多活动事件处理中统一接口与参数差异化设计模式

// 假设这样定义接口，但无法满足不同参数签名的需求
interface CampaignInterface {
    public function onFirstPurchase(User $user); // 无法为所有活动提供足够的灵活性
    public function onFirstTrade(Model $model);
}

<?php

interface User {} // 示例User接口或类
interface Model {} // 示例Model接口或类

interface CampaignInterface {
    /**
     * 处理首次购买事件。
     * @param User $user 触发购买的用户。
     * @param PurchaseContextInterface $context 包含购买相关的特定参数。
     */
    public function onFirstPurchase(User $user, PurchaseContextInterface $context);

    /**
     * 处理首次交易事件。
     * @param TradeContextInterface $context 包含交易相关的特定参数。
     */
    public function onFirstTrade(TradeContextInterface $context);
}

?>

<?php

// 首次购买事件的上下文接口
interface PurchaseContextInterface {
    // 可以定义一些通用的获取方法，例如：
    // public function getPurchaseAmount(): float;
    // public function getProductId(): string;
}

// 首次交易事件的上下文接口
interface TradeContextInterface {
    // 可以定义一些通用的获取方法，例如：
    // public function getTradePrice(): float;
    // public function getTradeModel(): Model;
}

?>

<?php

class FirstCampaign implements CampaignInterface {
    public function onFirstPurchase(User $user, PurchaseContextInterface $context) {
        // FirstCampaign可能需要arg1, arg2。假设FirstCampaignPurchaseContext提供了这些。
        if ($context instanceof FirstCampaignPurchaseContext) {
            $arg1 = $context->getArg1();
            $arg2 = $context->getArg2();
            // ... 使用$user, $arg1, $arg2 进行业务逻辑
            echo "FirstCampaign: User purchased with {$arg1}, {$arg2}\n";
        } else {
            // 处理非预期的上下文类型，或者抛出异常
            echo "FirstCampaign: Received unexpected PurchaseContextInterface\n";
        }
    }

    public function onFirstTrade(TradeContextInterface $context) {
        if ($context instanceof FirstCampaignTradeContext) {
            $price = $context->getPrice();
            $something = $context->getSomething();
            $model = $context->getModel();
            // ... 使用$price, $something, $model 进行业务逻辑
            echo "FirstCampaign: User traded with price {$price} and model {$model->getName()}\n";
        }
    }
}

class SecondCampaign implements CampaignInterface {
    public function onFirstPurchase(User $user, PurchaseContextInterface $context) {
        // SecondCampaign可能只关心User
        echo "SecondCampaign: User purchased\n";
        // 如果需要，也可以从context获取额外信息
    }

    public function onFirstTrade(TradeContextInterface $context) {
        if ($context instanceof SecondCampaignTradeContext) {
            $model = $context->getModel();
            echo "SecondCampaign: User traded with model {$model->getName()}\n";
        }
    }
}

?>

<?php

// FirstCampaign的首次购买上下文
class FirstCampaignPurchaseContext implements PurchaseContextInterface {
    private $arg1;
    private $arg2;

    public function __construct($arg1, $arg2) {
        $this->arg1 = $arg1;
        $this->arg2 = $arg2;
    }

    public function getArg1() { return $this->arg1; }
    public function getArg2() { return $this->arg2; }
}

// FirstCampaign的首次交易上下文
class FirstCampaignTradeContext implements TradeContextInterface {
    private $price;
    private $something;
    private Model $model;

    public function __construct($price, $something, Model $model) {
        $this->price = $price;
        $this->something = $something;
        $this->model = $model;
    }

    public function getPrice() { return $this->price; }
    public function getSomething() { return $this->something; }
    public function getModel(): Model { return $this->model; }
}

// SecondCampaign的首次购买上下文（可能不需要额外参数，但仍需实现接口）
class SecondCampaignPurchaseContext implements PurchaseContextInterface {
    // 可以在这里添加SecondCampaign特有的参数
}

// SecondCampaign的首次交易上下文
class SecondCampaignTradeContext implements TradeContextInterface {
    private Model $model;

    public function __construct(Model $model) {
        $this->model = $model;
    }

    public function getModel(): Model { return $this->model; }
}

// 示例User和Model实现
class ConcreteUser implements User {
    private $name;
    public function __construct($name) { $this->name = $name; }
    public function getName() { return $this->name; }
}
class ConcreteModel implements Model {
    private $name;
    public function __construct($name) { $this->name = $name; }
    public function getName() { return $this->name; }
}

?>

<?php

// 假设我们有一个事件触发器
function triggerFirstPurchaseEvent(CampaignInterface $campaign, User $user, PurchaseContextInterface $context) {
    $campaign->onFirstPurchase($user, $context);
}

function triggerFirstTradeEvent(CampaignInterface $campaign, TradeContextInterface $context) {
    $campaign->onFirstTrade($context);
}

// 实例化活动
$firstCampaign = new FirstCampaign();
$secondCampaign = new SecondCampaign();

// 实例化用户和模型
$user1 = new ConcreteUser("Alice");
$modelA = new ConcreteModel("Product A");
$modelB = new ConcreteModel("Product B");

// 触发 FirstCampaign 的首次购买事件
$firstCampaignPurchaseCtx = new FirstCampaignPurchaseContext("promo_code_123", 100.50);
triggerFirstPurchaseEvent($firstCampaign, $user1, $firstCampaignPurchaseCtx);
// 输出: FirstCampaign: User purchased with promo_code_123, 100.5

// 触发 SecondCampaign 的首次购买事件
$secondCampaignPurchaseCtx = new SecondCampaignPurchaseContext(); // 可能不需要额外参数
triggerFirstPurchaseEvent($secondCampaign, $user1, $secondCampaignPurchaseCtx);
// 输出: SecondCampaign: User purchased

// 触发 FirstCampaign 的首次交易事件
$firstCampaignTradeCtx = new FirstCampaignTradeContext(99.99, "extra_data", $modelA);
triggerFirstTradeEvent($firstCampaign, $firstCampaignTradeCtx);
// 输出: FirstCampaign: User traded with price 99.99 and model Product A

// 触发 SecondCampaign 的首次交易事件
$secondCampaignTradeCtx = new SecondCampaignTradeContext($modelB);
triggerFirstTradeEvent($secondCampaign, $secondCampaignTradeCtx);
// 输出: SecondCampaign: User traded with model Product B

?>