Massive refactor

- Use contextual namespaces within Flarum\Core
- Clean up and docblock everything
- Refactor Activity/Notification blueprint stuff
- Refactor Formatter stuff
- Refactor Search stuff
- Upgrade to JSON-API 1.0
- Removed “addedPosts” and “removedPosts” relationships from discussion
API. This was used for adding/removing event posts after renaming a
discussion etc. Instead we should make an additional request to get all
new posts

Todo:
- Fix Extenders and extensions
- Get rid of repository interfaces
- Fix other bugs I’ve inevitably introduced

src/Core/Activity/Activity.php

@@ -1,4 +1,6 @@
-<?php namespace Flarum\Core\Models;
+<?php namespace Flarum\Core\Activity;
+
+use Flarum\Core\Model;
 
 /**
  * Models a user activity record in the database.
@@ -16,23 +18,19 @@
 class Activity extends Model
 {
     /**
-     * The table associated with the model.
-     *
-     * @var string
+     * {@inheritdoc}
      */
     protected $table = 'activity';
 
     /**
-     * The attributes that should be mutated to dates.
-     *
-     * @var array
+     * {@inheritdoc}
      */
-    protected $dates = ['time'];
+    protected static $dateAttributes = ['time'];
 
     /**
      * A map of activity types and the model classes to use for their subjects.
      * For example, the 'posted' activity type, which represents that a user
-     * made a post, has the subject model class 'Flarum\Core\Models\Post'.
+     * made a post, has the subject model class 'Flarum\Core\Posts\Post'.
      *
      * @var array
      */
@@ -79,7 +77,7 @@ class Activity extends Model
      */
     public function user()
     {
-        return $this->belongsTo('Flarum\Core\Models\User', 'user_id');
+        return $this->belongsTo('Flarum\Core\Users\User', 'user_id');
     }
 
     /**
@@ -106,7 +104,8 @@ class Activity extends Model
      * Set the subject model for the given activity type.
      *
      * @param string $type The activity type.
-     * @param string $class The class name of the subject model for that type.
+     * @param string $subjectModel The class name of the subject model for that
+     *     type.
      * @return void
      */
     public static function setSubjectModel($type, $subjectModel)

src/Core/Activity/ActivityAbstract.php

@@ -1,5 +0,0 @@
-<?php namespace Flarum\Core\Activity;
-
-abstract class ActivityAbstract implements ActivityInterface
-{
-}

src/Core/Activity/ActivityRepositoryInterface.php

@@ -0,0 +1,18 @@
+<?php namespace Flarum\Core\Activity;
+
+use Flarum\Core\Users\User;
+
+interface ActivityRepositoryInterface
+{
+    /**
+     * Find a user's activity.
+     *
+     * @param integer $userId
+     * @param \Flarum\Core\Users\User $actor
+     * @param null|integer $count
+     * @param integer $start
+     * @param null|string $type
+     * @return \Illuminate\Database\Eloquent\Collection
+     */
+    public function findByUser($userId, User $actor, $count = null, $start = 0, $type = null);
+}

src/Core/Activity/ActivityServiceProvider.php

@@ -13,24 +13,29 @@ class ActivityServiceProvider extends ServiceProvider
     public function boot()
     {
         $this->extend([
-            (new Extend\EventSubscriber('Flarum\Core\Handlers\Events\UserActivitySyncer')),
+            (new Extend\EventSubscriber('Flarum\Core\Activity\Listeners\UserActivitySyncer')),
 
-            (new Extend\ActivityType('Flarum\Core\Activity\PostedActivity'))
+            (new Extend\ActivityType('Flarum\Core\Activity\PostedBlueprint'))
                 ->subjectSerializer('Flarum\Api\Serializers\PostBasicSerializer'),
 
-            (new Extend\ActivityType('Flarum\Core\Activity\StartedDiscussionActivity'))
+            (new Extend\ActivityType('Flarum\Core\Activity\StartedDiscussionBlueprint'))
                 ->subjectSerializer('Flarum\Api\Serializers\PostBasicSerializer'),
 
-            (new Extend\ActivityType('Flarum\Core\Activity\JoinedActivity'))
+            (new Extend\ActivityType('Flarum\Core\Activity\JoinedBlueprint'))
                 ->subjectSerializer('Flarum\Api\Serializers\UserBasicSerializer')
         ]);
     }
 
+    /**
+     * Register the service provider.
+     *
+     * @return void
+     */
     public function register()
     {
         $this->app->bind(
-            'Flarum\Core\Repositories\ActivityRepositoryInterface',
-            'Flarum\Core\Repositories\EloquentActivityRepository'
+            'Flarum\Core\Activity\ActivityRepositoryInterface',
+            'Flarum\Core\Activity\EloquentActivityRepository'
         );
     }
 }

src/Core/Activity/ActivitySyncer.php

@@ -1,12 +1,22 @@
 <?php namespace Flarum\Core\Activity;
 
-use Flarum\Core\Repositories\ActivityRepositoryInterface;
-use Flarum\Core\Models\Activity;
-
+/**
+ * The Activity Syncer commits activity blueprints to the database. Where a
+ * blueprint represents a single piece of activity, the syncer associates it
+ * with a particular user(s) and makes it available on their activity feed.
+ */
 class ActivitySyncer
 {
+    /**
+     * @var ActivityRepositoryInterface
+     */
     protected $activity;
 
+    /**
+     * Create a new instance of the activity syncer.
+     *
+     * @param ActivityRepositoryInterface $activity
+     */
     public function __construct(ActivityRepositoryInterface $activity)
     {
         $this->activity = $activity;
@@ -16,38 +26,92 @@ class ActivitySyncer
      * Sync a piece of activity so that it is present for the specified users,
      * and not present for anyone else.
      *
-     * @param \Flarum\Core\Activity\ActivityInterface $activity
+     * @param Blueprint $blueprint
      * @param \Flarum\Core\Models\User[] $users
      * @return void
      */
-    public function sync(ActivityInterface $activity, array $users)
+    public function sync(Blueprint $blueprint, array $users)
     {
-        Activity::unguard();
-
-        $attributes = [
-            'type'       => $activity::getType(),
-            'subject_id' => $activity->getSubject()->id,
-            'time'       => $activity->getTime()
-        ];
+        $attributes = $this->getAttributes($blueprint);
 
+        // Find all existing activity records in the database matching this
+        // blueprint. We will begin by assuming that they all need to be
+        // deleted in order to match the provided list of users.
         $toDelete = Activity::where($attributes)->get();
         $toInsert = [];
 
+        // For each of the provided users, check to see if they already have
+        // an activity record in the database. If they do, we can leave it be;
+        // otherwise, we will need to create a new one for them.
         foreach ($users as $user) {
-            $existing = $toDelete->where('user_id', $user->id)->first();
+            $existing = $toDelete->first(function ($activity) use ($user) {
+                return $activity->user_id === $user->id;
+            });
 
-            if ($k = $toDelete->search($existing)) {
-                $toDelete->pull($k);
+            if ($existing) {
+                $toDelete->forget($toDelete->search($existing));
             } else {
                 $toInsert[] = $attributes + ['user_id' => $user->id];
             }
         }
 
+        // Finally, delete all of the remaining activity records which weren't
+        // removed from this collection by the above loop. Insert the records
+        // we need to insert as well.
         if (count($toDelete)) {
-            Activity::whereIn('id', $toDelete->lists('id'))->delete();
+            $this->deleteActivity($toDelete->lists('id'));
         }
+
         if (count($toInsert)) {
-            Activity::insert($toInsert);
+            $this->createActivity($toInsert);
         }
     }
+
+    /**
+     * Delete a piece of activity for all users.
+     *
+     * @param Blueprint $blueprint
+     * @return void
+     */
+    public function delete(Blueprint $blueprint)
+    {
+        Activity::where($this->getAttributes($blueprint))->delete();
+    }
+
+    /**
+     * Delete a list of activity records.
+     *
+     * @param int[] $ids
+     */
+    protected function deleteActivity(array $ids)
+    {
+        Activity::whereIn('id', $ids)->delete();
+    }
+
+    /**
+     * Insert a list of activity record into the database.
+     *
+     * @param array[] $records An array containing arrays of activity record
+     *     attributes to insert.
+     */
+    protected function createActivity(array $records)
+    {
+        Activity::insert($records);
+    }
+
+    /**
+     * Construct an array of attributes to be stored in an activity record in
+     * the database, given an activity blueprint.
+     *
+     * @param Blueprint $blueprint
+     * @return array
+     */
+    protected function getAttributes(Blueprint $blueprint)
+    {
+        return [
+            'type'       => $blueprint::getType(),
+            'subject_id' => $blueprint->getSubject()->id,
+            'time'       => $blueprint->getTime()
+        ];
+    }
 }

src/Core/Activity/Blueprint.php

@@ -1,11 +1,16 @@
 <?php namespace Flarum\Core\Activity;
 
-interface ActivityInterface
+/**
+ * An activity Blueprint, when instantiated, represents a single piece of
+ * activity. The blueprint is used by the ActivitySyncer to commit the activity
+ * to the database.
+ */
+interface Blueprint
 {
     /**
      * Get the model that is the subject of this activity.
      *
-     * @return \Flarum\Core\Models\Model
+     * @return \Flarum\Core\Model
      */
     public function getSubject();
 

src/Core/Activity/EloquentActivityRepository.php

@@ -0,0 +1,35 @@
+<?php namespace Flarum\Core\Activity;
+
+use Flarum\Core\Users\User;
+
+class EloquentActivityRepository implements ActivityRepositoryInterface
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function findByUser($userId, User $actor, $limit = null, $offset = 0, $type = null)
+    {
+        $query = Activity::where('user_id', $userId)
+            ->whereIn('type', $this->getRegisteredTypes())
+            ->latest('time')
+            ->skip($offset)
+            ->take($limit);
+
+        if ($type !== null) {
+            $query->where('type', $type);
+        }
+
+        return $query->get();
+    }
+
+    /**
+     * Get a list of activity types that have been registered with the activity
+     * model.
+     *
+     * @return array
+     */
+    protected function getRegisteredTypes()
+    {
+        return array_keys(Activity::getSubjectModels());
+    }
+}

src/Core/Activity/JoinedActivity.php

@@ -1,33 +0,0 @@
-<?php namespace Flarum\Core\Activity;
-
-use Flarum\Core\Models\User;
-
-class JoinedActivity extends ActivityAbstract
-{
-    protected $user;
-
-    public function __construct(User $user)
-    {
-        $this->user = $user;
-    }
-
-    public function getSubject()
-    {
-        return $this->user;
-    }
-
-    public function getTime()
-    {
-        return $this->user->join_time;
-    }
-
-    public static function getType()
-    {
-        return 'joined';
-    }
-
-    public static function getSubjectModel()
-    {
-        return 'Flarum\Core\Models\User';
-    }
-}

src/Core/Activity/JoinedBlueprint.php

@@ -0,0 +1,59 @@
+<?php namespace Flarum\Core\Activity;
+
+use Flarum\Core\Users\User;
+
+/**
+ * An activity blueprint for the 'joined' activity type, which represents a user
+ * joining the forum.
+ */
+class JoinedBlueprint implements Blueprint
+{
+    /**
+     * The user who joined the forum.
+     *
+     * @var User
+     */
+    protected $user;
+
+    /**
+     * Create a new 'joined' activity blueprint.
+     *
+     * @param User $user The user who joined the forum.
+     */
+    public function __construct(User $user)
+    {
+        $this->user = $user;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getSubject()
+    {
+        return $this->user;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getTime()
+    {
+        return $this->user->join_time;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public static function getType()
+    {
+        return 'joined';
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public static function getSubjectModel()
+    {
+        return 'Flarum\Core\Users\User';
+    }
+}

src/Core/Activity/Listeners/UserActivitySyncer.php

@@ -0,0 +1,126 @@
+<?php namespace Flarum\Core\Activity\Listeners;
+
+use Flarum\Core\Activity\ActivitySyncer;
+use Flarum\Core\Activity\PostedBlueprint;
+use Flarum\Core\Activity\StartedDiscussionBlueprint;
+use Flarum\Core\Activity\JoinedBlueprint;
+use Flarum\Core\Posts\Post;
+use Flarum\Core\Posts\Events\PostWasPosted;
+use Flarum\Core\Posts\Events\PostWasDeleted;
+use Flarum\Core\Posts\Events\PostWasHidden;
+use Flarum\Core\Posts\Events\PostWasRestored;
+use Flarum\Core\Users\Events\UserWasRegistered;
+use Illuminate\Contracts\Events\Dispatcher;
+
+class UserActivitySyncer
+{
+    /**
+     * @var \Flarum\Core\Activity\ActivitySyncer
+     */
+    protected $activity;
+
+    /**
+     * @param \Flarum\Core\Activity\ActivitySyncer $activity
+     */
+    public function __construct(ActivitySyncer $activity)
+    {
+        $this->activity = $activity;
+    }
+
+    /**
+     * @param \Illuminate\Contracts\Events\Dispatcher $events
+     * @return void
+     */
+    public function subscribe(Dispatcher $events)
+    {
+        $events->listen('Flarum\Core\Events\PostWasPosted', __CLASS__.'@whenPostWasPosted');
+        $events->listen('Flarum\Core\Events\PostWasHidden', __CLASS__.'@whenPostWasHidden');
+        $events->listen('Flarum\Core\Events\PostWasRestored', __CLASS__.'@whenPostWasRestored');
+        $events->listen('Flarum\Core\Events\PostWasDeleted', __CLASS__.'@whenPostWasDeleted');
+        $events->listen('Flarum\Core\Events\UserWasRegistered', __CLASS__.'@whenUserWasRegistered');
+    }
+
+    /**
+     * @param \Flarum\Core\Posts\Events\PostWasPosted $event
+     * @return void
+     */
+    public function whenPostWasPosted(PostWasPosted $event)
+    {
+        $this->postBecameVisible($event->post);
+    }
+
+    /**
+     * @param \Flarum\Core\Posts\Events\PostWasHidden $event
+     * @return void
+     */
+    public function whenPostWasHidden(PostWasHidden $event)
+    {
+        $this->postBecameInvisible($event->post);
+    }
+
+    /**
+     * @param \Flarum\Core\Posts\Events\PostWasRestored $event
+     * @return void
+     */
+    public function whenPostWasRestored(PostWasRestored $event)
+    {
+        $this->postBecameVisible($event->post);
+    }
+
+    /**
+     * @param \Flarum\Core\Posts\Events\PostWasDeleted $event
+     * @return void
+     */
+    public function whenPostWasDeleted(PostWasDeleted $event)
+    {
+        $this->postBecameInvisible($event->post);
+    }
+
+    /**
+     * @param \Flarum\Core\Users\Events\UserWasRegistered $event
+     * @return void
+     */
+    public function whenUserWasRegistered(UserWasRegistered $event)
+    {
+        $blueprint = new JoinedBlueprint($event->user);
+
+        $this->activity->sync($blueprint, [$event->user]);
+    }
+
+    /**
+     * Sync activity to a post's author when a post becomes visible.
+     *
+     * @param \Flarum\Core\Posts\Post $post
+     * @return void
+     */
+    protected function postBecameVisible(Post $post)
+    {
+        $blueprint = $this->postedBlueprint($post);
+
+        $this->activity->sync($blueprint, [$post->user]);
+    }
+
+    /**
+     * Delete activity when a post becomes invisible.
+     *
+     * @param \Flarum\Core\Posts\Post $post
+     * @return void
+     */
+    protected function postBecameInvisible(Post $post)
+    {
+        $blueprint = $this->postedBlueprint($post);
+
+        $this->activity->delete($blueprint);
+    }
+
+    /**
+     * Create the appropriate activity blueprint for a post.
+     *
+     * @param \Flarum\Core\Posts\Post $post
+     * @return \Flarum\Core\Activity\Blueprint
+     */
+    protected function postedBlueprint(Post $post)
+    {
+        return $post->number == 1 ? new StartedDiscussionBlueprint($post) : new PostedBlueprint($post);
+    }
+}

src/Core/Activity/PostedActivity.php

@@ -1,33 +0,0 @@
-<?php namespace Flarum\Core\Activity;
-
-use Flarum\Core\Models\Post;
-
-class PostedActivity extends ActivityAbstract
-{
-    protected $post;
-
-    public function __construct(Post $post)
-    {
-        $this->post = $post;
-    }
-
-    public function getSubject()
-    {
-        return $this->post;
-    }
-
-    public function getTime()
-    {
-        return $this->post->time;
-    }
-
-    public static function getType()
-    {
-        return 'posted';
-    }
-
-    public static function getSubjectModel()
-    {
-        return 'Flarum\Core\Models\Post';
-    }
-}

src/Core/Activity/PostedBlueprint.php

@@ -0,0 +1,59 @@
+<?php namespace Flarum\Core\Activity;
+
+use Flarum\Core\Posts\Post;
+
+/**
+ * An activity blueprint for the 'posted' activity type, which represents a user
+ * posting in a discussion.
+ */
+class PostedBlueprint implements Blueprint
+{
+    /**
+     * The user who joined the forum.
+     *
+     * @var Post
+     */
+    protected $post;
+
+    /**
+     * Create a new 'posted' activity blueprint.
+     *
+     * @param Post $post The post that was made.
+     */
+    public function __construct(Post $post)
+    {
+        $this->post = $post;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getSubject()
+    {
+        return $this->post;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getTime()
+    {
+        return $this->post->time;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public static function getType()
+    {
+        return 'posted';
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public static function getSubjectModel()
+    {
+        return 'Flarum\Core\Posts\Post';
+    }
+}

src/Core/Activity/StartedDiscussionActivity.php

@@ -1,9 +0,0 @@
-<?php namespace Flarum\Core\Activity;
-
-class StartedDiscussionActivity extends PostedActivity
-{
-    public static function getType()
-    {
-        return 'startedDiscussion';
-    }
-}

src/Core/Activity/StartedDiscussionBlueprint.php

@@ -0,0 +1,16 @@
+<?php namespace Flarum\Core\Activity;
+
+/**
+ * An activity blueprint for the 'startedDiscussion' activity type, which
+ * represents a user starting a discussion.
+ */
+class StartedDiscussionBlueprint extends PostedBlueprint
+{
+    /**
+     * {@inheritdoc}
+     */
+    public static function getType()
+    {
+        return 'startedDiscussion';
+    }
+}

src/Core/Commands/ConfirmEmailCommand.php

@@ -1,11 +0,0 @@
-<?php namespace Flarum\Core\Commands;
-
-class ConfirmEmailCommand
-{
-    public $token;
-
-    public function __construct($token)
-    {
-        $this->token = $token;
-    }
-}

src/Core/Commands/DeleteAvatarCommand.php

@@ -1,20 +0,0 @@
-<?php namespace Flarum\Core\Commands;
-
-use RuntimeException;
-
-class DeleteAvatarCommand
-{
-    public $userId;
-
-    public $actor;
-
-    public function __construct($userId, $actor)
-    {
-        if (empty($userId) || !intval($userId)) {
-            throw new RuntimeException('No valid user ID specified.');
-        }
-
-        $this->userId = $userId;
-        $this->actor = $actor;
-    }
-}

src/Core/Commands/DeleteDiscussionCommand.php

@@ -1,14 +0,0 @@
-<?php namespace Flarum\Core\Commands;
-
-class DeleteDiscussionCommand
-{
-    public $discussionId;
-
-    public $user;
-
-    public function __construct($discussionId, $user)
-    {
-        $this->discussionId = $discussionId;
-        $this->user = $user;
-    }
-}

src/Core/Commands/DeletePostCommand.php

@@ -1,14 +0,0 @@
-<?php namespace Flarum\Core\Commands;
-
-class DeletePostCommand
-{
-    public $postId;
-
-    public $user;
-
-    public function __construct($postId, $user)
-    {
-        $this->postId = $postId;
-        $this->user = $user;
-    }
-}

src/Core/Commands/DeleteUserCommand.php

@@ -1,14 +0,0 @@
-<?php namespace Flarum\Core\Commands;
-
-class DeleteUserCommand
-{
-    public $userId;
-
-    public $user;
-
-    public function __construct($userId, $user)
-    {
-        $this->userId = $userId;
-        $this->user = $user;
-    }
-}

src/Core/Commands/EditDiscussionCommand.php

@@ -1,17 +0,0 @@
-<?php namespace Flarum\Core\Commands;
-
-class EditDiscussionCommand
-{
-    public $discussionId;
-
-    public $user;
-
-    public $data;
-
-    public function __construct($discussionId, $user, $data)
-    {
-        $this->discussionId = $discussionId;
-        $this->user = $user;
-        $this->data = $data;
-    }
-}

src/Core/Commands/EditPostCommand.php

@@ -1,17 +0,0 @@
-<?php namespace Flarum\Core\Commands;
-
-class EditPostCommand
-{
-    public $postId;
-
-    public $user;
-
-    public $data;
-
-    public function __construct($postId, $user, $data)
-    {
-        $this->postId = $postId;
-        $this->user = $user;
-        $this->data = $data;
-    }
-}

src/Core/Commands/EditUserCommand.php

@@ -1,17 +0,0 @@
-<?php namespace Flarum\Core\Commands;
-
-class EditUserCommand
-{
-    public $userId;
-
-    public $user;
-
-    public $data;
-
-    public function __construct($userId, $user, $data)
-    {
-        $this->userId = $userId;
-        $this->user = $user;
-        $this->data = $data;
-    }
-}

src/Core/Commands/GenerateAccessTokenCommand.php

@@ -1,11 +0,0 @@
-<?php namespace Flarum\Core\Commands;
-
-class GenerateAccessTokenCommand
-{
-    public $userId;
-
-    public function __construct($userId)
-    {
-        $this->userId = $userId;
-    }
-}

src/Core/Commands/PostReplyCommand.php

@@ -1,17 +0,0 @@
-<?php namespace Flarum\Core\Commands;
-
-class PostReplyCommand
-{
-    public $discussionId;
-
-    public $user;
-
-    public $data;
-
-    public function __construct($discussionId, $user, $data)
-    {
-        $this->discussionId = $discussionId;
-        $this->user = $user;
-        $this->data = $data;
-    }
-}

src/Core/Commands/ReadDiscussionCommand.php

@@ -1,17 +0,0 @@
-<?php namespace Flarum\Core\Commands;
-
-class ReadDiscussionCommand
-{
-    public $discussionId;
-
-    public $user;
-
-    public $readNumber;
-
-    public function __construct($discussionId, $user, $readNumber)
-    {
-        $this->discussionId = $discussionId;
-        $this->user = $user;
-        $this->readNumber = $readNumber;
-    }
-}

src/Core/Commands/ReadNotificationCommand.php

@@ -1,14 +0,0 @@
-<?php namespace Flarum\Core\Commands;
-
-class ReadNotificationCommand
-{
-    public $notificationId;
-
-    public $user;
-
-    public function __construct($notificationId, $user)
-    {
-        $this->notificationId = $notificationId;
-        $this->user = $user;
-    }
-}

src/Core/Commands/RegisterUserCommand.php

@@ -1,17 +0,0 @@
-<?php namespace Flarum\Core\Commands;
-
-class RegisterUserCommand
-{
-    public $forum;
-
-    public $user;
-
-    public $data;
-
-    public function __construct($user, $forum, $data)
-    {
-        $this->user = $user;
-        $this->forum = $forum;
-        $this->data = $data;
-    }
-}

src/Core/Commands/RequestPasswordResetCommand.php

@@ -1,11 +0,0 @@
-<?php namespace Flarum\Core\Commands;
-
-class RequestPasswordResetCommand
-{
-    public $email;
-
-    public function __construct($email)
-    {
-        $this->email = $email;
-    }
-}

src/Core/Commands/StartDiscussionCommand.php

@@ -1,17 +0,0 @@
-<?php namespace Flarum\Core\Commands;
-
-class StartDiscussionCommand
-{
-    public $user;
-
-    public $forum;
-
-    public $data;
-
-    public function __construct($user, $forum, $data)
-    {
-        $this->user = $user;
-        $this->forum = $forum;
-        $this->data = $data;
-    }
-}

src/Core/Commands/UploadAvatarCommand.php

@@ -1,31 +0,0 @@
-<?php namespace Flarum\Core\Commands;
-
-use Psr\Http\Message\UploadedFileInterface;
-use RuntimeException;
-
-class UploadAvatarCommand
-{
-    public $userId;
-
-    /**
-     * @var \Psr\Http\Message\UploadedFileInterface
-     */
-    public $file;
-
-    public $actor;
-
-    public function __construct($userId, UploadedFileInterface $file, $actor)
-    {
-        if (empty($userId) || !intval($userId)) {
-            throw new RuntimeException('No valid user ID specified.');
-        }
-
-        if (is_null($file)) {
-            throw new RuntimeException('No file to upload');
-        }
-
-        $this->userId = $userId;
-        $this->file = $file;
-        $this->actor = $actor;
-    }
-}

src/Core/CoreServiceProvider.php

@@ -1,15 +1,7 @@
 <?php namespace Flarum\Core;
 
-use Illuminate\Bus\Dispatcher as Bus;
-use Illuminate\Contracts\Container\Container;
+use Flarum\Core\Users\User;
 use Flarum\Support\ServiceProvider;
-use Flarum\Core\Models\CommentPost;
-use Flarum\Core\Models\Post;
-use Flarum\Core\Models\Model;
-use Flarum\Core\Models\Forum;
-use Flarum\Core\Models\User;
-use Flarum\Core\Models\Discussion;
-use Flarum\Core\Search\GambitManager;
 use Flarum\Extend;
 
 class CoreServiceProvider extends ServiceProvider
@@ -23,21 +15,14 @@ class CoreServiceProvider extends ServiceProvider
     {
         $this->loadViewsFrom(__DIR__.'/../../views', 'flarum');
 
-        $this->addEventHandlers();
-        $this->bootModels();
-        $this->addPostTypes();
-        $this->grantPermissions();
-        $this->mapCommandHandlers();
-    }
+        $this->app->make('Illuminate\Contracts\Bus\Dispatcher')->mapUsing(function ($command) {
+            return get_class($command).'Handler@handle';
+        });
 
-    public function mapCommandHandlers()
-    {
-        $this->app->make(Bus::class)->mapUsing(function ($command) {
-            return Bus::simpleMapping(
-                $command,
-                'Flarum\Core\Commands',
-                'Flarum\Core\Handlers\Commands'
-            );
+        Model::setValidator($this->app['validator']);
+
+        Forum::allow('*', function (Forum $forum, User $user, $action) {
+            return $user->hasPermission('forum.'.$action) ?: null;
         });
     }
 
@@ -48,205 +33,15 @@ class CoreServiceProvider extends ServiceProvider
      */
     public function register()
     {
-        // Register a singleton entity that represents this forum. This entity
-        // will be used to check for global forum permissions (like viewing the
-        // forum, registering, and starting discussions).
-        $this->app->singleton('flarum.forum', 'Flarum\Core\Models\Forum');
+        $this->app->singleton('flarum.forum', 'Flarum\Core\Forum');
 
         // TODO: probably use Illuminate's AggregateServiceProvider
         // functionality, because it includes the 'provides' stuff.
         $this->app->register('Flarum\Core\Activity\ActivityServiceProvider');
+        $this->app->register('Flarum\Core\Discussions\DiscussionsServiceProvider');
         $this->app->register('Flarum\Core\Formatter\FormatterServiceProvider');
         $this->app->register('Flarum\Core\Notifications\NotificationsServiceProvider');
-
-        // TODO: refactor these into the appropriate service providers, when
-        // (if) we restructure our namespaces per-entity
-        // (Flarum\Core\Discussions\DiscussionsServiceProvider, etc.)
-        $this->app->bind(
-            'Flarum\Core\Repositories\DiscussionRepositoryInterface',
-            'Flarum\Core\Repositories\EloquentDiscussionRepository'
-        );
-
-        $this->app->bind(
-            'Flarum\Core\Repositories\PostRepositoryInterface',
-            'Flarum\Core\Repositories\EloquentPostRepository'
-        );
-
-        $this->app->bind(
-            'Flarum\Core\Repositories\UserRepositoryInterface',
-            'Flarum\Core\Repositories\EloquentUserRepository'
-        );
-
-        $this->app->bind(
-            'Flarum\Core\Search\Discussions\Fulltext\DriverInterface',
-            'Flarum\Core\Search\Discussions\Fulltext\MySqlFulltextDriver'
-        );
-
-        $this->registerDiscussionGambits();
-        $this->registerUserGambits();
-        $this->registerAvatarsFilesystem();
-    }
-
-    public function registerAvatarsFilesystem()
-    {
-        $avatarsFilesystem = function (Container $app) {
-            return $app->make('Illuminate\Contracts\Filesystem\Factory')->disk('flarum-avatars')->getDriver();
-        };
-
-        $this->app->when('Flarum\Core\Handlers\Commands\UploadAvatarCommandHandler')
-            ->needs('League\Flysystem\FilesystemInterface')
-            ->give($avatarsFilesystem);
-
-        $this->app->when('Flarum\Core\Handlers\Commands\DeleteAvatarCommandHandler')
-            ->needs('League\Flysystem\FilesystemInterface')
-            ->give($avatarsFilesystem);
-    }
-
-    public function registerDiscussionGambits()
-    {
-        $this->app->instance('flarum.discussionGambits', [
-            'Flarum\Core\Search\Discussions\Gambits\AuthorGambit',
-            'Flarum\Core\Search\Discussions\Gambits\UnreadGambit'
-        ]);
-
-        $this->app->when('Flarum\Core\Search\Discussions\DiscussionSearcher')
-            ->needs('Flarum\Core\Search\GambitManager')
-            ->give(function (Container $app) {
-                $gambits = new GambitManager($app);
-
-                foreach ($app->make('flarum.discussionGambits') as $gambit) {
-                    $gambits->add($gambit);
-                }
-
-                $gambits->setFulltextGambit('Flarum\Core\Search\Discussions\Gambits\FulltextGambit');
-
-                return $gambits;
-            });
-    }
-
-    public function registerUserGambits()
-    {
-        $this->app->instance('flarum.userGambits', []);
-
-        $this->app->when('Flarum\Core\Search\Users\UserSearcher')
-            ->needs('Flarum\Core\Search\GambitManager')
-            ->give(function (Container $app) {
-                $gambits = new GambitManager($app);
-
-                foreach ($app->make('flarum.userGambits') as $gambit) {
-                    $gambits->add($gambit);
-                }
-
-                $gambits->setFulltextGambit('Flarum\Core\Search\Users\Gambits\FulltextGambit');
-
-                return $gambits;
-            });
-    }
-
-    public function addPostTypes()
-    {
-        $this->extend([
-            new Extend\PostType('Flarum\Core\Models\CommentPost'),
-            new Extend\PostType('Flarum\Core\Models\DiscussionRenamedPost')
-        ]);
-    }
-
-    public function addEventHandlers()
-    {
-        $this->extend([
-            new Extend\EventSubscriber('Flarum\Core\Handlers\Events\DiscussionMetadataUpdater'),
-            new Extend\EventSubscriber('Flarum\Core\Handlers\Events\UserMetadataUpdater'),
-            new Extend\EventSubscriber('Flarum\Core\Handlers\Events\EmailConfirmationMailer')
-        ]);
-    }
-
-    public function bootModels()
-    {
-        Model::setValidator($this->app['validator']);
-
-        CommentPost::setFormatter($this->app['flarum.formatter']);
-
-        User::setHasher($this->app['hash']);
-        User::setFormatter($this->app['flarum.formatter']);
-
-        User::registerPreference('discloseOnline', 'boolval', true);
-        User::registerPreference('indexProfile', 'boolval', true);
-    }
-
-    public function grantPermissions()
-    {
-        Forum::allow('*', function ($forum, $user, $action) {
-            if ($user->hasPermission('forum.'.$action)) {
-                return true;
-            }
-        });
-
-        Post::allow('*', function ($post, $user, $action) {
-            if ($post->discussion->can($user, $action.'Posts')) {
-                return true;
-            }
-        });
-
-        // When fetching a discussion's posts: if the user doesn't have permission
-        // to moderate the discussion, then they can't see posts that have been
-        // hidden by someone other than themself.
-        Discussion::addVisiblePostsScope(function ($query, User $user, Discussion $discussion) {
-            if (! $discussion->can($user, 'editPosts')) {
-                $query->where(function ($query) use ($user) {
-                    $query->whereNull('hide_user_id')
-                          ->orWhere('hide_user_id', $user->id);
-                });
-            }
-        });
-
-        Post::allow('view', function ($post, $user) {
-            if (! $post->hide_user_id || $post->can($user, 'edit')) {
-                return true;
-            }
-        });
-
-        // A post is allowed to be edited if the user has permission to moderate
-        // the discussion which it's in, or if they are the author and the post
-        // hasn't been deleted by someone else.
-        Post::allow('edit', function ($post, $user) {
-            if ($post->discussion->can($user, 'editPosts') ||
-                ($post->user_id == $user->id && (! $post->hide_user_id || $post->hide_user_id == $user->id))
-            ) {
-                return true;
-            }
-        });
-
-        User::allow('*', function ($discussion, $user, $action) {
-            if ($user->hasPermission('user.'.$action)) {
-                return true;
-            }
-        });
-
-        User::allow(['edit', 'delete'], function ($user, $actor) {
-            if ($user->id == $actor->id) {
-                return true;
-            }
-        });
-
-        Discussion::allow('*', function ($discussion, $user, $action) {
-            if ($user->hasPermission('discussion.'.$action)) {
-                return true;
-            }
-        });
-
-        // Allow a user to rename their own discussion.
-        Discussion::allow('rename', function ($discussion, $user) {
-            if ($discussion->start_user_id == $user->id) {
-                return true;
-                // @todo add limitations to time etc. according to a config setting
-            }
-        });
-
-        Discussion::allow('delete', function ($discussion, $user) {
-            if ($discussion->start_user_id == $user->id && $discussion->participants_count == 1) {
-                return true;
-                // @todo add limitations to time etc. according to a config setting
-            }
-        });
+        $this->app->register('Flarum\Core\Posts\PostsServiceProvider');
+        $this->app->register('Flarum\Core\Users\UsersServiceProvider');
     }
 }

src/Core/DatabaseServiceProvider.php

@@ -40,6 +40,8 @@ class DatabaseServiceProvider extends ServiceProvider
             $this->app->booting(function() {
                 $resolver = $this->app->make('Illuminate\Database\ConnectionResolverInterface');
                 Model::setConnectionResolver($resolver);
+
+                Model::setEventDispatcher($this->app->make('events'));
             });
         }
     }

src/Core/Discussions/Commands/DeleteDiscussion.php

@@ -0,0 +1,41 @@
+<?php namespace Flarum\Core\Discussions\Commands;
+
+use Flarum\Core\Users\User;
+
+class DeleteDiscussion
+{
+    /**
+     * The ID of the discussion to delete.
+     *
+     * @var int
+     */
+    public $discussionId;
+
+    /**
+     * The user performing the action.
+     *
+     * @var User
+     */
+    public $actor;
+
+    /**
+     * Any other user input associated with the action. This is unused by
+     * default, but may be used by extensions.
+     *
+     * @var array
+     */
+    public $data;
+
+    /**
+     * @param int $discussionId The ID of the discussion to delete.
+     * @param User $actor The user performing the action.
+     * @param array $data Any other user input associated with the action. This
+     *     is unused by default, but may be used by extensions.
+     */
+    public function __construct($discussionId, User $actor, array $data = [])
+    {
+        $this->discussionId = $discussionId;
+        $this->actor = $actor;
+        $this->data = $data;
+    }
+}

src/Core/Discussions/Commands/DeleteDiscussionHandler.php

@@ -0,0 +1,44 @@
+<?php namespace Flarum\Core\Discussions\Commands;
+
+use Flarum\Core\Discussions\DiscussionRepositoryInterface;
+use Flarum\Core\Discussions\Events\DiscussionWillBeDeleted;
+use Flarum\Core\Support\DispatchesEvents;
+
+class DeleteDiscussionHandler
+{
+    use DispatchesEvents;
+
+    /**
+     * @var \Flarum\Core\Discussions\DiscussionRepositoryInterface
+     */
+    protected $discussions;
+
+    /**
+     * @param \Flarum\Core\Discussions\DiscussionRepositoryInterface $discussions
+     */
+    public function __construct(DiscussionRepositoryInterface $discussions)
+    {
+        $this->discussions = $discussions;
+    }
+
+    /**
+     * @param \Flarum\Core\Discussions\Commands\DeleteDiscussion $command
+     * @return \Flarum\Core\Discussions\Discussion
+     */
+    public function handle(DeleteDiscussion $command)
+    {
+        $actor = $command->actor;
+
+        $discussion = $this->discussions->findOrFail($command->discussionId, $actor);
+
+        $discussion->assertCan($actor, 'delete');
+
+        event(new DiscussionWillBeDeleted($discussion, $actor, $command->data));
+
+        $discussion->delete();
+
+        $this->dispatchEventsFor($discussion);
+
+        return $discussion;
+    }
+}

src/Core/Discussions/Commands/EditDiscussion.php

@@ -0,0 +1,39 @@
+<?php namespace Flarum\Core\Discussions\Commands;
+
+use Flarum\Core\Users\User;
+
+class EditDiscussion
+{
+    /**
+     * The ID of the discussion to edit.
+     *
+     * @var integer
+     */
+    public $discussionId;
+
+    /**
+     * The user performing the action.
+     *
+     * @var \Flarum\Core\Users\User
+     */
+    public $actor;
+
+    /**
+     * The attributes to update on the discussion.
+     *
+     * @var array
+     */
+    public $data;
+
+    /**
+     * @param integer $discussionId The ID of the discussion to edit.
+     * @param \Flarum\Core\Users\User $actor The user performing the action.
+     * @param array $data The attributes to update on the discussion.
+     */
+    public function __construct($discussionId, User $actor, array $data)
+    {
+        $this->discussionId = $discussionId;
+        $this->actor = $actor;
+        $this->data = $data;
+    }
+}

src/Core/Discussions/Commands/EditDiscussionHandler.php

@@ -0,0 +1,50 @@
+<?php namespace Flarum\Core\Discussions\Commands;
+
+use Flarum\Core\Discussions\DiscussionRepositoryInterface;
+use Flarum\Core\Discussions\Events\DiscussionWillBeSaved;
+use Flarum\Core\Support\DispatchesEvents;
+
+class EditDiscussionHandler
+{
+    use DispatchesEvents;
+
+    /**
+     * @var DiscussionRepositoryInterface
+     */
+    protected $discussions;
+
+    /**
+     * @param DiscussionRepositoryInterface $discussions
+     */
+    public function __construct(DiscussionRepositoryInterface $discussions)
+    {
+        $this->discussions = $discussions;
+    }
+
+    /**
+     * @param EditDiscussion $command
+     * @return \Flarum\Core\Discussions\Discussion
+     * @throws \Flarum\Core\Exceptions\PermissionDeniedException
+     */
+    public function handle(EditDiscussion $command)
+    {
+        $actor = $command->actor;
+        $data = $command->data;
+        $attributes = array_get($data, 'attributes', []);
+
+        $discussion = $this->discussions->findOrFail($command->discussionId, $actor);
+
+        if (isset($attributes['title'])) {
+            $discussion->assertCan($actor, 'rename');
+            $discussion->rename($attributes['title'], $actor);
+        }
+
+        event(new DiscussionWillBeSaved($discussion, $actor, $data));
+
+        $discussion->save();
+
+        $this->dispatchEventsFor($discussion);
+
+        return $discussion;
+    }
+}

src/Core/Discussions/Commands/ReadDiscussion.php

@@ -0,0 +1,39 @@
+<?php namespace Flarum\Core\Discussions\Commands;
+
+use Flarum\Core\Users\User;
+
+class ReadDiscussion
+{
+    /**
+     * The ID of the discussion to mark as read.
+     *
+     * @var integer
+     */
+    public $discussionId;
+
+    /**
+     * The user to mark the discussion as read for.
+     *
+     * @var User
+     */
+    public $actor;
+
+    /**
+     * The number of the post to mark as read.
+     *
+     * @var integer
+     */
+    public $readNumber;
+
+    /**
+     * @param integer $discussionId The ID of the discussion to mark as read.
+     * @param User $actor The user to mark the discussion as read for.
+     * @param integer $readNumber The number of the post to mark as read.
+     */
+    public function __construct($discussionId, User $actor, $readNumber)
+    {
+        $this->discussionId = $discussionId;
+        $this->actor = $actor;
+        $this->readNumber = $readNumber;
+    }
+}

src/Core/Discussions/Commands/ReadDiscussionHandler.php

@@ -0,0 +1,51 @@
+<?php namespace Flarum\Core\Discussions\Commands;
+
+use Flarum\Core\Discussions\DiscussionRepositoryInterface;
+use Flarum\Core\Discussions\Events\DiscussionStateWillBeSaved;
+use Flarum\Core\Exceptions\PermissionDeniedException;
+use Flarum\Core\Support\DispatchesEvents;
+
+class ReadDiscussionHandler
+{
+    use DispatchesEvents;
+
+    /**
+     * @var DiscussionRepositoryInterface
+     */
+    protected $discussions;
+
+    /**
+     * @param DiscussionRepositoryInterface $discussions
+     */
+    public function __construct(DiscussionRepositoryInterface $discussions)
+    {
+        $this->discussions = $discussions;
+    }
+
+    /**
+     * @param ReadDiscussion $command
+     * @return \Flarum\Core\Discussions\DiscussionState
+     * @throws \Flarum\Core\Exceptions\PermissionDeniedException
+     */
+    public function handle(ReadDiscussion $command)
+    {
+        $actor = $command->actor;
+
+        if (! $actor->exists) {
+            throw new PermissionDeniedException;
+        }
+
+        $discussion = $this->discussions->findOrFail($command->discussionId, $actor);
+
+        $state = $discussion->stateFor($actor);
+        $state->read($command->readNumber);
+
+        event(new DiscussionStateWillBeSaved($state));
+
+        $state->save();
+
+        $this->dispatchEventsFor($state);
+
+        return $state;
+    }
+}

src/Core/Discussions/Commands/StartDiscussion.php

@@ -0,0 +1,30 @@
+<?php namespace Flarum\Core\Discussions\Commands;
+
+use Flarum\Core\Users\User;
+
+class StartDiscussion
+{
+    /**
+     * The user authoring the discussion.
+     *
+     * @var User
+     */
+    public $actor;
+
+    /**
+     * The discussion attributes.
+     *
+     * @var array
+     */
+    public $data;
+
+    /**
+     * @param User $actor The user authoring the discussion.
+     * @param array $data The discussion attributes.
+     */
+    public function __construct(User $actor, array $data)
+    {
+        $this->actor = $actor;
+        $this->data = $data;
+    }
+}

src/Core/Discussions/Commands/StartDiscussionHandler.php

@@ -1,43 +1,63 @@
-<?php namespace Flarum\Core\Handlers\Commands;
+<?php namespace Flarum\Core\Discussions\Commands;
 
+use Flarum\Core\Discussions\Events\DiscussionWillBeSaved;
+use Flarum\Core\Forum;
 use Illuminate\Contracts\Bus\Dispatcher;
-use Flarum\Core\Models\Discussion;
-use Flarum\Core\Events\DiscussionWillBeSaved;
-use Flarum\Core\Commands\PostReplyCommand;
+use Flarum\Core\Discussions\Discussion;
+use Flarum\Core\Posts\Commands\PostReply;
 use Flarum\Core\Support\DispatchesEvents;
 
-class StartDiscussionCommandHandler
+class StartDiscussionHandler
 {
     use DispatchesEvents;
 
+    /**
+     * @var Dispatcher
+     */
     protected $bus;
 
-    public function __construct(Dispatcher $bus)
+    /**
+     * @var Forum
+     */
+    protected $forum;
+
+    /**
+     * @param Dispatcher $bus
+     */
+    public function __construct(Dispatcher $bus, Forum $forum)
     {
         $this->bus = $bus;
+        $this->forum = $forum;
     }
 
-    public function handle($command)
+    /**
+     * @param StartDiscussion $command
+     * @return mixed
+     */
+    public function handle(StartDiscussion $command)
     {
-        $command->forum->assertCan($command->user, 'startDiscussion');
+        $actor = $command->actor;
+        $data = $command->data;
+
+        $this->forum->assertCan($actor, 'startDiscussion');
 
         // Create a new Discussion entity, persist it, and dispatch domain
         // events. Before persistance, though, fire an event to give plugins
         // an opportunity to alter the discussion entity based on data in the
         // command they may have passed through in the controller.
         $discussion = Discussion::start(
-            array_get($command->data, 'title'),
-            $command->user
+            array_get($data, 'attributes.title'),
+            $actor
         );
 
-        event(new DiscussionWillBeSaved($discussion, $command));
+        event(new DiscussionWillBeSaved($discussion, $actor, $data));
 
         $discussion->save();
 
         // Now that the discussion has been created, we can add the first post.
         // We will do this by running the PostReply command.
         $post = $this->bus->dispatch(
-            new PostReplyCommand($discussion->id, $command->user, $command->data)
+            new PostReply($discussion->id, $actor, $data)
         );
 
         // Before we dispatch events, refresh our discussion instance's
@@ -50,6 +70,6 @@ class StartDiscussionCommandHandler
 
         $discussion->save();
 
-        return $post->discussion;
+        return $discussion;
     }
 }

src/Core/Discussions/Discussion.php

@@ -1,13 +1,17 @@
-<?php namespace Flarum\Core\Models;
+<?php namespace Flarum\Core\Discussions;
 
+use Flarum\Core\Model;
+use Flarum\Core\Discussions\Events\DiscussionWasDeleted;
+use Flarum\Core\Discussions\Events\DiscussionWasStarted;
+use Flarum\Core\Discussions\Events\DiscussionWasRenamed;
+use Flarum\Core\Posts\Events\PostWasDeleted;
+use Flarum\Core\Posts\Post;
+use Flarum\Core\Posts\MergeablePost;
+use Flarum\Core\Users\Guest;
+use Flarum\Core\Users\User;
 use Flarum\Core\Support\EventGenerator;
 use Flarum\Core\Support\Locked;
 use Flarum\Core\Support\VisibleScope;
-use Flarum\Core\Events\DiscussionWasDeleted;
-use Flarum\Core\Events\DiscussionWasStarted;
-use Flarum\Core\Events\DiscussionWasRenamed;
-use Flarum\Core\Events\PostWasDeleted;
-use Flarum\Core\Models\User;
 
 class Discussion extends Model
 {
@@ -50,16 +54,16 @@ class Discussion extends Model
     /**
      * The user for which the state relationship should be loaded.
      *
-     * @var \Flarum\Core\Models\User
+     * @var User
      */
     protected static $stateUser;
 
     /**
-     * An array of callables that apply constraints to the visiblePosts query.
+     * An array of callables that apply constraints to the postsVisibleTo query.
      *
      * @var callable[]
      */
-    protected static $visiblePostsScopes = [];
+    protected static $postVisibilityScopes = [];
 
     /**
      * Boot the model.
@@ -94,8 +98,8 @@ class Discussion extends Model
      * Start a new discussion. Raises the DiscussionWasStarted event.
      *
      * @param string $title
-     * @param \Flarum\Core\Models\User $user
-     * @return \Flarum\Core\Models\Discussion
+     * @param User $user
+     * @return static
      */
     public static function start($title, User $user)
     {
@@ -105,6 +109,8 @@ class Discussion extends Model
         $discussion->start_time    = time();
         $discussion->start_user_id = $user->id;
 
+        $discussion->setRelation('startUser', $user);
+
         $discussion->raise(new DiscussionWasStarted($discussion));
 
         return $discussion;
@@ -114,7 +120,7 @@ class Discussion extends Model
      * Rename the discussion. Raises the DiscussionWasRenamed event.
      *
      * @param string $title
-     * @param \Flarum\Core\Models\User $user
+     * @param User $user
      * @return $this
      */
     public function rename($title, User $user)
@@ -132,7 +138,7 @@ class Discussion extends Model
     /**
      * Set the discussion's start post details.
      *
-     * @param \Flarum\Core\Models\Post $post
+     * @param \Flarum\Core\Posts\Post $post
      * @return $this
      */
     public function setStartPost(Post $post)
@@ -147,7 +153,7 @@ class Discussion extends Model
     /**
      * Set the discussion's last post details.
      *
-     * @param \Flarum\Core\Models\Post $post
+     * @param \Flarum\Core\Posts\Post $post
      * @return $this
      */
     public function setLastPost(Post $post)
@@ -211,7 +217,7 @@ class Discussion extends Model
      *     the same post as was originally intended to be saved. It also may not
      *     exist, if the merge logic resulted in deletion.
      */
-    public function mergePost(Mergable $post)
+    public function mergePost(MergeablePost $post)
     {
         $lastPost = $this->posts()->latest('time')->first();
 
@@ -225,21 +231,21 @@ class Discussion extends Model
      */
     public function posts()
     {
-        return $this->hasMany('Flarum\Core\Models\Post');
+        return $this->hasMany('Flarum\Core\Posts\Post');
     }
 
     /**
      * Define the relationship with the discussion's posts, but only ones which
      * are visible to the given user.
      *
-     * @param \Flarum\Core\Models\User $user
+     * @param User $user
      * @return \Illuminate\Database\Eloquent\Relations\HasMany
      */
-    public function visiblePosts(User $user)
+    public function postsVisibleTo(User $user)
     {
         $query = $this->posts();
 
-        foreach (static::$visiblePostsScopes as $scope) {
+        foreach (static::$postVisibilityScopes as $scope) {
             $scope($query, $user, $this);
         }
 
@@ -253,7 +259,7 @@ class Discussion extends Model
      */
     public function comments()
     {
-        return $this->visiblePosts(new Guest)->where('type', 'comment');
+        return $this->postsVisibleTo(new Guest)->where('type', 'comment');
     }
 
     /**
@@ -277,7 +283,7 @@ class Discussion extends Model
      */
     public function startPost()
     {
-        return $this->belongsTo('Flarum\Core\Models\Post', 'start_post_id');
+        return $this->belongsTo('Flarum\Core\Posts\Post', 'start_post_id');
     }
 
     /**
@@ -287,7 +293,7 @@ class Discussion extends Model
      */
     public function startUser()
     {
-        return $this->belongsTo('Flarum\Core\Models\User', 'start_user_id');
+        return $this->belongsTo('Flarum\Core\Users\User', 'start_user_id');
     }
 
     /**
@@ -297,7 +303,7 @@ class Discussion extends Model
      */
     public function lastPost()
     {
-        return $this->belongsTo('Flarum\Core\Models\Post', 'last_post_id');
+        return $this->belongsTo('Flarum\Core\Posts\Post', 'last_post_id');
     }
 
     /**
@@ -307,7 +313,7 @@ class Discussion extends Model
      */
     public function lastUser()
     {
-        return $this->belongsTo('Flarum\Core\Models\User', 'last_user_id');
+        return $this->belongsTo('Flarum\Core\Users\User', 'last_user_id');
     }
 
     /**
@@ -317,7 +323,7 @@ class Discussion extends Model
      */
     public function readers()
     {
-        return $this->belongsToMany('Flarum\Core\Models\User', 'users_discussions');
+        return $this->belongsToMany('Flarum\Core\Users\User', 'users_discussions');
     }
 
     /**
@@ -327,24 +333,24 @@ class Discussion extends Model
      * If no user is passed (i.e. in the case of eager loading the 'state'
      * relation), then the static `$stateUser` property is used.
      *
-     * @see \Flarum\Core\Models\Discussion::setStateUser()
+     * @see Discussion::setStateUser()
      *
-     * @param \Flarum\Core\Models\User $user
+     * @param User|null $user
      * @return \Illuminate\Database\Eloquent\Relations\HasOne
      */
     public function state(User $user = null)
     {
         $user = $user ?: static::$stateUser;
 
-        return $this->hasOne('Flarum\Core\Models\DiscussionState')->where('user_id', $user ? $user->id : null);
+        return $this->hasOne('Flarum\Core\Discussions\DiscussionState')->where('user_id', $user ? $user->id : null);
     }
 
     /**
      * Get the state model for a user, or instantiate a new one if it does not
      * exist.
      *
-     * @param \Flarum\Core\Models\User $user
-     * @return \Flarum\Core\Models\DiscussionState
+     * @param User $user
+     * @return \Flarum\Core\Discussions\DiscussionState
      */
     public function stateFor(User $user)
     {
@@ -362,7 +368,7 @@ class Discussion extends Model
     /**
      * Set the user for which the state relationship should be loaded.
      *
-     * @param \Flarum\Core\Models\User $user
+     * @param User $user
      */
     public static function setStateUser(User $user)
     {
@@ -376,8 +382,8 @@ class Discussion extends Model
      *     query. It is passed three parameters: the query builder object, the
      *     user to constrain posts for, and the discussion instance.
      */
-    public static function addVisiblePostsScope(callable $scope)
+    public static function addPostVisibilityScope(callable $scope)
     {
-        static::$visiblePostsScopes[] = $scope;
+        static::$postVisibilityScopes[] = $scope;
     }
 }

src/Core/Discussions/DiscussionRepositoryInterface.php

@@ -1,6 +1,6 @@
-<?php namespace Flarum\Core\Repositories;
+<?php namespace Flarum\Core\Discussions;
 
-use Flarum\Core\Models\User;
+use Flarum\Core\Users\User;
 
 interface DiscussionRepositoryInterface
 {
@@ -15,18 +15,18 @@ interface DiscussionRepositoryInterface
      * Find a discussion by ID, optionally making sure it is visible to a certain
      * user, or throw an exception.
      *
-     * @param  integer  $id
-     * @param  \Flarum\Core\Models\User  $user
-     * @return \Flarum\Core\Models\Discussion
+     * @param integer $id
+     * @param \Flarum\Core\Users\User $actor
+     * @return \Flarum\Core\Discussions\Discussion
      *
      * @throws \Illuminate\Database\Eloquent\ModelNotFoundException
      */
-    public function findOrFail($id, User $user = null);
+    public function findOrFail($id, User $actor = null);
 
     /**
      * Get the IDs of discussions which a user has read completely.
      *
-     * @param  \Flarum\Core\Models\User  $user
+     * @param \Flarum\Core\Users\User $user
      * @return array
      */
     public function getReadIds(User $user);

src/Core/Discussions/DiscussionState.php

@@ -1,6 +1,7 @@
-<?php namespace Flarum\Core\Models;
+<?php namespace Flarum\Core\Discussions;
 
-use Flarum\Core\Events\DiscussionWasRead;
+use Flarum\Core\Discussions\Events\DiscussionWasRead;
+use Flarum\Core\Model;
 use Flarum\Core\Support\EventGenerator;
 use Illuminate\Database\Eloquent\Builder;
 
@@ -16,16 +17,12 @@ class DiscussionState extends Model
     use EventGenerator;
 
     /**
-     * The table associated with the model.
-     *
-     * @var string
+     * {@inheritdoc}
      */
     protected $table = 'users_discussions';
 
     /**
-     * The attributes that should be mutated to dates.
-     *
-     * @var array
+     * {@inheritdoc}
      */
     protected static $dateAttributes = ['read_time'];
 
@@ -55,7 +52,7 @@ class DiscussionState extends Model
      */
     public function discussion()
     {
-        return $this->belongsTo('Flarum\Core\Models\Discussion', 'discussion_id');
+        return $this->belongsTo('Flarum\Core\Discussions\Discussion', 'discussion_id');
     }
 
     /**
@@ -65,14 +62,14 @@ class DiscussionState extends Model
      */
     public function user()
     {
-        return $this->belongsTo('Flarum\Core\Models\User', 'user_id');
+        return $this->belongsTo('Flarum\Core\Users\User', 'user_id');
     }
 
     /**
      * Set the keys for a save update query.
      *
-     * @param \Illuminate\Database\Eloquent\Builder $query
-     * @return \Illuminate\Database\Eloquent\Builder
+     * @param Builder $query
+     * @return Builder
      */
     protected function setKeysForSaveQuery(Builder $query)
     {

src/Core/Discussions/DiscussionsServiceProvider.php

@@ -0,0 +1,74 @@
+<?php namespace Flarum\Core\Discussions;
+
+use Flarum\Core\Search\GambitManager;
+use Flarum\Core\Users\User;
+use Flarum\Support\ServiceProvider;
+use Flarum\Extend;
+use Illuminate\Contracts\Container\Container;
+
+class DiscussionsServiceProvider extends ServiceProvider
+{
+    /**
+     * Bootstrap the application events.
+     *
+     * @return void
+     */
+    public function boot()
+    {
+        $this->extend([
+            new Extend\EventSubscriber('Flarum\Core\Discussions\Listeners\DiscussionMetadataUpdater')
+        ]);
+
+        Discussion::allow('*', function (Discussion $discussion, User $user, $action) {
+            return $user->hasPermission('discussion.'.$action) ?: null;
+        });
+
+        // Allow a user to rename their own discussion.
+        Discussion::allow('rename', function (Discussion $discussion, User $user) {
+            return $discussion->start_user_id == $user->id ?: null;
+            // TODO: add limitations to time etc. according to a config setting
+        });
+
+        Discussion::allow('delete', function (Discussion $discussion, User $user) {
+            return $discussion->start_user_id == $user->id && $discussion->participants_count == 1 ?: null;
+            // TODO: add limitations to time etc. according to a config setting
+        });
+    }
+
+    /**
+     * Register the service provider.
+     *
+     * @return void
+     */
+    public function register()
+    {
+        $this->app->bind(
+            'Flarum\Core\Discussions\DiscussionRepositoryInterface',
+            'Flarum\Core\Discussions\EloquentDiscussionRepository'
+        );
+
+        $this->app->bind(
+            'Flarum\Core\Discussions\Search\Fulltext\DriverInterface',
+            'Flarum\Core\Discussions\Search\Fulltext\MySqlFulltextDriver'
+        );
+
+        $this->app->instance('flarum.discussionGambits', [
+            'Flarum\Core\Discussions\Search\Gambits\AuthorGambit',
+            'Flarum\Core\Discussions\Search\Gambits\UnreadGambit'
+        ]);
+
+        $this->app->when('Flarum\Core\Discussions\Search\DiscussionSearcher')
+            ->needs('Flarum\Core\Search\GambitManager')
+            ->give(function (Container $app) {
+                $gambits = new GambitManager($app);
+
+                foreach ($app->make('flarum.discussionGambits') as $gambit) {
+                    $gambits->add($gambit);
+                }
+
+                $gambits->setFulltextGambit('Flarum\Core\Discussions\Search\Gambits\FulltextGambit');
+
+                return $gambits;
+            });
+    }
+}

src/Core/Discussions/EloquentDiscussionRepository.php

@@ -1,15 +1,14 @@
-<?php namespace Flarum\Core\Repositories;
+<?php namespace Flarum\Core\Discussions;
 
 use Illuminate\Database\Eloquent\Builder;
-use Flarum\Core\Models\Discussion;
-use Flarum\Core\Models\User;
+use Flarum\Core\Users\User;
 
 class EloquentDiscussionRepository implements DiscussionRepositoryInterface
 {
     /**
      * Get a new query builder for the discussions table.
      *
-     * @return \Illuminate\Database\Eloquent\Builder
+     * @return Builder
      */
     public function query()
     {
@@ -17,14 +16,12 @@ class EloquentDiscussionRepository implements DiscussionRepositoryInterface
     }
 
     /**
-     * Find a discussion by ID, optionally making sure it is visible to a certain
-     * user, or throw an exception.
+     * Find a discussion by ID, optionally making sure it is visible to a
+     * certain user, or throw an exception.
      *
-     * @param  integer  $id
-     * @param  \Flarum\Core\Models\User  $user
-     * @return \Flarum\Core\Models\Discussion
-     *
-     * @throws \Illuminate\Database\Eloquent\ModelNotFoundException
+     * @param integer $id
+     * @param \Flarum\Core\Users\User $user
+     * @return \Flarum\Core\Discussions\Discussion
      */
     public function findOrFail($id, User $user = null)
     {
@@ -36,7 +33,7 @@ class EloquentDiscussionRepository implements DiscussionRepositoryInterface
     /**
      * Get the IDs of discussions which a user has read completely.
      *
-     * @param  \Flarum\Core\Models\User  $user
+     * @param \Flarum\Core\Users\User $user
      * @return array
      */
     public function getReadIds(User $user)
@@ -50,9 +47,9 @@ class EloquentDiscussionRepository implements DiscussionRepositoryInterface
     /**
      * Scope a query to only include records that are visible to a user.
      *
-     * @param  \Illuminate\Database\Eloquent\Builder  $query
-     * @param  \Flarum\Core\Models\User  $user
-     * @return \Illuminate\Database\Eloquent\Builder
+     * @param Builder $query
+     * @param \Flarum\Core\Users\User $user
+     * @return Builder
      */
     protected function scopeVisibleTo(Builder $query, User $user = null)
     {

src/Core/Discussions/Events/DiscussionSearchWillBePerformed.php

@@ -0,0 +1,27 @@
+<?php namespace Flarum\Core\Discussions\Events;
+
+use Flarum\Core\Discussions\Search\DiscussionSearch;
+use Flarum\Core\Search\SearchCriteria;
+
+class DiscussionSearchWillBePerformed
+{
+    /**
+     * @var DiscussionSearch
+     */
+    public $search;
+
+    /**
+     * @var SearchCriteria
+     */
+    public $criteria;
+
+    /**
+     * @param DiscussionSearch $search
+     * @param SearchCriteria $criteria
+     */
+    public function __construct(DiscussionSearch $search, SearchCriteria $criteria)
+    {
+        $this->search = $search;
+        $this->criteria = $criteria;
+    }
+}

src/Core/Discussions/Events/DiscussionStateWillBeSaved.php

@@ -0,0 +1,19 @@
+<?php namespace Flarum\Core\Discussions\Events;
+
+use Flarum\Core\Discussions\DiscussionState;
+
+class DiscussionStateWillBeSaved
+{
+    /**
+     * @var DiscussionState
+     */
+    public $state;
+
+    /**
+     * @param DiscussionState $state
+     */
+    public function __construct(DiscussionState $state)
+    {
+        $this->state = $state;
+    }
+}

src/Core/Discussions/Events/DiscussionWasDeleted.php

@@ -0,0 +1,20 @@
+<?php namespace Flarum\Core\Discussions\Events;
+
+use Flarum\Core\Discussions\Discussion;
+use Flarum\Core\Users\User;
+
+class DiscussionWasDeleted
+{
+    /**
+     * @var Discussion
+     */
+    public $discussion;
+
+    /**
+     * @param Discussion $discussion
+     */
+    public function __construct(Discussion $discussion)
+    {
+        $this->discussion = $discussion;
+    }
+}

src/Core/Discussions/Events/DiscussionWasRead.php

@@ -0,0 +1,19 @@
+<?php namespace Flarum\Core\Discussions\Events;
+
+use Flarum\Core\Discussions\DiscussionState;
+
+class DiscussionWasRead
+{
+    /**
+     * @var DiscussionState
+     */
+    public $state;
+
+    /**
+     * @param DiscussionState $state
+     */
+    public function __construct(DiscussionState $state)
+    {
+        $this->state = $state;
+    }
+}

src/Core/Discussions/Events/DiscussionWasRenamed.php

@@ -0,0 +1,34 @@
+<?php namespace Flarum\Core\Discussions\Events;
+
+use Flarum\Core\Discussions\Discussion;
+use Flarum\Core\Users\User;
+
+class DiscussionWasRenamed
+{
+    /**
+     * @var Discussion
+     */
+    public $discussion;
+
+    /**
+     * @var User
+     */
+    public $actor;
+
+    /**
+     * @var string
+     */
+    public $oldTitle;
+
+    /**
+     * @param Discussion $discussion
+     * @param User $actor
+     * @param string $oldTitle
+     */
+    public function __construct(Discussion $discussion, User $actor, $oldTitle)
+    {
+        $this->discussion = $discussion;
+        $this->actor = $actor;
+        $this->oldTitle = $oldTitle;
+    }
+}

src/Core/Discussions/Events/DiscussionWasStarted.php

@@ -0,0 +1,19 @@
+<?php namespace Flarum\Core\Discussions\Events;
+
+use Flarum\Core\Discussions\Discussion;
+
+class DiscussionWasStarted
+{
+    /**
+     * @var Discussion
+     */
+    public $discussion;
+
+    /**
+     * @param Discussion $discussion
+     */
+    public function __construct(Discussion $discussion)
+    {
+        $this->discussion = $discussion;
+    }
+}

src/Core/Discussions/Events/DiscussionWillBeDeleted.php

@@ -0,0 +1,40 @@
+<?php namespace Flarum\Core\Discussions\Events;
+
+use Flarum\Core\Discussions\Discussion;
+use Flarum\Core\Users\User;
+
+class DiscussionWillBeDeleted
+{
+    /**
+     * The discussion that is going to be deleted.
+     *
+     * @var Discussion
+     */
+    public $discussion;
+
+    /**
+     * The user who is performing the action.
+     *
+     * @var User
+     */
+    public $actor;
+
+    /**
+     * Any user input associated with the command.
+     *
+     * @var array
+     */
+    public $data;
+
+    /**
+     * @param Discussion $discussion
+     * @param User $actor
+     * @param array $data
+     */
+    public function __construct(Discussion $discussion, User $actor, array $data = [])
+    {
+        $this->discussion = $discussion;
+        $this->actor = $actor;
+        $this->data = $data;
+    }
+}

src/Core/Discussions/Events/DiscussionWillBeSaved.php

@@ -0,0 +1,40 @@
+<?php namespace Flarum\Core\Discussions\Events;
+
+use Flarum\Core\Discussions\Discussion;
+use Flarum\Core\Users\User;
+
+class DiscussionWillBeSaved
+{
+    /**
+     * The discussion that will be saved.
+     *
+     * @var Discussion
+     */
+    public $discussion;
+
+    /**
+     * The user who is performing the action.
+     *
+     * @var User
+     */
+    public $actor;
+
+    /**
+     * Any user input associated with the command.
+     *
+     * @var array
+     */
+    public $data;
+
+    /**
+     * @param Discussion $discussion
+     * @param User $actor
+     * @param array $data
+     */
+    public function __construct(Discussion $discussion, User $actor, array $data = [])
+    {
+        $this->discussion = $discussion;
+        $this->actor = $actor;
+        $this->data = $data;
+    }
+}

src/Core/Discussions/Listeners/DiscussionMetadataUpdater.php

@@ -1,27 +1,28 @@
-<?php namespace Flarum\Core\Handlers\Events;
+<?php namespace Flarum\Core\Discussions\Listeners;
 
-use Flarum\Core\Models\Post;
-use Flarum\Core\Events\PostWasPosted;
-use Flarum\Core\Events\PostWasDeleted;
-use Flarum\Core\Events\PostWasHidden;
-use Flarum\Core\Events\PostWasRestored;
+use Flarum\Core\Posts\Post;
+use Flarum\Core\Posts\Events\PostWasPosted;
+use Flarum\Core\Posts\Events\PostWasDeleted;
+use Flarum\Core\Posts\Events\PostWasHidden;
+use Flarum\Core\Posts\Events\PostWasRestored;
 use Illuminate\Contracts\Events\Dispatcher;
 
 class DiscussionMetadataUpdater
 {
     /**
-     * Register the listeners for the subscriber.
-     *
-     * @param \Illuminate\Contracts\Events\Dispatcher $events
+     * @param Dispatcher $events
      */
     public function subscribe(Dispatcher $events)
     {
-        $events->listen('Flarum\Core\Events\PostWasPosted', __CLASS__.'@whenPostWasPosted');
-        $events->listen('Flarum\Core\Events\PostWasDeleted', __CLASS__.'@whenPostWasDeleted');
-        $events->listen('Flarum\Core\Events\PostWasHidden', __CLASS__.'@whenPostWasHidden');
-        $events->listen('Flarum\Core\Events\PostWasRestored', __CLASS__.'@whenPostWasRestored');
+        $events->listen(PostWasPosted::class, __CLASS__.'@whenPostWasPosted');
+        $events->listen(PostWasDeleted::class, __CLASS__.'@whenPostWasDeleted');
+        $events->listen(PostWasHidden::class, __CLASS__.'@whenPostWasHidden');
+        $events->listen(PostWasRestored::class, __CLASS__.'@whenPostWasRestored');
     }
 
+    /**
+     * @param PostWasPosted $event
+     */
     public function whenPostWasPosted(PostWasPosted $event)
     {
         $discussion = $event->post->discussion;
@@ -32,16 +33,25 @@ class DiscussionMetadataUpdater
         $discussion->save();
     }
 
+    /**
+     * @param PostWasDeleted $event
+     */
     public function whenPostWasDeleted(PostWasDeleted $event)
     {
         $this->removePost($event->post);
     }
 
+    /**
+     * @param PostWasHidden $event
+     */
     public function whenPostWasHidden(PostWasHidden $event)
     {
         $this->removePost($event->post);
     }
 
+    /**
+     * @param PostWasRestored $event
+     */
     public function whenPostWasRestored(PostWasRestored $event)
     {
         $discussion = $event->post->discussion;
@@ -52,6 +62,9 @@ class DiscussionMetadataUpdater
         $discussion->save();
     }
 
+    /**
+     * @param Post $post
+     */
     protected function removePost(Post $post)
     {
         $discussion = $post->discussion;

src/Core/Discussions/Search/DiscussionSearch.php

@@ -0,0 +1,55 @@
+<?php namespace Flarum\Core\Discussions\Search;
+
+use Flarum\Core\Search\Search;
+
+/**
+ * An object which represents the internal state of a search for discussions:
+ * the search query, the user performing the search, the fallback sort order,
+ * relevant post information, and a log of which gambits have been used.
+ */
+class DiscussionSearch extends Search
+{
+    /**
+     * {@inheritdoc}
+     */
+    protected $defaultSort = ['lastTime' => 'desc'];
+
+    /**
+     * @var array
+     */
+    protected $relevantPostIds = [];
+
+    /**
+     * Get the related IDs for each result.
+     *
+     * @return int[]
+     */
+    public function getRelevantPostIds()
+    {
+        return $this->relevantPostIds;
+    }
+
+    /**
+     * Set the relevant post IDs for a result.
+     *
+     * @param int $discussionId
+     * @param int[] $postIds
+     * @return void
+     */
+    public function setRelevantPostIds($discussionId, array $postIds)
+    {
+        $this->relevantPostIds[$discussionId] = $postIds;
+    }
+
+    /**
+     * Add a relevant post ID for a discussion result.
+     *
+     * @param int $discussionId
+     * @param int $postId
+     * @return void
+     */
+    public function addRelevantPostId($discussionId, $postId)
+    {
+        $this->relevantPostIds[$discussionId][] = $postId;
+    }
+}

src/Core/Discussions/Search/DiscussionSearcher.php

@@ -0,0 +1,124 @@
+<?php namespace Flarum\Core\Discussions\Search;
+
+use Flarum\Core\Discussions\Discussion;
+use Flarum\Core\Search\AppliesParametersToSearch;
+use Flarum\Core\Search\SearchCriteria;
+use Flarum\Core\Search\SearcherInterface;
+use Flarum\Core\Search\GambitManager;
+use Flarum\Core\Discussions\DiscussionRepositoryInterface;
+use Flarum\Core\Posts\PostRepositoryInterface;
+use Flarum\Core\Discussions\Events\DiscussionSearchWillBePerformed;
+use Flarum\Core\Search\SearchResults;
+use Illuminate\Database\Eloquent\Collection;
+
+/**
+ * Takes a DiscussionSearchCriteria object, performs a search using gambits,
+ * and spits out a DiscussionSearchResults object.
+ */
+class DiscussionSearcher
+{
+    use AppliesParametersToSearch;
+
+    /**
+     * @var GambitManager
+     */
+    protected $gambits;
+
+    /**
+     * @var DiscussionRepositoryInterface
+     */
+    protected $discussions;
+
+    /**
+     * @var PostRepositoryInterface
+     */
+    protected $posts;
+
+    /**
+     * @param GambitManager $gambits
+     * @param DiscussionRepositoryInterface $discussions
+     * @param PostRepositoryInterface $posts
+     */
+    public function __construct(
+        GambitManager $gambits,
+        DiscussionRepositoryInterface $discussions,
+        PostRepositoryInterface $posts
+    ) {
+        $this->gambits = $gambits;
+        $this->discussions = $discussions;
+        $this->posts = $posts;
+    }
+
+    /**
+     * @param SearchCriteria $criteria
+     * @param int|null $limit
+     * @param int $offset
+     * @param array $load An array of relationships to load on the results.
+     * @return SearchResults
+     */
+    public function search(SearchCriteria $criteria, $limit = null, $offset = 0, array $load = [])
+    {
+        $actor = $criteria->actor;
+
+        $query = $this->discussions->query()->whereVisibleTo($actor);
+
+        // Construct an object which represents this search for discussions.
+        // Apply gambits to it, sort, and paging criteria. Also give extensions
+        // an opportunity to modify it.
+        $search = new DiscussionSearch($query->getQuery(), $actor);
+
+        $this->gambits->apply($search, $criteria->query);
+        $this->applySort($search, $criteria->sort);
+        $this->applyOffset($search, $offset);
+        $this->applyLimit($search, $limit + 1);
+
+        event(new DiscussionSearchWillBePerformed($search, $criteria));
+
+        // Execute the search query and retrieve the results. We get one more
+        // results than the user asked for, so that we can say if there are more
+        // results. If there are, we will get rid of that extra result.
+        $discussions = $query->get();
+
+        if ($areMoreResults = ($limit > 0 && $discussions->count() > $limit)) {
+            $discussions->pop();
+        }
+
+        // The relevant posts relationship isn't a typical Eloquent
+        // relationship; rather, we need to extract that information from our
+        // search object. We will delegate that task and prevent Eloquent
+        // from trying to load it.
+        if (in_array('relevantPosts', $load)) {
+            $this->loadRelevantPosts($discussions, $search);
+
+            $load = array_diff($load, ['relevantPosts', 'relevantPosts.discussion', 'relevantPosts.user']);
+        }
+
+        Discussion::setStateUser($actor);
+        $discussions->load($load);
+
+        return new SearchResults($discussions, $areMoreResults);
+    }
+
+    /**
+     * Load relevant posts onto each discussion using information from the
+     * search.
+     *
+     * @param Collection $discussions
+     * @param DiscussionSearch $search
+     */
+    protected function loadRelevantPosts(Collection $discussions, DiscussionSearch $search)
+    {
+        $postIds = [];
+        foreach ($search->getRelevantPostIds() as $relevantPostIds) {
+            $postIds = array_merge($postIds, array_slice($relevantPostIds, 0, 2));
+        }
+
+        $posts = $postIds ? $this->posts->findByIds($postIds, $search->getActor())->load('user')->all() : [];
+
+        foreach ($discussions as $discussion) {
+            $discussion->relevantPosts = array_filter($posts, function ($post) use ($discussion) {
+                return $post->discussion_id == $discussion->id;
+            });
+        }
+    }
+}

src/Core/Discussions/Search/Fulltext/DriverInterface.php

@@ -1,4 +1,4 @@
-<?php namespace Flarum\Core\Search\Discussions\Fulltext;
+<?php namespace Flarum\Core\Discussions\Search\Fulltext;
 
 interface DriverInterface
 {

src/Core/Discussions/Search/Fulltext/MySqlFulltextDriver.php

@@ -1,6 +1,6 @@
-<?php namespace Flarum\Core\Search\Discussions\Fulltext;
+<?php namespace Flarum\Core\Discussions\Search\Fulltext;
 
-use Flarum\Core\Models\Post;
+use Flarum\Core\Posts\Post;
 
 class MySqlFulltextDriver implements DriverInterface
 {

src/Core/Discussions/Search/Gambits/AuthorGambit.php

@@ -0,0 +1,44 @@
+<?php namespace Flarum\Core\Discussions\Search\Gambits;
+
+use Flarum\Core\Discussions\Search\DiscussionSearch;
+use Flarum\Core\Users\UserRepositoryInterface;
+use Flarum\Core\Search\RegexGambit;
+use Flarum\Core\Search\Search;
+use LogicException;
+
+class AuthorGambit extends RegexGambit
+{
+    /**
+     * {@inheritdoc}
+     */
+    protected $pattern = 'author:(.+)';
+
+    /**
+     * @var UserRepositoryInterface
+     */
+    protected $users;
+
+    /**
+     * @param UserRepositoryInterface $users
+     */
+    public function __construct(UserRepositoryInterface $users)
+    {
+        $this->users = $users;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    protected function conditions(Search $search, array $matches, $negate)
+    {
+        if (! $search instanceof DiscussionSearch) {
+            throw new LogicException('This gambit can only be applied on a DiscussionSearch');
+        }
+
+        $username = trim($matches[1], '"');
+
+        $id = $this->users->getIdForUsername($username);
+
+        $search->getQuery()->where('start_user_id', $negate ? '!=' : '=', $id);
+    }
+}

src/Core/Discussions/Search/Gambits/FulltextGambit.php

@@ -0,0 +1,47 @@
+<?php namespace Flarum\Core\Discussions\Search\Gambits;
+
+use Flarum\Core\Discussions\Search\DiscussionSearch;
+use Flarum\Core\Posts\PostRepositoryInterface;
+use Flarum\Core\Search\Search;
+use Flarum\Core\Search\GambitInterface;
+use LogicException;
+
+class FulltextGambit implements GambitInterface
+{
+    /**
+     * @var PostRepositoryInterface
+     */
+    protected $posts;
+
+    /**
+     * @param PostRepositoryInterface $posts
+     */
+    public function __construct(PostRepositoryInterface $posts)
+    {
+        $this->posts = $posts;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function apply(Search $search, $bit)
+    {
+        if (! $search instanceof DiscussionSearch) {
+            throw new LogicException('This gambit can only be applied on a DiscussionSearch');
+        }
+
+        $posts = $this->posts->findByContent($bit, $search->getActor());
+
+        $discussions = [];
+        foreach ($posts as $post) {
+            $discussions[] = $id = $post->discussion_id;
+            $search->addRelevantPostId($id, $post->id);
+        }
+        $discussions = array_unique($discussions);
+
+        // TODO: implement negate (match for - at start of string)
+        $search->getQuery()->whereIn('id', $discussions);
+
+        $search->setDefaultSort(['id' => $discussions]);
+    }
+}

src/Core/Discussions/Search/Gambits/RegexGambit.php

@@ -1,6 +1,6 @@
 <?php namespace Flarum\Core\Search;
 
-abstract class GambitAbstract
+abstract class RegexGambit implements Gambit
 {
     protected $pattern;
 

src/Core/Discussions/Search/Gambits/UnreadGambit.php

@@ -0,0 +1,52 @@
+<?php namespace Flarum\Core\Discussions\Search\Gambits;
+
+use Flarum\Core\Discussions\DiscussionRepositoryInterface;
+use Flarum\Core\Discussions\Search\DiscussionSearch;
+use Flarum\Core\Search\RegexGambit;
+use Flarum\Core\Search\Search;
+use LogicException;
+
+class UnreadGambit extends RegexGambit
+{
+    /**
+     * {@inheritdoc}
+     */
+    protected $pattern = 'is:unread';
+
+    /**
+     * @var DiscussionRepositoryInterface
+     */
+    protected $discussions;
+
+    /**
+     * @param DiscussionRepositoryInterface $discussions
+     */
+    public function __construct(DiscussionRepositoryInterface $discussions)
+    {
+        $this->discussions = $discussions;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    protected function conditions(Search $search, array $matches, $negate)
+    {
+        if (! $search instanceof DiscussionSearch) {
+            throw new LogicException('This gambit can only be applied on a DiscussionSearch');
+        }
+
+        $actor = $search->getActor();
+
+        if ($actor->exists) {
+            $readIds = $this->discussions->getReadIds($actor);
+
+            $search->getQuery()->where(function ($query) use ($readIds, $negate, $actor) {
+                if (! $negate) {
+                    $query->whereNotIn('id', $readIds)->where('last_time', '>', $actor->read_time ?: 0);
+                } else {
+                    $query->whereIn('id', $readIds)->orWhere('last_time', '<=', $actor->read_time ?: 0);
+                }
+            });
+        }
+    }
+}

src/Core/Events/AvatarWillBeDeleted.php

@@ -1,16 +0,0 @@
-<?php namespace Flarum\Core\Events;
-
-use Flarum\Core\Models\User;
-
-class AvatarWillBeDeleted
-{
-    public $user;
-
-    public $command;
-
-    public function __construct(User $user, $command)
-    {
-        $this->user = $user;
-        $this->command = $command;
-    }
-}

src/Core/Events/AvatarWillBeUploaded.php

@@ -1,16 +0,0 @@
-<?php namespace Flarum\Core\Events;
-
-use Flarum\Core\Models\User;
-
-class AvatarWillBeUploaded
-{
-    public $user;
-
-    public $command;
-
-    public function __construct(User $user, $command)
-    {
-        $this->user = $user;
-        $this->command = $command;
-    }
-}

src/Core/Events/DiscussionSearchWillBePerformed.php

@@ -1,16 +0,0 @@
-<?php namespace Flarum\Core\Events;
-
-use Flarum\Core\Search\Discussions\DiscussionSearcher;
-
-class DiscussionSearchWillBePerformed
-{
-    public $searcher;
-
-    public $criteria;
-
-    public function __construct(DiscussionSearcher $searcher, $criteria)
-    {
-        $this->searcher = $searcher;
-        $this->criteria = $criteria;
-    }
-}

src/Core/Events/DiscussionStateWillBeSaved.php

@@ -1,16 +0,0 @@
-<?php namespace Flarum\Core\Events;
-
-use Flarum\Core\Models\DiscussionState;
-
-class DiscussionStateWillBeSaved
-{
-    public $state;
-
-    public $command;
-
-    public function __construct(DiscussionState $state, $command)
-    {
-        $this->state = $state;
-        $this->command = $command;
-    }
-}

src/Core/Events/DiscussionWasDeleted.php

@@ -1,13 +0,0 @@
-<?php namespace Flarum\Core\Events;
-
-use Flarum\Core\Models\Discussion;
-
-class DiscussionWasDeleted
-{
-    public $discussion;
-
-    public function __construct(Discussion $discussion)
-    {
-        $this->discussion = $discussion;
-    }
-}

src/Core/Events/DiscussionWasRead.php

@@ -1,13 +0,0 @@
-<?php namespace Flarum\Core\Events;
-
-use Flarum\Core\Models\DiscussionState;
-
-class DiscussionWasRead
-{
-    public $state;
-
-    public function __construct(DiscussionState $state)
-    {
-        $this->state = $state;
-    }
-}

src/Core/Events/DiscussionWasRenamed.php

@@ -1,20 +0,0 @@
-<?php namespace Flarum\Core\Events;
-
-use Flarum\Core\Models\Discussion;
-use Flarum\Core\Models\User;
-
-class DiscussionWasRenamed
-{
-    public $discussion;
-
-    public $user;
-
-    public $oldTitle;
-
-    public function __construct(Discussion $discussion, User $user, $oldTitle)
-    {
-        $this->discussion = $discussion;
-        $this->user = $user;
-        $this->oldTitle = $oldTitle;
-    }
-}

src/Core/Events/DiscussionWasStarted.php

@@ -1,13 +0,0 @@
-<?php namespace Flarum\Core\Events;
-
-use Flarum\Core\Models\Discussion;
-
-class DiscussionWasStarted
-{
-    public $discussion;
-
-    public function __construct(Discussion $discussion)
-    {
-        $this->discussion = $discussion;
-    }
-}

src/Core/Events/DiscussionWillBeDeleted.php

@@ -1,16 +0,0 @@
-<?php namespace Flarum\Core\Events;
-
-use Flarum\Core\Models\Discussion;
-
-class DiscussionWillBeDeleted
-{
-    public $discussion;
-
-    public $command;
-
-    public function __construct(Discussion $discussion, $command)
-    {
-        $this->discussion = $discussion;
-        $this->command = $command;
-    }
-}

src/Core/Events/DiscussionWillBeSaved.php

@@ -1,16 +0,0 @@
-<?php namespace Flarum\Core\Events;
-
-use Flarum\Core\Models\Discussion;
-
-class DiscussionWillBeSaved
-{
-    public $discussion;
-
-    public $command;
-
-    public function __construct(Discussion $discussion, $command)
-    {
-        $this->discussion = $discussion;
-        $this->command = $command;
-    }
-}

src/Core/Events/NotificationWillBeSent.php

@@ -1,16 +0,0 @@
-<?php namespace Flarum\Core\Events;
-
-use Flarum\Core\Notifications\NotificationInterface;
-
-class NotificationWillBeSent
-{
-    public $notification;
-
-    public $users;
-
-    public function __construct(NotificationInterface $notification, array &$users)
-    {
-        $this->notification = $notification;
-        $this->users = $users;
-    }
-}

src/Core/Events/PostWasDeleted.php

@@ -1,13 +0,0 @@
-<?php namespace Flarum\Core\Events;
-
-use Flarum\Core\Models\Post;
-
-class PostWasDeleted
-{
-    public $post;
-
-    public function __construct(Post $post)
-    {
-        $this->post = $post;
-    }
-}

src/Core/Events/PostWasHidden.php

@@ -1,13 +0,0 @@
-<?php namespace Flarum\Core\Events;
-
-use Flarum\Core\Models\Post;
-
-class PostWasHidden
-{
-    public $post;
-
-    public function __construct(Post $post)
-    {
-        $this->post = $post;
-    }
-}

src/Core/Events/PostWasPosted.php

@@ -1,13 +0,0 @@
-<?php namespace Flarum\Core\Events;
-
-use Flarum\Core\Models\Post;
-
-class PostWasPosted
-{
-    public $post;
-
-    public function __construct(Post $post)
-    {
-        $this->post = $post;
-    }
-}

src/Core/Events/PostWasRestored.php

@@ -1,13 +0,0 @@
-<?php namespace Flarum\Core\Events;
-
-use Flarum\Core\Models\Post;
-
-class PostWasRestored
-{
-    public $post;
-
-    public function __construct(Post $post)
-    {
-        $this->post = $post;
-    }
-}

src/Core/Events/PostWasRevised.php

@@ -1,13 +0,0 @@
-<?php namespace Flarum\Core\Events;
-
-use Flarum\Core\Models\Post;
-
-class PostWasRevised
-{
-    public $post;
-
-    public function __construct(Post $post)
-    {
-        $this->post = $post;
-    }
-}

src/Core/Events/PostWillBeDeleted.php

@@ -1,16 +0,0 @@
-<?php namespace Flarum\Core\Events;
-
-use Flarum\Core\Models\Post;
-
-class PostWillBeDeleted
-{
-    public $post;
-
-    public $command;
-
-    public function __construct(Post $post, $command)
-    {
-        $this->post = $post;
-        $this->command = $command;
-    }
-}

src/Core/Events/PostWillBeSaved.php

@@ -1,16 +0,0 @@
-<?php namespace Flarum\Core\Events;
-
-use Flarum\Core\Models\Post;
-
-class PostWillBeSaved
-{
-    public $post;
-
-    public $command;
-
-    public function __construct(Post $post, $command)
-    {
-        $this->post = $post;
-        $this->command = $command;
-    }
-}

src/Core/Events/UserAvatarWasChanged.php

@@ -1,13 +0,0 @@
-<?php namespace Flarum\Core\Events;
-
-use Flarum\Core\Models\User;
-
-class UserAvatarWasChanged
-{
-    public $user;
-
-    public function __construct(User $user)
-    {
-        $this->user = $user;
-    }
-}

src/Core/Events/UserBioWasChanged.php

@@ -1,13 +0,0 @@
-<?php namespace Flarum\Core\Events;
-
-use Flarum\Core\Models\User;
-
-class UserBioWasChanged
-{
-    public $user;
-
-    public function __construct(User $user)
-    {
-        $this->user = $user;
-    }
-}

src/Core/Events/UserEmailChangeWasRequested.php

@@ -1,16 +0,0 @@
-<?php namespace Flarum\Core\Events;
-
-use Flarum\Core\Models\User;
-
-class UserEmailChangeWasRequested
-{
-    public $user;
-
-    public $email;
-
-    public function __construct(User $user, $email)
-    {
-        $this->user = $user;
-        $this->email = $email;
-    }
-}

src/Core/Events/UserEmailWasChanged.php

@@ -1,13 +0,0 @@
-<?php namespace Flarum\Core\Events;
-
-use Flarum\Core\Models\User;
-
-class UserEmailWasChanged
-{
-    public $user;
-
-    public function __construct(User $user)
-    {
-        $this->user = $user;
-    }
-}

src/Core/Events/UserEmailWasConfirmed.php

@@ -1,13 +0,0 @@
-<?php namespace Flarum\Core\Events;
-
-use Flarum\Core\Models\User;
-
-class UserEmailWasConfirmed
-{
-    public $user;
-
-    public function __construct(User $user)
-    {
-        $this->user = $user;
-    }
-}

src/Core/Events/UserPasswordWasChanged.php

@@ -1,13 +0,0 @@
-<?php namespace Flarum\Core\Events;
-
-use Flarum\Core\Models\User;
-
-class UserPasswordWasChanged
-{
-    public $user;
-
-    public function __construct(User $user)
-    {
-        $this->user = $user;
-    }
-}

src/Core/Events/UserSearchWillBePerformed.php

@@ -1,16 +0,0 @@
-<?php namespace Flarum\Core\Events;
-
-use Flarum\Core\Search\Users\UserSearcher;
-
-class UserSearchWillBePerformed
-{
-    public $searcher;
-
-    public $criteria;
-
-    public function __construct(UserSearcher $searcher, $criteria)
-    {
-        $this->searcher = $searcher;
-        $this->criteria = $criteria;
-    }
-}

src/Core/Events/UserWasActivated.php

@@ -1,13 +0,0 @@
-<?php namespace Flarum\Core\Events;
-
-use Flarum\Core\Models\User;
-
-class UserWasActivated
-{
-    public $user;
-
-    public function __construct(User $user)
-    {
-        $this->user = $user;
-    }
-}

src/Core/Events/UserWasDeleted.php

@@ -1,13 +0,0 @@
-<?php namespace Flarum\Core\Events;
-
-use Flarum\Core\Models\User;
-
-class UserWasDeleted
-{
-    public $user;
-
-    public function __construct(User $user)
-    {
-        $this->user = $user;
-    }
-}

src/Core/Events/UserWasRegistered.php

@@ -1,13 +0,0 @@
-<?php namespace Flarum\Core\Events;
-
-use Flarum\Core\Models\User;
-
-class UserWasRegistered
-{
-    public $user;
-
-    public function __construct(User $user)
-    {
-        $this->user = $user;
-    }
-}

src/Core/Events/UserWasRenamed.php

@@ -1,13 +0,0 @@
-<?php namespace Flarum\Core\Events;
-
-use Flarum\Core\Models\User;
-
-class UserWasRenamed
-{
-    public $user;
-
-    public function __construct(User $user)
-    {
-        $this->user = $user;
-    }
-}

src/Core/Events/UserWillBeDeleted.php

@@ -1,16 +0,0 @@
-<?php namespace Flarum\Core\Events;
-
-use Flarum\Core\Models\User;
-
-class UserWillBeDeleted
-{
-    public $user;
-
-    public $command;
-
-    public function __construct(User $user, $command)
-    {
-        $this->user = $user;
-        $this->command = $command;
-    }
-}

src/Core/Events/UserWillBeSaved.php

@@ -1,16 +0,0 @@
-<?php namespace Flarum\Core\Events;
-
-use Flarum\Core\Models\User;
-
-class UserWillBeSaved
-{
-    public $user;
-
-    public $command;
-
-    public function __construct(User $user, $command)
-    {
-        $this->user = $user;
-        $this->command = $command;
-    }
-}

src/Core/Exceptions/ValidationFailureException.php

@@ -1,19 +1,37 @@
 <?php namespace Flarum\Core\Exceptions;
 
+use Exception;
 use Illuminate\Support\MessageBag;
+use DomainException;
 
-class ValidationFailureException extends \InvalidArgumentException
+class ValidationFailureException extends DomainException
 {
+    /**
+     * @var MessageBag
+     */
     protected $errors;
 
+    /**
+     * @var array
+     */
     protected $input = array();
 
+    /**
+     * @param string $message
+     * @param int $code
+     * @param Exception $previous
+     */
     public function __construct($message = '', $code = 0, Exception $previous = null)
     {
         parent::__construct($message, $code, $previous);
+
         $this->errors = new MessageBag;
     }
 
+    /**
+     * @param MessageBag $errors
+     * @return $this
+     */
     public function setErrors(MessageBag $errors)
     {
         $this->errors = $errors;
@@ -21,11 +39,18 @@ class ValidationFailureException extends \InvalidArgumentException
         return $this;
     }
 
+    /**
+     * @return MessageBag
+     */
     public function getErrors()
     {
         return $this->errors;
     }
 
+    /**
+     * @param array $input
+     * @return $this
+     */
     public function setInput(array $input)
     {
         $this->input = $input;
@@ -33,6 +58,9 @@ class ValidationFailureException extends \InvalidArgumentException
         return $this;
     }
 
+    /**
+     * @return array
+     */
     public function getInput()
     {
         return $this->input;

src/Core/Formatter/FormatterAbstract.php

@@ -1,48 +0,0 @@
-<?php namespace Flarum\Core\Formatter;
-
-use Flarum\Core\Models\Post;
-use Closure;
-
-abstract class FormatterAbstract
-{
-    public function beforePurification($text, Post $post = null)
-    {
-        return $text;
-    }
-
-    public function afterPurification($text, Post $post = null)
-    {
-        return $text;
-    }
-
-    protected function ignoreTags($text, array $tags, Closure $callback)
-    {
-        $chunks = preg_split('/(<.+?>)/is', $text, 0, PREG_SPLIT_DELIM_CAPTURE);
-
-        $openTag = null;
-
-        for ($i = 0; $i < count($chunks); $i++) {
-            if ($i % 2 === 0) { // even numbers are text
-                // Only process this chunk if there are no unclosed $ignoreTags
-                if (null === $openTag) {
-                    $chunks[$i] = $callback($chunks[$i]);
-                }
-            } else { // odd numbers are tags
-                // Only process this tag if there are no unclosed $ignoreTags
-                if (null === $openTag) {
-                    // Check whether this tag is contained in $ignoreTags and is not self-closing
-                    if (preg_match("`<(" . implode('|', $tags) . ").*(?<!/)>$`is", $chunks[$i], $matches)) {
-                        $openTag = $matches[1];
-                    }
-                } else {
-                    // Otherwise, check whether this is the closing tag for $openTag.
-                    if (preg_match('`</\s*' . $openTag . '>`i', $chunks[$i], $matches)) {
-                        $openTag = null;
-                    }
-                }
-            }
-        }
-
-        return implode($chunks);
-    }
-}

src/Core/Formatter/FormatterInterface.php

@@ -1,10 +1,31 @@
 <?php namespace Flarum\Core\Formatter;
 
-use Flarum\Core\Models\Post;
+use Flarum\Core\Model;
 
 interface FormatterInterface
 {
-    public function beforePurification($text, Post $post = null);
+    /**
+     * Configure the formatter manager before formatting takes place.
+     *
+     * @param FormatterManager $manager
+     */
+    public function config(FormatterManager $manager);
 
-    public function afterPurification($text, Post $post = null);
+    /**
+     * Format the text before purification takes place.
+     *
+     * @param string $text
+     * @param Model|null $model The entity that owns the text.
+     * @return string
+     */
+    public function formatBeforePurification($text, Model $model = null);
+
+    /**
+     * Format the text after purification takes place.
+     *
+     * @param string $text
+     * @param Model|null $model The entity that owns the text.
+     * @return string
+     */
+    public function formatAfterPurification($text, Model $model = null);
 }

src/Core/Formatter/FormatterManager.php

@@ -1,92 +1,143 @@
 <?php namespace Flarum\Core\Formatter;
 
+use Flarum\Core\Model;
 use Illuminate\Contracts\Container\Container;
 use HTMLPurifier;
 use HTMLPurifier_Config;
+use LogicException;
 
 class FormatterManager
 {
-    protected $formatters = [];
-
     /**
-     * The IoC container instance.
-     *
-     * @var \Illuminate\Contracts\Container\Container
+     * @var Container
      */
     protected $container;
 
-    public $config;
+    /**
+     * @var array
+     */
+    protected $formatters = [];
+
+    /**
+     * @var HTMLPurifier_Config
+     */
+    protected $htmlPurifierConfig;
 
     /**
      * Create a new formatter manager instance.
      *
-     * @param  \Illuminate\Contracts\Container\Container  $container
+     * @param Container $container
      */
     public function __construct(Container $container)
     {
         $this->container = $container;
 
-        // Studio does not yet merge autoload_files...
+        // TODO: Studio does not yet merge autoload_files...
         // https://github.com/franzliedke/studio/commit/4f0f4314db4ed3e36c869a5f79b855c97bdd1be7
         require __DIR__.'/../../../vendor/ezyang/htmlpurifier/library/HTMLPurifier.composer.php';
 
-        $this->config = HTMLPurifier_Config::createDefault();
-        $this->config->set('Core.Encoding', 'UTF-8');
-        $this->config->set('Core.EscapeInvalidTags', true);
-        $this->config->set('HTML.Doctype', 'HTML 4.01 Strict');
-        $this->config->set('HTML.Allowed', 'p,em,strong,a[href|title],ul,ol,li,code,pre,blockquote,h1,h2,h3,h4,h5,h6,br,hr,img[src|alt]');
-        $this->config->set('HTML.Nofollow', true);
+        $this->htmlPurifierConfig = $this->getDefaultHtmlPurifierConfig();
     }
 
-    public function add($name, $formatter, $priority = 0)
+    /**
+     * Get the HTMLPurifier configuration object.
+     *
+     * @return HTMLPurifier_Config
+     */
+    public function getHtmlPurifierConfig()
     {
-        $this->formatters[$name] = [$formatter, $priority];
+        return $this->htmlPurifierConfig;
     }
 
-    public function remove($name)
+    /**
+     * Add a new formatter.
+     *
+     * @param string $formatter
+     */
+    public function add($formatter)
     {
-        unset($this->formatters[$name]);
+        $this->formatters[] = $formatter;
     }
 
-    protected function getFormatters()
+    /**
+     * Format the given text using the collected formatters.
+     *
+     * @param string $text
+     * @param Model|null $model The entity that owns the text.
+     * @return string
+     */
+    public function format($text, Model $model = null)
     {
-        $sorted = [];
+        $formatters = $this->getFormatters();
 
-        foreach ($this->formatters as $array) {
-            list($formatter, $priority) = $array;
-            $sorted[$priority][] = $formatter;
-        }
-
-        ksort($sorted);
-
-        $result = [];
-
-        foreach ($sorted as $formatters) {
-            $result = array_merge($result, $formatters);
-        }
-
-        return $result;
-    }
-
-    public function format($text, $post = null)
-    {
-        $formatters = [];
-        foreach ($this->getFormatters() as $formatter) {
-            $formatters[] = $this->container->make($formatter);
+        foreach ($formatters as $formatter) {
+            $formatter->config($this);
         }
 
         foreach ($formatters as $formatter) {
-            $text = $formatter->beforePurification($text, $post);
+            $text = $formatter->formatBeforePurification($text, $model);
         }
 
-        $purifier = new HTMLPurifier($this->config);
-
-        $text = $purifier->purify($text);
+        $text = $this->purify($text);
 
         foreach ($formatters as $formatter) {
-            $text = $formatter->afterPurification($text, $post);
+            $text = $formatter->formatAfterPurification($text, $model);
         }
 
         return $text;
     }
+
+    /**
+     * Instantiate the collected formatters.
+     *
+     * @return FormatterInterface[]
+     */
+    protected function getFormatters()
+    {
+        $formatters = [];
+
+        foreach ($this->formatters as $formatter) {
+            $formatter = $this->container->make($formatter);
+
+            if (! $formatter instanceof FormatterInterface) {
+                throw new LogicException('Formatter ' . get_class($formatter)
+                    . ' does not implement ' . FormatterInterface::class);
+            }
+
+            $formatters[] = $formatter;
+        }
+
+        return $formatters;
+    }
+
+    /**
+     * Purify the given text, making sure it is safe to be displayed in web
+     * browsers.
+     *
+     * @param string $text
+     * @return string
+     */
+    protected function purify($text)
+    {
+        $purifier = new HTMLPurifier($this->htmlPurifierConfig);
+
+        return $purifier->purify($text);
+    }
+
+    /**
+     * Get the default HTMLPurifier config settings.
+     *
+     * @return HTMLPurifier_Config
+     */
+    protected function getDefaultHtmlPurifierConfig()
+    {
+        $config = HTMLPurifier_Config::createDefault();
+        $config->set('Core.Encoding', 'UTF-8');
+        $config->set('Core.EscapeInvalidTags', true);
+        $config->set('HTML.Doctype', 'HTML 4.01 Strict');
+        $config->set('HTML.Allowed', 'p,em,strong,a[href|title],ul,ol,li,code,pre,blockquote,h1,h2,h3,h4,h5,h6,br,hr,img[src|alt]');
+        $config->set('HTML.Nofollow', true);
+
+        return $config;
+    }
 }

src/Core/Formatter/FormatterServiceProvider.php

@@ -13,7 +13,7 @@ class FormatterServiceProvider extends ServiceProvider
     public function boot()
     {
         $this->extend([
-            new Extend\Formatter('linkify', 'Flarum\Core\Formatter\LinkifyFormatter')
+            new Extend\PostFormatter('Flarum\Core\Formatter\LinkifyFormatter')
         ]);
     }
 

src/Core/Formatter/LinkifyFormatter.php

@@ -1,18 +1,27 @@
 <?php namespace Flarum\Core\Formatter;
 
-use Flarum\Core\Models\Post;
+use Flarum\Core\Model;
 use Misd\Linkify\Linkify;
 
-class LinkifyFormatter extends FormatterAbstract
+class LinkifyFormatter extends TextFormatter
 {
+    /**
+     * @var Linkify
+     */
     protected $linkify;
 
+    /**
+     * @param Linkify $linkify
+     */
     public function __construct(Linkify $linkify)
     {
         $this->linkify = $linkify;
     }
 
-    public function beforePurification($text, Post $post = null)
+    /**
+     * {@inheritdoc}
+     */
+    protected function formatTextBeforePurification($text, Model $post = null)
     {
         return $this->linkify->process($text, ['attr' => ['target' => '_blank']]);
     }

src/Core/Formatter/TextFormatter.php

@@ -0,0 +1,120 @@
+<?php namespace Flarum\Core\Formatter;
+
+use Flarum\Core\Model;
+
+/**
+ * A formatter which formats a block of HTML, while leaving the contents
+ * of specific tags like <code> and <pre> untouched.
+ */
+abstract class TextFormatter implements FormatterInterface
+{
+    /**
+     * A list of tags to ignore when applying formatting.
+     *
+     * @var array
+     */
+    protected $ignoreTags = ['code', 'pre'];
+
+    /**
+     * {@inheritdoc}
+     */
+    public function config(FormatterManager $manager)
+    {
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function formatBeforePurification($text, Model $model = null)
+    {
+        return $this->formatAroundIgnoredTags($text, function ($text) use ($model) {
+            return $this->formatTextBeforePurification($text, $model);
+        });
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function formatAfterPurification($text, Model $model = null)
+    {
+        return $this->formatAroundIgnoredTags($text, function ($text) use ($model) {
+            return $this->formatTextAfterPurification($text, $model);
+        });
+    }
+
+    /**
+     * Format non-ignored text before purification has taken place.
+     *
+     * @param string $text
+     * @param Model $model
+     * @return mixed
+     */
+    protected function formatTextBeforePurification($text, Model $model = null)
+    {
+        return $text;
+    }
+
+    /**
+     * Format non-ignored text after purification has taken place.
+     *
+     * @param string $text
+     * @param Model $model
+     * @return string
+     */
+    protected function formatTextAfterPurification($text, Model $model = null)
+    {
+        return $text;
+    }
+
+    /**
+     * Run a callback on parts of the provided text that aren't within the list
+     * of ignored tags.
+     *
+     * @param string $text
+     * @param callable $callback
+     * @return string
+     */
+    protected function formatAroundIgnoredTags($text, callable $callback)
+    {
+        return $this->formatAroundTags($text, $this->ignoreTags, $callback);
+    }
+
+    /**
+     * Run a callback on parts of the provided text that aren't within the
+     * given list of tags.
+     *
+     * @param string $text
+     * @param array $tags
+     * @param callable $callback
+     * @return string
+     */
+    protected function formatAroundTags($text, array $tags, callable $callback)
+    {
+        $chunks = preg_split('/(<.+?>)/is', $text, 0, PREG_SPLIT_DELIM_CAPTURE);
+        $openTag = null;
+
+        for ($i = 0; $i < count($chunks); $i++) {
+            if ($i % 2 === 0) { // even numbers are text
+                // Only process this chunk if there are no unclosed $ignoreTags
+                if (null === $openTag) {
+                    $chunks[$i] = $callback($chunks[$i]);
+                }
+            } else { // odd numbers are tags
+                // Only process this tag if there are no unclosed $ignoreTags
+                if (null === $openTag) {
+                    // Check whether this tag is contained in $ignoreTags and is not self-closing
+                    if (preg_match("`<(" . implode('|', $tags) . ").*(?<!/)>$`is", $chunks[$i], $matches)) {
+                        $openTag = $matches[1];
+                    }
+                } else {
+                    // Otherwise, check whether this is the closing tag for $openTag.
+                    if (preg_match('`</\s*' . $openTag . '>`i', $chunks[$i], $matches)) {
+                        $openTag = null;
+                    }
+                }
+            }
+        }
+
+        return implode($chunks);
+    }
+}