#pragma once

#include <string>
#include <unordered_map>

#include <ngtcp2/ngtcp2.h>
#include <gnutls/gnutls.h>
#include <ev.h>

// Platform-specific socket includes and helpers
#ifdef _WIN32
    #include <winsock2.h>
    #include <ws2tcpip.h>
    #pragma comment(lib, "ws2_32.lib")
    using socket_t = SOCKET;
    #define CLOSE_SOCKET closesocket
    #define SOCKLEN_T int
    #define IS_INVALID_SOCKET(s) ((s) == INVALID_SOCKET)
    #define GET_LAST_ERROR() WSAGetLastError()
#else
    #include <sys/socket.h>
    #include <netinet/in.h>
    #include <arpa/inet.h>
    #include <unistd.h>
    #include <errno.h>
    #include <netdb.h>
    using socket_t = int;
    #define CLOSE_SOCKET close
    #define SOCKLEN_T socklen_t
    #define IS_INVALID_SOCKET(s) ((s) < 0)
    #define GET_LAST_ERROR() errno
#endif

namespace Artifact {

namespace {

struct Ngtcp2CidEqual {
    bool operator()(const ngtcp2_cid& a, const ngtcp2_cid& b) const noexcept {
        return a.datalen == b.datalen &&
               std::memcmp(a.data, b.data, a.datalen) == 0;
    }
};

struct Ngtcp2CidHash {
    size_t operator()(const ngtcp2_cid& cid) const noexcept {
        size_t h = cid.datalen;
        for (uint8_t i = 0; i < cid.datalen; ++i) {
            h = (h * 31) ^ cid.data[i];   // or better hash as above
        }
        return h;
    }
};

}

class Connection {
public:
    ngtcp2_settings settings;
    ngtcp2_transport_params transportParams;
    ngtcp2_callbacks callbacks;
    ngtcp2_cid dcid, scid;
    gnutls_session_t session;
    ngtcp2_conn * conn;
    
    Connection();

    void readPacket(ngtcp2_pkt_info * info, void * packet);
};

class ClientConnection: public Connection {
public:
    ClientConnection(std::string host, std::string port);
};

class ServerConnection: public Connection {
public:
    ngtcp2_path path;
    ServerConnection(ngtcp2_path path);
};

class ServerListener {
    socket_t socketDescriptor;
    std::unordered_map<ngtcp2_cid, std::unique_ptr<ServerConnection>, Ngtcp2CidHash, Ngtcp2CidEqual> connections;
    ngtcp2_addr localAddr;
    
    struct ev_loop * loop;
    ev_io watcher;
public:
    ServerListener(std::string port);
    static void onReadable(struct ev_loop *, ev_io * watcher, int);
    void run();
};

}