package morningalarm

import (
	"encoding/json"
	"os"
	"time"

	"github.com/robfig/cron/v3"
)

func (ma *MorningAlarm) nextAlarm() *time.Time {
	if len(ma.cr.Entries()) == 0 {
		return nil
	}

	min := ma.cr.Entries()[0].Next

	for _, entry := range ma.cr.Entries() {
		if entry.Next.Before(min) {
			min = entry.Next
		}
	}

	return &min
}

func (ma *MorningAlarm) addAlarm(spec string, name string) (cron.EntryID, error) {
	id, err := ma.cr.AddFunc(spec, ma.fireAlarm)

	if err != nil {
		return 0, err
	}

	ma.alarms = append(ma.alarms, alarm{
		id:   id,
		Time: spec,
		Name: name,
	})

	return id, nil
}

func (ma *MorningAlarm) saveAlarms() error {
	content, err := json.Marshal(ma.alarms)

	if err != nil {
		return err
	}

	err = os.WriteFile("alarms.json", content, 0644)

	if err != nil {
		return err
	}

	return nil
}

func (ma *MorningAlarm) loadAlarms() error {
	if _, err := os.Stat("alarms.json"); os.IsNotExist(err) {
		ma.alarms = []alarm{}
		return nil
	}

	content, err := os.ReadFile("alarms.json")

	if err != nil {
		return err
	}

	var ent []alarm
	err = json.Unmarshal(content, &ent)

	if err != nil {
		return err
	}

	for _, entry := range ent {
		_, err := ma.addAlarm(entry.Time, entry.Name)

		if err != nil {
			return err
		}
	}

	return nil
}

func (ma *MorningAlarm) fireAlarm() {
	ma.playWakeUpMusic()
}