package ticker

import (
	"context"
	"time"
)

var _ Ticker = (*ticker)(nil)

type Ticker interface {
	worker()

	Process(fun func())
	Stop()
}

type ticker struct {
	ticker *time.Ticker
	ctx    context.Context
	cancel context.CancelFunc
	f      func()
}

func New(d time.Duration, ctx ...context.Context) Ticker {
	if len(ctx) < 1 {
		ctx = append(ctx, context.Background())
	}
	c, cancelFunc := context.WithCancel(ctx[0])
	return &ticker{
		ticker: time.NewTicker(d),
		ctx:    c,
		cancel: cancelFunc,
	}
}

func (t *ticker) worker() {
	for {
		select {
		case <-t.ticker.C:
			t.f()
		case <-t.ctx.Done():
			return
		}
	}
}

func (t *ticker) Process(fun func()) {
	t.f = fun
	go t.worker()
}

func (t *ticker) Stop() {
	t.ticker.Stop()
	t.cancel()
}