feat: add similar_media

app/Http/Controllers/MediaController.php

@@ -377,13 +377,15 @@ public function show($id)
 
     // Get user's specific comment
     $userComment = $media->userComment();
-    
+
     // Get paginated comments
     $comments = $media->comments()
         ->with('user')
         ->latest()
         ->paginate(15);
 
+    $similarMedia = $this->similarMedia($media);
+
     return response()->json([
         'id' => $media->id,
         'title' => $media->title,
@@ -417,8 +419,53 @@ public function show($id)
             'user_comment_id' => $media->user_comment_id,
         ],
         'comments' => $comments,
+        'similar_media' => $similarMedia,
     ]);
 }
+
+// Media that shares categories / subcategories / tags with the given one,
+// ranked by how much they overlap. Excludes the media itself.
+private function similarMedia(Media $media, int $limit = 5)
+{
+    $categoryIds = $media->categories->pluck('id')->all();
+    $subCategoryIds = $media->subCategories->pluck('id')->all();
+    $tagIds = $media->tags->pluck('id')->all();
+
+    if (!$categoryIds && !$subCategoryIds && !$tagIds) {
+        return collect();
+    }
+
+    $userId = auth()->id();
+
+    return Media::query()
+        ->where('media.id', '!=', $media->id)
+        ->where('media.type', $media->type)
+        ->where(function ($q) use ($userId) {
+            $q->where('visibility', 'public')->orWhere('user_id', $userId);
+        })
+        ->where(function ($q) use ($categoryIds, $subCategoryIds, $tagIds) {
+            if ($categoryIds) {
+                $q->orWhereHas('categories', fn ($c) => $c->whereIn('categories.id', $categoryIds));
+            }
+            if ($subCategoryIds) {
+                $q->orWhereHas('subCategories', fn ($s) => $s->whereIn('sub_categories.id', $subCategoryIds));
+            }
+            if ($tagIds) {
+                $q->orWhereHas('tags', fn ($t) => $t->whereIn('tags.id', $tagIds));
+            }
+        })
+        ->withCount([
+            'categories as category_matches' => fn ($c) => $c->whereIn('categories.id', $categoryIds ?: [0]),
+            'subCategories as subcategory_matches' => fn ($s) => $s->whereIn('sub_categories.id', $subCategoryIds ?: [0]),
+            'tags as tag_matches' => fn ($t) => $t->whereIn('tags.id', $tagIds ?: [0]),
+        ])
+        ->with(['image', 'detailImage', 'categories', 'subCategories', 'tags'])
+        ->orderByRaw('(category_matches + subcategory_matches + tag_matches) desc')
+        ->orderByDesc('created_at')
+        ->limit($limit)
+        ->get();
+}
+
 public function rate(Request $request, $mediaId)
 {
     $request->validate([