// Tiny zero-dependency static file server for the repo root. Tooling, not course code.
// Usage: node scripts/serve.mjs [port]   (default 8000)
import { createServer } from 'node:http'
import { readFile, stat } from 'node:fs/promises'
import { extname, join, normalize, resolve, sep } from 'node:path'
import { fileURLToPath } from 'node:url'

const root = resolve(fileURLToPath(new URL('..', import.meta.url)))
const port = Number(process.argv[2] ?? 8000)
const types = {
  '.html': 'text/html; charset=utf-8', '.js': 'text/javascript; charset=utf-8',
  '.mjs': 'text/javascript; charset=utf-8', '.json': 'application/json', '.css': 'text/css',
  '.md': 'text/markdown; charset=utf-8', '.svg': 'image/svg+xml', '.png': 'image/png',
  '.wasm': 'application/wasm', '.map': 'application/json',
}

createServer(async (req, res) => {
  try {
    const path = normalize(decodeURIComponent(new URL(req.url, 'http://x').pathname))
    let file = join(root, path)
    if (file !== root && !file.startsWith(root + sep)) throw Object.assign(new Error(), { code: 'EACCES' })
    if ((await stat(file)).isDirectory()) file = join(file, 'index.html')
    const body = await readFile(file)
    res.writeHead(200, { 'content-type': types[extname(file)] ?? 'application/octet-stream' })
    res.end(body)
  } catch (e) {
    res.writeHead(e.code === 'EACCES' ? 403 : 404, { 'content-type': 'text/plain' })
    res.end(e.code === 'EACCES' ? 'forbidden' : 'not found')
  }
}).listen(port, () => console.log(`Serving ${root} on http://localhost:${port}`))