Advanced PHP Architecture

<?php
// Advanced OOP Example with Traits, Interfaces, and Abstract Classes

interface Repository {
    public function find($id);
    public function save($entity);
}

interface Cacheable {
    public function getCacheKey(): string;
    public function getCacheTTL(): int;
}

abstract class BaseRepository {
    protected $db;
    
    public function __construct(PDO $db) {
        $this->db = $db;
    }
    
    protected function beginTransaction() {
        $this->db->beginTransaction();
    }
    
    protected function commit() {
        $this->db->commit();
    }
    
    protected function rollback() {
        $this->db->rollBack();
    }
}

trait Timestampable {
    protected $createdAt;
    protected $updatedAt;
    
    public function setTimestamps(): void {
        $this->createdAt = new DateTime();
        $this->updatedAt = new DateTime();
    }
}

class User extends BaseRepository implements Cacheable {
    use Timestampable;
    
    private $id;
    private $name;
    private $email;
    
    public function __construct(array $data = []) {
        $this->hydrate($data);
        $this->setTimestamps();
    }
    
    private function hydrate(array $data): void {
        foreach ($data as $key => $value) {
            if (property_exists($this, $key)) {
                $this->$key = $value;
            }
        }
    }
    
    public function getCacheKey(): string {
        return 'user.' . $this->id;
    }
    
    public function getCacheTTL(): int {
        return 3600;
    }
    
    public function find($id) {
        // Implementation
    }
    
    public function save($entity) {
        // Implementation
    }
}
?>