1 files changed, 61 insertions, 0 deletions
diff --git a/apps/web/src/lib/timeline/bookmarks.ts b/apps/web/src/lib/timeline/bookmarks.ts
new file mode 100644
index 00000000..0b06c2f6
--- /dev/null
+++ b/apps/web/src/lib/timeline/bookmarks.ts
@@ -0,0 +1,61 @@
+import { roundToFrame } from "@/lib/time";
+
+export function findBookmarkIndex({
+	bookmarks,
+	frameTime,
+}: {
+	bookmarks: number[];
+	frameTime: number;
+}): number {
+	return bookmarks.findIndex(
+		(bookmark) => Math.abs(bookmark - frameTime) < 0.001,
+	);
+}
+
+export function isBookmarkAtTime({
+	bookmarks,
+	frameTime,
+}: {
+	bookmarks: number[];
+	frameTime: number;
+}): boolean {
+	return bookmarks.some((bookmark) => Math.abs(bookmark - frameTime) < 0.001);
+}
+
+export function toggleBookmarkInArray({
+	bookmarks,
+	frameTime,
+}: {
+	bookmarks: number[];
+	frameTime: number;
+}): number[] {
+	const bookmarkIndex = findBookmarkIndex({ bookmarks, frameTime });
+
+	if (bookmarkIndex !== -1) {
+		return bookmarks.filter((_, i) => i !== bookmarkIndex);
+	}
+
+	return [...bookmarks, frameTime].sort((a, b) => a - b);
+}
+
+export function removeBookmarkFromArray({
+	bookmarks,
+	frameTime,
+}: {
+	bookmarks: number[];
+	frameTime: number;
+}): number[] {
+	return bookmarks.filter(
+		(bookmark) => Math.abs(bookmark - frameTime) >= 0.001,
+	);
+}
+
+export function getFrameTime({
+	time,
+	fps,
+}: {
+	time: number;
+	fps: number;
+}): number {
+	return roundToFrame({ time, fps });
+}