
    // Finalize close call. We assume here that this callback comes
    // after onSignalingMessage.
    pc = null;
    setCallState(0);
    document.getElementById("startcall").disabled = false;
  }
}

function onSignalingMessage(msg) {
  var peer_id = parseInt(document.getElementById("peer_id").value);
  trace("Sending message to " + other_peers[peer_id] + 
        " (ID " + peer_id + "):\n" + msg);
  sendToPeer(peer_id, msg);
}

// Server interaction

function handleServerNotification(data) {
  trace("Server notification: " + data);
  notePeerAndMaybeCall(data);
}

function handlePeerMessage(peer_id, msg) {
  trace("Received message from " + other_peers[peer_id] + 
        " (ID " + peer_id + "):\n" + msg);
  // Assuming we have created a PeerConnection and that we receive the
  // message from the peer want to communicate with
  document.getElementById("peer_id").value = 
    peer_id;   // Ensure we reply to the same peer
  
  if (pc) {
    try {
      pc.processSignalingMessage(msg);
    } catch (e) {
      trace_warning("Signaling message error: " + e.description);
    }
    if (call_state == 1)
      setCallState(3);
  } else {
    createPeerConnection();
    pc.processSignalingMessage(msg);
  }
}

function getIntHeader(r, name) {
  var val = r.getResponseHeader(name);
  trace("header value: " + val);
  return val != null && val.length ? parseInt(val) : -1;
}

function hangingGetCallback() {
  try {
    if (hanging_get.readyState != 4)
      return;
    if (hanging_get.status != 200) {
      trace("server error, status: " + hanging_get.status + ", text: " + 
            hanging_get.statusText);
      disconnect();
    } else {
      var peer_id = getIntHeader(hanging_get, "Pragma");
      if (peer_id == my_id) {
        handleServerNotification(hanging_get.responseText);
      } else {
        handlePeerMessage(peer_id, hanging_get.responseText);
      }
    }

    if (hanging_get) {
      hanging_get.abort();
      hanging_get = null;
    }

    if (my_id != -1)
      window.setTimeout(startHangingGet, 0);
  } catch (e) {
    trace("Hanging get error: " + e.description);
  }
}

function onHangingGetTimeout() {
  trace("hanging get timeout. issuing again.");
  hanging_get.abort();
  hanging_get = null;
  if (my_id != -1)
    window.setTimeout(startHangingGet, 0);
}

function startHangingGet() {
  try {
    hanging_get = new XMLHttpRequest();
    hanging_get.onreadystatechange = hangingGetCallback;
    hanging_get.ontimeout = onHangingGetTimeout;
    hanging_get.open("GET", server + "/wait?peer_id=" + my_id, true);
    hanging_get.send();  
  } catch (e) {
    trace("error" + e.description);
  }
}

function sendToPeer(peer_id, data) {
  if (my_id == -1) {
    alert("Not connected");
    return;
  }
  if (peer_id == my_id) {
    alert("Can't send a message to oneself :)");
    return;
  }
  var r = new XMLHttpRequest();
  r.open("POST", server + "/message?peer_id=" + my_id + "&to=" + 
         peer_id, false);
  r.setRequestHeader("Content-Type", "text/plain");
  r.send(data);
  r = null;
}

function notePeerAndMaybeCall(peerInfo) {
  var parsed = peerInfo.split(",");
  if (parseInt(parsed[2]) != 0) {
    trace("Peer came on: " + peerInfo);
    other_peers[parseInt(parsed[1])] = parsed[0];
    // If we're not already in a call, call it.
    if (!document.getElementById("startcall").disabled) {
      document.getElementById("peer_id").value = parsed[1];
      startCall();
    }
  } else {
    trace("Peer went away: " + peerInfo);
    other_peers[parseInt(parsed[1])] = null;
  }
}

function signInCallback() {
  try {
    if (request.readyState == 4) {
      if (request.status == 200) {
        var peers = request.responseText.split("\n");
        my_id = parseInt(peers[0].split(",")[1]);
        trace("My id: " + my_id);
        for (var i = 1; i < peers.length; ++i) {
          if (peers[i].length > 0) {
            trace("Peer " + i + ": " + peers[i]);
            notePeerAndMaybeCall(peers[i]);
          }
        }
        startHangingGet();
        request = null;
      }
    }
  } catch (e) {
    trace("error: " + e.description);
  }
}

function signIn() {
  try {
    request = new XMLHttpRequest();
    request.onreadystatechange = signInCallback;
    request.open("GET", server + "/sign_in?" + local_name, true);
    request.send();
  } catch (e) {
    trace("error: " + e.description);
  }
}

function connect() {
  local_name = document.getElementById("local").value.toLowerCase();
  server = document.getElementById("server").value.toLowerCase();
  if (local_name.length == 0) {
    alert("I need a name please.");
    document.getElementById("local").focus();
  } else {
    document.getElementById("connect").disabled = true;
    document.getElementById("disconnect").disabled = false;
    trace("Connecting to server");
    signIn();
  }
}

function disconnect() {
  if (request) {
    request.abort();
    request = null;
  }
  
  if (hanging_get) {
    hanging_get.abort();
    hanging_get = null;
  }

  if (my_id != -1) {
    request = new XMLHttpRequest();
    request.open("GET", server + "/sign_out?peer_id=" + my_id, false);
    request.send();
    request = null;
    my_id = -1;
  }

  document.getElementById("connect").disabled = false;
  document.getElementById("disconnect").disabled = true;
}

function toggleLog()
{
  document.getElementById('debug').hidden =! 
    document.getElementById('debug').hidden;
}

window.onbeforeunload = disconnect;

// TODO: Add audio here when available. Note: now it's hard coded, 
// audio will also be started.
navigator.webkitGetUserMedia("video", gotStream, gotStreamFailed);

</script>
</head>

<body>
<h1>WebRTC autocaller</h1>
This page should show your local camera, and connect to a remote browser.
<table border="0">

<tr>
<th align="left">Local Preview</th>
<th align="left">Remote Video</th>
</tr>
<tr>
<td><video width="320" height="240" id="localView" autoplay="autoplay">
    </video></td>
<td><video width="640" height="480" id="remoteView" autoplay="autoplay">
    </video></td>
</tr>
<tr>
<td valign="top">
<form>
Target peer ID: <input type="text" id="peer_id" size="3" value="1"/><br>
<button id="startcall" onclick="startCall();">(4) Start call</button><br>
<button id="stopcall" onclick="stopCall();" disabled="true">(5) Stop call
</button><br>
<!--<input type="button" value="Test 1" onclick="test1()"/><br>-->
</form>
</td>
<td valign="top">
<button onclick="toggleExtraButtons();">Toggle extra buttons</button><br>
<button id="createPcBtn" onclick="createPeerConnection();" hidden="true">
  Create peer connection</button><br>
<button id="addStreamBtn" onclick="addStream();" hidden="true">
  Add stream</button><br>
</td>
</tr>

<tr><td colspan="2">
(1) Server: <input type="text" id="server" value="http://localhost:8888" />
<br>
(2) Your name: <input type="text" id="local" value="caller"/>
<button id="connect" onclick="connect();" disabled="true">(3) Connect</button>
<button id="disconnect" onclick="disconnect();" disabled="true">(6) Disconnect
</button>
<br>
&nbsp;<br>
<button onclick="toggleLog()">Toggle view log</button>
<button onclick="document.getElementById('debug').innerHTML='';">
  Clear log</button>
<pre id="debug">
</pre>
</td></tr>

</table>
</body>
<script>
// On init, we connect to the server.
connect();
</script>

</html>