#pragma once

#include <iostream>
#include <string>
#include "Log.hpp"
#include <cerrno>
#include <cstring>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <cstdio>
#define SIZE 1024

class UdpServer
{
public:
    UdpServer(uint16_t port, std::string ip = "")
        : _port(port), _ip(ip), _sockfd(-1)
    {
    }
    ~UdpServer()
    {
        if (_sockfd >= 0)
            close(_sockfd);
    }
    bool initServer()
    {
        // 1. 创建套接字
        _sockfd = socket(AF_INET, SOCK_DGRAM, 0);
        if (_sockfd < 0)
        {
            logMessage(FATAL, "%d:%s", errno, strerror(errno));
            exit(2);
        }
        logMessage(DEBUG, "%s: %d", "create socket success, sockfd", _sockfd);
        // 2. 绑定:将用户设置的IP和PORT在内核中与当前进程强关联
        // 2.1 填充属性
        struct sockaddr_in local;
        bzero(&local, sizeof(local));
        local.sin_family = AF_INET;
        local.sin_port = htons(_port);
        local.sin_addr.s_addr = _ip.empty() ? INADDR_ANY : inet_addr(_ip.c_str());
        if (bind(_sockfd, (struct sockaddr *)&(local), sizeof(local)) < 0)
        {
            logMessage(FATAL, "bind():errno:%d:%s", errno, strerror(errno));
            exit(2);
        }
        logMessage(NORMAL, "initialize udp server...%s", strerror(errno));
        return true;
    }
    void Start()
    {
        char buffer[SIZE]; // 用来存放读取的数据
        char result[256];  // 保存处理结果
        std::string cmd;   // 保存命令, 用于回写
        for (;;)
        {
            memset(buffer, 0, sizeof(buffer));
            memset(result, 0, sizeof(result));

            struct sockaddr_in peer;    // 客户端属性集合[输出型参数]
            bzero(&peer, sizeof(peer)); // 初始化空间
            socklen_t len = sizeof(peer);
            // 1. 读取数据
            ssize_t s = recvfrom(_sockfd, buffer, sizeof(buffer), 0,
                                 (struct sockaddr *)&peer, &len);
            // 2. 处理数据:提取缓冲区中的命令
            if (s > 0)
            {
                buffer[s] = '\0';
                FILE *fp = popen(buffer, "r");
                if (fp == nullptr) // 读取失败
                {
                    logMessage(ERROR, "popen: %d:%s", errno, strerror(errno));
                    continue; // 继续读取
                }
                // 过滤非法指令
                if (strcasestr(buffer, "rm") != nullptr || strcasestr(buffer, "rmdir") != nullptr)
                {
                    std::string err_msg = "非法指令: rm/rmdir...";
                    std::cout << err_msg << buffer << std::endl;
                    sendto(_sockfd, err_msg.c_str(), err_msg.size(), 0,
                           (struct sockaddr *)&peer, len);
                }
                while (fgets(result, sizeof(result), fp) != nullptr)
                {
                    cmd += result;
                }
                pclose(fp);
            }
            // 3. 写回数据
            sendto(_sockfd, cmd.c_str(), cmd.size(), 0,
                   (struct sockaddr *)&peer, len);
        }
    }

private:
    uint16_t _port;  // 端口号
    std::string _ip; // IP地址
    int _sockfd;     // 套接字文件描述符
};