package utils

import (
	"time"
)

var _ Timer = (*timer)(nil)

type Timer interface {
	i()
	Reset(t time.Duration)
	Stop() bool
	TimeRemaining() time.Duration
	Calc() *time.Timer
	Canceled()
}

type timer struct {
	timer  *time.Timer
	end    time.Time
	Cancel chan struct{}
}

func NewTimer(t time.Duration) Timer {
	return &timer{time.NewTimer(t), time.Now().Add(t), make(chan struct{})}
}

func (s *timer) i() {}

func (s *timer) Reset(t time.Duration) {
	if !s.timer.Stop() {
		select {
		case <-s.timer.C:
		default:
		}
	}
	s.timer.Reset(t)
	s.end = time.Now().Add(t)
}

func (s *timer) Stop() bool {
	return s.timer.Stop()
}

func (s *timer) TimeRemaining() time.Duration {
	return s.end.Sub(time.Now())
}

func (s *timer) Calc() *time.Timer {
	return s.timer
}

func (s *timer) Canceled() {
	s.Cancel <- struct{}{}
}