#!/usr/bin/env node
// Serve the localized production build so the language switcher actually works locally.
// `ng build --localize` emits dist/.../browser/{nl,en}/ (each with base href /nl/ or /en/).
// Plain `ng serve` (npm start) serves only nl at /, so switching 404s there — this static
// server serves both locale subdirs with per-locale SPA fallback (a miss under /<locale>/…
// serves that locale's index.html), so deep-link switches resolve. Demo only, not prod infra.
import { createServer, request as httpRequest } from 'node:http';
import { readFile } from 'node:fs/promises';
import { join, extname, normalize } from 'node:path';

const ROOT = 'dist/atomic-design-poc/browser';
const PORT = Number(process.env.PORT ?? 4300);
// Reverse-proxy /api → backend so the served app is the whole demo, not just static pages.
// Docker sets API_PROXY_TARGET=http://api:5000; locally it defaults to the dev backend.
const API_TARGET = new URL(process.env.API_PROXY_TARGET ?? 'http://localhost:5000');
const MIME = {
  '.html': 'text/html',
  '.js': 'text/javascript',
  '.mjs': 'text/javascript',
  '.css': 'text/css',
  '.json': 'application/json',
  '.svg': 'image/svg+xml',
  '.ico': 'image/x-icon',
  '.woff2': 'font/woff2',
  '.png': 'image/png',
};

const send = (res, status, body, type) => {
  res.writeHead(status, { 'content-type': type });
  res.end(body);
};

createServer(async (req, res) => {
  const rawUrl = req.url ?? '/';
  // Proxy API calls to the backend (keep the raw url incl. query).
  if (rawUrl.startsWith('/api')) {
    const proxied = httpRequest(
      {
        hostname: API_TARGET.hostname,
        port: API_TARGET.port,
        path: rawUrl,
        method: req.method,
        headers: req.headers,
      },
      (pr) => {
        res.writeHead(pr.statusCode ?? 502, pr.headers);
        pr.pipe(res);
      },
    );
    proxied.on('error', () => send(res, 502, 'Bad gateway (API)', 'text/plain'));
    req.pipe(proxied);
    return;
  }
  const url = decodeURIComponent(rawUrl.split('?')[0]);
  const rel = normalize(url).replace(/^(\.\.[/\\])+/, ''); // no path traversal
  // nl (source) is served at the ROOT (subPath ''); en lives under /en/.
  const isEn = url === '/en' || url.startsWith('/en/');
  const indexPath = isEn ? join(ROOT, 'en', 'index.html') : join(ROOT, 'index.html');
  try {
    // A real asset (nl at root, en under /en/) — otherwise fall through to the SPA index.
    if (url === '/' || url === '/en' || url === '/en/') throw new Error('serve index');
    const file = await readFile(join(ROOT, rel));
    send(res, 200, file, MIME[extname(rel)] ?? 'application/octet-stream');
  } catch {
    // SPA fallback to the requested locale's index.html.
    try {
      send(res, 200, await readFile(indexPath), 'text/html');
    } catch {
      send(res, 404, 'Not found', 'text/plain');
    }
  }
}).listen(PORT, () => {
  console.log(`Serving ${ROOT} at http://localhost:${PORT}/  (nl at /, en at /en/)`);
});