data-channel.js

/*  WebRTC consist of a few moving pieces

    - A signal mechanism for peers
    - A signal mechanism to send offers & answers

    - A simplified peerConnection function
*/

var uuid = require("node-uuid")
    , equal = require("assert").equal
    , WriteStream = require("write-stream")
    , extract = require("extract")

    , Peers = require("peers-signal")

    , PeerConnection = require("peer-connection")

    , id = uuid()
    , peers = Peers("discoverynetwork.co/service"
        , "unique group name")
    , connectionHash = {}

peers.on("create", function handlePeer(peer) {
    if (peer.id < self.id) {
        // Other peer will open the connection
        return
    }

    var stream = connect(peer)

    // Connected peer is an echo stream
    stream.pipe(WriteStream(function (message) {
        equal(message, "hello world")
    }))

    stream.write("hello world")
})

var self = peers.add({ id: id })

listen(peers, self, function (stream) {
    // I am an echo stream
    stream.pipe(stream)
})

function connect(peer) {
    var pc = connectionHash[peer.id] = PeerConnection()

    pc.createOffer(function (err, offer) {
        peer.emit("offer", [self.id, offer])
    })

    return pc.connect()
}

function listen(peers, self, callback) {
    self.on("offer", extract(function (id, offer) {
        var pc = connectionHash[id] = PeerConnection()

        pc.setRemote(offer)

        pc.createAnswer(function (err, answer) {
            peers.get(id).emit("answer", [self.id, answer])

            pc.on("connection", callback)
        })
    }))

    self.on("answer", extract(function (id, answer) {
        var pc = connectionHash[id]

        pc.setRemote(answer)
    }))
}