基于测试目的的模型重构

class Customer
{
    public function save(array $data, $id = NULL)
    {
        // create or update
        if (empty($id)) {
            $customer = new \Entities\Customer();
        } else {
            $customer = $this->findById((int) $id);
        }

        $birthday = new DateTime();
        list($day, $month, $year) = explode("/", $data['birthday']);
        $birthday->setDate($year, $month, $day);

        $customer->setFirstName($data['firstName']);
        $customer->setLastName($data['lastName']);
        $customer->setCompany($data['company']);
        $languageModel = new Application_Model_Language();
        $customer->setLanguage($languageModel->findById($data['language']));
        $resellerShopModel = new Application_Model_ResellerShop();
        $customer->setResellerShop($resellerShopModel->findById($data['resellerShop']));
        $customer->setEmail($data['email']);
        $customer->setPhone($data['phone']);
        $customer->setGender($data['gender']);
        $customer->setBirthday($birthday);
        $customer->setType($data['type']);
        $customerSectorModel = new Application_Model_CustomerSector();
        $customer->setSector($customerSectorModel->findById($data['sector']));
        $customerReferenceModel = new Application_Model_CustomerReference();
        $customer->setReference($customerReferenceModel->findById($data['reference']));
        if (isset($data['password'])) {
            $customer->setPassword($this->_hashPassword($data['password']));
        }

        return $customer;
    }
}