#include "beerservice.h"

#include <QJsonDocument>
#include <QJsonObject>
#include <QJsonArray>
#include <QStandardPaths>
#include <QFile>
#include <QDebug>

#include "settingsservice.h"

BeerService::BeerService()
    : QObject{nullptr}
{
    m_actions = {
        { ActionGet, "get" },
        { ActionAdd, "add" },
        { ActionDelete, "del" },
        { ActionModify, "mod" }
    };

    restoreStash();

    connect(&m_socket, &QWebSocket::textMessageReceived, this, [this](QString message) {
        QJsonParseError err;
        QJsonDocument doc = QJsonDocument::fromJson(message.toLocal8Bit(), &err);
        if (err.error != QJsonParseError::NoError) {
            qWarning() << "Json parse error:" << err.errorString() << message;
            return;
        }

        QString entity = doc.object().value("entity").toString();
        const QList<QObject *> listeners = m_listeners.values(entity);
        for (QObject *listener : listeners) {
            QString event = doc.object().value("event").toString();
            QVariant data = doc.object().value("data").toVariant();
            QMetaObject::invokeMethod(listener, event.toLatin1(), Qt::QueuedConnection, Q_ARG(QVariant, data));
        }
    });

    connect(&m_socket, &QWebSocket::errorOccurred, this, [this](QAbstractSocket::SocketError error) {
        qInfo() << error << m_socket.errorString();
    });

    connect(&m_socket, &QWebSocket::connected, this, [this]() {
        while (!m_commandStash.isEmpty()) {
            sendCommand(m_commandStash.takeFirst().toMap());
        }
    });

    connect(&m_socket, &QWebSocket::stateChanged, this, &BeerService::connectedChanged);

    connect(settings(), &SettingsService::serverAddressChanged, this, &BeerService::reconnect);
    connect(settings(), &SettingsService::selectedUserIdChanged, this, &BeerService::reconnect);

    reconnect();
}

BeerService::~BeerService()
{
    saveStash();
    m_socket.close();
}

SettingsService *BeerService::settings() const
{
    return SettingsService::instance();
}

void BeerService::sendCommand(const QString &entity, Action action, const QVariantMap &data)
{
    Q_ASSERT(action != ActionUndefined);

    sendCommand(QVariantMap {
                    { "entity", entity },
                    { "action", m_actions[action] },
                    { "data", data }
                });
}

void BeerService::connectListener(QObject *listener)
{
    QString entity = listener->property("entity").toString();
    m_listeners.insert(entity, listener);
}

void BeerService::removeListener(QObject *listener)
{
    QString entity = listener->property("entity").toString();
    m_listeners.remove(entity, listener);
}

QString BeerService::stashFileName() const
{
    return QStandardPaths::writableLocation(QStandardPaths::CacheLocation) + "/command.stash";
}

void BeerService::saveStash() const
{
    if (m_commandStash.isEmpty()) {
        return;
    }

    QFile stash(stashFileName());
    if (stash.open(QIODevice::WriteOnly)) {
        stash.write(QJsonDocument::fromVariant(m_commandStash).toJson(QJsonDocument::Compact));
        stash.close();
    } else {
        qWarning() << stash.errorString();
    }
}

void BeerService::restoreStash()
{
    QFile stash(stashFileName());
    if (stash.open(QIODevice::ReadOnly)) {
        QJsonDocument doc = QJsonDocument::fromJson(stash.readAll());
        m_commandStash = doc.array().toVariantList();
        stash.close();
        stash.remove();
    } else {
        qWarning() << stash.errorString();
    }
}

void BeerService::reconnect()
{
    if (connected()) {
        m_socket.close();
    }

    QString userId = settings()->selectedUserId();
    QUrl serverUrl(QString("ws://%1").arg(settings()->serverAddress()));

    QNetworkRequest request(serverUrl);
    request.setRawHeader("Authorization", "Basic " + QString("%1:pass").arg(userId).toLatin1().toBase64());
    m_socket.open(request);

}

void BeerService::sendCommand(const QVariantMap &command)
{
    if (connected()) {
        QJsonDocument doc = QJsonDocument::fromVariant(command);
        m_socket.sendTextMessage(doc.toJson(QJsonDocument::Compact));
    } else {
        m_commandStash << command;
    }
}

bool BeerService::connected() const
{
    return QAbstractSocket::ConnectedState == m_socket.state();
}