#include "hichess_server.h"

#define UDP_SERVER_PORT 45454
#define UDP_CLIENT_PORT 45455
#define WEB_PORT 54545


Player::Player(const QString& name, QWebSocket *wsocket)
    : m_wsocket(wsocket)
    , m_name(name)
{}

bool Player::operator==(const Player &other) const
{
    return QString::compare(m_name, other.getName(), Qt::CaseInsensitive);
}

Game::Game(const PlayerPair &players)
    : m_name(QString("%1 vs %2").arg(players.first.getName(), players.second.getName()))
    , m_players(QRandomGenerator::global()->bounded(1) ?
                    players :
                    qMakePair(players.second, players.first))
{}

bool Game::operator==(const Game &other) const
{
    return QString::compare(m_name, other.getName(), Qt::CaseInsensitive);
}

HichessServer::HichessServer(QObject *parent)
    : QObject(parent)
{
    m_udpServer = new QUdpSocket(this);
    m_webServer = new QWebSocketServer("HichessServer", QWebSocketServer::NonSecureMode, this);

    connect(m_udpServer, &QUdpSocket::readyRead, this, &HichessServer::processPendingDatagrams);
    connect(m_webServer, &QWebSocketServer::newConnection, this, &HichessServer::onNewConnection);
    connect(m_webServer, &QWebSocketServer::serverError, this,
            [](QWebSocketProtocol::CloseCode closeCode) { qDebug() << Q_FUNC_INFO << closeCode; });

    QList<QNetworkInterface> interfaces = QNetworkInterface::allInterfaces();
    foreach (QNetworkInterface interface, interfaces)
        if (interface.isValid() &&
            !interface.flags().testFlag(QNetworkInterface::IsLoopBack) &&
            !interface.flags().testFlag(QNetworkInterface::IsPointToPoint) &&
            interface.flags().testFlag(QNetworkInterface::IsUp) &&
            interface.flags().testFlag(QNetworkInterface::IsRunning))
        {
            QList<QNetworkAddressEntry> addresses = interface.addressEntries();
            foreach (QNetworkAddressEntry address, addresses)
                if (!address.ip().isNull() &&
                    !address.ip().isLoopback() &&
                    address.ip().protocol() == QUdpSocket::IPv4Protocol)
                {
                    qDebug() << Q_FUNC_INFO << "IP: " << address.ip().toString();
                    qDebug() << Q_FUNC_INFO << "Bound: " << m_udpServer->bind(address.ip(), UDP_SERVER_PORT, QUdpSocket::ShareAddress);
                    qDebug() << Q_FUNC_INFO << "Port: " << m_udpServer->localAddress() << m_udpServer->localPort();
                    qDebug() << Q_FUNC_INFO << "Listening: " << m_webServer->listen(address.ip(), WEB_PORT);
                    return;
                }
        }
}

void HichessServer::processPendingDatagrams()
{
    QUdpSocket *socket = qobject_cast<QUdpSocket*>(sender());
    if (socket && socket->hasPendingDatagrams()) {
        QNetworkDatagram datagram = socket->receiveDatagram();
        qDebug() << Q_FUNC_INFO << "Datagram data: " << datagram.data();

        if (datagram.data().startsWith("User = ")) {
            qDebug() << Q_FUNC_INFO << "Datagram data is valid, parsing...";
            QString username = datagram.data().mid(7);
            QRegularExpression rx("[A-Za-z0-9_]{6,15}");

            if (rx.match(username).hasMatch()) {
                qDebug() << Q_FUNC_INFO << "Parsed username is valid...";
                auto found = std::find_if(m_allPlayers.begin(), m_allPlayers.end(), [username](Player p) {
                    return p.getName() == username;
                });

                if (found == m_allPlayers.end()) {
                    qDebug() << Q_FUNC_INFO << username << "Username is not occupied";
                    qDebug() << Q_FUNC_INFO << "Url: " << m_webServer->serverUrl().toString().toUtf8();
                    m_usernameQueue.enqueue(username);
                    socket->writeDatagram(m_webServer->serverUrl().toString().toUtf8(), datagram.senderAddress(), UDP_CLIENT_PORT);
                } else
                    qDebug() << Q_FUNC_INFO << username << " username is already occupied";
            } else
                qDebug() << Q_FUNC_INFO << username << " is not a valid username";
        }
    }
}

void HichessServer::addClient(QWebSocket *client)
{
    if (client == nullptr) {
        qDebug() << Q_FUNC_INFO << " Client is nullptr";
        return;
    }
    qDebug() << Q_FUNC_INFO << "Client: " << client;

    connect(client, &QWebSocket::disconnected, this, [this, client]() {
        qDebug() << Q_FUNC_INFO << client << "disconnected";
        removeClient(client);
    });
    connect(client, &QWebSocket::textMessageReceived, this, [](){});
    connect(client, QOverload<QAbstractSocket::SocketError>::of(&QWebSocket::error),
        [=](QAbstractSocket::SocketError error){ qDebug() << Q_FUNC_INFO << error; });
    connect(client, &QObject::destroyed, this, []() {qDebug() << Q_FUNC_INFO << "destroyed"; });

    if (!m_usernameQueue.isEmpty()) {
        qDebug() << Q_FUNC_INFO << "There are queued usernames";

        QString username = m_usernameQueue.dequeue();
        qDebug() << Q_FUNC_INFO << "Username: " << username;

        m_playerQueue.enqueue({username, client});
        m_allPlayers.append({username, client});

        if (m_playerQueue.size() > 1) {
            qDebug() << Q_FUNC_INFO << "There are more than 1 queued players. Found pair for a game...";
            PlayerPair players = {m_playerQueue.dequeue(), m_playerQueue.dequeue()};

            Game game(players);
            m_games.append(game);
        }
        foreach (auto p, m_allPlayers)
            qDebug() << Q_FUNC_INFO << "Players: " << p.getName();
        foreach (auto g, m_games)
            qDebug() << Q_FUNC_INFO << "Games: " << g.getName();
    } else
        qDebug() << Q_FUNC_INFO << "There are no queued usernames";
}

void HichessServer::removeClient(QWebSocket *client)
{
    auto p = std::find_if(m_allPlayers.begin(), m_allPlayers.end(), [client](const Player &p){ return p.getWSocket() == client; });
    if (p != m_allPlayers.end()){
        qDebug() << Q_FUNC_INFO << "Found the client to remove";
        qDebug() << Q_FUNC_INFO << "Username: " << p->getName() << ", socket: " << client;

        m_allPlayers.removeAll(*p);
        m_playerQueue.removeAll(*p);

        foreach (Game g, m_games) {
            if (g.getWhite() == *p) {
                qDebug() << Q_FUNC_INFO << "Found game with insufficient players. White player is missing.";
                m_games.removeAll(g);
                g.getBlack().getWSocket()->sendTextMessage(p->getName() + " left the game");
                break;
            } else if (g.getBlack() == *p) {
                qDebug() << Q_FUNC_INFO << "Found game with insufficient players. Black player is missing.";
                m_games.removeAll(g);
                g.getBlack().getWSocket()->sendTextMessage(p->getName() + " left the game");
                break;
            } else
                qDebug() << Q_FUNC_INFO << "Client is not inside a game";
        }
        p->getWSocket()->deleteLater();
        qDebug() << Q_FUNC_INFO << p->getName() << " left the game";
    }
}

void HichessServer::onNewConnection()
{
    qDebug() << Q_FUNC_INFO;
    auto cli = m_webServer->nextPendingConnection();
    addClient(cli);
}

void HichessServer::onTextMessageReceived()
{
}