package main

import (
	"fmt"
	"os"
	"time"
)

func loadTS(tspath string) (timestamp *time.Time, err error) {
	if _, err = os.Stat(tspath); os.IsNotExist(err) {
		init := time.Unix(0, 0)
		timestamp = &init

		err = saveTS(tspath, timestamp)
		return
	}

	var fd *os.File
	fd, err = os.Open(tspath)
	if err != nil {
		return
	}
	defer fd.Close()

	var init int64
	_, err = fmt.Fscanf(fd, "%d", &init)
	if err != nil {
		return
	}

	tmp := time.Unix(init, 0)
	timestamp = &tmp

	return
}

func saveTS(tspath string, ts *time.Time) error {
	fd, err := os.Create(tspath)
	if err != nil {
		return err
	}
	defer fd.Close()

	_, err = fmt.Fprintf(fd, "%d", ts.Unix())
	if err != nil {
		return err
	}

	return nil
}