Feature/incoming refer (#76)

* Dial: handle incoming REFER on either leg by calling referHook, if configured

* lint

* modify payload of referHook

* support target.trunk on rest createCall api

* bugfix: gather partial result hook was not working

* lint

* handling of incoming REFER

lib/session/call-session.js

@@ -521,6 +521,29 @@ class CallSession extends Emitter {
     task.doConferenceMuteNonModerators(this, opts);
   }
 
+  async _lccSipRequest(callSid, opts) {
+    const {sip_request} = opts;
+    const {method, content_type, content, headers = {}} = sip_request;
+    if (!this.hasStableDialog) {
+      this.logger.info('CallSession:_lccSipRequest - invalid command as we do not have a stable call');
+      return;
+    }
+    try {
+      const res = await this.dlg.request({
+        method,
+        headers: {
+          ...headers,
+          'Content-Type': content_type,
+          'Content': content
+        }
+      });
+      this.logger.debug({res}, `CallSession:_lccSipRequest got response to ${method}`);
+      return res;
+    } catch (err) {
+      this.logger.error({err}, `CallSession:_lccSipRequest - error sending ${method}`);
+    }
+  }
+
   /**
    * perform live call control -- whisper to one party or the other on a call
    * @param {array} opts - array of play or say tasks
@@ -596,6 +619,10 @@ class CallSession extends Emitter {
     else if (opts.conf_mute_status) {
       await this._lccConfMuteStatus(callSid, opts);
     }
+    else if (opts.sip_request) {
+      const res = await this._lccSipRequest(callSid, opts);
+      return {status: res.status, reason: res.reason};
+    }
 
     // whisper may be the only thing we are asked to do, or it may that
     // we are doing a whisper after having muted, paused reccording etc..
@@ -752,7 +779,11 @@ class CallSession extends Emitter {
     } catch (err) {
       if (err === CALLER_CANCELLED_ERR_MSG) {
         this.logger.error(err, 'caller canceled quickly before we could respond, ending call');
-        this._notifyCallStatusChange({callStatus: CallStatus.NoAnswer, sipStatus: 487});
+        this._notifyCallStatusChange({
+          callStatus: CallStatus.NoAnswer,
+          sipStatus: 487,
+          sipReason: 'Request Terminated'
+        });
         this._callReleased();
       }
       else {
@@ -862,9 +893,10 @@ class CallSession extends Emitter {
       this.dlg.on('destroy', this._callerHungup.bind(this));
       this.wrapDialog(this.dlg);
       this.dlg.callSid = this.callSid;
-      this.emit('callStatusChange', {sipStatus: 200, callStatus: CallStatus.InProgress});
+      this.emit('callStatusChange', {sipStatus: 200, sipReason: 'OK', callStatus: CallStatus.InProgress});
 
       this.dlg.on('modify', this._onReinvite.bind(this));
+      this.dlg.on('refer', this._onRefer.bind(this));
 
       this.logger.debug(`CallSession:propagateAnswer - answered callSid ${this.callSid}`);
     }
@@ -890,6 +922,22 @@ class CallSession extends Emitter {
     }
   }
 
+  /**
+   * Handle incoming REFER if we are in a dial task
+   * @param {*} req
+   * @param {*} res
+   */
+  _onRefer(req, res) {
+    const task = this.currentTask;
+    const sd = task.sd;
+    if (task && TaskName.Dial === task.name && sd) {
+      task.handleRefer(this, req, res);
+    }
+    else {
+      res.send(501);
+    }
+  }
+
   /**
    * create and endpoint if we don't have one; otherwise simply return
    * the current media server and endpoint that are associated with this call
@@ -1075,7 +1123,7 @@ class CallSession extends Emitter {
    * @param {number} sipStatus - current sip status
    * @param {number} [duration] - duration of a completed call, in seconds
    */
-  _notifyCallStatusChange({callStatus, sipStatus, duration}) {
+  _notifyCallStatusChange({callStatus, sipStatus, sipReason, duration}) {
     if (this.callMoved) return;
 
     /* race condition: we hang up at the same time as the caller */
@@ -1088,7 +1136,7 @@ class CallSession extends Emitter {
       (!duration && callStatus !== CallStatus.Completed),
     'duration MUST be supplied when call completed AND ONLY when call completed');
 
-    this.callInfo.updateCallStatus(callStatus, sipStatus);
+    this.callInfo.updateCallStatus(callStatus, sipStatus, sipReason);
     if (typeof duration === 'number') this.callInfo.duration = duration;
     try {
       this.notifier.request('call:status', this.call_status_hook, this.callInfo.toJSON());