server.js

import { handler } from './build/handler.js';
import axios from 'axios';

import express from 'express';
import compression from 'compression';
import sharp from 'sharp';

const app = express();

app.get('/healthcheck', (_req, res) => {
  res.send('ok');
});

app.use(compression());

app.use((req, res, next) => {
  if (req.path.startsWith('/_app/immutable/') || req.path === '/background.webp') {
    res.header('cache-control', 'max-age=31536000');
  } else if (req.path.startsWith('/fonts/')) {
    res.header('cache-control', 'max-age=31536000');
  }

  next();
});

app.get('/api/thumbnail/:id', async (req, res) => {
  try {
    const id = req.params.id;

    /**
     * @type {import('http').IncomingMessage}
     */
    const data = (
      await axios.get(`https://i.ytimg.com/vi/${id}/original.jpg`, {
        responseType: 'stream'
      })
    ).data;

    res.header('content-type', 'image/webp');
    res.header('cache-control', 'max-age=1209600');

    data.pipe(sharp().resize(640, 360)).pipe(res);
  } catch {
    res.status(404).send('not found');
  }
});

app.use(handler);

app.listen(3000, () => {
  console.log('Listening on port 3000');
});