PHP로 개발된 쇼핑몰의 기간한정 판매활동의 유효성 평가

商品表 (products)
- id (商品ID)
- name (商品名称)
- price (商品价格)

活动表 (deals)
- id (活动ID)
- product_id (关联的商品ID)
- start_time (活动开始时间)
- end_time (活动结束时间)
- discount (活动折扣)

function getActiveDeals() {
    $now = time();
    $query = "SELECT * FROM deals WHERE start_time <= $now AND end_time >= $now";
    // 执行数据库查询...
    // 返回活动列表...
}

$activeDeals = getActiveDeals();
foreach ($activeDeals as $deal) {
    $productId = $deal['product_id'];
    $product = getProductById($productId);

    echo "抢购商品：{$product['name']}";
    echo "原价：{$product['price']}";
    echo "折扣价：{$product['price'] * $deal['discount']}";
    echo "剩余时间：{$deal['end_time'] - time()}秒";
    // 显示商品的抢购按钮...
}

function purchaseDeal($dealId, $userId) {
    $deal = getDealById($dealId);
    $product = getProductById($deal['product_id']);

    $currentPrice = $product['price'] * $deal['discount'];

    // 检查用户的余额是否足够支付
    $balance = getUserBalance($userId);
    if ($balance < $currentPrice) {
        return "余额不足";
    }

    // 扣除用户的余额
    deductUserBalance($userId, $currentPrice);

    // 生成订单并将订单写入数据库
    createOrder($userId, $dealId, $currentPrice);

    return "购买成功";
}