class Tenant {
    private static $currentTenant = null;
    
    public static function setTenant($tenantId) {
        if (!is_numeric($tenantId) || $tenantId <= 0) {
            error_log("Invalid tenant ID: " . $tenantId);
            throw new InvalidArgumentException("Nevažeći ID firme");
        }
        
        $_SESSION['tenant_id'] = (int)$tenantId;
        self::$currentTenant = (int)$tenantId;
        
        error_log("Tenant postavljen na: " . $tenantId);
    }
    
    public static function getTenantId() {
        $tenantId = $_SESSION['tenant_id'] ?? 1;
        
        // Ako nema session, možda je korisnik izlogovan
        if (!isset($_SESSION['tenant_id'])) {
            error_log("Tenant ID nije postavljen u sessionu, koristim default 1");
        }
        
        return $tenantId;
    }
    
    public static function checkUserTenant($db, $userId) {
        try {
            $query = "SELECT tenant_id FROM users WHERE id = :user_id AND is_active = 1";
            $stmt = $db->prepare($query);
            $stmt->bindParam(":user_id", $userId, PDO::PARAM_INT);
            $stmt->execute();
            
            $user = $stmt->fetch(PDO::FETCH_ASSOC);
            $result = $user && $user['tenant_id'] == self::getTenantId();
            
            if (!$result) {
                error_log("Korisnik $userId ne pripada tenantu " . self::getTenantId());
            }
            
            return $result;
            
        } catch (PDOException $e) {
            error_log("Greška pri provjeri tenanta: " . $e->getMessage());
            return false;
        }
    }
    
    // Dodatna metoda za reset tenant-a
    public static function clearTenant() {
        unset($_SESSION['tenant_id']);
        self::$currentTenant = null;
    }
}