/* Copyright (C) 2015
 * swift project Community / Contributors
 *
 * This file is part of swift project. It is subject to the license terms in the LICENSE file found in the top-level
 * directory of this distribution and at http://www.swift-project.org/license.html. No part of swift project,
 * including this file, may be copied, modified, propagated, or distributed except according to the terms
 * contained in the LICENSE file.
 */

//! \file

#ifndef BLACKCORE_AIRSPACE_ANALYZER_H
#define BLACKCORE_AIRSPACE_ANALYZER_H

#include "blackcore/blackcoreexport.h"
#include "blackcore/network.h"
#include "blackmisc/simulation/airspaceaircraftsnapshot.h"
#include "blackmisc/simulation/remoteaircraftprovider.h"
#include "blackmisc/simulation/ownaircraftprovider.h"
#include "blackmisc/worker.h"
#include "blackmisc/pq/time.h"
#include "blackmisc/aviation/callsign.h"
#include <QObject>
#include <QHash>
#include <QReadWriteLock>

namespace BlackCore
{
    //! Class monitoring and analyzing (closest aircraft, outdated aircraft / watchdog) airspace
    //! in background.
    //!
    //! \details Watchdog functionality: This class was introduced due to a flaw in the VATSIM server implementation: Every client needs to send an add/delete packet on its own to inform other
    //!          clients nearby. The server does not take care of that. When a client crashes, no delete packet is ever sent. This class therefore monitors callsigns and emits a timeout signal if it
    //!          wasn't resetted during the specified timeout value.
    //!
    class BLACKCORE_EXPORT CAirspaceAnalyzer :
        public BlackMisc::CContinuousWorker,
        public BlackMisc::Simulation::COwnAircraftAware,
        public BlackMisc::Simulation::CRemoteAircraftAware
    {
        Q_OBJECT

    public:
        //! List of callsigns and their last activity
        typedef QHash<BlackMisc::Aviation::CCallsign, qint64> CCallsignTimestampSet;

        //! Constructor
        CAirspaceAnalyzer(BlackMisc::Simulation::IOwnAircraftProvider *ownAircraftProvider,
                          BlackMisc::Simulation::IRemoteAircraftProvider *remoteAircraftProvider,
                          INetwork *network, QObject *parent);

        //! Get the latest snapshot
        //! \threadsafe
        BlackMisc::Simulation::CAirspaceAircraftSnapshot getLatestAirspaceAircraftSnapshot() const;

        //! Render restrictions in simulator
        void setSimulatorRenderRestrictionsChanged(bool restricted, bool enabled, int maxAircraft, const BlackMisc::PhysicalQuantities::CLength &maxRenderedDistance, const BlackMisc::PhysicalQuantities::CLength &maxRenderedBoundary);

        //! Gracefully shut down, e.g. for thread safety
        void gracefulShutdown();

        //! Destructor
        virtual ~CAirspaceAnalyzer();

    public slots:
        //! Clear
        void clear();

    signals:
        //! Callsign has timed out
        void timeoutAircraft(const BlackMisc::Aviation::CCallsign &callsign);

        //! Callsign has timed out
        void timeoutAtc(const BlackMisc::Aviation::CCallsign &callsign);

        //! New aircraft snapshot
        void airspaceAircraftSnapshot(const BlackMisc::Simulation::CAirspaceAircraftSnapshot &snapshot);

    private slots:
        //! Remove callsign from watch list
        void ps_watchdogRemoveAircraftCallsign(const BlackMisc::Aviation::CCallsign &callsign);

        //! Remove callsign from watch list
        void ps_watchdogRemoveAtcCallsign(const BlackMisc::Aviation::CCallsign &callsign);

        //! Reset timestamp for callsign
        void ps_watchdogTouchAircraftCallsign(const BlackMisc::Aviation::CAircraftSituation &situation, const BlackMisc::Aviation::CTransponder &transponder);

        //! Reset timestamp for callsign
        void ps_watchdogTouchAtcCallsign(const BlackMisc::Aviation::CCallsign &callsign, const BlackMisc::PhysicalQuantities::CFrequency &frequency,
                                         const BlackMisc::Geo::CCoordinateGeodetic &position, const BlackMisc::PhysicalQuantities::CLength &range);

        //! Connection status of network changed
        void ps_onConnectionStatusChanged(BlackCore::INetwork::ConnectionStatus oldStatus, BlackCore::INetwork::ConnectionStatus newStatus);

        //! Run a check
        void ps_timeout();

    private:
        //! Check for time outs
        void watchdogCheckTimeouts();

        //! Analyze the airspace
        void analyzeAirspace();

        QTimer m_timer {this}; //!< multi purpose timer for snapshots and watchdog

        // watchdog
        CCallsignTimestampSet m_aircraftCallsignTimestamps; //!< for watchdog (pilots)
        CCallsignTimestampSet m_atcCallsignTimestamps;      //!< for watchdog (ATC)
        BlackMisc::PhysicalQuantities::CTime m_timeoutAircraft = {15, BlackMisc::PhysicalQuantities::CTimeUnit::s() }; //!< Timeout value for watchdog functionality
        BlackMisc::PhysicalQuantities::CTime m_timeoutAtc = {50, BlackMisc::PhysicalQuantities::CTimeUnit::s() }; //!< Timeout value for watchdog functionality
        qint64 m_lastWatchdogCallMsSinceEpoch;

        // snapshot
        BlackMisc::Simulation::CAirspaceAircraftSnapshot m_latestAircraftSnapshot;
        bool m_simulatorRenderedAircraftRestricted = false;
        bool m_simulatorRenderingEnabled = true;
        int m_simulatorMaxRenderedAircraft = -1;
        BlackMisc::PhysicalQuantities::CLength m_simulatorMaxRenderedDistance { 0.0, BlackMisc::PhysicalQuantities::CLengthUnit::nullUnit() };
        BlackMisc::PhysicalQuantities::CLength m_simulatorMaxRenderedBoundary { 0.0, BlackMisc::PhysicalQuantities::CLengthUnit::nullUnit() };
        mutable QReadWriteLock m_lockSnapshot;      //!< lock snapshot
        mutable QReadWriteLock m_lockRestrictions;  //!< lock simulator restrictions
    };

} // namespace

#endif