#include <iostream>
#include <netdb.h>
#include <sstream>
#include <unistd.h>

int main(int c, char **a) {
    const char *port = (c < 2 ? "4444" : a[1]);
    int family = (c < 3 ? AF_INET6 : AF_INET), status, one = 1, zero = 0;

    addrinfo *res, hints{.ai_flags = AI_PASSIVE, .ai_family = family, .ai_protocol = IPPROTO_TCP};
    if ((status = getaddrinfo(nullptr, port, &hints, &res))) {
        std::cerr << "Getaddrinfo failed: " << gai_strerror(status) << std::endl;
        return 1;
    }

    int s = socket(res->ai_family, res->ai_socktype, 0);
    setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));
    // setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, &zero, sizeof(zero));
    if (bind(s, res->ai_addr, res->ai_addrlen)) { perror("Bind failed"); return 1; }
    freeaddrinfo(res);
    listen(s, 1); std::cout << "Listening on port \e[1;33m" << port << "\e[0m" << std::endl;

    while (1) {
        sockaddr *cliAddr = (sockaddr *)new sockaddr_storage;
        socklen_t cliAddrLen = sizeof(sockaddr_storage);
        int c = accept(s, cliAddr, &cliAddrLen);
        if (c == -1) { 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 << "  [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;
        write(c, msg.str().c_str(), msg.str().length());
        shutdown(c, SHUT_RDWR); close(c);
    }
}