initial work on dial verb

lib/call-session.js

@@ -1,11 +1,6 @@
 const Emitter = require('events');
-/*
 const config = require('config');
-const {forwardInDialogRequests} = require('drachtio-fn-b2b-sugar');
-const {parseUri, SipError} = require('drachtio-srf');
-const debug = require('debug')('jambonz:sbc-inbound');
-const assert = require('assert');
-*/
+
 class CallSession extends Emitter {
   constructor(req, res) {
     super();
@@ -14,6 +9,11 @@ class CallSession extends Emitter {
     this.srf = req.srf;
     this.logger = req.locals.logger;
     this.application = req.locals.application;
+    this.resources = new Map();
+
+    req.on('cancel', this._onCallerHangup.bind(this));
+
+    this.on('callStatusChange', this._onCallStatusChange.bind(this));
   }
 
   async exec() {
@@ -26,13 +26,69 @@ class CallSession extends Emitter {
       } catch (err) {
         this.logger.error({err, task}, 'Error executing task');
       }
-      this.logger.info('finished all tasks');
+      this.logger.info('CallSession: finished all tasks');
       if (!this.res.finalResponseSent) {
-        this.logger.info('auto-generating non-success response to invite');
+        this.logger.info('CallSession: auto-generating non-success response to invite');
         this.res.send(603);
       }
+      this._clearResources();
     }
   }
+
+  addResource(name, resource) {
+    this.logger.debug(`CallSession:addResource: adding ${name}`);
+    this.resources.set(name, resource);
+  }
+
+  getResource(name) {
+    return this.resources.get(name);
+  }
+
+  removeResource(name) {
+    this.logger.debug(`CallSession:removeResource: removing ${name}`);
+    this.resources.delete(name);
+  }
+
+  async createOrRetrieveEpAndMs(remoteSdp) {
+    const mrf = this.srf.locals.mrf;
+    let ms = this.getResource('ms');
+    let ep = this.getResource('epIn');
+    if (ms && ep) return {ms, ep};
+
+    // get a media server
+    if (!ms) {
+      ms = await mrf.connect(config.get('freeswitch'));
+      this.addResource('ms', ms);
+    }
+    if (!ep) {
+      ep = await ms.createEndpoint({remoteSdp});
+      this.addResource('epIn', ep);
+    }
+    return {ms, ep};
+  }
+
+  /**
+   * clear down resources
+   * (note: we remove in reverse order they were added since mediaserver
+   * is typically added first and I prefer to destroy it after any resources it holds)
+   */
+  _clearResources() {
+    for (const [name, resource] of Array.from(this.resources).reverse()) {
+      try {
+        this.logger.info(`CallSession:_clearResources: deleting ${name}`);
+        if (resource.connected) resource.destroy();
+      } catch (err) {
+        this.logger.error(err, `CallSession:_clearResources: error deleting ${name}`);
+      }
+    }
+  }
+
+  _onCallerHangup(evt) {
+    this.logger.debug('CallSession: caller hung before connection');
+  }
+  _onCallStatusChange(evt) {
+    this.logger.debug(evt, 'CallSession:_onCallStatusChange');
+  }
 }
 
 module.exports = CallSession;