package gmredis

import (
	"fmt"
	"time"

	"gitee.com/micro-tools/wf/util/gconv"

	"gitee.com/micro-tools/wf/util/guid"
)

type Lock struct {
}

//LockWithTimeout  设置分布式 lockTime 锁设置的ttl时间 ; waitTime 等待时间
func (c *Lock) LockWithTimeout(key string, lockTime, waitTime int) (string, bool) {
	id := guid.S()
	name := "lock:" + key
	end := time.Now().Add(time.Second * time.Duration(waitTime))
	for time.Now().Before(end) {
		res, err := Get().Str.SetNX(name, id)
		if err != nil {
			return "", false
		} else {
			if res {
				res, err = Get().Key.Expire(name, lockTime)
				if err != nil {
					return "", false
				} else {
					if res {
						return id, true
					} else {
						return "", false
					}
				}
			} else {
				n, err := Get().Key.TTl(name)
				if err != nil {
					return "", false
				}
				if n == -1 {
					// 如果key存在，但是没有设置剩余时间
					_, _ = Get().Key.Expire(name, lockTime)
				}
			}
		}
		time.Sleep(time.Microsecond)
	}
	return "", false
}

//ReleaseLock 释放锁 id LockWithTimeout 返回的记录，用于比较存储中的一致性
func (c *Lock) ReleaseLock(key, id string) error {
	name := "lock:" + key
	has, err := Get().Key.Exists(name)
	if err != nil {
		return err
	}
	if has {
		res, err := Get().Str.Get(name)
		if err != nil {
			return err
		}
		if id == gconv.String(res) {
			_, _ = Get().Key.Del(name)
			return nil
		} else {
			return fmt.Errorf("id %s != %s", id, gconv.String(res))
		}
	} else {
		return fmt.Errorf("key %s is not exist", key)
	}
}