// terrasync.hxx -- scenery fetcher
//
// Copyright (C) 2011  Thorsten Brehm <brehmt@gmail.com>
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License as
// published by the Free Software Foundation; either version 2 of the
// License, or (at your option) any later version.
//
// This program 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
// General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
//
// $Id$

#ifndef TERRASYNC_HXX_
#define TERRASYNC_HXX_

#include <set>

#include <simgear/props/props.hxx>
#include <simgear/structure/subsystem_mgr.hxx>
#include <simgear/props/tiedpropertylist.hxx>

class SGPath;
class SGBucket;

namespace simgear
{
const int NOWHERE = -9999;

class BufferedLogCallback;

class SGTerraSync : public SGSubsystem
{
public:
    SGTerraSync();
    virtual ~SGTerraSync();

    // Subsystem API.
    void bind() override;
    void init() override;
    void reinit() override;
    void shutdown() override;
    void unbind() override;
    void update(double) override;

    // Subsystem identification.
    static const char* staticSubsystemClassId() { return "terrasync"; }

    /// notify terrasync that the sim was repositioned, as opposed to
    /// us travelling in a direction. Avoid last_lat / last_lon blocking
    /// certain tiles when we reposition.
    void reposition();

    bool isIdle();

    bool scheduleTile(const SGBucket& bucket);

    void syncAreaByPath(const std::string& aPath);

    void setRoot(SGPropertyNode_ptr root);

    /// retrive the associated log object, for displaying log
    /// output somewhere (a UI, presumably)
    BufferedLogCallback* log() const
        { return _log; }

    /**
     * Test if a scenery directory is queued or actively syncing.
     * File path is the tile name, eg 'e001n52' or 'w003n56'. Will return true
     * if either the Terrain or Objects variant is being synced.
     *
     */
    bool isTileDirPending(const std::string& sceneryDir) const;


    void scheduleDataDir(const std::string& dataDir);

    bool isDataDirPending(const std::string& dataDir) const;

protected:
    void syncAirportsModels();
    string_list getSceneryPathSuffixes() const;

    class WorkerThread;

private:
    void writeWarningFile(const SGPath& sceneryDir);

private:
    WorkerThread* _workerThread;
    SGPropertyNode_ptr _terraRoot;
    SGPropertyNode_ptr _renderingRoot;
    SGPropertyNode_ptr _stalledNode;
    SGPropertyNode_ptr _cacheHits;
    SGPropertyNode_ptr _busyNode;
    SGPropertyNode_ptr _activeNode;
    SGPropertyNode_ptr _enabledNode;
    SGPropertyNode_ptr _availableNode;
    SGPropertyNode_ptr _updateCountNode;
    SGPropertyNode_ptr _errorCountNode;
    SGPropertyNode_ptr _tileCountNode;
    SGPropertyNode_ptr _cacheHitsNode;
    SGPropertyNode_ptr _transferRateBytesSecNode;
    SGPropertyNode_ptr _pendingKbytesNode;
    SGPropertyNode_ptr _downloadedKBtesNode;
    SGPropertyNode_ptr _extractPendingKbytesNode;
    SGPropertyNode_ptr _maxErrorsNode;

    // we manually bind+init TerraSync during early startup
    // to get better overlap of slow operations (Shared Models sync
    // and nav-cache rebuild). As a result we need to track the bind/init
    // state explicitly to avoid duplicate calls.
    bool _bound, _inited;

    simgear::TiedPropertyList _tiedProperties;
    BufferedLogCallback* _log;

    /// if we disabled TerraSync due to errors, this is the time at which we will restart it
    /// automatically.
    SGTimeStamp _retryTime;
    unsigned int _retryBackOffSeconds = 0;
};

}

#endif /* TERRASYNC_HXX_ */
