replace progress percentage with actual file size

app/ytdlp.go

@@ -4,6 +4,8 @@ import (
 	"context"
 	"encoding/json"
 	"os"
+	"path/filepath"
+	"sync"
 	"time"
 
 	"github.com/lrstanley/go-ytdlp"
@@ -95,42 +97,80 @@ func GetFormats(url string) (*FormatOptions, error) {
 	return formatOpts, nil
 }
 
+func dirSize(path string) int {
+	var total int64
+	filepath.Walk(path, func(_ string, info os.FileInfo, err error) error {
+		if err == nil && !info.IsDir() {
+			total += info.Size()
+		}
+		return nil
+	})
+	return int(total)
+}
+
 func DownloadVideo(out_dir, temp_dir, url string, opts DownloadOptions, progressChan chan<- ProgressUpdate) {
-	defer close(progressChan)
+	var mu sync.Mutex
+	currentPhase := "downloading"
+	currentFilename := ""
+
+	// Poll the temp directory for actual bytes-on-disk progress.
+	// The yt-dlp progress callback only tracks phase/filename since
+	// DownloadedBytes from the callback is unreliable for DASH streams.
+	var wg sync.WaitGroup
+	wg.Add(1)
+	stopPoll := make(chan struct{})
+	go func() {
+		defer wg.Done()
+		ticker := time.NewTicker(500 * time.Millisecond)
+		defer ticker.Stop()
+		for {
+			select {
+			case <-stopPoll:
+				return
+			case <-ticker.C:
+				mu.Lock()
+				phase := currentPhase
+				filename := currentFilename
+				mu.Unlock()
+				progressChan <- ProgressUpdate{
+					Phase:           phase,
+					DownloadedBytes: dirSize(temp_dir),
+					Filename:        filename,
+				}
+			}
+		}
+	}()
+
+	defer func() {
+		close(stopPoll)
+		wg.Wait()
+		close(progressChan)
+	}()
 
 	homePath := "home:" + out_dir
 	tempPath := "temp:" + temp_dir
 
-	var lastPhase string
-
 	dl := ytdlp.New().
 		SetExecutable(ytdlpBinary).
 		Paths(homePath).
 		Paths(tempPath).
 		RecodeVideo("mp4").
 		ProgressFunc(100*time.Millisecond, func(prog ytdlp.ProgressUpdate) {
-			// Detect phase transition -- differentiate "downloading" as the main download
-			// and "post processing" when the file name changes, preventing it from appearing "reset"
+			if prog.Status == ytdlp.ProgressStatusFinished ||
+				prog.Status == ytdlp.ProgressStatusStarting ||
+				prog.Status == ytdlp.ProgressStatusError {
+				return
+			}
+
 			phase := "downloading"
-			if prog.Status == ytdlp.ProgressStatusDownloading && prog.Percent() == 0.0 {
-				// If we already had progress, it's likely post-processing
-				if lastPhase == "downloading" {
-					phase = "post-processing"
-				}
-			} else if prog.Status != ytdlp.ProgressStatusDownloading {
+			if prog.Status == ytdlp.ProgressStatusPostProcessing {
 				phase = "post-processing"
 			}
 
-			lastPhase = phase
-
-			progressChan <- ProgressUpdate{
-				Status:       prog.Status,
-				Percent:      prog.PercentString(),
-				PercentFloat: prog.Percent(),
-				ETA:          prog.ETA(),
-				Filename:     prog.Filename,
-				Phase:        phase,
-			}
+			mu.Lock()
+			currentPhase = phase
+			currentFilename = prog.Filename
+			mu.Unlock()
 		}).
 		Output("%(title)s.%(ext)s")