Refactor subs_* functions for remote use

The subs_* functions in subs.php have made a lot of assumptions
about users versus profiles. I've refactored the functions to
be methods of the Subscription class instead, and to use Profile
objects throughout.

Some of the checks for blocks or existing subscriptions depended
on users or profiles, so I've moved those methods around a bit.

I've left stubs for the subs_* functions until we get time to replace
them.

classes/Subscription.php

@@ -24,7 +24,7 @@ if (!defined('STATUSNET') && !defined('LACONICA')) { exit(1); }
  */
 require_once INSTALLDIR.'/classes/Memcached_DataObject.php';
 
-class Subscription extends Memcached_DataObject 
+class Subscription extends Memcached_DataObject
 {
     ###START_AUTOCODE
     /* the code below is auto generated do not remove the above tag */
@@ -34,8 +34,8 @@ class Subscription extends Memcached_DataObject
     public $subscribed;                      // int(4)  primary_key not_null
     public $jabber;                          // tinyint(1)   default_1
     public $sms;                             // tinyint(1)   default_1
-    public $token;                           // varchar(255)  
-    public $secret;                          // varchar(255)  
+    public $token;                           // varchar(255)
+    public $secret;                          // varchar(255)
     public $created;                         // datetime()   not_null
     public $modified;                        // timestamp()   not_null default_CURRENT_TIMESTAMP
 
@@ -45,9 +45,155 @@ class Subscription extends Memcached_DataObject
 
     /* the code above is auto generated do not remove the tag below */
     ###END_AUTOCODE
-    
+
     function pkeyGet($kv)
     {
         return Memcached_DataObject::pkeyGet('Subscription', $kv);
     }
+
+    /**
+     * Make a new subscription
+     *
+     * @param Profile $subscriber party to receive new notices
+     * @param Profile $other      party sending notices; publisher
+     *
+     * @return Subscription new subscription
+     */
+
+    static function start($subscriber, $other)
+    {
+        if (!$subscriber->hasRight(Right::SUBSCRIBE)) {
+            throw new Exception(_('You have been banned from subscribing.'));
+        }
+
+        if (self::exists($subscriber, $other)) {
+            throw new Exception(_('Already subscribed!'));
+        }
+
+        if ($other->hasBlocked($subscriber)) {
+            throw new Exception(_('User has blocked you.'));
+        }
+
+        if (Event::handle('StartSubscribe', array($subscriber, $other))) {
+
+            $sub = new Subscription();
+
+            $sub->subscriber = $subscriber->id;
+            $sub->subscribed = $other->id;
+            $sub->created    = common_sql_now();
+
+            $result = $sub->insert();
+
+            if (!$result) {
+                common_log_db_error($sub, 'INSERT', __FILE__);
+                throw new Exception(_('Could not save subscription.'));
+            }
+
+            $sub->notify();
+
+            self::blow('user:notices_with_friends:%d', $subscriber->id);
+
+            $subscriber->blowSubscriptionsCount();
+            $other->blowSubscribersCount();
+
+            $otherUser = User::staticGet('id', $other->id);
+
+            if (!empty($otherUser) &&
+                $otherUser->autosubscribe &&
+                !self::exists($other, $subscriber) &&
+                !$subscriber->hasBlocked($other)) {
+
+                $auto = new Subscription();
+
+                $auto->subscriber = $subscriber->id;
+                $auto->subscribed = $other->id;
+                $auto->created    = common_sql_now();
+
+                $result = $auto->insert();
+
+                if (!$result) {
+                    common_log_db_error($auto, 'INSERT', __FILE__);
+                    throw new Exception(_('Could not save subscription.'));
+                }
+
+                $auto->notify();
+            }
+
+            Event::handle('EndSubscribe', array($subscriber, $other));
+        }
+
+        return true;
+    }
+
+    function notify()
+    {
+        # XXX: add other notifications (Jabber, SMS) here
+        # XXX: queue this and handle it offline
+        # XXX: Whatever happens, do it in Twitter-like API, too
+
+        $this->notifyEmail();
+    }
+
+    function notifyEmail()
+    {
+        $subscribedUser = User::staticGet('id', $this->subscribed);
+
+        if (!empty($subscribedUser)) {
+
+            $subscriber = Profile::staticGet('id', $this->subscriber);
+
+            mail_subscribe_notify_profile($subscribedUser, $subscriber);
+        }
+    }
+
+    /**
+     * Cancel a subscription
+     *
+     */
+
+    function cancel($subscriber, $other)
+    {
+        if (!self::exists($subscriber, $other)) {
+            throw new Exception(_('Not subscribed!'));
+        }
+
+        // Don't allow deleting self subs
+
+        if ($subscriber->id == $other->id) {
+            throw new Exception(_('Couldn\'t delete self-subscription.'));
+        }
+
+        if (Event::handle('StartUnsubscribe', array($subscriber, $other))) {
+
+            $sub = Subscription::pkeyGet(array('subscriber' => $subscriber->id,
+                                               'subscribed' => $other->id));
+
+            // note we checked for existence above
+
+            assert(!empty($sub));
+
+            $result = $sub->delete();
+
+            if (!$result) {
+                common_log_db_error($sub, 'DELETE', __FILE__);
+                throw new Exception(_('Couldn\'t delete subscription.'));
+            }
+
+            self::blow('user:notices_with_friends:%d', $subscriber->id);
+
+            $subscriber->blowSubscriptionsCount();
+            $other->blowSubscribersCount();
+
+            Event::handle('EndUnsubscribe', array($subscriber, $other));
+        }
+
+        return;
+    }
+
+    function exists($subscriber, $other)
+    {
+        $sub = Subscription::pkeyGet(array('subscriber' => $subscriber->id,
+                                           'subscribed' => $other->id));
+        return (empty($sub)) ? false : true;
+    }
 }