• connect PbxSignal API
• register to the PBX with NO_MEDIA_CALL flag
• handle incoming Signaling requests with facility type "presence_subscribe"
• connect this calls
• store call id for later use
• send Signaling request for particular call with facility type "presence_notify"
  

new PbxApi("PbxSignal").onconnected(function (conn) {
    log("PbxSignal: connected");

    connections.push(conn);

    conn.send(JSON.stringify({ "api": "PbxSignal", "mt": "Register", "flags": "NO_MEDIA_CALL" }));

    conn.onmessage(function (msg) {
        var obj = JSON.parse(msg);
        log(msg);

        if (obj.mt == "RegisterResult") {
            log("PBXSignal: registration result " + JSON.stringify(obj));
        }

        if (obj.mt == "Signaling") {
            if (obj.sig.type == "setup") {

                // handle incoming presence_subscribe call
                // the callid "obj.call" required later for sending badge notifications
                if (obj.sig.fty.some(function (v) { return v.type === "presence_subscribe"; })) {
                    log("PbxSignal: incoming presence subscription for user " + obj.sig.cg.sip);

                    // connect call
                    conn.send(JSON.stringify({ "mt": "Signaling", "api": "PbxSignal", "call": obj.call, "sig": { "type": "conn" } }));


                    // send notification with badge count 2
                    conn.send(JSON.stringify(
                        {
                            "api": "PbxSignal",
                            "mt": "Signaling",
                            "call": obj.call,
                            "sig": {
                                "fty": [
                                    {
                                        "contact": "app:",
                                        "note": "#badge:2",
                                        "status": "open",
                                        "type": "presence_notify"
                                    }
                                ],
                                "type": "facility"
                            },
                            "src": "badge"
                        }
                    ));
                    
                }
            }
            
        }
         
    });

    conn.onclose(function () {
        log("PbxSignal: disconnected");
    });
});