#include <cstdio>
#include <iostream>
#include <winsock2.h>
#include <cstring>
#include <vector>
#include <windows.h>

std::string longToIp(long ip)
{
    int b[32];
    std::string fin[4];
    int it = 0;
    while (ip > 0)
    {
        int tmp = ip % 2 == 0 ? 0 : 1;
        b[it] = tmp;
        ip /= 2;

        if (it % 8 == 0 && it != 0)
        {
            int tmp1 = 0;
            for (int i = it - 8, j = 0; i < it; i++, j++)
            {
                tmp1 += pow(2, j)*b[i];
            }
            char tmp2[4];
            _itoa_s(tmp1, tmp2, 4, 10);
            fin[(int)floor(it / 8.0) - 1] = tmp2;

        }
        it++;

    }

    int tmp1 = 0;
    for (int i = 0; i < it % 8; i++)
    {
        tmp1 += pow(2, i)*b[(it - it % 8) + i];
    }

    char tmp2[4];
    _itoa_s(tmp1, tmp2, 4, 10);
    fin[3] = tmp2;

    std::string res;

    for (int i = 0; i < 4; i++)
    {
        res += fin[i];
        if (i != 3)
            res += '.';
    }

    return res;
}

class Client
{
public:
    SOCKADDR_IN addr;
    int addrLength;
    Client()
    {
        addrLength = sizeof(addr);
    }
    bool Compare(const Client& other)
    {
        if (other.addr.sin_addr.S_un.S_addr == addr.sin_addr.S_un.S_addr
            && other.addr.sin_port == addr.sin_port)
        {
            return true;
        }
        else
        {
            return false;
        }
    }
};


int main()
{
    WSADATA WsaData;
    SOCKET sock;

    int err = WSAStartup(0x0101, &WsaData);
    if (err == SOCKET_ERROR)
    {
        printf("WSAStartup() failed: %ld\n", GetLastError());
        system("pause>>void");
        return 1;
    }

    if ((sock = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
    {
        std::cout << "Cannot create a socket" << std::endl;
        system("pause>>void");
        return 1;
    }

    SOCKADDR_IN sin;
    sin.sin_family = AF_INET;
    sin.sin_port = htons(80);
    sin.sin_addr.s_addr = htonl(INADDR_ANY);

    if (bind(sock, (SOCKADDR*)&sin, sizeof(sin)) < 0)
    {
        std::cout << "Bind error: " << GetLastError() << std::endl;
        system("pause>>void");
        return 1;
    }

    int err3 = listen(sock, SOMAXCONN);

    std::vector<Client> from;

    while (true)
    {
        char recvBuff[256];
        Client client;

            int n = recvfrom(sock, recvBuff, 256, 0, (sockaddr*)&client.addr, (int*)&client.addrLength);
            if (n < 0)
            {
                std::cout << "Get <0 bytes: " << n << std::endl;
            }
            else
            {
                std::cout << "Received: " << n << " bytes, from ip: " << longToIp(client.addr.sin_addr.S_un.S_addr).data()
                    << "  from port: " << htons(client.addr.sin_port) << std::endl;
                std::string str = recvBuff;
                str.resize(n);
                std::cout << str.data() << std::endl;

                bool add = true;

                if (from.size() > 0)
                {
                    for (size_t i = 0; i < from.size(); i++)
                    {
                        if (!from[i].Compare(client))
                        {
                            sendto(sock, recvBuff, n, 0, (sockaddr*)&from[i].addr, from[i].addrLength);
                        }
                        else
                        {
                            add = false;
                        }
                    }
                }
                if (add)
                {
                    from.push_back(client);
                }
            }
        }
    

    closesocket(sock);

    system("pause>>void");
    return 0;
}