import type {RiffStructure, StrhBox} from './riff-box';
import {getStrhBox, getStrlBoxes} from './traversal';

export const getStrhForIndex = (
	structure: RiffStructure,
	trackId: number,
): StrhBox => {
	const boxes = getStrlBoxes(structure);
	const box = boxes[trackId];
	if (!box) {
		throw new Error('Expected box');
	}

	const strh = getStrhBox(box.children);
	if (!strh) {
		throw new Error('strh');
	}

	return strh;
};