package lock

import (
	"context"
	"errors"
	"eta/eta_api/utils"
	"fmt"
	"github.com/go-redis/redis/v8"
	"time"
)

const (
	lockName = "lock:"
)

var (
	ctx = context.Background()
)

func AcquireLock(key string, expiration int, Holder string) bool {
	script := redis.NewScript(`local key = KEYS[1]
			local clientId = ARGV[1]
			local expiration = tonumber(ARGV[2])
			if redis.call("EXISTS", key) == 0 then
				redis.call("SET", key, clientId, "EX", expiration)
				return 1
			else
				return 0
			end`)
	lockey := fmt.Sprintf("%s%s", lockName, key)
	result, err := script.Run(ctx, utils.Rc.RedisClient(), []string{lockey}, Holder, expiration).Int()
	if err != nil {
		fmt.Printf("加锁失败：err: %v", err)
		return false
	}
	if result == 1 {
		return true
	}
	return false
}

func TryLock(key string, expiration int, Holder string, timeout time.Duration) error {
	script := redis.NewScript(`
        local session = ARGV[1]
        local current = redis.call("hget", KEYS[1], session)
        if current then
            local count = tonumber(current)
            if count > 0 then
                redis.call("hincrby", KEYS[1], session, 1)
                return 1
            else
                return 0
            end
        else
            redis.call("hset", KEYS[1], session, 1)
            redis.call("expire", KEYS[1], 10)
            return 1
        end
    `)
	start := time.Now()
	for {
		result, err := script.Run(context.Background(), utils.Rc.RedisClient(), []string{key}, Holder).Result()
		if err != nil {
			return err
		}
		if result.(int64) == 1 {
			//go renewLock()
			return nil
		}

		if time.Since(start) >= timeout {
			return errors.New("获取锁超时")
		}
		time.Sleep(200 * time.Millisecond)
	}
}
//
//func renewLock() {
//	for {
//		time.Sleep(5 * time.Second)
//
//		script := redis.NewScript(1, `
//            local session = ARGV[1]
//            local current = redis.call("hget", KEYS[1], session)
//            if current then
//                local count = tonumber(current)
//                if count > 0 then
//                    redis.call("expire", KEYS[1], 10)
//                    return 1
//                else
//                    return 0
//                end
//            else
//                return 0
//            end
//        `)
//
//		result, err := script.Run(r.ctx, r.client, []string{r.key}, r.session).Result()
//		if err != nil {
//			fmt.Println("Failed to renew lock:", err)
//			return
//		}
//
//		if result.(int64) == 0 {
//			fmt.Println("Lock not held by current client, stopping renewal")
//			return
//		}
//	}
//}

func ReleaseLock(key string, holder string) bool {
	script := redis.NewScript(`
	   if redis.call("get", KEYS[1]) == ARGV[1] then
	       return redis.call("del", KEYS[1])
	   else
	       return 0
	   end
	`)
	lockey := fmt.Sprintf("%s%s", lockName, key)
	result, err := script.Run(ctx, utils.Rc.RedisClient(), []string{lockey}, holder).Int()
	if err != nil {
		fmt.Printf("解锁失败：err: %v", err)
		return false
	}
	if result == 1 {
		return true
	}
	return false
}