import type { Context } from "hono";

/** Parse a route param as a positive integer id. Returns null if invalid. */
export function parseId(raw: string | undefined): number | null {
	if (!raw) return null;
	const n = Number.parseInt(raw, 10);
	return Number.isFinite(n) && n > 0 ? n : null;
}

/**
 * Require a positive integer id param. Returns the id, or responds 400
 * and returns null. Callers check for null and return the response.
 */
export function requireId(c: Context, name: string): number | null {
	const id = parseId(c.req.param(name));
	if (id == null) {
		c.status(400);
		return null;
	}
	return id;
}

/** True if value is one of the allowed strings. */
export function isOneOf<T extends string>(value: unknown, allowed: readonly T[]): value is T {
	return typeof value === "string" && (allowed as readonly string[]).includes(value);
}