package yascron

import (
	"time"
)

type TaskId int

type CronTask struct {
	id             TaskId
	name           string
	timeExpression string
	schedule       Schedule
	next           time.Time
	prev           time.Time
	job            Job
}

func NewCronTask(name, timeExpression string, f func()) *CronTask {
	t := &CronTask{
		name:           name,
		timeExpression: timeExpression,
		job:            FuncJob(f),
	}
	return t
}

func (c *CronTask) NextExecTime() time.Time {
	return c.schedule.Next(time.Now())
}

// implement sort.Sort
type byTime []*CronTask

func (s byTime) Len() int      { return len(s) }
func (s byTime) Swap(i, j int) { s[i], s[j] = s[j], s[i] }
func (s byTime) Less(i, j int) bool {
	if s[i].next.IsZero() {
		return false
	}
	if s[j].next.IsZero() {
		return true
	}
	return s[i].next.Before(s[j].next)
}