1 files changed, 304 insertions, 0 deletions
diff --git a/apps/web/src/lib/timeline/element-utils.ts b/apps/web/src/lib/timeline/element-utils.ts
new file mode 100644
index 00000000..a167e548
--- /dev/null
+++ b/apps/web/src/lib/timeline/element-utils.ts
@@ -0,0 +1,304 @@
+import { DEFAULT_TEXT_ELEMENT } from "@/constants/text-constants";
+import { TIMELINE_CONSTANTS } from "@/constants/timeline-constants";
+import type {
+	CreateTimelineElement,
+	CreateVideoElement,
+	CreateImageElement,
+	CreateStickerElement,
+	CreateUploadAudioElement,
+	CreateLibraryAudioElement,
+	TextElement,
+	TimelineElement,
+	TimelineTrack,
+	AudioElement,
+	VideoElement,
+	ImageElement,
+	StickerElement,
+	UploadAudioElement,
+} from "@/types/timeline";
+
+export function canElementHaveAudio(
+	element: TimelineElement,
+): element is AudioElement | VideoElement {
+	return element.type === "audio" || element.type === "video";
+}
+
+export function canElementBeHidden(
+	element: TimelineElement,
+): element is VideoElement | ImageElement | TextElement | StickerElement {
+	return element.type !== "audio";
+}
+
+export function hasMediaId(
+	element: TimelineElement,
+): element is UploadAudioElement | VideoElement | ImageElement {
+	return "mediaId" in element;
+}
+
+export function requiresMediaId({
+	element,
+}: {
+	element: CreateTimelineElement;
+}): boolean {
+	return (
+		element.type === "video" ||
+		element.type === "image" ||
+		(element.type === "audio" && element.sourceType === "upload")
+	);
+}
+
+export function checkElementOverlaps({
+	elements,
+}: {
+	elements: TimelineElement[];
+}): boolean {
+	const sortedElements = [...elements].sort(
+		(a, b) => a.startTime - b.startTime,
+	);
+
+	for (let i = 0; i < sortedElements.length - 1; i++) {
+		const current = sortedElements[i];
+		const next = sortedElements[i + 1];
+
+		const currentEnd = current.startTime + current.duration;
+
+		if (currentEnd > next.startTime) return true;
+	}
+
+	return false;
+}
+
+export function resolveElementOverlaps({
+	elements,
+}: {
+	elements: TimelineElement[];
+}): TimelineElement[] {
+	const sortedElements = [...elements].sort(
+		(a, b) => a.startTime - b.startTime,
+	);
+	const resolvedElements: TimelineElement[] = [];
+
+	for (let i = 0; i < sortedElements.length; i++) {
+		const current = { ...sortedElements[i] };
+
+		if (resolvedElements.length > 0) {
+			const previous = resolvedElements[resolvedElements.length - 1];
+			const previousEnd = previous.startTime + previous.duration;
+
+			if (current.startTime < previousEnd) {
+				current.startTime = previousEnd;
+			}
+		}
+
+		resolvedElements.push(current);
+	}
+
+	return resolvedElements;
+}
+
+export function wouldElementOverlap({
+	elements,
+	startTime,
+	endTime,
+	excludeElementId,
+}: {
+	elements: TimelineElement[];
+	startTime: number;
+	endTime: number;
+	excludeElementId?: string;
+}): boolean {
+	return elements.some((el) => {
+		if (excludeElementId && el.id === excludeElementId) return false;
+		const elEnd = el.startTime + el.duration;
+		return startTime < elEnd && endTime > el.startTime;
+	});
+}
+
+export function buildTextElement({
+	raw,
+	startTime,
+}: {
+	raw: Partial<Omit<TextElement, "type" | "id">>;
+	startTime: number;
+}): CreateTimelineElement {
+	const t = raw as Partial<TextElement>;
+
+	return {
+		type: "text",
+		name: t.name ?? DEFAULT_TEXT_ELEMENT.name,
+		content: t.content ?? DEFAULT_TEXT_ELEMENT.content,
+		duration: t.duration ?? TIMELINE_CONSTANTS.DEFAULT_ELEMENT_DURATION,
+		startTime,
+		trimStart: 0,
+		trimEnd: 0,
+		fontSize:
+			typeof t.fontSize === "number"
+				? t.fontSize
+				: DEFAULT_TEXT_ELEMENT.fontSize,
+		fontFamily: t.fontFamily ?? DEFAULT_TEXT_ELEMENT.fontFamily,
+		color: t.color ?? DEFAULT_TEXT_ELEMENT.color,
+		backgroundColor: t.backgroundColor ?? DEFAULT_TEXT_ELEMENT.backgroundColor,
+		textAlign: t.textAlign ?? DEFAULT_TEXT_ELEMENT.textAlign,
+		fontWeight: t.fontWeight ?? DEFAULT_TEXT_ELEMENT.fontWeight,
+		fontStyle: t.fontStyle ?? DEFAULT_TEXT_ELEMENT.fontStyle,
+		textDecoration: t.textDecoration ?? DEFAULT_TEXT_ELEMENT.textDecoration,
+		transform: t.transform ?? DEFAULT_TEXT_ELEMENT.transform,
+		opacity: t.opacity ?? DEFAULT_TEXT_ELEMENT.opacity,
+	};
+}
+
+export function buildStickerElement({
+	iconName,
+	startTime,
+}: {
+	iconName: string;
+	startTime: number;
+}): CreateStickerElement {
+	return {
+		type: "sticker",
+		name: iconName.split(":")[1] || iconName,
+		iconName,
+		duration: TIMELINE_CONSTANTS.DEFAULT_ELEMENT_DURATION,
+		startTime,
+		trimStart: 0,
+		trimEnd: 0,
+		transform: { scale: 1, position: { x: 0, y: 0 }, rotate: 0 },
+		opacity: 1,
+	};
+}
+
+export function buildVideoElement({
+	mediaId,
+	name,
+	duration,
+	startTime,
+}: {
+	mediaId: string;
+	name: string;
+	duration: number;
+	startTime: number;
+}): CreateVideoElement {
+	return {
+		type: "video",
+		mediaId,
+		name,
+		duration,
+		startTime,
+		trimStart: 0,
+		trimEnd: 0,
+		muted: false,
+		hidden: false,
+		transform: { scale: 1, position: { x: 0, y: 0 }, rotate: 0 },
+		opacity: 1,
+	};
+}
+
+export function buildImageElement({
+	mediaId,
+	name,
+	duration,
+	startTime,
+}: {
+	mediaId: string;
+	name: string;
+	duration: number;
+	startTime: number;
+}): CreateImageElement {
+	return {
+		type: "image",
+		mediaId,
+		name,
+		duration,
+		startTime,
+		trimStart: 0,
+		trimEnd: 0,
+		hidden: false,
+		transform: { scale: 1, position: { x: 0, y: 0 }, rotate: 0 },
+		opacity: 1,
+	};
+}
+
+export function buildUploadAudioElement({
+	mediaId,
+	name,
+	duration,
+	startTime,
+	buffer,
+}: {
+	mediaId: string;
+	name: string;
+	duration: number;
+	startTime: number;
+	buffer?: AudioBuffer;
+}): CreateUploadAudioElement {
+	const element: CreateUploadAudioElement = {
+		type: "audio",
+		sourceType: "upload",
+		mediaId,
+		name,
+		duration,
+		startTime,
+		trimStart: 0,
+		trimEnd: 0,
+		volume: 1,
+		muted: false,
+	};
+	if (buffer) {
+		element.buffer = buffer;
+	}
+	return element;
+}
+
+export function buildLibraryAudioElement({
+	sourceUrl,
+	name,
+	duration,
+	startTime,
+	buffer,
+}: {
+	sourceUrl: string;
+	name: string;
+	duration: number;
+	startTime: number;
+	buffer?: AudioBuffer;
+}): CreateLibraryAudioElement {
+	const element: CreateLibraryAudioElement = {
+		type: "audio",
+		sourceType: "library",
+		sourceUrl,
+		name,
+		duration,
+		startTime,
+		trimStart: 0,
+		trimEnd: 0,
+		volume: 1,
+		muted: false,
+	};
+	if (buffer) {
+		element.buffer = buffer;
+	}
+	return element;
+}
+
+export function getElementsAtTime({
+	tracks,
+	time,
+}: {
+	tracks: TimelineTrack[];
+	time: number;
+}): { trackId: string; elementId: string }[] {
+	const result: { trackId: string; elementId: string }[] = [];
+
+	for (const track of tracks) {
+		for (const element of track.elements) {
+			const elementStart = element.startTime;
+			const elementEnd = element.startTime + element.duration;
+
+			if (time > elementStart && time < elementEnd) {
+				result.push({ trackId: track.id, elementId: element.id });
+			}
+		}
+	}
+
+	return result;
+}