[QUESTION] Bar doesn't display right info.

[AYehia0]

First, I would like to thank you for this cool project.
I have some troubles making it work properly, I would really appreciate your help 😄

I am downloading a playlist of tracks, and I am trying to display multiple bars for each track but I am having some issues since the download size isn't known as I am streaming a m3u8 track and downloading segments into one file as follows :

func Download(track DownloadTrack, dlpath string, prog *mpb.Progress) string {
         // validation ...
        // ...
	// check if the track is hls
	if track.Quality != "low" {
                // downloading the m3u8 file to extract the segments
		resp, err := http.Get(track.Url)
		if err != nil {
			return ""
		}
		defer resp.Body.Close()

		segments := getSegments(resp.Body)
		DownloadM3u8(path, prog, segments)

		return path
	}
	// more code
	// ...
}

and I am using concurrency to download multiple tracks :

var wg sync.WaitGroup
plDownloadTracks := getPlaylistDownloadTracks(soundData, clientId)
p := mpb.New(mpb.WithWaitGroup(&wg),
	mpb.WithWidth(64),
	mpb.WithRefreshRate(180*time.Millisecond),
)

for _, dlT := range plDownloadTracks {
	wg.Add(1)
	go func(dlT []soundcloud.DownloadTrack) {
		defer wg.Done()

		t := getTrack(dlT, true)
		fp := soundcloud.Download(t, downloadPath, p)

		// silent indication of already existing files
		if fp == "" {
			return
		}
		soundcloud.AddMetadata(t, fp)
	}(dlT)
}
wg.Wait()

fmt.Printf("\n%s Playlist saved to : %s\n", theme.Green("[-]"), theme.Magenta(downloadPath))
return

what's interesting is the DownloadM3u8, I create a progressbar and start downloading segments:

// using the goroutine to download each segment concurrently and wait till all finished
func DownloadM3u8(filepath string, prog *mpb.Progress, segments []string) error {

	file, _ := os.OpenFile(filepath, os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0644)
	var wg sync.WaitGroup

        // I create a progressbar with 0 totalSize
	dlbar := prog.AddBar(0,
		mpb.PrependDecorators(
			decor.CountersKibiByte("% .2f / % .2f"),
		),
		mpb.AppendDecorators(
			decor.EwmaETA(decor.ET_STYLE_GO, 90),
			decor.Name(" -- "),
			decor.EwmaSpeed(decor.UnitKiB, "% .2f", 60),
		),
	)
	for _, segment := range segments {
		wg.Add(1)
		downloadSeg(&wg, segment, file, dlbar)
	}
	return nil
}

in the downloadSeg function I am copying the data to the file and incrementing the bar :

func downloadSeg(wg *sync.WaitGroup, segmentURI string, file *os.File, dlbar *mpb.Bar) {
	resp, err := http.Get(segmentURI)
	if err != nil {
		return
	}
	defer resp.Body.Close()
	// reader := dlbar.ProxyReader(resp.Body)
	// defer reader.Close()
	_, err = io.Copy(file, reader)
	dlbar.IncrInt64(resp.ContentLength)
	dlbar.SetTotal(dlbar.Current()+resp.ContentLength, false)

	if err != nil {
		return
	}
}

the problem with dlbar.SetTotal() is doesn't reach 100% also when using ProxyReader it displays wrong final files sizes.
Here the sizes are right but no speed indication.

when swapping the 2 lines IncrInt64 with SetTotal it reaches 100% in no time.
also adding prog.Wait() hangs the program after finishing.

sorry If I am making it complicated, I am a beginner in go.