// RateLimitConf 速率配置, 允許多長時間通過多少次.
type RateLimitConf struct {
	Limit int64
	Timer time.Duration
}
// exampleLimiterMap 接口請求速率配置, 建議放入redis/數(shù)據(jù)庫同步本地緩存.
var exampleLimiterMap = map[string]RateLimitConf{
	"/v1/hello": {Limit: 2, Timer: time.Minute},
}
// LimiterMiddle 分布式限流中間件.
func LimiterMiddle(ctx iris.Context) {
	var (
		uri    = ctx.Request().RequestURI
		client = redis.NewClusterClient()
		key    = uri
	)
	conf, ok := exampleLimiterMap[uri]
	if ok {
		limiter := redis_rate.NewLimiter(client)
		if _, _, b := limiter.Allow(key, conf.Limit, conf.Timer); !b {
			r, _ := httpcode.NewRequest(ctx, nil)
			r.Code(httpcode.TooManyReq, fmt.Errorf("req rate limit"), nil)
			return
		}
	}
	ctx.Next()
}

// exampleStandAloneLimiterMap 單機接口請求速率配置.
var exampleStandAloneLimiterMap = map[string]*rate.Limiter{
	"/v1/hello": rate.NewLimiter(rate.Every(time.Minute), 2),
}
// StandAloneLimiterMiddle 單機限流中間件.
func StandAloneLimiterMiddle(ctx iris.Context) {
	var (
		uri = ctx.Request().RequestURI
	)
	limiter, ok := exampleStandAloneLimiterMap[uri]
	if ok {
		if b := limiter.Allow(); !b {
			r, _ := httpcode.NewRequest(ctx, nil)
			r.Code(httpcode.TooManyReq, fmt.Errorf("req rate limit"), nil)
			return
		}
	}
	ctx.Next()
}