implamented Aroll cuter

handlers/zoom.go

@@ -0,0 +1,38 @@
+package handlers
+
+import (
+	"encoding/json"
+	"net/http"
+
+	"aroll/transcode"
+	"aroll/ws"
+)
+
+type zoomRequest struct {
+	Zoom     float64 `json:"zoom"`     // 1–100, percentage of total duration to show
+	Center   float64 `json:"center"`   // scroll center in seconds
+	Duration float64 `json:"duration"` // total video duration in seconds
+}
+
+func ZoomHandler(hub *ws.Hub) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodPost {
+			http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
+			return
+		}
+
+		var req zoomRequest
+		if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+			http.Error(w, "bad JSON: "+err.Error(), http.StatusBadRequest)
+			return
+		}
+
+		h := transcode.HandlerZoom{Center: req.Center}
+		result := h.TimelineZoom(req.Zoom, req.Duration)
+
+		data, _ := json.Marshal(result)
+		hub.Broadcast(data)
+
+		w.WriteHeader(http.StatusAccepted)
+	}
+}