/**
 * The running worker answers on 127.0.0.1:<control port> so the CLI (in an
 * SSH session) can ask for its status, stop it, or take snapshots. The token
 * changes every run and is kept in runtime.json in the user's own profile.
 */
import { readJson } from './config';

export interface Runtime {
	pid: number;
	watchdogPid: number | null;
	port: number;
	token: string;
	startedAt: string;
	version: string;
}

export async function callWorker<T>(
	runtimePath: string,
	path: string,
	init: { method?: string; timeoutMs?: number } = {}
): Promise<T | null> {
	const runtime = await readJson<Runtime>(runtimePath);
	if (!runtime) return null;
	try {
		const response = await fetch(`http://127.0.0.1:${runtime.port}${path}`, {
			method: init.method ?? 'GET',
			headers: { 'x-vash-token': runtime.token },
			signal: AbortSignal.timeout(init.timeoutMs ?? 4000)
		});
		if (!response.ok) return null;
		return (await response.json()) as T;
	} catch {
		return null;
	}
}

export function authorized(request: Request, token: string) {
	const given = request.headers.get('x-vash-token') ?? '';
	if (given.length !== token.length) return false;
	let diff = 0;
	for (let index = 0; index < token.length; index++)
		diff |= given.charCodeAt(index) ^ token.charCodeAt(index);
	return diff === 0;
}