ArticleManager um LIKES erweitert...

Einführung einer dynamischen Like-Funktion für Beiträge

php/model/Article.php

@@ -7,13 +7,14 @@
  */
 class Article
 {
-    public $id;
+    private $id;
-    public $title;
+    private $title;
-    public $content;
+    private $content;
-    public $author;
+    private $author;
-    public $creationDate;
+    private $creationDate;
-    public $category;
+    private $category;
-    public $tags;
+    private $tags;
+    private $likes;
 
     /**
      * Konstruktor
@@ -26,7 +27,7 @@ class Article
      * @param $tags string optionale Schlagworte für eine bessere Suche
      * @param $creationDate string Datum der Beitragserstellung
      */
-    public function __construct(int $id, string $title, string $content, string $author, string $category, string $tags, string $creationDate)
+    public function __construct(int $id, string $title, string $content, string $author, string $category, string $tags, string $creationDate, array $likes = [])
     {
         $this->id = $id;
         $this->title = $title;
@@ -35,6 +36,7 @@ class Article
         $this->creationDate = $creationDate;
         $this->category = $category;
         $this->tags = $tags;
+        $this->likes = $likes;
     }
 
     /**
@@ -67,7 +69,7 @@ class Article
 
     /**
      * Gibt den Content eines Beitrags zurück.
-     * TODO: Content muss noch definiert werden.
+     *
      * @return string
      */
     public function getContent(): string
@@ -77,7 +79,7 @@ class Article
 
     /**
      * Setzt den Content eines Beitrags.
-     * TODO: Content muss noch definiert werden.
+     *
      * @param $content
      * @return void
      */
@@ -141,7 +143,34 @@ class Article
         $this->tags = $tags;
     }
 
+    /**
+     * Gibt alle User-IDs zurück, die diesen Beitrag geliked haben.
+     * @return array
+     */
+    public function getLikes(): array
+    {
+        return $this->likes;
+    }
 
+    /**
+     * Gibt die Gesamtzahl der Likes zurück.
+     * @return int
+     */
+    public function getLikeCount(): int
+    {
+        return count($this->likes);
+    }
+
+    /**
+     * Prüft, ob ein bestimmter Nutzer den Beitrag bereits geliked hat.
+     *
+     * @param string $userId
+     * @return bool
+     */
+    public function hasLiked(string $userId): bool
+    {
+        return in_array($userId, $this->likes);
+    }
 
 }
 ?>

php/model/ArticleManagerDAO.php

@@ -92,6 +92,18 @@ interface ArticleManagerDAO
      */
     public function getArticlesByCategory($category);
 
+    /**
+     * Registriert oder entfernt ein Like eines Nutzers für einen Beitrag.
+     * Wenn schon geliked -> Unlike
+     * Wenn noch nicht geliked -> Like
+     *
+     * @param int $articleId Die ID des Beitrags
+     * @param string $userId Die ID des Nutzers
+     * @return bool True wenn geliked, False wenn unliked
+     * @throws InternalServerErrorException
+     * @throws NotFoundException
+     */
+    public function toggleLike(int $articleId, string $userId): bool;
 
 }
 ?>

php/model/DatabaseArticleManager.php

@@ -23,6 +23,7 @@ class DatabaseArticleManager implements ArticleManagerDAO {
 
                 $db = $this->getConnection();
 
+                // Tabelle für Beiträge
                 $db->exec("
                     CREATE TABLE articles (
                         id INTEGER PRIMARY KEY AUTOINCREMENT,
@@ -33,6 +34,15 @@ class DatabaseArticleManager implements ArticleManagerDAO {
                         tags TEXT,
                         created TIMESTAMP DEFAULT CURRENT_TIMESTAMP
                     );");
+
+                // Tabelle für Likes
+                $db->exec("
+                CREATE TABLE likes (
+                    article_id INTEGER,
+                    user_id TEXT,
+                    PRIMARY KEY (article_id, user_id),
+                    FOREIGN KEY (article_id) REFERENCES articles(id) ON DELETE CASCADE
+                );");
                 unset($db);
             } catch (PDOException $e) {
                 throw new InternalServerErrorException($e->getMessage());
@@ -189,6 +199,8 @@ class DatabaseArticleManager implements ArticleManagerDAO {
             $row = $command->fetch(PDO::FETCH_ASSOC);
 
             if ($row) {
+                $likes = $this->getLikesForArticle(intval($row['id']));
+
                 return new Article(
                     intval($row['id']),
                     $row['title'],
@@ -196,7 +208,8 @@ class DatabaseArticleManager implements ArticleManagerDAO {
                     $row['author'],
                     $row['category'],
                     $row['tags'],
-                    $row['created']
+                    $row['created'],
+                    $likes
                 );
             }
 
@@ -254,6 +267,8 @@ class DatabaseArticleManager implements ArticleManagerDAO {
             $filteredArticles = [];
 
             foreach ($rows as $row) {
+                $likes = $this->getLikesForArticle(intval($row['id']));
+
                 $filteredArticles[] = new Article(
                     intval($row['id']),
                     $row['title'],
@@ -261,7 +276,8 @@ class DatabaseArticleManager implements ArticleManagerDAO {
                     $row['author'],
                     $row['category'],
                     $row['tags'],
-                    $row['created']
+                    $row['created'],
+                    $likes
                 );
             }
 
@@ -287,6 +303,8 @@ class DatabaseArticleManager implements ArticleManagerDAO {
             $filteredArticles = [];
 
             foreach ($rows as $row) {
+                $likes = $this->getLikesForArticle(intval($row['id']));
+
                 $filteredArticles[] = new Article(
                     intval($row['id']),
                     $row['title'],
@@ -294,7 +312,8 @@ class DatabaseArticleManager implements ArticleManagerDAO {
                     $row['author'],
                     $row['category'],
                     $row['tags'],
-                    $row['created']
+                    $row['created'],
+                    $likes
                 );
             }
 
@@ -341,6 +360,8 @@ class DatabaseArticleManager implements ArticleManagerDAO {
             $filteredArticles = [];
 
             foreach ($rows as $row) {
+                $likes = $this->getLikesForArticle(intval($row['id']));
+
                 $filteredArticles[] = new Article(
                     intval($row['id']),
                     $row['title'] ?? '',
@@ -348,7 +369,8 @@ class DatabaseArticleManager implements ArticleManagerDAO {
                     $row['author'] ?? '',
                     $row['category'] ?? '',
                     $row['tags'] ?? '',
-                    $row['created'] ?? '' // Nutzt 'created' aus deiner DB-Struktur
+                    $row['created'] ?? '',
+                    $likes
                 );
             }
 
@@ -359,4 +381,69 @@ class DatabaseArticleManager implements ArticleManagerDAO {
         }
     }
 
+    /**
+     * Holt alle User-IDs, die einen bestimmten Beitrag geliked haben.
+     *
+     * @return String[] UserIDs
+     * @throws InternalServerErrorException
+     */
+    private function getLikesForArticle(int $articleId): array
+    {
+        try {
+            $db = $this->getConnection();
+            $sql = "SELECT user_id FROM likes WHERE article_id = :article_id;";
+            $command = $db->prepare($sql);
+            $command->execute([':article_id' => $articleId]);
+
+            return $command->fetchAll(PDO::FETCH_COLUMN) ?: [];
+        } catch (PDOException $e) {
+            return [];
+        }
+    }
+
+    public function toggleLike(int $articleId, string $userId): bool
+    {
+        // prüfen, ob der Artikel überhaupt existiert
+        $article = $this->getArticle($articleId);
+        if (!$article) {
+            throw new NotFoundException("missing_id");
+        }
+
+        try {
+            $db = $this->getConnection();
+
+            // prüfen, ob das Like bereits existiert
+            $checkSql = "SELECT COUNT(*) FROM likes WHERE article_id = :article_id AND user_id = :user_id;";
+            $checkCommand = $db->prepare($checkSql);
+            $checkCommand->execute([
+                ':article_id' => $articleId,
+                ':user_id'    => $userId
+            ]);
+
+            $hasLiked = (int)$checkCommand->fetchColumn() > 0;
+
+            if ($hasLiked) {
+                // wenn bereits geliked -> Unlike
+                $deleteSql = "DELETE FROM likes WHERE article_id = :article_id AND user_id = :user_id;";
+                $deleteCommand = $db->prepare($deleteSql);
+                $deleteCommand->execute([
+                    ':article_id' => $articleId,
+                    ':user_id'    => $userId
+                ]);
+                return false; // gibt false zurück, da der Beitrag jetzt nicht mehr geliked ist
+            } else {
+                // wenn noch nicht geliked -> Like
+                $insertSql = "INSERT INTO likes (article_id, user_id) VALUES (:article_id, :user_id);";
+                $insertCommand = $db->prepare($insertSql);
+                $insertCommand->execute([
+                    ':article_id' => $articleId,
+                    ':user_id'    => $userId
+                ]);
+                return true; // gibt true zurück, da der Beitrag jetzt geliked ist
+            }
+
+        } catch (PDOException $e) {
+            throw new InternalServerErrorException("internal_error");
+        }
+    }
 }