/**
 * FSDB Organizer: By Email
 *
 * Organizes by splitting an email into its components, eg:
 *
 * com/example.com/soandso@example.com
 *
 * A symlinking index based on this organizer might look like:
 *           fsdb root          index tld    domain         email
 *   [                        ][ V  ][ V ][    V    ][        V         ]
 *   /path/to/db/root/.indexes/email/com/example.com/soandso@example.com
 *
 * @module
 */

import sanitize from '../utils/sanitize.ts';

const EMAIL_REGEX = /^(?<username>.+)@(?<domain>(?<hostname>.+)\.(?<tld>.+))$/;
export default function by_email(email: string): string[] {
	const { groups: { username, domain, hostname, tld } } = {
		groups: {
			username: undefined,
			domain: undefined,
			hostname: undefined,
			tld: undefined
		},
		...(email.match(EMAIL_REGEX) ?? {})
	};

	if (typeof username === 'undefined' || typeof domain === 'undefined' || typeof hostname === 'undefined' || typeof tld === 'undefined') {
		return [];
	}

	return [sanitize(tld), sanitize(domain), sanitize(email), `${sanitize(email)}.json`];
}