package main

import (
	"context"
	"log"
	"sync/atomic"
	"time"

	"golang.org/x/time/rate"
)

func main() {
	var (
		rps      = 100000
		duration = 10 * time.Second
	)

	requests := rps * int(duration.Seconds())

	ctx, endCancel := context.WithTimeout(context.Background(), duration)
	defer endCancel()

	count := newCounter(ctx)
	count.logState()

	limiter := rate.NewLimiter(rate.Every(time.Second/time.Duration(rps)), 1)
	for i := 0; i < requests; i++ {
		count.inc()

		err := limiter.Wait(ctx)
		if err != nil {
			log.Println("Limiter error", err)
			break
		}
	}
}

type counter struct {
	ctx context.Context
	i   int64
}

func newCounter(context context.Context) *counter {
	return &counter{
		ctx: context,
		i:   0,
	}
}

func (c *counter) inc() {
	atomic.AddInt64(&c.i, 1)
}

func (c *counter) get() int64 {
	return atomic.LoadInt64(&c.i)
}

func (c *counter) logState() {
	go func() {
		for {
			select {
			case <-c.ctx.Done():
				return
			default:
			}

			before := c.get()
			time.Sleep(time.Second)
			after := c.get()
			log.Println(after - before)
		}
	}()
}