// Copyright 2019 getensh.com. All rights reserved.
// Use of this source code is governed by getensh.com.

package cache

import (
	"sync"
	"time"
)

type Lock struct {
	Key   string
	Ttl   int64
	stop  bool
	mutex sync.Mutex
}

// 监听过期
func (lock *Lock) watchLock() {
	sleepTime := time.Duration(lock.Ttl * 2 / 3)
	for {
		time.Sleep(sleepTime * time.Second)
		lock.mutex.Lock()
		if lock.stop {
			lock.mutex.Unlock()
			return
		}
		redisCache.Expire(lock.Key, lock.Ttl)
		lock.mutex.Unlock()
	}
}

func (lock *Lock) stopWatch() {
	lock.stop = true
}

func (lock *Lock) RedisLock() bool {
	if lock.Key == "" {
		return false
	}
	res, err := redisCache.SetNxEx(lock.Key, "lock", lock.Ttl)
	// redis 操作失败
	if err != nil {
		return false
	}

	// 上锁成功
	if res {
		go lock.watchLock()
		return true
	}
	return false
}

func (lock *Lock) RedisUnlock() {
	// 释放分布式锁
	lock.mutex.Lock()
	defer lock.mutex.Unlock()
	lock.stopWatch()
	redisCache.Del(lock.Key)
}

func RedisLock(key string) bool {
	res, err := redisCache.SetNxEx(key, "lock", 60)
	// redis 操作失败
	if err != nil {
		return false
	}

	// 上锁成功
	if res {
		return true
	}
	return false
}

func RedisUnlock(key string) {
	// 释放分布式锁
	redisCache.Del(key)
}