const PORT = process.env.PORT || 3001
const BACKEND_URL = process.env.BACKEND_URL || 'http://localhost:3000'

Bun.serve({
  port: PORT,
  async fetch(req) {
    const url = new URL(req.url)

    // API proxy to backend
    if (url.pathname.startsWith('/api/')) {
      const backendUrl = `${BACKEND_URL}${url.pathname}${url.search}`
      const headers = new Headers(req.headers)

      // Forward cookies
      const cookie = req.headers.get('cookie')
      if (cookie) {
        headers.set('cookie', cookie)
      }

      const backendReq = new Request(backendUrl, {
        method: req.method,
        headers,
        body: req.method !== 'GET' && req.method !== 'HEAD' ? await req.text() : undefined,
      })

      const backendRes = await fetch(backendReq)

      // Forward Set-Cookie headers
      const setCookies = backendRes.headers.get('set-cookie')
      const responseHeaders = new Headers(backendRes.headers)

      if (setCookies) {
        responseHeaders.set('set-cookie', setCookies)
      }

      return new Response(backendRes.body, {
        status: backendRes.status,
        statusText: backendRes.statusText,
        headers: responseHeaders,
      })
    }

    // Serve static files from public directory
    const staticFile = Bun.file(`./public${url.pathname}`)
    if (await staticFile.exists()) {
      return new Response(staticFile)
    }

    // For all other routes (SPA routing), serve index.html
    const indexFile = Bun.file('./public/index.html')
    return new Response(indexFile, {
      headers: {
        'Content-Type': 'text/html',
      },
    })
  },
  development: {
    hmr: true,
  },
})

console.log(`Frontend server running on http://localhost:${PORT}`)
console.log(`Proxying API requests to ${BACKEND_URL}`)