import * as yaml from 'yaml';

export function process_frontmatter(raw_document: string, parse = true) {
	if (! raw_document.startsWith('---\n')) {
		return {
			frontmatter: null,
			document: raw_document,
		};
	}

	const end_index = raw_document.slice(3).indexOf('\n---\n') + 3;
	
	if (end_index === 2) {
		return {
			frontmatter: null,
			document: raw_document,
		};
	}

	const formatter_yaml = raw_document.slice(3, end_index);
	const document = raw_document.slice(end_index + 4);
	const frontmatter = parse ? yaml.parse(formatter_yaml) : formatter_yaml;

	return { frontmatter, document };
}