Silent timeline removed when hitting export

frontend/src/App.tsx

@@ -10,6 +10,7 @@ type WsMsg =
   | { type: 'segments'; segments: { start: number; end: number }[]; duration: number }
   | { type: 'progress'; percent: number }
   | { type: 'done'; message: string }
+  | { type: 'timeline'; segments: { start: number; end: number }[]; duration: number }
   | { type: 'error'; message: string }
 
 type Phase = 'idle' | 'uploading' | 'analyzing' | 'ready' | 'exporting' | 'done'
@@ -66,6 +67,13 @@ export default function App() {
           return { ...prev, progress: msg.percent }
         case 'done':
           return { ...prev, phase: 'done', outputFile: msg.message, progress: 100 }
+        case 'timeline':
+          return {
+            ...prev,
+            phase: 'ready',
+            duration: msg.duration,
+            segments: msg.segments.map((s) => ({ ...s, kept: true })),
+          }
         case 'error':
           return { ...prev, phase: 'ready', error: msg.message }
         default:
@@ -86,7 +94,7 @@ export default function App() {
     minSilence: number,
     padding: number,
   ) => {
-    setState((prev) => ({ ...prev, phase: 'analyzing', segments: [], error: null }))
+    setState((prev) => ({ ...prev, phase: 'analyzing', segments: [], outputFile: null, error: null }))
     try {
       const res = await fetch('/analyze', {
         method: 'POST',
@@ -136,7 +144,7 @@ export default function App() {
       const res = await fetch('/export', {
         method: 'POST',
         headers: { 'Content-Type': 'application/json' },
-        body: JSON.stringify({ filename: state.filename, segments: kept }),
+        body: JSON.stringify({ filename: state.filename, segments: kept, duration: state.duration }),
       })
       if (!res.ok) throw new Error(await res.text())
     } catch (e) {
@@ -254,7 +262,7 @@ export default function App() {
               </div>
             )}
 
-            {state.phase === 'done' && state.outputFile && (
+            {state.outputFile && (
               <div className="done-panel">
                 <span className="done-check">✓</span>
                 <p>Export complete!</p>

handlers/export.go

@@ -14,6 +14,13 @@ import (
 type exportRequest struct {
 	Filename string              `json:"filename"`
 	Segments []transcode.Segment `json:"segments"`
+	Duration float64             `json:"duration"`
+}
+
+type updateTimeLine struct {
+	Type     string              `json:"type"`
+	Segments []transcode.Segment `json:"segments"`
+	Duration float64             `json:"duration"`
 }
 
 func ExportHandler(st *store.Store, hub *ws.Hub) http.HandlerFunc {
@@ -28,6 +35,7 @@ func ExportHandler(st *store.Store, hub *ws.Hub) http.HandlerFunc {
 			http.Error(w, "bad JSON: "+err.Error(), http.StatusBadRequest)
 			return
 		}
+
 		if len(req.Segments) == 0 {
 			http.Error(w, "no segments", http.StatusBadRequest)
 			return
@@ -50,15 +58,30 @@ func ExportHandler(st *store.Store, hub *ws.Hub) http.HandlerFunc {
 				return
 			}
 
-			msg, _ := json.Marshal(map[string]string{
+			doneMsg, _ := json.Marshal(map[string]string{
 				"type":    "done",
 				"message": outputKey,
 			})
-			hub.Broadcast(msg)
+			hub.Broadcast(doneMsg)
+
+			// Build normalized segments for the exported video: timestamps start at 0
+			// with no gaps, so the timeline reflects the exported file's layout.
+			var normalized []transcode.Segment
+			cursor := 0.0
+			for _, seg := range req.Segments {
+				dur := seg.End - seg.Start
+				normalized = append(normalized, transcode.Segment{Start: cursor, End: cursor + dur})
+				cursor += dur
+			}
+			timelineMsg, _ := json.Marshal(updateTimeLine{
+				Type:     "timeline",
+				Segments: normalized,
+				Duration: cursor,
+			})
+			hub.Broadcast(timelineMsg)
 		}()
 
 		w.WriteHeader(http.StatusAccepted)
-
 		log.Println("Export handler works")
 	}
 }

handlers/zoom.go

@@ -27,8 +27,7 @@ func ZoomHandler(hub *ws.Hub) http.HandlerFunc {
 			return
 		}
 
-		h := transcode.HandlerZoom{Center: req.Center}
+		result := transcode.TimelineZoom(req.Center, req.Zoom, req.Duration)
-		result := h.TimelineZoom(req.Zoom, req.Duration)
 
 		data, _ := json.Marshal(result)
 		hub.Broadcast(data)

transcode/timeline.go

@@ -1,10 +1,5 @@
 package transcode
 
-// HandlerZoom holds the current scroll center for timeline zoom calculations.
-type HandlerZoom struct {
-	Center float64 // center of the visible window in seconds
-}
-
 // ZoomResult is the result of a TimelineZoom calculation.
 type ZoomResult struct {
 	Type      string  `json:"type"`
@@ -14,13 +9,13 @@ type ZoomResult struct {
 }
 
 // TimelineZoom computes the visible time window for the given zoomPercentage
-// (1–100, where 100 = full duration visible) centered on h.Center.
+// (1–100, where 100 = full duration visible) centered on zoomCenter.
-func (h *HandlerZoom) TimelineZoom(zoomPercentage, duration float64) *ZoomResult {
+func TimelineZoom(zoomCenter, zoomPercentage, duration float64) *ZoomResult {
 	visibleDuration := duration * (zoomPercentage / 100)
 	half := visibleDuration / 2
 
-	viewStart := h.Center - half
+	viewStart := zoomCenter - half
-	viewEnd := h.Center + half
+	viewEnd := zoomCenter + half
 
 	// Clamp to [0, duration], shifting the window rather than just truncating
 	// so the visible span stays the same size when near the edges.