--
 -- This DSM app 
 --   o plays early media from a file in the DB
 --   o sends a HTTP request to a web server
 --   o SUBSCRIBEs to registration state 
 --   o if registration becomes active (at least one active contact), it sends back "300 Multiple Choices"
 --   o otherwise (timeout) it sends back "480 Not found"
 
 -- Parameters (P-App-Param):
 --    audio_id   - indicating audio file in DB
 --    expiration - subscription expiration/waiting time (default: 60)
 --    caller     - caller passed to notification web app
 --    callee     - callee passed to notification web app
 --    domain     - domain passed to notification web app
 --
 --  Example: P-App-Param: audio_id=rbt;expiration=30;caller=+43111111111;callee=+432222222222;domain=sip.sipwise.com
 -- 
 -- Example DB: 
 --  CREATE TABLE `audio_files` (
 --    `id` varchar(20) DEFAULT NULL,
 --    `data` mediumblob
 --  ) ENGINE=MyISAM DEFAULT CHARSET=latin1;
 
 import(mod_utils);
 import(mod_dlg);
 import(mod_subscription);
 import(mod_xml);
 import(mod_mysql);
 import(mod_curl);
 
 initial state START;
 

 transition "SIP dialog error" START - exception; test(#type=="dlg") / {
   log(1, "Error in accepting call:");
   logParams(1);
   set($connect_session=0);
   stop(false);
 } -> END;
 

 transition "DB exception" START - exception / {
   log(1, "Error in initializing mobile push:");
   logAll(1);
   dlg.reply(500, "Server Internal Error");
   stop(false);
 } -> END;
 
 transition "invite" START - invite / {
   if test($config.enable_rbt=="yes") {
     if test($audio_id != "") {
       mysql.connect();
       throwOnError();
       -- play waiting file from DB
       if test($config.play_looped=="yes") {
         mysql.playDBAudioLooped(SELECT data FROM provisioning.audio_files WHERE id="$audio_id", rbt.wav);
       } else {
         mysql.playDBAudio(SELECT data FROM provisioning.audio_files WHERE id="$audio_id", rbt.wav);
       }
       throwOnError();
       mysql.disconnect();
     }
   }
 
   -- send 183 with early media
   dlg.acceptInvite(183, "Progress");

   throwOnError();

   -- no default 200 OK
   set($connect_session=0);
 
   -- start RTP processing 
   connectMedia();
 

   -- no need to process incoming RTP (also no RTP timeout needed)

   disableReceiving();

   -- create subscription to reg event
   set($r.domain=@domain);
   set($r.user=@user);
   set($r.from_user=$config.subscription_user);
   set($r.pwd=$config.subscription_pwd);
   set($r.event="reg");
   if test($config.proxy != "") {
     set($r.proxy=$config.proxy);
   }
   if test($config.use_subscription_id == "yes") {
     utils.getNewId(r.id);
   }
   if test($expiration != "") {
     set($r.expires=$expiration);
   } else {
     set($r.expires=60);
   }
 
   subscription.create(r);
 
   if test($r.handle == "") {
     log(1, "Subscription creation failed!");
     logVars(1);
     dlg.reply(500, "Server Internal Error");
     stop(false);
     throw(subscription);
   }
 
   -- send HTTP request

   set($curl.timeout=15);

   if test($config.use_post=="yes") {
     curl.postDiscardResult($config.push_server_url, $caller;$callee;$domain)
   } else {
     curl.getForm($config.push_server_url, $caller;$callee;$domain)
   }
 
   -- set Timer on our side, too (server subscription timing could be broken...)
   setTimer(1, $r.expires);
 
 } -> WAITING;
 
 state WAITING;
 

 transition "RTP timeout - ignore" WAITING - rtpTimeout / set(#processed=true) -> WAITING;
 

 transition "subscription failed" WAITING - subscription(#status=="failed") / {
   log(1, "Subscription failed:");
   logParams(1);
   logVars(1); 
   dlg.reply(500, "Server Internal Error");
   stop(false);
 } -> END;
 
 function evaluateRegNotifyBody() {
   xml.parseSIPMsgBody("SipSubscriptionBody", "substatus");
   -- namespaces to be used:
   set($substatus.ns="a=urn:ietf:params:xml:ns:reginfo")
   -- look for an active contact
   xml.evalXPath("/a:reginfo/a:registration/a:contact[@state='active']", "substatus");
   xml.XPathResultCount($active_contacts="substatus.xpath");
 };
 
 function releaseRegEvalObjects() {
   freeObject("substatus");
   freeObject("substatus.xpath");
 };
 
 function replyWith300() {

   if test($has_replied!="yes") {
     set($dlg.reply.hdrs="Contact: ");
     append($dlg.reply.hdrs, @local_uri);
     append($dlg.reply.hdrs, $config.extra_3xx_uri_append);
     dlg.reply(300, "Multiple Choices");
     set($has_replied="yes");
   }
   stop(false);
 };
 
 function replyWith480() {
   if test($has_replied!="yes") {
     dlg.reply(480, "Not found");
     set($has_replied="yes");
   }

   stop(false);
 };
 
 transition "NOTIFY received, with body" WAITING - subscription(#status!="terminated"); test(#has_body=="true") / {
   evaluateRegNotifyBody();
 
   if test($active_contacts != 0) {
     replyWith300();
     subscription.remove($r.handle);
   }
 
   releaseRegEvalObjects();
 } -> WAITING;
 
 transition "NOTIFY received, no body" WAITING - subscription(#status!="terminated")  / {
   log(3, "subscription active");
   logParams(3);
 } -> WAITING;
 
 transition "NOTIFY received, terminated (but with body)" WAITING - subscription(#status=="terminated"); test(#has_body=="true") / {
   evaluateRegNotifyBody();
 
   if test($active_contacts != 0) {
     replyWith300();
   } else {

     replyWith480();

   }
   releaseRegEvalObjects();
 } -> END;
 
 transition "NOTIFY received, subscription terminated" WAITING - subscription(#status=="terminated") / {

   replyWith480();

 } -> END;
 
 transition "timer hit" WAITING - timer(#id==1) / {
   subscription.remove($r.handle);

   replyWith480();

 } -> END;
 

 transition "CANCEL received" WAITING - hangup / {
   subscription.remove($r.handle);

   dlg.reply(487, "Request Terminated");

   stop(false);
 } -> END;
 

 state END;