import { renderToString } from "react-dom/server";
import { StaticRouter } from "react-router-dom";
import { AuthProvider } from "./providers/AuthProvider";
import { SsrDataProvider } from "./ssr/context";
import { matchSsrRoute, type ApiFetch } from "./ssr/routes";
import type { SsrData, SsrHead } from "./ssr/types";
import App from "./app";

type RenderResult =
  /** Not a server-rendered route - serve the client-only shell. */
  | { kind: "spa" }
  /** Server-rendered route whose content is missing - shell, with a 404. */
  | { kind: "not-found" }
  | { kind: "ssr"; html: string; data: SsrData; head: SsrHead };

async function render(url: string, api: ApiFetch): Promise<RenderResult> {
  const pathname = new URL(url, "http://ssr.invalid").pathname;
  const matched = matchSsrRoute(pathname);
  if (!matched) return { kind: "spa" };

  const loaded = await matched.route.load(api, matched.params);
  if (!loaded) return { kind: "not-found" };

  // The visitor's session is deliberately not resolved here: auth-dependent
  // chrome renders logged-out on the server and AuthProvider fills it in after
  // hydration, which keeps these pages cacheable and hydration-safe.
  const html = renderToString(
    <SsrDataProvider data={loaded.data}>
      <AuthProvider>
        <StaticRouter location={url}>
          <App />
        </StaticRouter>
      </AuthProvider>
    </SsrDataProvider>,
  );

  return { kind: "ssr", html, data: loaded.data, head: loaded.head };
}

export { render };
export { defaultHead } from "./ssr/routes";
export type { RenderResult };