import { browser } from '$app/environment';
import { base } from '$app/paths';
import { redirect } from '@sveltejs/kit';
import type { ClientSession } from '../hooks.server';
import { goto } from '$app/navigation';

/**
 * Returns `true` if scopes are all included in session, otherwise either attempts to re-login with the new scope added (unless `getScopeOnFail` is false) and returns false
 *
 * Check the return value of this, even if getScopeOnFail is true; navigating client-side may not stop thread immediately!
 */
export const checkScope = (
  session: ClientSession | null | undefined,
  /** The scopes we want */
  neededScopes: string[],
  /** Redirect to login page if the scopes aren't found */
  getScopeOnFail = false,
  /** The target URL if redirecting */
  next?: string
) => {
  const scopes = session?.tokens.scope?.split(' ') ?? [];
  if (!neededScopes.find((v) => !scopes.includes(v))) return true;
  else if (getScopeOnFail) {
    const targetUrl = `${base}/login?${
      next || browser
        ? `next=${next ?? encodeURIComponent(location.href)}&`
        : ''
    }scope=${encodeURIComponent(
      [...scopes, ...neededScopes]
        .filter((v, i, a) => a.indexOf(v) === i)
        .join(' ')
    )}`;
    if (browser) goto(targetUrl);
    else throw redirect(307, targetUrl);
  }
  return false;
};