feat: add tag filtering to blog posts and implement JSON_CONTAINS DQL function

config/packages/doctrine.yaml

@@ -18,6 +18,9 @@ doctrine:
                 alias: App
         controller_resolver:
             auto_mapping: false
+        dql:
+            string_functions:
+                JSON_CONTAINS: App\Shared\Doctrine\JsonContains
 
 when@test:
     doctrine:

docs/api/blog.md

@@ -15,6 +15,7 @@ List published blog posts.
 |-------|------|----------|---------|-------------|
 | `page` | integer | ❌ | 1 | Page number |
 | `limit` | integer | ❌ | 20 | Items per page |
+| `tag` | string | ❌ | — | Filter by exact tag **name** (e.g. `?tag=دیابت`). Blog tags are stored as a JSON array of names; only blogs whose `tags` array contains this exact name are returned. |
 
 ### Response `200`
 ```json

src/Blog/Controller/BlogController.php

@@ -60,9 +60,10 @@ class BlogController extends BaseController
     {
         $page  = max(1, (int) $request->query->get('page', 1));
         $limit = min(50, max(1, (int) $request->query->get('limit', 20)));
+        $tag   = $request->query->get('tag') ?: null;
 
-        $blogs = array_map(fn(Blog $b) => $b->toListArray(), $this->blogRepo->findPublished($page, $limit));
-        $total = $this->blogRepo->countPublished();
+        $blogs = array_map(fn(Blog $b) => $b->toListArray(), $this->blogRepo->findPublished($page, $limit, $tag));
+        $total = $this->blogRepo->countPublished($tag);
 
         return $this->paginated($blogs, $total, $page, $limit);
     }

src/Blog/Repository/BlogRepository.php

@@ -14,24 +14,40 @@ class BlogRepository extends ServiceEntityRepository
     public function findBySlug(string $slug): ?Blog { return $this->findOneBy(['slug' => $slug]); }
 
     /** @return Blog[] published, newest first */
-    public function findPublished(int $page = 1, int $limit = 20): array
+    public function findPublished(int $page = 1, int $limit = 20, ?string $tag = null): array
     {
-        return $this->createQueryBuilder('b')
+        $qb = $this->createQueryBuilder('b')
             ->where('b.status = :status')
             ->setParameter('status', Blog::STATUS_PUBLISHED)
             ->orderBy('b.createdAt', 'DESC')
             ->setFirstResult(($page - 1) * $limit)
-            ->setMaxResults($limit)
-            ->getQuery()->getResult();
+            ->setMaxResults($limit);
+
+        $this->applyTagFilter($qb, $tag);
+
+        return $qb->getQuery()->getResult();
     }
 
-    public function countPublished(): int
+    public function countPublished(?string $tag = null): int
     {
-        return (int) $this->createQueryBuilder('b')
+        $qb = $this->createQueryBuilder('b')
             ->select('COUNT(b.id)')
             ->where('b.status = :status')
-            ->setParameter('status', Blog::STATUS_PUBLISHED)
-            ->getQuery()->getSingleScalarResult();
+            ->setParameter('status', Blog::STATUS_PUBLISHED);
+
+        $this->applyTagFilter($qb, $tag);
+
+        return (int) $qb->getQuery()->getSingleScalarResult();
+    }
+
+    private function applyTagFilter(\Doctrine\ORM\QueryBuilder $qb, ?string $tag): void
+    {
+        if ($tag === null || $tag === '') {
+            return;
+        }
+        // Blog.tags is a JSON array of tag names; match exact name membership.
+        $qb->andWhere('JSON_CONTAINS(b.tags, :tag) = 1')
+           ->setParameter('tag', json_encode($tag, JSON_UNESCAPED_UNICODE));
     }
 
     public function save(Blog $e, bool $flush = true): void { $this->getEntityManager()->persist($e); if ($flush) $this->getEntityManager()->flush(); }

src/Shared/Doctrine/JsonContains.php

@@ -0,0 +1,38 @@
+<?php
+
+namespace App\Shared\Doctrine;
+
+use Doctrine\ORM\Query\AST\Functions\FunctionNode;
+use Doctrine\ORM\Query\AST\Node;
+use Doctrine\ORM\Query\Parser;
+use Doctrine\ORM\Query\SqlWalker;
+use Doctrine\ORM\Query\TokenType;
+
+/**
+ * JSON_CONTAINS(json_doc, candidate) DQL function for MariaDB/MySQL.
+ * Usage: WHERE JSON_CONTAINS(b.tags, :tag) = 1
+ */
+class JsonContains extends FunctionNode
+{
+    private Node $jsonDoc;
+    private Node $candidate;
+
+    public function parse(Parser $parser): void
+    {
+        $parser->match(TokenType::T_IDENTIFIER);
+        $parser->match(TokenType::T_OPEN_PARENTHESIS);
+        $this->jsonDoc = $parser->StringPrimary();
+        $parser->match(TokenType::T_COMMA);
+        $this->candidate = $parser->StringPrimary();
+        $parser->match(TokenType::T_CLOSE_PARENTHESIS);
+    }
+
+    public function getSql(SqlWalker $sqlWalker): string
+    {
+        return sprintf(
+            'JSON_CONTAINS(%s, %s)',
+            $this->jsonDoc->dispatch($sqlWalker),
+            $this->candidate->dispatch($sqlWalker)
+        );
+    }
+}