使用抽象工厂模式，根据不同的条件返回不同的工厂对象。

实现代码如下：

// 定义一个抽象工厂接口
interface AbstractFactory {
   public function createProductA();
   public function createProductB();
}

// 实现具体工厂类
class ConcreteFactoryForType1 implements AbstractFactory {
   public function createProductA() {
      return new ProductType1A();
   }
   public function createProductB() {
      return new ProductType1B();
   }
}

class ConcreteFactoryForType2 implements AbstractFactory {
   public function createProductA() {
      return new ProductType2A();
   }
   public function createProductB() {
      return new ProductType2B();
   }
}

// 定义抽象产品接口
interface AbstractProductA {
   public function usefulFunctionA(): string;
}

interface AbstractProductB {
   public function usefulFunctionB(): string;
}

// 实现具体产品类
class ProductType1A implements AbstractProductA {
   public function usefulFunctionA(): string {
      return "The result of the product A1.";
   }
}

class ProductType1B implements AbstractProductB {
   public function usefulFunctionB(): string {
      return "The result of the product B1.";
   }
}

class ProductType2A implements AbstractProductA {
   public function usefulFunctionA(): string {
      return "The result of the product A2.";
   }
}

class ProductType2B implements AbstractProductB {
   public function usefulFunctionB(): string {
      return "The result of the product B2.";
   }
}

// 客户端代码，根据不同条件调用不同的工厂来获取不同类型的对象
$clientCode = function (AbstractFactory $factory) {
    $productA = $factory->createProductA();
    $productB = $factory->createProductB();

    echo $productA->usefulFunctionA() . "
";
    echo $productB->usefulFunctionB() . "
";
};

// 调用客户端代码
$clientCode(new ConcreteFactoryForType1());

$clientCode(new ConcreteFactoryForType2());