#include <iostream>
#include <sstream>
#include <winsock2.h>                        //  ┐
#include <ws2tcpip.h>                        //  ├ inne pliku nagłówkowe dla winsock
#pragma comment(lib, "Ws2_32.lib")           //  ┘

// pomocnicza funkcja dla prostszej obsługi błędów
inline char *getLastErrorMessage() {
    static thread_local char msgBuf[1024];
    FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM, nullptr, WSAGetLastError(), 0, msgBuf, 1024, nullptr);
    return msgBuf;
}

int main(int c, char **a) {
    WSADATA wsadata{};                       //  ┐ no i standardowo trzeba
    WSAStartup(MAKEWORD(2, 2),&wsadata);     //  ┘ zainicjalizować winsock

    const char *port = (c < 2 ? "4444" : a[1]);
    int family = (c < 3 ? AF_INET6 : AF_INET), status;

                                            // zwróć uwagę że tutaj jest ustawiane też socktype 
    addrinfo *res, hints{.ai_flags = AI_PASSIVE, .ai_family = family, .ai_socktype = SOCK_STREAM, .ai_protocol = IPPROTO_TCP};
    if ((status = getaddrinfo(nullptr, port, &hints, &res))) {
        std::cerr << "Getaddrinfo failed: " << gai_strerror(status) << std::endl;
        return 1;
    }

    SOCKET s = socket(res->ai_family, res->ai_socktype, 0), one = 1, zero = 0;
    setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (char*)&one, sizeof(one));
    // windows domyślnie dla AF_INET6 słucha tylko na IPv6; poniższa linia zmienia to zachowanie
    setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, (char*)&zero, sizeof(zero));
    if (bind(s, res->ai_addr, res->ai_addrlen) == SOCKET_ERROR)
        { std::cerr << "Bind  failed: " << getLastErrorMessage() << std::endl; return 1; }
    freeaddrinfo(res);

    listen(s, 1); std::cout << "Listening on port " << port << std::endl;

    while (1) {
        sockaddr *cliAddr = (sockaddr *)new sockaddr_storage;
        socklen_t cliAddrLen = sizeof(sockaddr_storage);
        SOCKET c = accept(s, cliAddr, &cliAddrLen);
        if (c == INVALID_SOCKET) { perror("Bind failed"); return 1; }
        std::stringstream msg;

        msg << "Client connected from:" << std::endl;

        char host[NI_MAXHOST], port[NI_MAXSERV];

        status = getnameinfo(cliAddr, cliAddrLen,
                    host, NI_MAXHOST,
                    port, NI_MAXSERV,
                    0);
        if (status) std::cerr << "Getnameinfo failed: " << gai_strerror(status) << std::endl;
        msg << "\r  [resolved] address: " << host << "  port: " << port << std::endl;

        status = getnameinfo(cliAddr, cliAddrLen,
                    host, NI_MAXHOST,
                    port, NI_MAXSERV,
                    NI_NUMERICHOST | NI_NUMERICSERV);
        if (status) std::cerr << "Getnameinfo failed: " << gai_strerror(status) << std::endl;
        msg << "  [numeric ] address: " << host << "  port: " << port << std::endl;
        
        delete cliAddr;
        std::cout << msg.str() << std::flush;
        send(c, msg.str().c_str(), msg.str().length(), 0);
        shutdown(c, SD_BOTH); closesocket(c);
    }
}