1 files changed, 147 insertions, 0 deletions
diff --git a/apps/web/src/timeline/track-element-update.ts b/apps/web/src/timeline/track-element-update.ts
new file mode 100644
index 00000000..7d86a4e8
--- /dev/null
+++ b/apps/web/src/timeline/track-element-update.ts
@@ -0,0 +1,147 @@
+import type { SceneTracks, TimelineElement, TimelineTrack } from "@/timeline";
+
+export function findTrackInSceneTracks({
+	tracks,
+	trackId,
+}: {
+	tracks: SceneTracks;
+	trackId: string;
+}): TimelineTrack | null {
+	if (tracks.main.id === trackId) {
+		return tracks.main;
+	}
+
+	return (
+		tracks.overlay.find((track) => track.id === trackId) ??
+		tracks.audio.find((track) => track.id === trackId) ??
+		null
+	);
+}
+
+export function updateTrackInSceneTracks({
+	tracks,
+	trackId,
+	update,
+}: {
+	tracks: SceneTracks;
+	trackId: string;
+	update: <TTrack extends TimelineTrack>(track: TTrack) => TTrack;
+}): SceneTracks {
+	if (tracks.main.id === trackId) {
+		return {
+			...tracks,
+			main: update(tracks.main),
+		};
+	}
+
+	const overlayTrackIndex = tracks.overlay.findIndex((track) => track.id === trackId);
+	if (overlayTrackIndex >= 0) {
+		return {
+			...tracks,
+			overlay: tracks.overlay.map((track, index) =>
+				index === overlayTrackIndex ? update(track) : track,
+			),
+		};
+	}
+
+	const audioTrackIndex = tracks.audio.findIndex((track) => track.id === trackId);
+	if (audioTrackIndex >= 0) {
+		return {
+			...tracks,
+			audio: tracks.audio.map((track, index) =>
+				index === audioTrackIndex ? update(track) : track,
+			),
+		};
+	}
+
+	return tracks;
+}
+
+function updateElementInTrack<TTrack extends TimelineTrack>({
+	track,
+	elementId,
+	update,
+	elementPredicate,
+}: {
+	track: TTrack;
+	elementId: string;
+	update: (element: TimelineElement) => TimelineElement;
+	elementPredicate?: (element: TimelineElement) => boolean;
+}): TTrack {
+	const nextElements = track.elements.map((element) => {
+		if (element.id !== elementId) {
+			return element;
+		}
+		if (elementPredicate && !elementPredicate(element)) {
+			return element;
+		}
+		return update(element);
+	});
+
+	return {
+		...track,
+		elements: nextElements,
+	} as TTrack;
+}
+
+export function updateElementInSceneTracks({
+	tracks,
+	trackId,
+	elementId,
+	update,
+	elementPredicate,
+}: {
+	tracks: SceneTracks;
+	trackId: string;
+	elementId: string;
+	update: (element: TimelineElement) => TimelineElement;
+	elementPredicate?: (element: TimelineElement) => boolean;
+}): SceneTracks {
+	if (tracks.main.id === trackId) {
+		return {
+			...tracks,
+			main: updateElementInTrack({
+				track: tracks.main,
+				elementId,
+				update,
+				elementPredicate,
+			}),
+		};
+	}
+
+	const overlayTrackIndex = tracks.overlay.findIndex((track) => track.id === trackId);
+	if (overlayTrackIndex >= 0) {
+		return {
+			...tracks,
+			overlay: tracks.overlay.map((track, index) =>
+				index === overlayTrackIndex
+					? updateElementInTrack({
+							track,
+							elementId,
+							update,
+							elementPredicate,
+						})
+					: track,
+			),
+		};
+	}
+
+	const audioTrackIndex = tracks.audio.findIndex((track) => track.id === trackId);
+	if (audioTrackIndex >= 0) {
+		return {
+			...tracks,
+			audio: tracks.audio.map((track, index) =>
+				index === audioTrackIndex
+					? updateElementInTrack({
+							track,
+							elementId,
+							update,
+							elementPredicate,
+						})
+					: track,
+			),
+		};
+	}
+
+	return tracks;
+}