package limit

import (
	"gd_auth_check/common.in/cache"
	"gd_auth_check/common.in/config"

	"github.com/go-redis/redis"
	"github.com/google/uuid"
)

const (
	releaseScript = `
	local ext = redis.call("exists", KEYS[1])
	if ext == 1 then 
		local token_key = redis.call("get", KEYS[1])
		if token_key and #token_key > 0 then
			redis.call("hincrby", token_key, "used", -1)
			redis.call("del",  KEYS[1])
		end
	elseif ext == 0 then
		local used = redis.call("hget", KEYS[2], "used")
		if used - 1 >= 0 then 
			redis.call("hincrby", KEYS[2], "used", -1)
		end
	end`

	redisUsedTokenKey = "rate_limit:used_token:"
)

func getToken(from string) string {
	return uuid.New().String() + "-" + from
}

func getTokenfrom(token string) string {
	return token[len(token)-1:]
}

func storeToken(store *cache.RedisCache, pre, tokenKey, token string) {
	expire, _ := config.Conf.RateLimit.RescueTickerTime.Int64()
	_, _ = store.SetEx(redisUsedTokenKey+tokenKey+":"+token, expire, pre+tokenKey)
}

func releaseToken(store *cache.RedisCache, pre, tokenKey, token string) bool {
	_, err := store.Eval(releaseScript, []string{
		redisUsedTokenKey + tokenKey + ":" + token,
		pre + tokenKey,
	}, []string{})

	// err == redis.Nil -> success
	if err != redis.Nil {
		// 报错
		// TODO
		return false
	}

	return true
}