package main

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

var commandWeekDescription = "get week in this year and week begin and end offset by this week"

func commandWeek(args []string) {
	var err error
	offset := 0
	if len(args) == 2 {
		offset, err = strconv.Atoi(args[1])
		if err != nil {
			fmt.Printf("expect `%v` to be a integer\n", args[1])
			os.Exit(1)
		}
	} else if len(args) > 2 {
		fmt.Printf("only accept 1 argument, got %v\n", len(args)-1)
		os.Exit(1)
	}
	offsetTime := time.Hour * time.Duration(offset) * 7 * 24
	targetTime := time.Now().Add(offsetTime)
	_, week := targetTime.ISOWeek()
	weekday := int(targetTime.Weekday())
	// make Sunday = 7
	if weekday == 0 {
		weekday = 7
	}
	weekBegin := targetTime.Add(time.Hour * 24 * time.Duration(weekday-1) * -1)
	weekEnd := targetTime.Add(time.Hour * 24 * time.Duration(7-weekday))
	fmt.Printf("week-%v-%v-%v\n", week, weekBegin.Format("0102"), weekEnd.Format("0102"))
}