package challenge

import (
	"fmt"
	"strconv"
	"strings"
	"time"
)

const day = 24 * time.Hour

func parseClock(value string) (time.Duration, error) {
	parts := strings.Split(value, ":")
	if len(parts) != 3 {
		return 0, fmt.Errorf("bad time %q", value)
	}
	h, err := strconv.Atoi(parts[0])
	if err != nil {
		return 0, err
	}
	m, err := strconv.Atoi(parts[1])
	if err != nil {
		return 0, err
	}
	s, err := strconv.Atoi(parts[2])
	if err != nil {
		return 0, err
	}
	if h < 0 || h > 23 || m < 0 || m > 59 || s < 0 || s > 59 {
		return 0, fmt.Errorf("bad time %q", value)
	}
	return time.Duration(h)*time.Hour + time.Duration(m)*time.Minute + time.Duration(s)*time.Second, nil
}

func formatClock(d time.Duration) string {
	d %= day
	if d < 0 {
		d += day
	}
	h := int(d / time.Hour)
	d -= time.Duration(h) * time.Hour
	m := int(d / time.Minute)
	d -= time.Duration(m) * time.Minute
	s := int(d / time.Second)
	return fmt.Sprintf("%02d:%02d:%02d", h, m, s)
}

func formatDuration(d time.Duration) string {
	if d < 0 {
		d = 0
	}
	h := int(d / time.Hour)
	d -= time.Duration(h) * time.Hour
	m := int(d / time.Minute)
	d -= time.Duration(m) * time.Minute
	s := int(d / time.Second)
	return fmt.Sprintf("%02d:%02d:%02d", h, m, s)
}