#pragma once

#include <iostream>
#include <string>
#include <poll.h>
#include <memory>
#include "Socket.hpp"
#include "Log.hpp"

using namespace Net_Work;

const static int gdefaultport = 8888;
const static int gbacklog = 8;
const int gnum = 1024;

class PollServer
{
    void HandlerEvent()
    {
        for (int i = 0; i < _num; i++)
        {
            if (_rfds[i].fd == -1)
                continue;

            int fd = _rfds[i].fd;
            short revents = _rfds[i].events;
            if (revents & POLLIN) // 判断是否是读准备就绪
            {
                if (fd == _listensock->GetSockFd()) // 监听fd建立新链接(链接就绪)
                {
                    lg.LogMessage(Info, "get a new link\n");
                    std::string clientip;
                    uint16_t clientport;
                    // 这里已经不会再阻塞了，select已经检测到了listensock已经就绪了！！！
                    int sock = _listensock->AcceptConnection(&clientip, &clientport);
                    if (!sock)
                    {
                        lg.LogMessage(Error, "accept error\n");
                        return;
                    }
                    lg.LogMessage(Info, "get a client, client info is# %s: %d, fd: %d\n", clientip.c_str(), clientport, sock);
                    // 这里已经获取连接成功
                    // 连接已经建立好，不能确定对方是否发数据
                    // read？write？绝对不能！！！read 底层数据是否就绪时不确定的！谁清楚fd上面是否有读事件呢？select！
                    // 新链接fd到来的时候，要把新的fd, 想办法交给select托管 -- 只需要添加到数组_rfds_array中即可
                    int pos = 0;
                    for (; pos < _num; pos++)
                    {
                        if (_rfds[pos].fd == -1)
                        {
                            _rfds[pos].fd = sock;
                            _rfds[pos].events = POLLIN;
                            lg.LogMessage(Info, "get a new link, fd is : %d\n", sock);
                            break;
                        }
                    }
                    // 数组满了
                    if (pos == _num)
                    {
                        // 1.扩容
                        // 2.关闭
                        close(sock);
                        lg.LogMessage(Warning, "server is full...!\n");
                    }
                }
                else // 普通的读事件就绪
                {
                    // 这里读取已经不会卡住
                    char buffer[1024];
                    ssize_t n = recv(fd, buffer, sizeof(buffer)-1, 0);
                    if (n > 0)
                    {
                        lg.LogMessage(Info, "client say# %s\n", buffer);
                        std::string message = ": 你好呀，少年";
                        message += buffer;
                        send(fd, message.c_str(), message.size(), 0);
                    }
                    else
                    {
                        lg.LogMessage(Warning, "client quit, maybe close or error, close fd : %d\n", fd);
                        close(fd);
                        // 取消poll关系
                        _rfds[i].fd = -1;
                        _rfds[i].events = 0;
                        _rfds[i].revents = 0;
                    }
                }
            }
        }
    }

public:
    PollServer(int port = gdefaultport) : _port(port), _listensock(new TcpSocket()), _num(gnum)
    {
    }

    void InitServer()
    {
        // 创建套接字+bind
        _listensock->BuildListenSocketMethod(_port, gbacklog);
        _rfds = new struct pollfd[_num];
        for (int i = 0; i < _num; i++)
        {
            _rfds[i].fd = -1;
            _rfds[i].events = 0;
            _rfds[i].revents = 0;
        }
        // 最开始只有一个文件描述符
        _rfds[0].fd = _listensock->GetSockFd();
        _rfds[0].events = POLLIN; // 读
    }
    
    void Loop()
    {
        _running = true;
        while (_running)
        {
            // 设定时间
            int timeout = 1000;// 0 或 -1(阻塞式)
            // PrintDebug();
            // 最大的fd要能够动态更新
            // rfds本质是一个输入输出型参数，rfds是在select调用返回的时候，不断被修改，所以，每次都要重置
            int n = poll(_rfds, _num, timeout); // 返回准备就绪的fd,并设置到rfds中(也可能是之前设设置的fd准备就绪并返回)
            switch (n)
            {
            case 0:
                lg.LogMessage(Info, "poll timeout...\n");
                break;
            case -1:
                lg.LogMessage(Error, "poll error!!!\n");
                break;
            default:
                // 正常的就绪的fd
                // 第一次等待client建立连接
                lg.LogMessage(Info, "select success, begin event handler\n");
                HandlerEvent(); // 准备就绪的fd集合(读集合) _rfds_array: 3,4,5,6,7,8,9,10 -> rfds: 4,5,6
                break;
            }
        }
        _running = false;
    }
    void Stop()
    {
        _running = false;
    }

    void PrintDebug()
    {
        std::cout << "current select rfds list is : ";
        for (int i = 0; i < _num; i++)
        {
            if (_rfds[i].fd == -1)
                continue;
            else
                std::cout << _rfds[i].fd << " ";
        }
        std::cout << std::endl;
    }

    ~PollServer()
    {
        delete[] _rfds;
    }

private:
    std::unique_ptr<Socket> _listensock;
    int _port;
    int _running;
    struct pollfd *_rfds;
    int _num;
};