@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {
    @Resource
    private ISeckillVoucherService seckillVoucherService;
    @Resource
    private RedisIdWorker redisIdWorker;
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Resource
    private RedissonClient redissonClient;
    @Override
    public Result seckillVoucher(Long voucherId) {
        //1 查詢優(yōu)惠券信息
        SeckillVoucher seckillVoucher = seckillVoucherService.getById(voucherId);
        //2 判斷秒殺是否開始
        LocalDateTime now = LocalDateTime.now(); //現(xiàn)在時間
        LocalDateTime beginTime = seckillVoucher.getBeginTime(); //開始時間
        LocalDateTime endTime = seckillVoucher.getEndTime(); //結(jié)束時間
        if (now.isBefore(beginTime)) {
            return Result.fail("秒殺還未開始");
        }
        //3 判斷秒殺是否結(jié)束
        if (now.isAfter(endTime)) {
            return Result.fail("秒殺已結(jié)束");
        }
        //4 判斷庫存是否充足
        int stock = (int) seckillVoucher.getStock();
        if (stock == 0 && stock <= 0) {
            return Result.fail("庫存不足");
        }
        //確保一人一單 用戶ID和代金券ID聯(lián)合查詢
        Long userId = UserHolder.getUser().getId();
        //先獲取鎖 再提交事務(wù)
        //synchronized (userId.toString().intern()) {
        //創(chuàng)建鎖對象
        //SimpleRedisLock simpleRedisLock = new SimpleRedisLock("order:" + userId, stringRedisTemplate);
        RLock lock = redissonClient.getLock("lock:order:" + userId);
        //獲取鎖
        boolean isLock = lock.tryLock();
        //判斷是否獲取鎖成功
        if (!isLock){
            //獲取鎖失敗 返回錯誤或失敗
            return Result.fail("不允許重復下單");
        }
        try {
            //獲取事務(wù)的代理對象
            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
            return proxy.creatVoucherOrder(voucherId);
        } finally {
            //釋放鎖
            lock.unlock();
        }
        //}//事務(wù)提交之后在釋放鎖
    }
    /**
     * 這里對于加鎖做出一些解釋：如果鎖加在整個方法上，那么就會導
     *  致鎖的粒度過大，導致每個進程進來都會鎖住，所以要控制鎖的粒度
     */
    @Transactional
    public Result creatVoucherOrder(Long voucherId) {
        Long userId = UserHolder.getUser().getId();
        Integer count = query().eq("user_id", userId).eq("voucher_id", voucherId).count();
        if (count > 0) {
            return Result.fail("用戶已經(jīng)購買過了");
        }
        //5 扣減庫存-
        boolean success = seckillVoucherService.update()
                .setSql("stock = stock -1 ")  //樂觀鎖
                .eq("voucher_id", voucherId).gt("stock", 0) //判斷庫存是否大于0: where id = ? and stock > 0
                .update();
        if (!success) {
            return Result.fail("庫存不足");
        }
        //6 創(chuàng)建訂單
        //6.1 訂單ID
        VoucherOrder voucherOrder = new VoucherOrder();
        long orderid = RedisIdWorker.nextId("order");
        voucherOrder.setVoucherId(orderid);
        //6.2 用戶ID
        voucherOrder.setUserId(userId);
        //6.3 代金券ID
        voucherOrder.setVoucherId(voucherId);
        save(voucherOrder);
        //7 返回訂單id
        return Result.ok(orderid);
    }
}