import type { NextConfig } from "next";

/**
 * Static export, served by the FastAPI app.
 *
 * The alternative — running `next start` alongside uvicorn — means a Node
 * runtime in the image, a second process to supervise and health-check, and a
 * second thing that can be down while the other is up. muse has no use for
 * SSR: every view is behind auth and driven by live JSON, so there is nothing
 * to render on a server that the client would not immediately re-render.
 *
 * So `next build` emits plain files into out/, FastAPI serves them, and the
 * deployment stays what it was: one container, one process, one healthcheck.
 * The auth middleware still guards the whole surface, because it is the same
 * server handing out the HTML.
 */
const isProd = process.env.NODE_ENV === "production";
const API = process.env.MUSE_API_ORIGIN ?? "http://127.0.0.1:5041";

const nextConfig: NextConfig = {
  ...(isProd ? { output: "export" as const } : {}),

  // No Next image optimiser without a server. Artwork already arrives from
  // Deezer's CDN at the size it is displayed, so there is nothing to optimise.
  images: { unoptimized: true },

  // Dev only: `next dev` on :3000 proxies the API to the FastAPI process so
  // the browser sees a single origin and cookies behave as they do in prod.
  ...(isProd
    ? {}
    : {
        async rewrites() {
          return [
            { source: "/api/:path*", destination: `${API}/api/:path*` },
            { source: "/auth/:path*", destination: `${API}/auth/:path*` },
            { source: "/healthz", destination: `${API}/healthz` },
          ];
        },
      }),
};

export default nextConfig;