1 files changed, 83 insertions, 0 deletions
diff --git a/apps/web/src/hooks/use-timeline-element-resize.ts b/apps/web/src/hooks/use-timeline-element-resize.ts
new file mode 100644
index 00000000..b12087ea
--- /dev/null
+++ b/apps/web/src/hooks/use-timeline-element-resize.ts
@@ -0,0 +1,83 @@
+import { useState } from "react";
+import { ResizeState, TimelineElement, TimelineTrack } from "@/types/timeline";
+
+interface UseTimelineElementResizeProps {
+  element: TimelineElement;
+  track: TimelineTrack;
+  zoomLevel: number;
+  onUpdateTrim: (
+    trackId: string,
+    elementId: string,
+    trimStart: number,
+    trimEnd: number
+  ) => void;
+}
+
+export function useTimelineElementResize({
+  element,
+  track,
+  zoomLevel,
+  onUpdateTrim,
+}: UseTimelineElementResizeProps) {
+  const [resizing, setResizing] = useState<ResizeState | null>(null);
+
+  const handleResizeStart = (
+    e: React.MouseEvent,
+    elementId: string,
+    side: "left" | "right"
+  ) => {
+    e.stopPropagation();
+    e.preventDefault();
+
+    setResizing({
+      elementId,
+      side,
+      startX: e.clientX,
+      initialTrimStart: element.trimStart,
+      initialTrimEnd: element.trimEnd,
+    });
+  };
+
+  const updateTrimFromMouseMove = (e: { clientX: number }) => {
+    if (!resizing) return;
+
+    const deltaX = e.clientX - resizing.startX;
+    const deltaTime = deltaX / (50 * zoomLevel);
+
+    if (resizing.side === "left") {
+      const newTrimStart = Math.max(
+        0,
+        Math.min(
+          element.duration - element.trimEnd - 0.1,
+          resizing.initialTrimStart + deltaTime
+        )
+      );
+      onUpdateTrim(track.id, element.id, newTrimStart, element.trimEnd);
+    } else {
+      const newTrimEnd = Math.max(
+        0,
+        Math.min(
+          element.duration - element.trimStart - 0.1,
+          resizing.initialTrimEnd - deltaTime
+        )
+      );
+      onUpdateTrim(track.id, element.id, element.trimStart, newTrimEnd);
+    }
+  };
+
+  const handleResizeMove = (e: React.MouseEvent) => {
+    updateTrimFromMouseMove(e);
+  };
+
+  const handleResizeEnd = () => {
+    setResizing(null);
+  };
+
+  return {
+    resizing,
+    isResizing: resizing !== null,
+    handleResizeStart,
+    handleResizeMove,
+    handleResizeEnd,
+  };
+}