Defer text message sends until FastCGI response is sent for real calls

Not deferring dummy calls because we can't tell that they were made if
we do so, as error_logs don't get piped back to nginx after finishing
the response.

bootstrap/services.php

@@ -131,6 +131,28 @@ public function isAuthorized(Request $req, $id) {
     }
 }
 
+class TaskQueue implements Countable
+{
+    protected $tasks = [];
+
+    public function push($task)
+    {
+        $this->tasks[] = $task;
+    }
+
+    public function count()
+    {
+        return count($this->tasks);
+    }
+
+    public function __invoke()
+    {
+        foreach ($this->tasks as $task) {
+            $task();
+        }
+    }
+}
+
 return function(\Slim\Container $container, $env) {
     $container['view'] = function() {return new View(__DIR__ . '/../templates');};
     $container['raffleService'] = function($c) use ($env) {return new RaffleService(
@@ -139,17 +161,23 @@ public function isAuthorized(Request $req, $id) {
     );};
     $container['auth'] = function(\Slim\Container $c) {return new Auth($c->get('raffleService'));};
 
-    $container['sms'] = function() use ($env) {
+    $container['taskQueue'] = function() { return new TaskQueue(); };
+
+    $container['sms'] = function($c) use ($env) {
+        if (isset($env['DUMMY_SMS_WAIT_MS'])) { // not deferring because error_log is turned off after fcgi disconnects
+            return new DummySMS($env['DUMMY_SMS_WAIT_MS']);
+        }
+
+        return new DeferredSMS((function($env) : SMS
+        {
             if (isset($env['TWILIO_SID'])) {
                 return new TwilioSMS($env['TWILIO_SID'], $env['TWILIO_TOKEN'], $env['PHONE_NUMBER']);
             }
             if (isset($env['NEXMO_KEY'])) {
                 return new NexmoSMS($env['NEXMO_KEY'], $env['NEXMO_SECRET'], $env['PHONE_NUMBER']);
             }
-        if (isset($env['DUMMY_SMS_WAIT_MS'])) {
-            return new DummySMS($env['DUMMY_SMS_WAIT_MS']);
-        }
             throw new InvalidArgumentException('Could not find SMS service creds, and a dummy timeout was not supplied.');
+        })($env), $c['taskQueue']);
     };
 
     $container['addCookieToResponse'] = $container->protect(function(Response $res, $name, $properties) {

bootstrap/smsServices.php

@@ -5,6 +5,25 @@ interface SMS
     public function send($to, $text);
 }
 
+class DeferredSMS implements SMS
+{
+    protected $actual;
+    protected $queue;
+
+    public function __construct(SMS $actual, TaskQueue $queue)
+    {
+        $this->actual = $actual;
+        $this->queue = $queue;
+    }
+
+    public function send($to, $text)
+    {
+        $this->queue->push(function() use ($to, $text) {
+            $this->actual->send($to, $text);
+        });
+    }
+}
+
 class TwilioSMS implements SMS
 {
     protected $sid;

public/index.php

@@ -3,7 +3,12 @@
 require __DIR__ . '/../vendor/autoload.php';
 
 $app = new \Slim\App();
-call_user_func(require __DIR__ . '/../bootstrap/services.php', $app->getContainer(), $_SERVER + $_ENV);
+call_user_func(require __DIR__ . '/../bootstrap/services.php', $container = $app->getContainer(), $_SERVER + $_ENV);
 call_user_func(require __DIR__ . '/../bootstrap/routes.php', $app);
 
 $app->run();
+
+if (count($queuedTasks = $container->get('taskQueue'))) {
+    fastcgi_finish_request();
+    $queuedTasks();
+}