import http from 'node:http'
import fs from 'node:fs'
import path from 'node:path'
import { fileURLToPath } from 'node:url'

const __dirname = path.dirname(fileURLToPath(import.meta.url))
const port = Number(process.env.PORT || 7676)
const distDir = path.resolve(process.env.DIST_DIR || path.join(__dirname, '..', 'dist'))
const rawBase = String(process.env.VITE_BASE_PATH ?? '/admin/').trim() || '/admin/'
const publicBase = rawBase === '/' ? '' : rawBase.replace(/\/+$/, '')

const MIME = {
  '.html': 'text/html; charset=utf-8',
  '.js': 'text/javascript; charset=utf-8',
  '.mjs': 'text/javascript; charset=utf-8',
  '.css': 'text/css; charset=utf-8',
  '.json': 'application/json; charset=utf-8',
  '.map': 'application/json; charset=utf-8',
  '.svg': 'image/svg+xml',
  '.png': 'image/png',
  '.jpg': 'image/jpeg',
  '.jpeg': 'image/jpeg',
  '.gif': 'image/gif',
  '.webp': 'image/webp',
  '.ico': 'image/x-icon',
  '.woff': 'font/woff',
  '.woff2': 'font/woff2',
  '.ttf': 'font/ttf',
  '.txt': 'text/plain; charset=utf-8',
  '.webmanifest': 'application/manifest+json',
}

function sendFile(res, filePath) {
  const type = MIME[path.extname(filePath).toLowerCase()] || 'application/octet-stream'
  res.writeHead(200, { 'Content-Type': type, 'Cache-Control': 'public, max-age=0' })
  fs.createReadStream(filePath).pipe(res)
}

function sendIndex(res) {
  sendFile(res, path.join(distDir, 'index.html'))
}

function resolveSafe(urlPath) {
  const decoded = decodeURIComponent(urlPath.split('?')[0] || '/')
  const relative = publicBase && decoded.startsWith(`${publicBase}/`)
    ? decoded.slice(publicBase.length)
    : publicBase && decoded === publicBase
      ? '/'
      : decoded
  const target = path.resolve(distDir, `.${relative}`)
  if (!target.startsWith(distDir)) return null
  return target
}

const server = http.createServer((req, res) => {
  const url = req.url || '/'
  const pathname = decodeURIComponent(url.split('?')[0] || '/')

  if (pathname === '/health' || (publicBase && pathname === `${publicBase}/health`)) {
    res.writeHead(200, { 'Content-Type': 'text/plain' })
    return res.end('ok')
  }

  if (publicBase && pathname === publicBase) {
    res.writeHead(302, { Location: `${publicBase}/` })
    return res.end()
  }

  if (publicBase && pathname === '/') {
    res.writeHead(302, { Location: `${publicBase}/` })
    return res.end()
  }

  const target = resolveSafe(url)
  if (target && fs.existsSync(target) && fs.statSync(target).isFile()) {
    return sendFile(res, target)
  }

  return sendIndex(res)
})

server.listen(port, '0.0.0.0', () => {
  console.log(`fabric-trade admin listening on ${port} → ${publicBase || ''}/`)
})