func main() {
	bar := progress.New(100)
	for i := 0; i < 100; i++ {
		time.Sleep(time.Second / 10)
		bar.Done(1)
	}
	bar.Finish()
}

type Bar struct {
	total         int64         // 總進(jìn)度
	current       int64         // 當(dāng)前進(jìn)度
	filler        string        // 進(jìn)度填充字符
	filler_length int64         // 進(jìn)度條長度
	time_format   string        // 進(jìn)度條時(shí)間格式
	interval      time.Duration // 打印時(shí)間間隔
	begin         time.Time     // 任務(wù)開始時(shí)間
}

// New 新建進(jìn)度條實(shí)例
func New(total int64, opts ...func(*Bar)) *Bar {
	bar := &Bar{
		total:         total,
		filler:        "█",
		filler_length: 25,
		time_format:   "15:04:05", // 2006-01-02T15:04:05
		interval:      time.Second,
		begin:         time.Now(),
	}
	for _, opt := range opts {
		opt(bar)
	}
	// 定時(shí)打印
	ticker := time.NewTicker(bar.interval)
	go func() {
		for bar.current < bar.total {
			fmt.Print(bar.get_progress_string())// 打印進(jìn)度
			<-ticker.C
		}
	}()
	return bar
}
// Done 更新完成進(jìn)度
func (bar *Bar) Done(i int64) {
	bar.current += i
}
// Finish 完成最后進(jìn)度條
func (bar *Bar) Finish() {
	fmt.Println(bar.get_progress_string())
}
// WithFiller 設(shè)置進(jìn)度條填充字符
func WithFiller(filler string) func(*Bar) {
	return func(bar *Bar) {
		if len(bar.filler) != 0 {
			bar.filler = filler
		}
	}
}

//get_percent 獲取進(jìn)度百分比,區(qū)間0-100
func (bar *Bar) get_percent() int64 {
	return bar.current * 100 / bar.total
}

//get_eta 獲取eta時(shí)間
func (bar *Bar) get_eta(now time.Time) string {
	eta := (now.Unix() - bar.begin.Unix()) * 100 / (bar.get_percent() + 1)
	return bar.begin.Add(time.Second * time.Duration(eta)).Format(bar.time_format)
}

//get_progress_string 獲取打印控制臺(tái)字符串
func (bar *Bar) get_progress_string() string {
	fills := bar.get_percent() * bar.filler_length / 100
	for i := int64(0); i < bar.filler_length; i++ {
		switch {
		case i < fills:
			chunks[i] = bar.filler
		default:
			chunks[i] = " "
		}
	}
	now := time.Now()
	eta := bar.get_eta(now)
	qps := bar.current / (now.Unix() - bar.begin.Unix() + 1)
	return fmt.Sprintf("\r[%s]%d/%d [eta]%s [qps]%d ", strings.Join(chunks, ""), bar.current, bar.total, eta, qps)
}