import type { AppConfig, Feature, FeatureFactory } from "@stc/contracts";
import { composeServer, loadConfig, type ComposeOptions } from "@stc/core";
import indexHtml from "../../web/index.html";
import { packageMigrations, productFeatures } from "./features";

export interface StartOptions extends ComposeOptions {}

/**
 * Composes the features (core `composeServer`) and serves them with the SPA. Bun routes win over `fetch`;
 * "/api/*" falls through to the composed app, so unknown API paths are 404 rather than the SPA.
 */
export async function startServer(config: AppConfig, features: (Feature | FeatureFactory)[], opts: StartOptions = {}) {
  const composed = await composeServer(config, features, opts);
  const { app } = composed;
  let server: Bun.Server<undefined>;
  try {
    server = Bun.serve({
      port: config.port,
      routes: { ...app.routes, "/api/*": (req) => app.fetch(req), "/*": indexHtml },
      fetch: (req) => app.fetch(req),
      // Production (NODE_ENV=production, as in the Docker image) bundles the SPA once, minified, without HMR.
      development: process.env.NODE_ENV !== "production",
    });
  } catch (e) {
    await composed.stop();
    throw e;
  }
  return {
    server,
    ctx: composed.ctx,
    features: composed.features,
    async stop() {
      await server.stop(true);
      await composed.stop();
    },
  };
}

if (import.meta.main) {
  const config = loadConfig();
  const { server } = await startServer(config, productFeatures(), { migrations: packageMigrations });
  console.log(`STCourses listening on ${server.url}`);
}