Get rid of Repository interfaces

src/Core/Posts/PostRepository.php

@@ -0,0 +1,181 @@
+<?php namespace Flarum\Core\Posts;
+
+use Illuminate\Database\Eloquent\Builder;
+use Illuminate\Database\Eloquent\ModelNotFoundException;
+use Flarum\Core\Users\User;
+use Flarum\Core\Discussions\Discussion;
+use Flarum\Core\Discussions\Search\Fulltext\DriverInterface;
+
+// TODO: In some cases, the use of a post repository incurs extra query expense,
+// because for every post retrieved we need to check if the discussion it's in
+// is visible. Especially when retrieving a discussion's posts, we can end up
+// with an inefficient chain of queries like this:
+// 1. Api\Discussions\ShowAction: get discussion (will exit if not visible)
+// 2. Discussion@postsVisibleTo: get discussion tags (for post visibility purposes)
+// 3. Discussion@postsVisibleTo: get post IDs
+// 4. EloquentPostRepository@getIndexForNumber: get discussion
+// 5. EloquentPostRepository@getIndexForNumber: get discussion tags (for post visibility purposes)
+// 6. EloquentPostRepository@getIndexForNumber: get post index for number
+// 7. EloquentPostRepository@findWhere: get post IDs for discussion to check for discussion visibility
+// 8. EloquentPostRepository@findWhere: get post IDs in visible discussions
+// 9. EloquentPostRepository@findWhere: get posts
+// 10. EloquentPostRepository@findWhere: eager load discussion onto posts
+// 11. EloquentPostRepository@findWhere: get discussion tags to filter visible posts
+// 12. Api\Discussions\ShowAction: eager load users
+// 13. Api\Discussions\ShowAction: eager load groups
+// 14. Api\Discussions\ShowAction: eager load mentions
+// 14. Serializers\DiscussionSerializer: load discussion-user state
+
+class PostRepository
+{
+    protected $fulltext;
+
+    public function __construct(DriverInterface $fulltext)
+    {
+        $this->fulltext = $fulltext;
+    }
+
+    /**
+     * Find a post by ID, optionally making sure it is visible to a certain
+     * user, or throw an exception.
+     *
+     * @param integer $id
+     * @param \Flarum\Core\Users\User $actor
+     * @return \Flarum\Core\Posts\Post
+     *
+     * @throws \Illuminate\Database\Eloquent\ModelNotFoundException
+     */
+    public function findOrFail($id, User $actor = null)
+    {
+        $posts = $this->findByIds([$id], $actor);
+
+        if (! count($posts)) {
+            throw new ModelNotFoundException;
+        }
+
+        return $posts->first();
+    }
+
+    /**
+     * Find posts that match certain conditions, optionally making sure they
+     * are visible to a certain user, and/or using other criteria.
+     *
+     * @param array $where
+     * @param \Flarum\Core\Users\User|null $actor
+     * @param array $sort
+     * @param integer $count
+     * @param integer $start
+     * @return \Illuminate\Database\Eloquent\Collection
+     */
+    public function findWhere($where = [], User $actor = null, $sort = [], $count = null, $start = 0)
+    {
+        $query = Post::where($where)
+            ->skip($start)
+            ->take($count);
+
+        foreach ((array) $sort as $field => $order) {
+            $query->orderBy($field, $order);
+        }
+
+        $ids = $query->lists('id');
+
+        return $this->findByIds($ids, $actor);
+    }
+
+    /**
+     * Find posts by their IDs, optionally making sure they are visible to a
+     * certain user.
+     *
+     * @param array $ids
+     * @param \Flarum\Core\Users\User|null $actor
+     * @return \Illuminate\Database\Eloquent\Collection
+     */
+    public function findByIds(array $ids, User $actor = null)
+    {
+        $ids = $this->filterDiscussionVisibleTo($ids, $actor);
+
+        $posts = Post::with('discussion')->whereIn('id', (array) $ids)->get();
+
+        return $this->filterVisibleTo($posts, $actor);
+    }
+
+    /**
+     * Find posts by matching a string of words against their content,
+     * optionally making sure they are visible to a certain user.
+     *
+     * @param string $string
+     * @param \Flarum\Core\Users\User|null $actor
+     * @return \Illuminate\Database\Eloquent\Collection
+     */
+    public function findByContent($string, User $actor = null)
+    {
+        $ids = $this->fulltext->match($string);
+
+        $ids = $this->filterDiscussionVisibleTo($ids, $actor);
+
+        $query = Post::select('id', 'discussion_id')->whereIn('id', $ids);
+
+        foreach ($ids as $id) {
+            $query->orderByRaw('id != ?', [$id]);
+        }
+
+        $posts = $query->get();
+
+        return $this->filterVisibleTo($posts, $actor);
+    }
+
+    /**
+     * Get the position within a discussion where a post with a certain number
+     * is. If the post with that number does not exist, the index of the
+     * closest post to it will be returned.
+     *
+     * @param integer $discussionId
+     * @param integer $number
+     * @param \Flarum\Core\Users\User|null $actor
+     * @return integer
+     */
+    public function getIndexForNumber($discussionId, $number, User $actor = null)
+    {
+        $query = Discussion::find($discussionId)
+            ->postsVisibleTo($actor)
+            ->where('time', '<', function ($query) use ($discussionId, $number) {
+                $query->select('time')
+                      ->from('posts')
+                      ->where('discussion_id', $discussionId)
+                      ->whereNotNull('number')
+                      ->take(1)
+
+                      // We don't add $number as a binding because for some
+                      // reason doing so makes the bindings go out of order.
+                      ->orderByRaw('ABS(CAST(number AS SIGNED) - '.(int) $number.')');
+            });
+
+        return $query->count();
+    }
+
+    protected function filterDiscussionVisibleTo($ids, User $actor)
+    {
+        // For each post ID, we need to make sure that the discussion it's in
+        // is visible to the user.
+        if ($actor) {
+            $ids = Discussion::join('posts', 'discussions.id', '=', 'posts.discussion_id')
+                ->whereIn('posts.id', $ids)
+                ->whereVisibleTo($actor)
+                ->get(['posts.id'])
+                ->lists('id');
+        }
+
+        return $ids;
+    }
+
+    protected function filterVisibleTo($posts, User $actor)
+    {
+        if ($actor) {
+            $posts = $posts->filter(function ($post) use ($actor) {
+                return $post->can($actor, 'view');
+            });
+        }
+
+        return $posts;
+    }
+}