import { html, type TemplateResult } from 'lit';

import './pages/home-page.js';
import './pages/about-page.js';
import './pages/not-found-page.js';

/**
 * Shared route table.
 *
 * `@lit-labs/router` is deliberately not used here: it reads `window` and
 * installs global listeners on connect, so it cannot run during server
 * rendering. This table is plain data instead, which means the server and the
 * browser resolve a URL through exactly the same code — the only way to be
 * confident the two renders agree.
 */
export interface AppRoute {
  /** Exact pathname to match. */
  readonly path: string;
  readonly label: string;
  readonly render: () => TemplateResult;
}

export const routes: readonly AppRoute[] = [
  { path: '/', label: 'Home', render: () => html`<home-page></home-page>` },
  { path: '/about', label: 'About', render: () => html`<about-page></about-page>` },
];

/**
 * Resolves a pathname to markup, falling back to the 404 page.
 *
 * Matching is exact string comparison, which covers a static set of routes.
 * For parameterised routes swap this for `URLPattern` — it is available in
 * Node and in current browsers, so it stays isomorphic.
 */
export function renderRoute(pathname: string): TemplateResult {
  const route = routes.find((candidate) => candidate.path === pathname);
  return route ? route.render() : html`<not-found-page></not-found-page>`;
}

/** Whether a pathname corresponds to a real route; used for 404 status codes. */
export function routeExists(pathname: string): boolean {
  return routes.some((candidate) => candidate.path === pathname);
}