Feature/siprec server (#140)

* initial support for siprec/agent assist

* call siprec middleware

* logger fix

* remove verbs that are not valid in a siprec call session

lib/session/call-session.js

@@ -228,6 +228,13 @@ class CallSession extends Emitter {
     return this.constructor.name === 'ConfirmCallSession';
   }
 
+  /**
+   * returns true if this session is a SipRecCallSession
+   */
+  get isSipRecCallSession() {
+    return this.constructor.name === 'SipRecCallSession';
+  }
+
   /**
    * returns true if this session is a SmsCallSession
    */
@@ -908,6 +915,22 @@ class CallSession extends Emitter {
       this.logger.debug('CallSession:replaceApplication - ignoring because call is gone');
       return;
     }
+
+    if (this.isSipRecCallSession) {
+      const pruned = tasks.filter((t) =>
+        [TaskName.Config, TaskName.Listen, TaskName.Transcribe].includes(t.name)
+      );
+      if (0 === pruned.length) {
+        this.logger.info({tasks},
+          'CallSession:replaceApplication - only config, transcribe and/or listen allowed on an incoming siprec call');
+        return;
+      }
+      if (pruned.length < tasks.length) {
+        this.logger.info(
+          'CallSession:replaceApplication - removing verbs that are not allowed for incoming siprec call');
+        tasks = pruned;
+      }
+    }
     this.tasks = tasks;
     this.taskIdx = 0;
     this.stackIdx++;

lib/session/siprec-call-session.js

@@ -0,0 +1,56 @@
+const InboundCallSession = require('./inbound-call-session');
+const {createSipRecPayload} = require('../utils/siprec-utils');
+/**
+ * @classdesc Subclass of InboundCallSession.  This represents a CallSession that is
+ * established for an inbound SIPREC call.
+ * @extends InboundCallSession
+ */
+class SipRecCallSession extends InboundCallSession {
+  constructor(req, res) {
+    super(req, res);
+
+    const {sdp1, sdp2, metadata} = req.locals.siprec;
+    this.sdp1 = sdp1;
+    this.sdp2 = sdp2;
+    this.metadata = metadata;
+
+    setImmediate(this._answerSipRecCall.bind(this));
+  }
+
+  async _answerSipRecCall() {
+    try {
+      this.ms = this.getMS();
+      this.ep = await this.ms.createEndpoint({remoteSdp: this.sdp1});
+      this.ep2 = await this.ms.createEndpoint({remoteSdp: this.sdp2});
+      await this.ep.bridge(this.ep2);
+      const combinedSdp = await createSipRecPayload(this.ep.local.sdp, this.ep2.local.sdp, this.logger);
+      this.logger.debug({
+        sdp1: this.sdp1,
+        sdp2: this.sdp2,
+        combinedSdp
+      }, 'SipRecCallSession:_answerSipRecCall - created SIPREC payload');
+      this.dlg = await this.srf.createUAS(this.req, this.res, {
+        headers: {
+          'X-Trace-ID': this.req.locals.traceId,
+          'X-Call-Sid': this.req.locals.callSid
+        },
+        localSdp: combinedSdp
+      });
+    } catch (err) {
+      this.logger.error({err}, 'SipRecCallSession:_answerSipRecCall error:');
+      if (this.res && !this.res.finalResponseSent) this.res.send(500);
+      this._callReleased();
+    }
+  }
+
+  _callReleased() {
+    /* release that second endpoint we created, then call superclass implementation */
+    if (this.ep2?.connected) {
+      this.ep2.destroy();
+      this.ep2 = null;
+    }
+    super._callReleased();
+  }
+}
+
+module.exports = SipRecCallSession;