// SPDX-License-Identifier: LGPL-3.0-or-later

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
*
* nymea-remoteproxy
* Tunnel proxy server for the nymea remote access
*
* Copyright (C) 2013 - 2024, nymea GmbH
* Copyright (C) 2024 - 2025, chargebyte austria GmbH
*
* This file is part of nymea-remoteproxy.
*
* nymea-remoteproxy is free software: you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation, either version 3
* of the License, or (at your option) any later version.
*
* nymea-remoteproxy is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with nymea-remoteproxy. If not, see <https://www.gnu.org/licenses/>.
*
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

#include "engine.h"
#include "monitorserver.h"
#include "loggingcategories.h"

#include <QFile>
#include <QJsonDocument>

namespace remoteproxy {

MonitorServer::MonitorServer(const QString &serverName, QObject *parent) :
    QObject(parent),
    m_serverName(serverName)
{

}

MonitorServer::~MonitorServer()
{
    stopServer();
}

bool MonitorServer::running() const
{
    if (!m_server)
        return false;

    return m_server->isListening();
}

void MonitorServer::sendMonitorData(QLocalSocket *clientConnection, const QVariantMap &dataMap)
{
    QByteArray data = QJsonDocument::fromVariant(dataMap).toJson(QJsonDocument::Compact) + "\n";
    qCDebug(dcMonitorServer()) << "Sending monitor data" << qUtf8Printable(data);
    clientConnection->write(data);
    clientConnection->flush();
}

void MonitorServer::onMonitorConnected()
{
    QLocalSocket *clientConnection = m_server->nextPendingConnection();
    connect(clientConnection, &QLocalSocket::disconnected, this, &MonitorServer::onMonitorDisconnected);
    connect(clientConnection, &QLocalSocket::readyRead, this, &MonitorServer::onMonitorReadyRead);
    m_clients.append(clientConnection);
    qCDebug(dcMonitorServer()) << "New monitor connected.";
}

void MonitorServer::onMonitorDisconnected()
{
    qCDebug(dcMonitorServer()) << "Monitor disconnected.";
    QLocalSocket *clientConnection = static_cast<QLocalSocket *>(sender());
    m_clients.removeAll(clientConnection);
    clientConnection->deleteLater();
}

void MonitorServer::onMonitorReadyRead()
{
    QLocalSocket *clientConnection = qobject_cast<QLocalSocket*>(sender());
    QByteArray data = clientConnection->readAll();
    QJsonParseError error;
    QJsonDocument jsonDoc = QJsonDocument::fromJson(data, &error);
    if(error.error != QJsonParseError::NoError) {
        qCWarning(dcMonitorServer()) << "Failed to parse JSON data from monitor:" << error.errorString();
        clientConnection->close();
        return;
    }

    processRequest(clientConnection, jsonDoc.toVariant().toMap());
}

void MonitorServer::processRequest(QLocalSocket *clientConnection, const QVariantMap &request)
{
    /* Refresh method. If no params, it will return the active list of connections

         TODO: filter for uuid's, ip's, names etc...

         {
            "method": "refresh",
            "params": {
                "printAll": bool
            }
         }

     */

    // Note: as simple as possible...no error handling, either you know what you do, or you see nothing here.
    if (request.contains("method")) {
        if (request.value("method").toString() == "refresh") {
            bool printAll = false;
            if (request.contains("params")) {
                QVariantMap params = request.value("params").toMap();
                if (params.contains("printAll")) {
                    printAll = params.value("printAll").toBool();
                }
            }

            sendMonitorData(clientConnection, Engine::instance()->buildMonitorData(printAll));
            return;
        }
    }

    // Not a valid request. Close the connection
    qCWarning(dcMonitorServer()) << "Could not understand the request. Closing connection.";
    clientConnection->close();
}

void MonitorServer::startServer()
{    
    qCDebug(dcMonitorServer()) << "Starting server on" << m_serverName;

    // Make sure the monitor can be created
    if (QFile::exists(m_serverName)) {
        qCDebug(dcMonitorServer()) << "Clean up old monitor socket";
        QFile::remove(m_serverName);
    }

    m_server = new QLocalServer(this);
    m_server->setSocketOptions(QLocalServer::UserAccessOption | QLocalServer::GroupAccessOption | QLocalServer::OtherAccessOption);

    if (!m_server->listen(m_serverName)) {
        qCWarning(dcMonitorServer()) << "Could not start local server for monitor on" << m_serverName << m_server->errorString();
        delete m_server;
        m_server = nullptr;
        return;
    }

    connect(m_server, &QLocalServer::newConnection, this, &MonitorServer::onMonitorConnected);
    qCDebug(dcMonitorServer()) << "Started successfully on" << m_serverName;
}

void MonitorServer::stopServer()
{
    if (!m_server)
        return;

    qCDebug(dcMonitorServer()) << "Stop server" << m_serverName;
    foreach (QLocalSocket *clientConnection, m_clients) {
        clientConnection->close();
    }

    m_server->close();
    delete m_server;
    m_server = nullptr;
}

void MonitorServer::updateClients(const QVariantMap &dataMap)
{
    // Send each monitor the current data
    foreach (QLocalSocket *clientConnection, m_clients) {
        sendMonitorData(clientConnection, dataMap);
    }
}

}