// UDP Sender service for sending frames to SPORE nodes

const dgram = require('dgram');

class UdpSender {
  constructor(port = 4210) {
    this.port = port;
    this.socket = null;
    this.isRunning = false;
  }

  start() {
    if (this.isRunning) {
      return;
    }

    this.socket = dgram.createSocket('udp4');
    this.isRunning = true;

    this.socket.on('error', (err) => {
      console.error('UDP Sender socket error:', err);
    });

    this.socket.bind(0, () => {
      // Bind to any available port
      this.socket.setBroadcast(true);
      console.log(`UDP Sender ready on port ${this.socket.address().port}`);
    });
  }

  stop() {
    if (!this.isRunning) {
      return;
    }

    this.isRunning = false;

    if (this.socket) {
      this.socket.close();
      this.socket = null;
    }

    console.log('UDP Sender stopped');
  }

  sendToNode(nodeIp, message) {
    if (!this.socket) {
      return false;
    }

    const buffer = Buffer.from(message, 'utf8');
    
    return new Promise((resolve, reject) => {
      this.socket.send(buffer, 0, buffer.length, this.port, nodeIp, (err) => {
        if (err) {
          console.error(`Error sending to node ${nodeIp}:`, err);
          reject(err);
          return;
        }
        resolve(true);
      });
    });
  }

  broadcastToAll(message) {
    if (!this.socket) {
      return false;
    }

    const buffer = Buffer.from(message, 'utf8');
    this.socket.setBroadcast(true);

    return new Promise((resolve, reject) => {
      this.socket.send(buffer, 0, buffer.length, this.port, '255.255.255.255', (err) => {
        if (err) {
          console.error('Error broadcasting message:', err);
          reject(err);
          return;
        }
        resolve(true);
      });
    });
  }
}

module.exports = UdpSender;