/******************************************************************************
*
* 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 "Debug.h"
#include "File.h"
#include "FileCheck.h"
#include "TextDisplay.h"
#include "TextView.h"

#include <QApplication>
#include <algorithm>

//* used to monitor file changes
//____________________________________________________
FileCheck::FileCheck( QObject* parent ):
    QObject( parent ),
    Counter( "FileCheck" )
{
    Debug::Throw( "FileCheck::FileCheck.\n" );
    connect( &fileSystemWatcher_, SIGNAL(fileChanged(QString)), SLOT(_fileChanged(QString)) );
}

//______________________________________________________
void FileCheck::registerDisplay( TextDisplay* display )
{
    Debug::Throw( "FileCheck::registerDisplay.\n" );
    if( !isAssociated( display ) ) { Base::Key::associate( this, display ); }
}

//______________________________________________________
void FileCheck::addFile( const QString& file )
{

    Debug::Throw() << "FileCheck::addFile: " << file << endl;
    if( files_.find( file ) == files_.end() )
    {
        files_.insert( file );
        fileSystemWatcher_.addPath( file );
    }

}

//______________________________________________________
void FileCheck::removeFile( const QString& file )
{

    Debug::Throw() << "FileCheck::removeFile: " << file << endl;
    files_.remove( file );
    fileSystemWatcher_.removePath( file );

    return;

}

//______________________________________________________
void FileCheck::_fileChanged( const QString& file )
{

    Debug::Throw() << "FileCheck::_fileChanged: " << file << endl;

    // filecheck data
    File local( file );
    FileCheckData data( local );
    if( !local.exists() )
    {

        data.setFlag( FileCheckData::Flag::Removed );
        data.setTimeStamp( TimeStamp::now() );
        removeFile( file );

    } else {

        data.setFlag( FileCheckData::Flag::Modified );
        data.setTimeStamp( local.lastModified() );

    }

    _checkData( data );

}

//______________________________________________________________________________
void FileCheck::_checkData( const FileCheckData& data )
{

    Base::KeySet<TextDisplay> displays( this );
    const auto displayIter( std::find_if( displays.begin(), displays.end(), TextDisplay::SameFileFTor( data.file().expanded() ) ) );
    if( displayIter != displays.end() )
    {

        // assign to this display and others
        Base::KeySet<TextDisplay> associatedDisplays( *displayIter );
        associatedDisplays.insert( *displayIter );
        for( const auto& display:associatedDisplays )
        {

            // check whether data are still relevant for this display
            if( !( data.flag() == FileCheckData::Flag::Removed || (display->lastSaved().isValid() && (*displayIter)->lastSaved() < data.timeStamp()) ) )
            { continue; }

            (*displayIter)->setFileCheckData( data );
            if( !( display->isActive() && display->BaseEditor::hasFocus() ) )
            { continue; }

            // retrieve associated TextView
            Base::KeySet<TextView> views( display );
            if( !views.empty() ) (*views.begin())->checkDisplayModifications( *displayIter );

        }

    } else {

        // permanently remove file from list
        removeFile( data.file() );

    }

}