support unsubscribing

controllers/push.php

@@ -24,8 +24,9 @@ $app->get('/callback-fail', function() use($app) {
 $app->post('/', function() use($app) {
   $params = $app->request()->params();
 
-  switch(k($params, 'hub_mode')) {
+  switch($mode=k($params, 'hub_mode')) {
     case 'subscribe':
+    case 'unsubscribe':
 
       // Sanity check the request params
       $topic = k($params, 'hub_topic');
@@ -39,32 +40,48 @@ $app->post('/', function() use($app) {
         push_error($app, 'Callback URL was invalid');
       }
 
-      // If we've already seen the topic, assume it's valid and don't check it again
-      if(!db\feed_from_url($topic)) {
-        $topic_head = request\get_head($topic);
-        if($topic_head && !request\response_is($topic_head['status'], 2)) {
-          push_error($app, "The topic URL returned a " . $topic_head['status'] . " status code");
-        } else {
-          push_error($app, 'We tried to verify the topic URL exists but it didn\'t respond to a HEAD request.');
+      if($mode == 'subscribe') {
+        // If we've already seen the topic, assume it's valid and don't check it again
+        if(!db\feed_from_url($topic)) {
+          $topic_head = request\get_head($topic);
+          if($topic_head && !request\response_is($topic_head['status'], 2)) {
+            push_error($app, "The topic URL returned a " . $topic_head['status'] . " status code");
+          } else {
+            push_error($app, 'We tried to verify the topic URL exists but it didn\'t respond to a HEAD request.');
+          }
         }
-      }
 
-      // Find or create the feed given the topic URL
-      $feed = db\find_or_create('feeds', ['feed_url'=>$topic], [
-        'hash' => db\random_hash(),
-      ], true);
+        // Find or create the feed given the topic URL
+        $feed = db\find_or_create('feeds', ['feed_url'=>$topic], [
+          'hash' => db\random_hash(),
+        ], true);
+
+        // Find or create the subscription for this callback URL and feed
+        $subscription = db\find_or_create('subscriptions', ['feed_id'=>$feed->id, 'callback_url'=>$callback], [
+          'hash' => db\random_hash()
+        ], true);
+        // Always set a new requested date and challenge
+        $subscription->date_requested = db\now();
+        $subscription->challenge = db\random_hash();
+        $subscription->save();
+
+        // Queue the worker to validate the subscription
+        DeferredTask::queue('PushTask', 'verify_subscription', [$subscription->id, 'subscribe']);
+
+      } else {
+        $feed = db\feed_from_url($topic);
+        if(!$feed) {
+          push_error($app, 'The topic was not found, so there is no subscription active');
+        }
 
-      // Find or create the subscription for this callback URL and feed
-      $subscription = db\find_or_create('subscriptions', ['feed_id'=>$feed->id, 'callback_url'=>$callback], [
-        'hash' => db\random_hash()
-      ], true);
-      // Always set a new requested date and challenge
-      $subscription->date_requested = db\now();
-      $subscription->challenge = db\random_hash();
-      $subscription->save();
+        $subscription = db\find('subscriptions', ['feed_id'=>$feed->id, 'callback_url'=>$callback]);
+        if(!$subscription) {
+          push_error($app, 'There was no subscription found for this callback URL and topic');
+        }
 
-      // Queue the worker to validate the subscription
-      DeferredTask::queue('PushTask', 'verify_subscription', $subscription->id);
+        // Queue the worker to validate the subscription
+        DeferredTask::queue('PushTask', 'verify_subscription', [$subscription->id, 'unsubscribe']);
+      }
 
       $app->response()->status(202);
       echo "The subscription request is being validated. Check the status here:\n";
@@ -72,7 +89,6 @@ $app->post('/', function() use($app) {
 
       break;
 
-    case 'unsubscribe':
 
       break;
   }

lib/PushTask.php

@@ -3,32 +3,32 @@ use BarnabyWalters\Mf2;
 
 class PushTask {
 
-  public static function verify_subscription($subscription_id) {
+  public static function verify_subscription($subscription_id, $mode) {
 
     $subscription = db\get_by_id('subscriptions', $subscription_id);
     if($subscription) {
       $feed = db\get_by_id('feeds', $subscription->feed_id);
 
-      $url = parse_url($subscription->callback_url);
-
       // Choose the expiration for the subscription
       $lease_seconds = 86400*3;
       $exp_ts = time() + $lease_seconds;
       $exp_date = date('Y-m-d H:i:s', $exp_ts);
 
       $push_params = [
-        'hub.mode' => 'subscribe',
+        'hub.mode' => ($mode == 'subscribe' ?an> 'subscribe' : 'unsubscribe'),
         'hub.topic' => $feed->feed_url,
-        'hub.challenge' => $subscription->challenge,
-        'hub.lease_seconds' => $lease_seconds
+        'hub.challenge' => $subscription->challenge
       ];
+      if($mode == 'subscribe') {
+        $push_params['hub.lease_seconds'] = $lease_seconds;
+      }
 
+      $url = parse_url($subscription->callback_url);
       if($q=k($url, 'query')) {
         parse_str($q, $existing_params);
         $push_params = array_merge($push_params, $existing_params);
       }
       $url['query'] = http_build_query($push_params);
-
       $url = build_url($url);
 
       $response = request\get_url($url, true);
@@ -37,22 +37,30 @@ class PushTask {
 
       if(request\response_is($response['status'], 2) && $response['body'] == $subscription->challenge) {
         // The subscriber replied with a 2xx status code and confirmed the challenge string.
-        // The subscription is confirmed and active.
-        $subscription->date_confirmed = db\now();
-        $subscription->lease_seconds = $lease_seconds;
-        $subscription->date_expires = $exp_date;
-        db\set_updated($subscription);
-        $subscription->active = 1;
+
+        if($mode == 'subscribe') {
+          // The subscription is confirmed and active.
+          $subscription->date_confirmed = db\now();
+          $subscription->lease_seconds = $lease_seconds;
+          $subscription->date_expires = $exp_date;
+          $subscription->active = 1;
+          echo "Subscriber verified the request and is now subscribed\n";
+        } else {
+          $subscription->date_unsubscribed = db\now();
+          $subscription->active = 0;
+          echo "Subscriber verified the request and is now unsubscribed\n";
+        }
 
       } else {
-        // The subscriber did not confirm the subscription, so reject it
+        // The subscriber did not confirm the subscription, so reject the request
+        echo "Subscriber did not echo the challenge\n";
 
       }
 
+      db\set_updated($subscription);
       $subscription->save();
 
       print_r($response);
-
     }
 
   }

lib/db_helpers.php

@@ -41,6 +41,17 @@ function find_or_create($table, $where, $defaults, $autosave=false) {
   return $item;
 }
 
+function find($table, $where) {
+  $item = ORM::for_table($table);
+
+  // Where is an associative array of key/val combos
+  foreach($where as $c=>$v) {
+    $item = $item->where($c, $v);
+  }
+
+  return $item->find_one();
+}
+
 function feed_from_url($url) {
   return ORM::for_table('feeds')->where('feed_url', $url)->find_one();
 }