Begin coffee snowflake proxy

proxy/snowflake.coffee

@@ -0,0 +1,108 @@
+###
+A Coffeescript WebRTC snowflake proxy
+Using Copy-paste signaling for now.
+###
+
+# Janky state machine
+MODE =
+  INIT:       0
+  CONNECTING: 1
+  CHAT:       2
+currentMode = MODE.INIT
+
+config = {
+  iceServers: [
+    { urls: ["stun:stun.l.google.com:19302"] }
+  ]
+}
+
+# DOM elements
+$chatlog = null
+$send = null
+$input = null
+
+
+window.PeerConnection = window.RTCPeerConnection ||
+                        window.mozRTCPeerConnection || window.webkitRTCPeerConnection
+window.RTCIceCandidate = window.RTCIceCandidate || window.mozRTCIceCandidate;
+window.RTCSessionDescription = window.RTCSessionDescription || window.mozRTCSessionDescription
+
+class Snowflake
+
+class ProxyPair
+
+#
+## -- DOM & Input Functionality -- ##
+#
+
+welcome = ->
+  log "== snowflake JS proxy =="
+  log "Input offer from the snowflake client:"
+
+# Log to the message window.
+log = (msg) ->
+  $chatlog.value += msg + "\n"
+  console.log msg
+  # Scroll to latest
+  $chatlog.scrollTop = $chatlog.scrollHeight
+
+# Local input from keyboard into message window.
+acceptInput = () ->
+  msg = $input.value
+  switch currentMode
+    when MODE.INIT
+      if msg.startsWith("start")
+        start(true)
+      else
+        Signalling.receive msg
+    when MODE.CONNECTING
+      Signalling.receive msg
+    when MODE.CHAT
+      data = msg
+      log(data)
+      channel.send(data)
+    else
+      log("ERROR: " + msg)
+  $input.value = "";
+  $input.focus()
+
+# Signalling channel - just tells user to copy paste to the peer.
+# Eventually this should go over the facilitator.
+Signalling =
+  send: (msg) ->
+    log "---- Please copy the below to peer ----\n"
+    log JSON.stringify(msg)
+    log "\n"
+
+  receive: (msg) ->
+    recv = ""
+    try
+      recv = JSON.parse msg
+    catch e
+      log "Invalid JSON."
+      return
+    # Begin as answerer if peerconnection doesn't exist yet.
+    start false if !pc
+    desc = recv['sdp']
+    ice = recv['candidate']
+    if !desc && ! ice
+      log "Invalid SDP."
+      return false
+    receiveDescription recv if desc
+    receiveICE recv         if ice
+
+init = ->
+  $chatlog = document.getElementById('chatlog')
+  $chatlog.value = ""
+
+  $send = document.getElementById('send')
+  $send.onclick = acceptInput
+
+  $input = document.getElementById('input')
+  $input.focus()
+  $input.onkeydown = (e) =>
+    if 13 == e.keyCode  # enter
+      $send.onclick()
+  welcome()
+
+window.onload = init