像微信支付一样处理苹果支付服务端回调

# 订单表
mysql> desc orders;
+------------------+---------------------+------+-----+---------+----------------+
| Field            | Type                | Null | Key | Default | Extra          |
+------------------+---------------------+------+-----+---------+----------------+
| id               | bigint(20) unsigned | NO   | PRI | NULL    | auto_increment |
| no               | varchar(255)        | NO   | UNI | NULL    |                |
| trade_no         | varchar(255)        | YES  |     | NULL    |                |
| status           | tinyint(4)          | NO   |     | NULL    |                |
| origin_no        | varchar(255)        | YES  |     | NULL    |                |
+------------------+---------------------+------+-----+---------+----------------+

# 用户签约表
mysql> desc member_contracts;
+-----------------+---------------------+------+-----+---------+-------+
| Field           | Type                | Null | Key | Default | Extra |
+-----------------+---------------------+------+-----+---------+-------+
| user_id         | bigint(20) unsigned | NO   | PRI | NULL    |       |
| status          | tinyint(4)          | NO   |     | NULL    |       |
| contract_id     | varchar(255)        | NO   | MUL | NULL    |       |
+-----------------+---------------------+------+-----+---------+-------+

## 客户端请求创建订单接口生成订单号`$uuid`, 返回给客户端放入`appAccountToken`
INSERT INTO orders(no) VALUES('$uuid');

## 解析服务端回调, 确认`notificationType=SUBSCRIBED`且二级事件`subtype in INITIAL_BUY RESUBSCRIBE AUTO_RENEW_ENABLED`(根据自己要求处理事件, 验证商品`ID`和包名等是否符合条件)
## 重要的字段: appAccountToken,transactionId,originalTransactionId,expiresDate
## 1. 查询 appAccountToken 订单是否存在
select * from orders where no='{$appAccountToken}' limit 1 => $id;
## 2. 修改订单状态信息, 包括已付款
update orders set trace_no='$transactionId', origin_no='$originalTransactionId' where id=$id;
## 3. 修改用户订阅状态
update member_contracts set contract_id='$originalTransactionId';
## ... 赠送会员等等等

## notificationType=DID_RENEW
## 1. 通过`transactionId`查询订单是否存在, 如果存在直接返回已经通知过
select * from orders where trade_no='{$transactionId}' limit 1 => $id
## 2. 如果不存在, 那么通过 originalTransactionId 查询到订阅表, 得到订阅的创建订单信息;
select * from member_contracts where contract_id='$originalTransactionId' limit 1;
## 3. 通过订阅表信息直接插入一条已付款的订单信息
INSERT INTO orders(no, trade_no, origin_no) VALUES('$uuid', '$transactionId', '$originalTransactionId');
## ... 赠送会员等等等

update member_contracts set status=xxx where contract_id='$originalTransactionId';

// 获取商品信息
products = try await Product.products(for: Set(productIds))

// 支付，先请求服务端创建订单接口获得 uuid
let uuid = Product.PurchaseOption.appAccountToken(UUID.init(uuidString: "$uuid")!)
let result = try await product.purchase(options: [uuid])

//处理支付结果，此时苹果内部已经进行了JWS校验
switch result {
    case .success(let verificationResult):
        // 把 verificationResult 发给服务端去校验, 防止苹果服务端回调慢
        // 把 verificationResult 发给服务端去校验, 防止苹果服务端回调慢
        // 把 verificationResult 发给服务端去校验, 防止苹果服务端回调慢
    case .userCancelled:
        //处理取消
    case .pending:
        //交易可能会在未来成功，通过Transaction.updates进行通知。
}