#ifndef FileCheck_h
#define FileCheck_h

/******************************************************************************
*
* Copyright (C) 2002 Hugo PEREIRA <mailto: hugo.pereira@free.fr>
*
* This 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 software 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, see <http://www.gnu.org/licenses/>.
*
*******************************************************************************/

#include "File.h"
#include "Key.h"
#include "TimeStamp.h"

#include <QBasicTimer>
#include <QFileSystemWatcher>
#include <QObject>
#include <QTimerEvent>
#include <QSet>

class TextDisplay;

//* handles threads for file auto-save
class FileCheck: public QObject, public Base::Key, private Base::Counter<FileCheck>
{

    //* Qt meta object declaration
    Q_OBJECT

    public:

    //* constructor
    explicit FileCheck( QObject* = nullptr );

    //* register new dispay
    void registerDisplay( TextDisplay* );

    //* add file
    void addFile( const QString& );

    //* remove file
    void removeFile( const QString& );

    //* used to monitor file changes
    class Data
    {
        public:

        //* flag
        enum Flag
        {
            None,
            Removed,
            Modified
        };

        //* constructor
        explicit Data( File file = File(), Flag flag = None, TimeStamp stamp = TimeStamp() ):
            file_( file ),
            flag_( flag ),
            timeStamp_( stamp )
        {}

        //* file
        void setFile( const File& file )
        { file_ = file; }

        //* file
        const File& file() const
        { return file_; }

        //* flag
        void setFlag( const Flag& flag )
        { flag_ = flag; }

        //* flag
        const Flag& flag() const
        { return flag_; }

        //* timestamp
        void setTimeStamp( const TimeStamp& stamp )
        { timeStamp_ = stamp; }

        //* timestamp
        const TimeStamp& timeStamp() const
        { return timeStamp_; }

        private:

        //* file
        File file_;

        //* flag
        Flag flag_;

        //* timestamp
        TimeStamp timeStamp_;

    };

    //* map data to file
    using DataSet = QSet<Data>;


    //* file system watcher
    const QFileSystemWatcher& fileSystemWatcher() const
    { return fileSystemWatcher_; }

    protected:

    //* timer event, to handle multiple file modification at once
    void timerEvent( QTimerEvent* event ) override;

    private Q_SLOTS:

    void _fileChanged( const QString& );

    private:

    //* file system watcher
    QFileSystemWatcher fileSystemWatcher_;

    //* file set
    using FileSet = QSet<QString>;

    //* file set
    FileSet files_;

    //* map files and modification data
    DataSet data_;

    //* resize timer
    QBasicTimer timer_;

};

//* equal to operator
inline bool operator == ( const FileCheck::Data& first, const FileCheck::Data& second )
{ return first.file() == second.file(); }

//* less than operator
inline bool operator < ( const FileCheck::Data& first, const FileCheck::Data& second )
{ return first.file() < second.file(); }

inline uint qHash( const FileCheck::Data& data )
{ return qHash( data.file() ); }

#endif