Blog CMS Architecture

<?php
// Database connection with PDO
class Database {
    private static ?PDO $instance = null;

    public static function connect(): PDO {
        if (self::$instance === null) {
            self::$instance = new PDO(
                'mysql:host=localhost;dbname=blog_cms;charset=utf8mb4',
                'root', '', [
                    PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
                    PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC
                ]
            );
        }
        return self::$instance;
    }
}

// Post Model
class Post {
    public static function findAll(int $limit = 10, int $offset = 0): array {
        $db = Database::connect();
        $stmt = $db->prepare(
            'SELECT p.*, u.name AS author_name 
             FROM posts p JOIN users u ON p.author_id = u.id 
             WHERE p.status = "published"
             ORDER BY p.created_at DESC LIMIT :limit OFFSET :offset'
        );
        $stmt->bindValue(':limit', $limit, PDO::PARAM_INT);
        $stmt->bindValue(':offset', $offset, PDO::PARAM_INT);
        $stmt->execute();
        return $stmt->fetchAll();
    }

    public static function create(array $data): bool {
        $db = Database::connect();
        $stmt = $db->prepare(
            'INSERT INTO posts (title, slug, content, author_id, status) 
             VALUES (:title, :slug, :content, :author_id, :status)'
        );
        return $stmt->execute([
            ':title' => htmlspecialchars($data['title']),
            ':slug' => self::createSlug($data['title']),
            ':content' => $data['content'],
            ':author_id' => $data['author_id'],
            ':status' => $data['status'] ?? 'draft'
        ]);
    }

    private static function createSlug(string $title): string {
        return strtolower(preg_replace('/[^a-z0-9]+/i', '-', trim($title)));
    }
}

// Authentication
class Auth {
    public static function login(string $email, string $password): bool {
        $db = Database::connect();
        $stmt = $db->prepare('SELECT * FROM users WHERE email = :email');
        $stmt->execute([':email' => $email]);
        $user = $stmt->fetch();

        if ($user && password_verify($password, $user['password'])) {
            $_SESSION['user_id'] = $user['id'];
            $_SESSION['user_name'] = $user['name'];
            $_SESSION['user_role'] = $user['role'];
            return true;
        }
        return false;
    }

    public static function register(string $name, string $email, string $password): bool {
        $hash = password_hash($password, PASSWORD_BCRYPT);
        $db = Database::connect();
        $stmt = $db->prepare('INSERT INTO users (name, email, password) VALUES (?, ?, ?)');
        return $stmt->execute([$name, $email, $hash]);
    }
}
?>