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

const int BACKLOG = 5;

void listen(int port) {
    int server_fd, new_socket;
    struct sockaddr_in address;
    int addrlen = sizeof(address);

    // 创建socket
    if ((server_fd = socket(AF_INET, SOCK_STREAM, 0)) == 0) {
        perror("socket failed");
        exit(EXIT_FAILURE);
    }

    // 设置服务器地址和端口号
    address.sin_family = AF_INET;
    address.sin_addr.s_addr = INADDR_ANY;
    address.sin_port = htons(port);

    // 绑定socket到地址
    if (bind(server_fd, (struct sockaddr *)&address, sizeof(address))<0) {
        perror("bind failed");
        exit(EXIT_FAILURE);
    }

    // 开始监听客户端连接
    if (listen(server_fd, BACKLOG) < 0) {
        perror("listen failed");
        exit(EXIT_FAILURE);
    }

    std::cout << "Server started, listening on port " << port << std::endl;

    while(true) {
        // 接受客户端连接请求并处理
        if ((new_socket = accept(server_fd, (struct sockaddr *)&address, (socklen_t*)&addrlen)) < 0) {
            perror("accept failed");
            exit(EXIT_FAILURE);
        }
      
        std::cout << "New client connected: " << inet_ntoa(address.sin_addr) << ":" << ntohs(address.sin_port) << std::endl;
      
        // 处理客户端请求
        char buffer[1024] = {0};
        int valread = read(new_socket , buffer, 1024);
        std::cout << "Received message: " << buffer << std::endl;

        const char* msg = "Hello from server!";
        send(new_socket, msg, strlen(msg), 0);

        // 关闭连接
        close(new_socket);
    }
}