fix: panic on resume and pause download before starting to allow file priority selection

dummy.torrent

@@ -0,0 +1 @@
+d8:announce15:http://a.b.c/tr13:creation datei1e4:infod6:lengthi100e4:name9:dummy.txt12:piece lengthi16384e6:pieces20:12345678901234567890ee

internal/app/controller.go

@@ -65,6 +65,10 @@ func (c *Controller) StartTorrent(path, outputRoot string) error {
 	return nil
 }
 
+func (c *Controller) StartTorrentDownload() {
+	c.engine.StartDownload()
+}
+
 func (c *Controller) DownloadMagnet(magnetURI string) error {
 	cfg, _ := config.Load()
 	outDir := "."

internal/torrent/engine.go

@@ -47,6 +47,7 @@ type Engine struct {
 	portManager *portforward.PortManager
 
 	cancel context.CancelFunc
+	downloadCtx context.Context
 
 	incomingConns chan net.Conn
 
@@ -345,6 +346,9 @@ func (e *Engine) LoadTorrent(path, outputRoot string) error {
 
 	downloadCtx, cancel := context.WithCancel(context.Background())
 	e.swapCancel(cancel)
+	e.mu.Lock()
+	e.downloadCtx = downloadCtx
+	e.mu.Unlock()
 
 	if strings.HasPrefix(path, "magnet:") {
 		go e.loadMagnet(downloadCtx, path, outputRoot)
@@ -360,10 +364,38 @@ func (e *Engine) LoadTorrent(path, outputRoot string) error {
 		return err
 	}
 
-	e.startTorrent(downloadCtx, tf, outputRoot)
+	e.mu.Lock()
+	e.torrent = tf
+	if tf.InfoHash != [20]byte{} && len(tf.PieceHashes) > 0 {
+		e.totalPieces = len(tf.PieceHashes)
+		e.pieceStates = make([]PieceState, len(tf.PieceHashes))
+		e.outputPath = buildOutputPath(tf, outputRoot)
+	}
+	e.phase = "stopped"
+	e.mu.Unlock()
+
 	return nil
 }
 
+func (e *Engine) StartDownload() {
+	e.mu.Lock()
+	tf := e.torrent
+	out := e.outputRoot
+	phase := e.phase
+	
+	if tf == nil || phase != "stopped" && phase != "failed" {
+		e.mu.Unlock()
+		return
+	}
+
+	downloadCtx, cancel := context.WithCancel(context.Background())
+	e.downloadCtx = downloadCtx
+	e.cancel = cancel
+	e.mu.Unlock()
+
+	go e.startTorrent(downloadCtx, tf, out)
+}
+
 func (e *Engine) loadMagnet(ctx context.Context, uri, outputRoot string) {
 	ml, err := magnet.Parse(uri)
 	if err != nil {
@@ -423,7 +455,13 @@ func (e *Engine) loadMagnet(ctx context.Context, uri, outputRoot string) {
 		tf.Name = hex.EncodeToString(ml.InfoHash[:])
 	}
 
-	e.startTorrent(ctx, tf, outputRoot)
+	e.mu.Lock()
+	e.torrent = tf
+	e.totalPieces = len(tf.PieceHashes)
+	e.pieceStates = make([]PieceState, len(tf.PieceHashes))
+	e.outputPath = buildOutputPath(tf, outputRoot)
+	e.phase = "stopped"
+	e.mu.Unlock()
 }
 
 func (e *Engine) downloadMetadataFromPeers(ctx context.Context, infoHash [20]byte, name string, peersCh <-chan []PeerStatus, initialPeers []PeerStatus) (*torrentfile.TorrentFile, error) {
@@ -603,7 +641,10 @@ func (e *Engine) Status() Status {
 		status.TotalBytes = int64(e.torrent.Length)
 		status.PieceLength = e.torrent.PieceLength
 		status.PieceCount = len(e.torrent.PieceHashes)
-		status.Files = append(status.Files, e.torrent.Files...)
+		
+		status.Files = make([]torrentfile.File, len(e.torrent.Files))
+		copy(status.Files, e.torrent.Files)
+		
 		status.Announce = e.torrent.Announce
 	}
 	if e.lastErr != nil {

multi.torrent

@@ -0,0 +1 @@
+d8:announce30:http://localhost:8000/announce4:infod5:filesld6:lengthi100e4:pathl9:file1.txteed6:lengthi200e4:pathl9:file2.txteee4:name7:testdir12:piece lengthi16384e6:pieces20:12345678901234567890ee

ui/ui.go

@@ -637,11 +637,12 @@ func (m model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 
 		case key.Matches(msg, keys.PauseResume):
 			phase := m.status.Phase
-			if phase == "stopped" || phase == "failed" || phase == "" {
-				m.loadingMetadata = true
-				return m, tea.Batch(m.spinner.Tick, startTorrentCmd(m.controller, m.torrentPath, m.outputDir, m.inputs[2].Value()))
-			}
+			if phase == "stopped" || phase == "failed" {
+				m.controller.StartTorrentDownload()
+				return m, nil
+			} else if phase != "" {
 				m.controller.StopTorrent()
+			}
 		case key.Matches(msg, keys.OpenNew):
 			m.controller.StopTorrent()
 			m.mainMenuMode = true