package pomodoro

import "time"

// Represents a timer
type Timer struct {
	TimeLeft chan int  // signals time left on every second
	End      chan bool // signal on successful end
	Abort    chan bool // signal on premature end
	stop     chan bool // internal channel
	wait     chan bool // internal channel
	resume   chan bool // internal channel
}

// Initializes a new timer with fresh channels
func (t Timer) Init() Timer {
	return Timer{
		TimeLeft: make(chan int),
		End:      make(chan bool, 1),
		Abort:    make(chan bool, 1),
		stop:     make(chan bool, 1),
		wait:     make(chan bool, 1),
		resume:   make(chan bool, 1),
	}
}

// Start the timer (goroutine)
func (t *Timer) StartAsync(duration int) {
	go t.Start(duration)
}

// Start the timer (blocking)
func (t *Timer) Start(duration int) {
	tick := time.NewTicker(time.Second)
	for timeLeft := duration; timeLeft > 0; {
		select {
		case <-t.stop:
			t.Abort <- true
			return
		case <-t.wait:
			<-t.resume
			continue
		case <-tick.C:
			timeLeft--
		default:
			t.TimeLeft <- timeLeft
		}
	}
	t.TimeLeft <- 0

	t.End <- true
}

func (t *Timer) Stop() {
	t.resume <- true
	t.stop <- true
}

func (t *Timer) Pause() {
	t.wait <- true
}

func (t *Timer) Resume() {
	t.resume <- true
}