From 70f717821c8f604aff936c4af23118944fd41cdf Mon Sep 17 00:00:00 2001
From: IanM <ian@morland.me>
Date: Wed, 6 Nov 2024 23:07:35 +0000
Subject: [PATCH] constrain to within Q&A tags

---
 src/Search/BestAnswerPostFilter.php | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/src/Search/BestAnswerPostFilter.php b/src/Search/BestAnswerPostFilter.php
index e79e9c6..feccc62 100644
--- a/src/Search/BestAnswerPostFilter.php
+++ b/src/Search/BestAnswerPostFilter.php
@@ -13,8 +13,10 @@
 
 use Flarum\Filter\FilterInterface;
 use Flarum\Filter\FilterState;
+use Flarum\Tags\Tag;
 use Flarum\User\User;
 use Illuminate\Database\Query\Builder;
+use Illuminate\Support\Collection;
 
 class BestAnswerPostFilter implements FilterInterface
 {
@@ -45,5 +47,20 @@ protected function constrain(Builder $query, User $actor, bool $negate)
             $query->whereNotNull('discussions.best_answer_post_id')
                 ->whereColumn('posts.id', '=', 'discussions.best_answer_post_id');
         }
+
+        // Constrain to discussions within the allowed Q&A tags
+        $query->whereIn('discussions.id', function ($subQuery) use ($actor) {
+            $subQuery->select('discussion_id')
+                ->from('discussion_tag')
+                ->whereIn('tag_id', $this->allowedQnATags($actor));
+        });
+    }
+
+    protected function allowedQnATags(User $actor): Collection
+    {
+        return Tag::query()
+            ->whereVisibleTo($actor)
+            ->where('is_qna', true)
+            ->pluck('id');
     }
 }