snapdrop/app/elements/p2p-network/p2p-network.html

<script src="../../bower_components/peerjs/peer.min.js"></script>
<link rel="import" href="file-transfer-protocol.html">
<dom-module id="p2p-network">
    <template>
    </template>
    <script>
    'use strict';
    Polymer({
        is: 'p2p-network',
        properties: {
            me: {
                type: String
            }
        },
        attached: function() {
            this._connectedPeers = {};
            this._initCallbacks = [];
            this._unsendMsgs = {};
            window.onunload = window.onbeforeunload = function() {
                if (!!this._peer && !this._peer.destroyed) {
                    this._peer.destroy();
                }
            }.bind(this);
        },
        initialize: function() {
            clearInterval(this.reconnectTimer);
            this.reconnectTimer = undefined;
            var options;
            if (window.debug) {
                options = {
                    host: window.location.hostname,
                    port: 3002,
                    path: 'peerjs'
                };
            } else {
                options = {
                    host: 'snapdrop.net',
                    port: 443,
                    path: 'peerjs',
                    secure: true
                };
            }
            this._peer = new Peer(this.me, options);
            this._peer.on('open', function(id) {
                console.log('My peer ID is: ' + id);
                this.set('me', id);
                this._peerOpen = true;
                this._initCallbacks.forEach(function(cb) {
                    cb();
                });
            }.bind(this));

            this._peer.on('connection', this.connect.bind(this));
            this._peer.on('error', function(err) {
                console.error(err);
                //ugly hack to find out error type
                if (err.message.indexOf('Could not connect to peer') > -1) {
                    delete this._connectedPeers[this.peer];
                    return;
                }
                if (err.message.indexOf('Lost connection to server') > -1) {
                    this._peer.destroy();
                    this._reconnect();
                    return;
                }
            }.bind(this));
        },

        connect: function(c) {
            var peer = c.peer;

            if (c.label === 'file') {
                c.on('data', function(data) {
                    console.log(data);
                    var dataView = new Uint8Array(data.file);
                    var dataBlob = new Blob([dataView]);
                    this.fire('file-received', {
                        from: peer,
                        blob: dataBlob,
                        name: data.name,
                    });

                }.bind(this));
            }

            if (c.label === 'system') {
                c.on('data', function(data) {
                    data.from = peer;
                    this.fire('system-event', data);
                }.bind(this));
            }
        },
        connectToPeer: (function() {
            function request(requestedPeer, callback) {
                return function() {

                    //system messages channel
                    var s = this._peer.connect(requestedPeer, {
                        label: 'system'
                    });

                    s.on('open', function() {
                        this.connect(s);
                        if (callback) {
                            callback();
                        }
                    }.bind(this));
                    s.on('error', function(err) {
                        console.log(err);
                        if (err.message.indexOf('Connection is not open') > -1) {
                            console.err('Handle this error!!');
                        }
                    });

                    //files channel
                    var f = this._peer.connect(requestedPeer, {
                        label: 'file',
                        reliable: true
                    });
                    f.on('open', function() {
                        this.connect(f);

                    }.bind(this));
                    f.on('error', function(err) {
                        console.log(err);
                    });
                };
            }
            return function(requestedPeer, callback) {
                if (this._peer.connections[requestedPeer]) {
                    callback();
                    return;
                }
                if (this._peerOpen) {
                    request(requestedPeer, callback).bind(this)();
                } else {
                    this._initCallbacks.push(request(requestedPeer, callback).bind(this));
                }

            };
        }()),
        _sendFile: function(peerId, file) {
            var conns = this._peer.connections[peerId];
            if (conns) {
                conns.forEach(function(conn) {
                    if (conn.label === 'file') {
                        conn.send(file);
                        console.log('send file via WebRTC');
                    }
                }.bind(this));
            }
        },
        _sendSystemEvent: function(peerId, msg) {
            var conns = this._peer.connections[peerId];
            if (conns) {
                conns.forEach(function(conn) {
                    if (conn.label === 'system') {
                        conn.send(msg);
                    }
                }.bind(this));
            }
        },
        _reconnect: function(e) {
            //try to reconnect after 3s 
            if (!this.reconnectTimer) {
                this.reconnectTimer = setInterval(this.initialize.bind(this), 3000);
            }
        }
    });
    </script>
</dom-module>