#pragma once
#include <iostream>
#include <string>
#include <sys/types.h>
#include <sys/socket.h>
#include <unistd.h>
#include <cstring>
#include <cstdio>
#include <strings.h>
#include <cerrno>
#include <cstdlib>
#include <signal.h>
#include <netinet/in.h>
#include <ctype.h>
#include <sys/wait.h>
#include <pthread.h>
#include <arpa/inet.h>
#include <mutex>
#include <thread>
#include <cassert>
#include "log.hpp"
#include <memory>
using namespace std;
#define PORT 8080
#define BACKLOG 8
class TcpServer
{
private:
    TcpServer(int port = PORT)
        : _port(port)
    {
    }
    TcpServer(const TcpServer &copy) = delete;

public:
    static TcpServer *GetInstance(int port = PORT)
    {
        if (_singleton == nullptr) // 双检查加锁,只有第一次进来时需要加锁,其他情况不用加锁
        {
            _mtx.lock();
            if (_singleton == nullptr) // 第一次调用才创建实例!
            {
                _singleton = new TcpServer(port);
                _singleton->InitServer();
            }
            _mtx.unlock();
        }
        return _singleton;
    }
    void InitServer()
    {
        Socket();
        Bind();
        Listen();
    }
    void Socket()
    {
        _listensock = socket(AF_INET, SOCK_STREAM, 0);
        if (_listensock < 0)
        {
            logMessage(ERROR, "socket error  [%s], [%d]", __FILE__, __LINE__);
            exit(1);
        }
        int opt = 1;
        setsockopt(_listensock, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)); // 设置套接字可以被复用,一旦服务器挂掉,可以立马使用一样的端口号重新启动服务器
        logMessage(DEBUG, "socket success  [%s], [%d]", __FILE__, __LINE__);
    }
    void Bind()
    {
        struct sockaddr_in local;
        memset(&local, 0, sizeof(local));
        local.sin_family = AF_INET;
        local.sin_port = htons(_port);
        local.sin_addr.s_addr = INADDR_ANY; // 云服务器不能直接bind公网IP,INADDR_ANY随机绑定本主机IP
        if (bind(_listensock, (struct sockaddr *)&local, sizeof(local)) < 0)
        {
            logMessage(ERROR, "bind error  [%s], [%d]", __FILE__, __LINE__);
            exit(2);
        }
        logMessage(DEBUG, "bind success  [%s], [%d]", __FILE__, __LINE__);
    }
    void Listen()
    {
        if (listen(_listensock, BACKLOG) < 0)
        {
            logMessage(ERROR, "listen error  [%s], [%d]", __FILE__, __LINE__);
            exit(3);
        }
        logMessage(DEBUG, "listen success  [%s], [%d]", __FILE__, __LINE__);
    }
    ~TcpServer()
    {
        if (_listensock >= 0)
            close(_listensock);
    }
    int Sock()
    {
        return _listensock;
    }

private:
    int _port;
    int _listensock = -1;
    static TcpServer *_singleton;
    static mutex _mtx;
};
mutex TcpServer::_mtx;
TcpServer *TcpServer::_singleton = nullptr;