fix: set PYTHONUNBUFFERED=1 to force real-time progress output

yt-dlp is a Python script. When stderr is a pipe (not a TTY), Python
buffers output, causing progress updates to arrive in large chunks or
only at the end. Setting PYTHONUNBUFFERED=1 forces line-buffered output,
giving real-time progress.

internal/dl/progress.go

@@ -3,6 +3,7 @@ package dl
 import (
 	"bufio"
 	"io"
+	"log/slog"
 	"regexp"
 	"strconv"
 	"strings"
@@ -25,8 +26,6 @@ func parseProgressLine(line string) *progressUpdate {
 	if line == "" || !strings.HasPrefix(line, "[download]") {
 		return nil
 	}
-	// Try to extract the simple percentage from the default format:
-	// [download] 45.2% of 123.45MiB at 2.34MiB/s ETA 00:45
 	m := progressRE.FindStringSubmatch(line)
 	if m == nil {
 		return nil
@@ -38,12 +37,10 @@ func parseProgressLine(line string) *progressUpdate {
 
 	u := &progressUpdate{pct: pct}
 
-	// Extract speed and ETA from remaining parts
 	rest := line
 	if idx := strings.Index(rest, "%"); idx >= 0 {
 		rest = rest[idx+1:]
 	}
-	// Look for "at <speed>"
 	if atIdx := strings.Index(rest, " at "); atIdx >= 0 {
 		afterAt := rest[atIdx+4:]
 		if spaceIdx := strings.Index(afterAt, " "); spaceIdx >= 0 {
@@ -51,7 +48,6 @@ func parseProgressLine(line string) *progressUpdate {
 			rest = afterAt[spaceIdx:]
 		}
 	}
-	// Look for "ETA <duration>"
 	if etaIdx := strings.Index(rest, "ETA "); etaIdx >= 0 {
 		etaStr := strings.TrimSpace(rest[etaIdx+4:])
 		u.eta = etaStr
@@ -63,16 +59,29 @@ func parseProgressLine(line string) *progressUpdate {
 // readProgress reads yt-dlp stderr and sends progress updates to the channel.
 // The caller is responsible for closing the updates channel.
 func readProgress(stderr io.ReadCloser, updates chan<- *domain.DownloadJob, job *domain.DownloadJob) {
+	var stderrBuf strings.Builder
 	scanner := bufio.NewScanner(stderr)
+	lineCount := 0
+	matchCount := 0
 	for scanner.Scan() {
 		line := scanner.Text()
+		lineCount++
+
+		if stderrBuf.Len() < 4096 {
+			stderrBuf.WriteString(line)
+			stderrBuf.WriteByte('\n')
+		}
+
 		parsed := parseProgressLine(line)
 		if parsed == nil {
 			continue
 		}
+		matchCount++
 		job.Progress = parsed.pct
 		job.Speed = parsed.speed
 		job.ETA = parsed.eta
 		updates <- job
 	}
+	job.StderrLog = stderrBuf.String()
+	slog.Info("readProgress finished", "url", job.URL, "lines", lineCount, "matches", matchCount, "stderr_len", len(job.StderrLog))
 }

internal/dl/ytdlp.go

@@ -265,6 +265,7 @@ func (c *Client) StartDownload(job *domain.DownloadJob, downloadDir string) (<-c
 	slog.Info("starting download", "url", job.URL, "format", formatID)
 
 	cmd := exec.Command(c.binaryPath, args...)
+	cmd.Env = append(os.Environ(), "PYTHONUNBUFFERED=1")
 
 	stderr, err := cmd.StderrPipe()
 	if err != nil {
@@ -315,7 +316,7 @@ func (c *Client) StartDownload(job *domain.DownloadJob, downloadDir string) (<-c
 			<-progressDone
 			if err != nil {
 				job.Status = domain.StatusFailed
-				slog.Error("download failed", "url", job.URL, "error", err)
+				slog.Error("download failed", "url", job.URL, "error", err, "stderr", job.StderrLog)
 			} else {
 				job.Status = domain.StatusCompleted
 			}

internal/domain/types.go

@@ -128,6 +128,7 @@ type DownloadJob struct {
 	FilePath       string
 	Title          string
 	QuotaApplied   bool
+	StderrLog      string
 	CancelCh       chan struct{}
 	Cmd            *exec.Cmd
 }

internal/handler/download.go

@@ -70,7 +70,15 @@ func (h *Handler) handleURLInput(ctx context.Context, chatID int64, text string,
 		if strings.Contains(errMsg, "DRM") {
 			youtubeURL, ytTitle, searchErr := h.YtDlp.SearchYoutube(text)
 			if searchErr != nil {
-				h.sendText(ctx, chatID, fmt.Sprintf("This content is DRM protected and no YouTube alternative was found: %s", errMsg))
+				kb := models.InlineKeyboardMarkup{
+					InlineKeyboard: [][]models.InlineKeyboardButton{
+						{{Text: "Search on YouTube", CallbackData: "drm_search"}},
+						{{Text: "Cancel", CallbackData: "pending_cancel"}},
+					},
+				}
+				h.Bot.SendMessage(ctx, &tgbot.SendMessageParams{
+					ChatID: chatID, Text: "This content is DRM protected and no YouTube alternative was found automatically. Try searching by name:", ReplyMarkup: kb,
+				})
 				return
 			}
 			h.sendText(ctx, chatID, fmt.Sprintf("This content is DRM protected. Found on YouTube: %s", ytTitle))
@@ -388,6 +396,8 @@ func (h *Handler) runDownload(ctx context.Context, job *domain.DownloadJob) {
 
 	lastProgress := 0.0
 	for upd := range updates {
+		slog.Info("progress update", "pct", upd.Progress, "speed", upd.Speed, "status", upd.Status)
+
 		h.mu.Lock()
 		currentJob := h.activeJobs[job.UserID]
 		h.mu.Unlock()
@@ -411,18 +421,23 @@ func (h *Handler) runDownload(ctx context.Context, job *domain.DownloadJob) {
 			return
 		}
 
-		if upd.Progress-lastProgress >= domain.ProgressThreshold || upd.Status == domain.StatusCompleted {
+		// Always show the first real progress update, then throttle at 5% intervals
+		if upd.Progress > 0 && lastProgress == 0 {
+			lastProgress = upd.Progress
+		} else if upd.Progress-lastProgress < domain.ProgressThreshold && upd.Status != domain.StatusCompleted {
+			continue
+		} else {
 			lastProgress = upd.Progress
-
-			if upd.Progress > domain.QuotaProgressThreshold && !job.QuotaApplied && job.FileSize > 0 {
-				job.QuotaApplied = true
-				h.applyQuota(job.UserID, job.FileSize)
-			}
-
-			kb := progressKeyboard(upd.Progress, upd.Speed, upd.ETA)
-			text := fmt.Sprintf("Downloading: %s", job.Title)
-			h.editText(ctx, job.ChatID, job.MessageID, text, &kb)
 		}
+
+		if upd.Progress > domain.QuotaProgressThreshold && !job.QuotaApplied && job.FileSize > 0 {
+			job.QuotaApplied = true
+			h.applyQuota(job.UserID, job.FileSize)
+		}
+
+		kb := progressKeyboard(upd.Progress, upd.Speed, upd.ETA)
+		text := fmt.Sprintf("Downloading: %s", job.Title)
+		h.editText(ctx, job.ChatID, job.MessageID, text, &kb)
 	}
 
 	h.mu.Lock()

internal/handler/handler.go

@@ -24,6 +24,7 @@ type PendingKind string
 
 const (
 	PendingURL PendingKind = "url"
+	PendingDRM PendingKind = "drm"
 )
 
 type PendingInput struct {
@@ -235,6 +236,9 @@ func (h *Handler) HandleCallback(ctx context.Context, cb *models.CallbackQuery)
 	case data == "deleteaccount":
 		h.deleteAccountPrompt(ctx, chatID, msgID, userID)
 		h.answerCb(ctx, cb.ID)
+	case data == "drm_search":
+		h.promptForInput(ctx, chatID, msgID, userID, PendingDRM, "Enter a search query to find this content on YouTube:", nil)
+		h.answerCb(ctx, cb.ID)
 	case data == "pending_cancel":
 		h.backToMenu(ctx, chatID, msgID, cb.ID, userID)
 	default:
@@ -296,11 +300,23 @@ func (h *Handler) processPendingInput(ctx context.Context, msg *models.Message,
 	switch pi.Kind {
 	case PendingURL:
 		h.handleURLInput(ctx, msg.Chat.ID, text, userID)
+	case PendingDRM:
+		h.handleDRMSearch(ctx, msg.Chat.ID, text, userID)
 	default:
 		h.sendText(ctx, msg.Chat.ID, "Unknown input type")
 	}
 }
 
+func (h *Handler) handleDRMSearch(ctx context.Context, chatID int64, text string, userID int64) {
+	youtubeURL, ytTitle, err := h.YtDlp.SearchYoutube(text)
+	if err != nil {
+		h.sendText(ctx, chatID, fmt.Sprintf("No results found for '%s'. Try a different search query or send a YouTube URL directly.", text))
+		return
+	}
+	h.sendText(ctx, chatID, fmt.Sprintf("Found on YouTube: %s", ytTitle))
+	h.handleURLInput(ctx, chatID, youtubeURL, userID)
+}
+
 func (h *Handler) promptForInput(ctx context.Context, chatID int64, msgID int, userID int64, kind PendingKind, prompt string, data map[string]string) {
 	kb := models.InlineKeyboardMarkup{
 		InlineKeyboard: [][]models.InlineKeyboardButton{