Method processProgressMsg

internal/tui/process.go:17–78

(msg events.ProgressMsg)

)

func (m *RootModel) processProgressMsg(msg events.ProgressMsg) tea.Cmd {
	d := m.FindDownloadByID(msg.DownloadID)
	if d == nil || d.done || d.paused {
		return nil
	}

	prevDownloaded := d.Downloaded
	d.Downloaded = msg.Downloaded
	d.Total = msg.Total
	d.Speed = msg.Speed
	d.Elapsed = msg.Elapsed
	d.Connections = msg.ActiveConnections

	// Keep "Resuming..." visible until we observe actual transfer.
	if d.resuming && (d.Speed > 0 || d.Downloaded > prevDownloaded) {
		d.resuming = false
	}

	// Update Chunk State if provided
	if msg.BitmapWidth > 0 && len(msg.ChunkBitmap) > 0 {
		if d.state != nil && msg.Total > 0 {
			d.state.SetTotalSize(msg.Total)
		}
		// We only get bitmap, no progress array (to save bandwidth)
		// State needs to be updated carefully
		if d.state != nil {
			d.state.RestoreBitmap(msg.ChunkBitmap, msg.ActualChunkSize)
		}
		if d.state != nil && len(msg.ChunkProgress) > 0 {
			d.state.SetChunkProgress(msg.ChunkProgress)
		}
	}

	var cmd tea.Cmd
	if d.Total > 0 {
		percentage := float64(d.Downloaded) / float64(d.Total)
		cmd = d.progress.SetPercent(percentage)
	}

	// Update speed graph history with EMA smoothing for smooth transitions
	if time.Since(m.lastSpeedHistoryUpdate) >= GraphUpdateInterval {
		totalSpeed := float64(m.calcTotalSpeedBps())
		// EMA smooth against previous graph point for visual continuity
		var smoothed float64
		if m.Settings != nil && config.Resolve[bool](m.Settings.General.LiveSpeedGraph) {
			smoothed = totalSpeed
		} else if len(m.SpeedHistory) > 0 {
			prev := m.SpeedHistory[len(m.SpeedHistory)-1]
			const graphAlpha = 0.3 // Graph smoothing factor
			smoothed = graphAlpha*totalSpeed + (1-graphAlpha)*prev
		} else {
			smoothed = totalSpeed
		}
		if len(m.SpeedHistory) > 0 {
			m.SpeedHistory = append(m.SpeedHistory[1:], smoothed)
		}
		m.lastSpeedHistoryUpdate = time.Now()
	}