import { MEMORY_RULE } from "./constants";

export type Resolver = (v: any) => void;

/**
 * Settle-once wait: register a resolver in `map` under `key`, resolve with the delivered
 * value or null on timeout. Whichever side fires FIRST performs cleanup inside its own
 * callback (single-threaded event loop ⇒ no window where a late answer finds a resolver
 * whose race already ended and gets silently dropped).
 */
export function createWait(map: Map<string, Resolver>, key: string, timeoutMs: number): Promise<any> {
	return new Promise((resolve) => {
		const timer = setTimeout(() => {
			map.delete(key); // after this, a late answer takes the injection path
			resolve(null);
		}, timeoutMs);
		map.set(key, (v: any) => {
			clearTimeout(timer);
			map.delete(key);
			resolve(v);
		});
	});
}

/** Provenance envelope. All peer-supplied text must be sanitized by the caller. */
export function envelope(opts: {
	kind: string;
	from: string;
	to: string;
	thread: string;
	body: string;
	extra?: string;
}): string {
	return (
		`[[AGENT-COMM]]\n` +
		`kind: ${opts.kind}\n` +
		`from: ${opts.from}\n` +
		`to: ${opts.to}\n` +
		`thread: ${opts.thread}\n` +
		`at: ${new Date().toISOString()}\n` +
		`---\n${opts.body}\n` +
		(opts.extra ? `---\n${opts.extra}\n` : "") +
		`${MEMORY_RULE}\n` +
		`[[/AGENT-COMM]]`
	);
}