From 85251b17b179c5e68f89c560f0e38809961b6ebd Mon Sep 17 00:00:00 2001
From: Stefano <stefano.scafiti96@gmail.com>
Date: Sat, 20 Nov 2021 17:36:52 +0100
Subject: [PATCH] Add progress bar

---
 pb.go | 114 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 114 insertions(+)
 create mode 100644 pb.go

diff --git a/pb.go b/pb.go
new file mode 100644
index 0000000..f0688ab
--- /dev/null
+++ b/pb.go
@@ -0,0 +1,114 @@
+package main
+
+import (
+	"time"
+
+	"github.com/vbauerster/mpb/v7"
+	"github.com/vbauerster/mpb/v7/decor"
+)
+
+type ProgressState string
+
+const (
+	ProgressStateConnecting  ProgressState = "connecting"
+	ProgressStateDownloading ProgressState = "downloading"
+	ProgressStateCompleted   ProgressState = "done"
+	ProgressStateAborted     ProgressState = "aborted"
+)
+
+type ProgressBar interface {
+	Increment(n int)
+	SetTotal(n int)
+	SetFileName(fileName string)
+	SetState(state ProgressState)
+}
+
+type progressBarImpl struct {
+	progress *mpb.Progress
+	*mpb.Bar
+	state    ProgressState
+	total    int
+	fileName string
+}
+
+const (
+	barRefreshRateDefault = 180 * time.Millisecond
+	barWidthDefault       = 40
+	barMaxFileNameWidth   = 35
+)
+
+func createMpbBar(p *mpb.Progress, total int, taskName string, state ProgressState, queueBar *mpb.Bar) *mpb.Bar {
+	displayName := cutStr(taskName, barMaxFileNameWidth)
+
+	len := len(displayName)
+	if len != 0 {
+		displayName += ":"
+		len += 2
+	}
+
+	options := []mpb.BarOption{
+		mpb.PrependDecorators(
+			decor.Name(displayName, decor.WC{W: len, C: decor.DidentRight}),
+			decor.Name(string(state), decor.WCSyncSpaceR),
+			decor.CountersKibiByte("% .2f / % .2f"),
+		),
+		mpb.AppendDecorators(
+			decor.EwmaETA(decor.ET_STYLE_GO, 90),
+			decor.Name(" ] "),
+			decor.EwmaSpeed(decor.UnitKiB, "% .2f", 60),
+		),
+	}
+
+	if queueBar != nil {
+		options = append([]mpb.BarOption{
+			mpb.BarQueueAfter(queueBar),
+			mpb.BarFillerClearOnComplete(),
+		}, options...)
+	}
+
+	return p.Add(int64(total),
+		mpb.NewBarFiller(mpb.BarStyle().Rbound("|")),
+		options...,
+	)
+}
+
+func newProgressBarImpl() *progressBarImpl {
+	progress := mpb.New(
+		mpb.WithWidth(barWidthDefault),
+		mpb.WithRefreshRate(barRefreshRateDefault),
+	)
+
+	bar := createMpbBar(progress, 0, "", ProgressStateConnecting, nil)
+	return &progressBarImpl{
+		progress: progress,
+		total:    0,
+		state:    ProgressStateConnecting,
+		Bar:      bar,
+	}
+}
+
+func (bar *progressBarImpl) SetTotal(n int) {
+	bar.total = n
+	bar.Bar.SetTotal(int64(n), false)
+}
+
+func (bar *progressBarImpl) SetFileName(fileName string) {
+	bar.fileName = fileName
+}
+
+func (bar *progressBarImpl) Increment(n int) {
+	bar.IncrBy(n)
+	bar.DecoratorEwmaUpdate(time.Second)
+}
+
+func (bar *progressBarImpl) SetState(state ProgressState) {
+	if state != bar.state {
+		oldBar := bar.Bar
+		bar.Bar = createMpbBar(bar.progress, bar.total, bar.fileName, state, bar.Bar)
+		oldBar.SetTotal(0, true)
+	}
+}
+
+func NewProgressBar() ProgressBar {
+	return newProgressBarImpl()
+}