const { WebSocketServer } = require('ws')
const http = require('http')
const url = require('url')

// WebSocket-Server starten
const wss = new WebSocketServer({ noServer: true })

// HTTP-Server zum Empfangen von POST-Anfragen zum Versenden von Nachrichten
const server = http.createServer((req, res) => {
  // CORS Header setzen
  res.setHeader('Access-Control-Allow-Origin', '*')
  res.setHeader('Access-Control-Allow-Methods', 'POST, OPTIONS')
  res.setHeader('Access-Control-Allow-Headers', 'Content-Type')

  // Preflight-Request
  if (req.method === 'OPTIONS') {
    res.writeHead(204)
    res.end()
    return
  }

  // Nachricht per POST empfangen
  if (req.method === 'POST' && req.url === '/send') {
    let body = ''
    req.on('data', chunk => { body += chunk })
    req.on('end', () => {
      const message = JSON.parse(body)
      const isBroadcast = !Array.isArray(message.targetUserIds)
      const type = message.type || 'notification'

      let sentCount = 0

      wss.clients.forEach((client) => {
        const shouldSend =
          client.readyState === 1 &&
          (isBroadcast || (
            Array.isArray(message.targetUserIds) &&
            client.steamId &&
            message.targetUserIds.includes(client.steamId)
          ))

        if (shouldSend) {
          client.send(JSON.stringify({
            type,
            ...message
          }))
          sentCount++
        }
      })

      console.log(`[WS] Nachricht vom Typ "${type}" an ${sentCount} Client(s) gesendet.`)
      res.writeHead(200)
      res.end('Nachricht gesendet.')
    })
  } else {
    res.writeHead(404)
    res.end()
  }
})

wss.on('connection', (ws, req) => {
  const parsedUrl = url.parse(req.url, true)
  const steamId = parsedUrl.query.steamId

  if (!steamId) {
    console.warn('[WS] Verbindung ohne steamId - wird geschlossen')
    ws.close()
    return
  }

  ws.steamId = steamId
  console.log(`[WS] Verbunden: steamId=${steamId}`)

  ws.on('close', () => {
    console.log(`[WS] Verbindung geschlossen für ${steamId}`)
  })
})

// WebSocket Upgrade akzeptieren
server.on('upgrade', (req, socket, head) => {
  wss.handleUpgrade(req, socket, head, (ws) => {
    wss.emit('connection', ws, req)
  })
})

// Server starten
server.listen(3001, () => {
  console.log('✅ WebSocket Server läuft auf Port 3001')
})