// UdpListener.java
package home;

import java.io.IOException;
import java.net.*;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class UdpListener extends NetworkBase {
    private DatagramSocket socket;
    private ExecutorService receiverThread;
    private byte[] buffer = new byte[1024];

    public UdpListener(String host, int port) {
        this.host = host;
        this.port = port;
    }

    @Override
    public boolean start() throws Exception {
        try {
            InetAddress localAddress = InetAddress.getByName(host);
            socket = new DatagramSocket(port, localAddress);
            socket.setSoTimeout(1000); // 设置超时以便可以检查停止状态

            isRunning.set(true);
            startReceiver();
            notifyStatus("UDP监听已启动 - " + host + ":" + port, true);
            return true;

        } catch (BindException e) {
            notifyError("端口 " + port + " 被占用，请选择其他端口");
            return false;
        } catch (Exception e) {
            notifyError("启动UDP监听失败: " + e.getMessage());
            return false;
        }
    }

    @Override
    public void stop() {
        isRunning.set(false);
        if (socket != null && !socket.isClosed()) {
            socket.close();
        }
        if (receiverThread != null) {
            receiverThread.shutdownNow();
        }
        notifyStatus("UDP监听已停止", false);
    }

    @Override
    public boolean sendData(String data) throws Exception {
        // UDP发送数据需要目标地址，这里不实现发送功能
        return false;
    }

    /**
     * 向指定IP和端口发送数据 - 新增方法
     * @param data 要发送的数据字节数组
     * @param ip 目标IP地址
     * @param port 目标端口
     * @return 是否发送成功
     */
    public boolean sendDataTo(byte[] data, String ip, int port) {
        if (socket == null || socket.isClosed() || !isRunning.get()) {
            notifyError("UDP Socket未就绪，无法发送数据");
            return false;
        }

        try {
            InetAddress targetAddress = InetAddress.getByName(ip);
            DatagramPacket packet = new DatagramPacket(data, data.length, targetAddress, port);
            socket.send(packet);

            // 记录发送成功
            System.out.println("UDP数据已发送至 " + ip + ":" + port + "，数据长度: " + data.length);
            return true;

        } catch (UnknownHostException e) {
            notifyError("未知的主机地址: " + ip);
            return false;
        } catch (IOException e) {
            notifyError("发送UDP数据失败: " + e.getMessage());
            return false;
        } catch (Exception e) {
            notifyError("发送数据时发生错误: " + e.getMessage());
            return false;
        }
    }

    /**
     * 向指定IP和端口发送字符串数据 - 新增方法
     * @param data 要发送的字符串数据
     * @param ip 目标IP地址
     * @param port 目标端口
     * @return 是否发送成功
     */
    public boolean sendDataTo(String data, String ip, int port) {
        if (data == null) {
            return false;
        }
        return sendDataTo(data.getBytes(), ip, port);
    }

    @Override
    public boolean isConnected() {
        return isRunning.get() && socket != null && !socket.isClosed();
    }

    private void startReceiver() {
        receiverThread = Executors.newSingleThreadExecutor();
        receiverThread.execute(() -> {
            while (isRunning.get() && socket != null && !socket.isClosed()) {
                try {
                    DatagramPacket packet = new DatagramPacket(buffer, buffer.length);
                    socket.receive(packet);

                    // 提取接收到的数据
                    byte[] receivedData = new byte[packet.getLength()];
                    System.arraycopy(packet.getData(), packet.getOffset(), receivedData, 0, packet.getLength());

                    String fromAddress = packet.getAddress().getHostAddress() + ":" + packet.getPort();

                    // 使用统一的数据处理方法 - 修改这里
                    handleReceivedData(receivedData, fromAddress);

                } catch (SocketTimeoutException e) {
                    // 超时正常，继续循环检查停止状态
                } catch (Exception e) {
                    if (isRunning.get()) {
                        notifyError("接收数据错误: " + e.getMessage());
                    }
                }
            }
        });
    }
}