#include <iostream>
#include <string>
#include <thread>
#include <chrono>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <fcntl.h>
#include <cstring>

// UDP监听函数
void UDPListen(const std::string& targetIP, int targetPort) {
    // 创建UDP套接字
    int sockfd = socket(AF_INET, SOCK_DGRAM, 0);
    if (sockfd == -1) {
        std::cout << "Failed to create socket." << std::endl;
        return;
    }

    // 设置套接字为非阻塞模式
    int flags = fcntl(sockfd, F_GETFL, 0);
    fcntl(sockfd, F_SETFL, flags | O_NONBLOCK);

    // 设置目标地址和端口
    sockaddr_in targetAddr;
    std::memset(&targetAddr, 0, sizeof(targetAddr));
    targetAddr.sin_family = AF_INET;
    targetAddr.sin_port = htons(targetPort);
    if (inet_pton(AF_INET, targetIP.c_str(), &(targetAddr.sin_addr)) <= 0) {
        std::cout << "Invalid target IP address." << std::endl;
        close(sockfd);
        return;
    }

    // 绑定本地地址和端口
    sockaddr_in localAddr;
    std::memset(&localAddr, 0, sizeof(localAddr));
    localAddr.sin_family = AF_INET;
    localAddr.sin_port = htons(targetPort); // 可以根据实际需求选择本地端口
    localAddr.sin_addr.s_addr = INADDR_ANY;
    if (bind(sockfd, (const sockaddr*)&localAddr, sizeof(localAddr)) == -1) {
        std::cout << "Failed to bind socket." << std::endl;
        close(sockfd);
        return;
    }

    // 监听和接收数据
    char buffer[1024];
    while (true) {
        std::memset(buffer, 0, sizeof(buffer));

        // 接收数据
        ssize_t bytesRead = recvfrom(sockfd, buffer, sizeof(buffer) - 1, 0, NULL, NULL);
        if (bytesRead > 0) {
            // 打印接收到的数据
            std::cout << "Received: " << buffer << std::endl;
        }

        // 检测网络连接状态
        int error = 0;
        socklen_t len = sizeof(error);
        if (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &error, &len) != 0) {
            std::cout << "Failed to get socket option." << std::endl;
            close(sockfd);
            return;
        }

        // 检查网络连接状态
        bool networkConnected = (error == 0);

        // 如果网络断开，等待网络恢复
        while (!networkConnected) {
            // 打印等待网络恢复的提示信息
            std::cout << "Network disconnected. Waiting for network recovery..." << std::endl;

            // 等待一段时间后重新检测网络连接状态
            std::this_thread::sleep_for(std::chrono::seconds(5));

            // 检测网络连接状态
            if (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &error, &len) != 0) {
                std::cout << "Failed to get socket option." << std::endl;
                close(sockfd);
                return;
            }

            // 检查网络连接状态
            networkConnected = (error == 0);
        }
    }

    // 关闭套接字
    close(sockfd);
}

// 主函数
int main() {
    std::string targetIP = "192.168.1.3";
    int targetPort = 56100;

    // 创建监听线程
    std::thread listenThread(UDPListen, targetIP, targetPort);

    // 等待监听线程结束（这个例子中，永远不会结束）
    listenThread.join();

    return 0;
}