1 files changed, 289 insertions, 0 deletions
diff --git a/apps/web/src/hooks/timeline/use-bookmark-drag.ts b/apps/web/src/hooks/timeline/use-bookmark-drag.ts
new file mode 100644
index 00000000..faf28e40
--- /dev/null
+++ b/apps/web/src/hooks/timeline/use-bookmark-drag.ts
@@ -0,0 +1,289 @@
+import {
+	useState,
+	useCallback,
+	useEffect,
+	useRef,
+	type RefObject,
+} from "react";
+import { useEditor } from "@/hooks/use-editor";
+import { useShiftKey } from "@/hooks/use-shift-key";
+import { DRAG_THRESHOLD_PX } from "@/constants/timeline-constants";
+import { snapTimeToFrame } from "@/lib/time";
+import { getMouseTimeFromClientX } from "@/lib/timeline/drag-utils";
+import { useTimelineSnapping } from "@/hooks/timeline/use-timeline-snapping";
+import type { Bookmark } from "@/types/timeline";
+import type { SnapPoint } from "@/hooks/timeline/use-timeline-snapping";
+
+export interface BookmarkDragState {
+	isDragging: boolean;
+	bookmarkTime: number | null;
+	currentTime: number;
+}
+
+interface PendingBookmarkDrag {
+	bookmarkTime: number;
+	startMouseX: number;
+	startMouseY: number;
+}
+
+interface UseBookmarkDragProps {
+	zoomLevel: number;
+	scrollRef: RefObject<HTMLElement | null>;
+	snappingEnabled: boolean;
+	onSnapPointChange?: (snapPoint: SnapPoint | null) => void;
+}
+
+export function useBookmarkDrag({
+	zoomLevel,
+	scrollRef,
+	snappingEnabled,
+	onSnapPointChange,
+}: UseBookmarkDragProps) {
+	const editor = useEditor();
+	const isShiftHeldRef = useShiftKey();
+	const tracks = editor.timeline.getTracks();
+	const activeScene = editor.scenes.getActiveScene();
+	const bookmarks = activeScene?.bookmarks ?? [];
+	const playheadTime = editor.playback.getCurrentTime();
+	const duration = editor.timeline.getTotalDuration();
+
+	const { findSnapPoints, snapToNearestPoint } = useTimelineSnapping();
+
+	const [dragState, setDragState] = useState<BookmarkDragState>({
+		isDragging: false,
+		bookmarkTime: null,
+		currentTime: 0,
+	});
+	const [isPendingDrag, setIsPendingDrag] = useState(false);
+	const pendingDragRef = useRef<PendingBookmarkDrag | null>(null);
+	const lastMouseXRef = useRef(0);
+
+	const startDrag = useCallback(
+		({
+			bookmarkTime,
+			initialCurrentTime,
+		}: {
+			bookmarkTime: number;
+			initialCurrentTime: number;
+		}) => {
+			setDragState({
+				isDragging: true,
+				bookmarkTime,
+				currentTime: initialCurrentTime,
+			});
+		},
+		[],
+	);
+
+	const endDrag = useCallback(() => {
+		setDragState({
+			isDragging: false,
+			bookmarkTime: null,
+			currentTime: 0,
+		});
+	}, []);
+
+	const getSnapResult = useCallback(
+		({
+			rawTime,
+			excludeBookmarkTime,
+		}: {
+			rawTime: number;
+			excludeBookmarkTime: number;
+		}): { snappedTime: number; snapPoint: SnapPoint | null } => {
+			const shouldSnap = snappingEnabled && !isShiftHeldRef.current;
+			if (!shouldSnap) {
+				return { snappedTime: rawTime, snapPoint: null };
+			}
+
+			const snapPoints = findSnapPoints({
+				tracks,
+				playheadTime,
+				bookmarks,
+				excludeBookmarkTime,
+			});
+			const result = snapToNearestPoint({
+				targetTime: rawTime,
+				snapPoints,
+				zoomLevel,
+			});
+			return {
+				snappedTime: result.snappedTime,
+				snapPoint: result.snapPoint,
+			};
+		},
+		[
+			snappingEnabled,
+			findSnapPoints,
+			snapToNearestPoint,
+			tracks,
+			playheadTime,
+			bookmarks,
+			zoomLevel,
+			isShiftHeldRef,
+		],
+	);
+
+	useEffect(() => {
+		if (!dragState.isDragging && !isPendingDrag) return;
+
+		const handleMouseMove = (event: MouseEvent) => {
+			lastMouseXRef.current = event.clientX;
+
+			const scrollContainer = scrollRef.current;
+			if (!scrollContainer) return;
+
+			if (isPendingDrag && pendingDragRef.current) {
+				const { startMouseX, startMouseY, bookmarkTime } =
+					pendingDragRef.current;
+				const deltaX = Math.abs(event.clientX - startMouseX);
+				const deltaY = Math.abs(event.clientY - startMouseY);
+
+				if (deltaX <= DRAG_THRESHOLD_PX && deltaY <= DRAG_THRESHOLD_PX) {
+					return;
+				}
+
+				const activeProject = editor.project.getActive();
+				if (!activeProject) return;
+
+				const scrollLeft = scrollContainer.scrollLeft;
+				const mouseTime = getMouseTimeFromClientX({
+					clientX: event.clientX,
+					containerRect: scrollContainer.getBoundingClientRect(),
+					zoomLevel,
+					scrollLeft,
+				});
+				const frameSnappedTime = snapTimeToFrame({
+					time: Math.max(0, Math.min(mouseTime, duration)),
+					fps: activeProject.settings.fps,
+				});
+				const { snappedTime: initialTime } = getSnapResult({
+					rawTime: frameSnappedTime,
+					excludeBookmarkTime: bookmarkTime,
+				});
+
+				startDrag({
+					bookmarkTime,
+					initialCurrentTime: initialTime,
+				});
+				pendingDragRef.current = null;
+				setIsPendingDrag(false);
+				return;
+			}
+
+			if (!dragState.isDragging || dragState.bookmarkTime === null) return;
+
+			const activeProject = editor.project.getActive();
+			if (!activeProject) return;
+
+			const scrollLeft = scrollContainer.scrollLeft;
+			const mouseTime = getMouseTimeFromClientX({
+				clientX: event.clientX,
+				containerRect: scrollContainer.getBoundingClientRect(),
+				zoomLevel,
+				scrollLeft,
+			});
+			const clampedTime = Math.max(0, Math.min(mouseTime, duration));
+			const frameSnappedTime = snapTimeToFrame({
+				time: clampedTime,
+				fps: activeProject.settings.fps,
+			});
+			const snapResult = getSnapResult({
+				rawTime: frameSnappedTime,
+				excludeBookmarkTime: dragState.bookmarkTime,
+			});
+
+			setDragState((previousDragState) => ({
+				...previousDragState,
+				currentTime: snapResult.snappedTime,
+			}));
+			onSnapPointChange?.(snapResult.snapPoint);
+		};
+
+		document.addEventListener("mousemove", handleMouseMove);
+		return () => document.removeEventListener("mousemove", handleMouseMove);
+	}, [
+		dragState.isDragging,
+		dragState.bookmarkTime,
+		zoomLevel,
+		duration,
+		editor.project,
+		scrollRef,
+		isPendingDrag,
+		startDrag,
+		getSnapResult,
+		onSnapPointChange,
+	]);
+
+	useEffect(() => {
+		if (!dragState.isDragging) return;
+
+		const handleMouseUp = () => {
+			if (dragState.bookmarkTime === null) {
+				endDrag();
+				onSnapPointChange?.(null);
+				return;
+			}
+
+			const clampedTime = Math.max(
+				0,
+				Math.min(dragState.currentTime, duration),
+			);
+
+			editor.scenes.moveBookmark({
+				fromTime: dragState.bookmarkTime,
+				toTime: clampedTime,
+			});
+
+			endDrag();
+			onSnapPointChange?.(null);
+		};
+
+		document.addEventListener("mouseup", handleMouseUp);
+		return () => document.removeEventListener("mouseup", handleMouseUp);
+	}, [
+		dragState.isDragging,
+		dragState.bookmarkTime,
+		dragState.currentTime,
+		duration,
+		endDrag,
+		onSnapPointChange,
+		editor.scenes,
+	]);
+
+	useEffect(() => {
+		if (!isPendingDrag) return;
+
+		const handleMouseUp = () => {
+			pendingDragRef.current = null;
+			setIsPendingDrag(false);
+			onSnapPointChange?.(null);
+		};
+
+		document.addEventListener("mouseup", handleMouseUp);
+		return () => document.removeEventListener("mouseup", handleMouseUp);
+	}, [isPendingDrag, onSnapPointChange]);
+
+	const handleBookmarkMouseDown = useCallback(
+		({ event, bookmark }: { event: React.MouseEvent; bookmark: Bookmark }) => {
+			if (event.button !== 0) return;
+
+			event.preventDefault();
+			event.stopPropagation();
+
+			pendingDragRef.current = {
+				bookmarkTime: bookmark.time,
+				startMouseX: event.clientX,
+				startMouseY: event.clientY,
+			};
+			setIsPendingDrag(true);
+		},
+		[],
+	);
+
+	return {
+		dragState,
+		handleBookmarkMouseDown,
+		lastMouseXRef,
+	};
+}