import type { LocalCredentials } from "./auth";

export enum ResourceId {
	Game = "gameid",
}

export function getUser(locals: { user: LocalCredentials }) {
	// SvelteKit screws up this type somehow, and it's important to explicitely set it
	// here.
	const user: LocalCredentials = locals.user;

	if (user.kind !== "Bearer") {
		throw new Error("bad user information");
	}

	return user;
}

export function getParam(params: Partial<Record<string, string>>, resource: ResourceId) {
	const id = params[resource];

	if (!id) {
		return null;
	}

	return id;
}

export async function getBody<T>(
	request: Request,
	dataGuard: (body: unknown) => body is T,
) {
	let body: unknown;

	try {
		body = await request.json();
	} catch (err) {
		return null;
	}

	if (!dataGuard(body)) {
		throw new Error("data guard failed");
	}

	return body;
}