/*
  Copyright (c) 2009 Tobias Koenig <tokoe@kde.org>

  This library is free software; you can redistribute it and/or modify it
  under the terms of the GNU Library General Public License as published by
  the Free Software Foundation; either version 2 of the License, or (at your
  option) any later version.

  This library 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 Library General Public
  License for more details.

  You should have received a copy of the GNU Library General Public License
  along with this library; see the file COPYING.LIB.  If not, write to the
  Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  02110-1301, USA.
*/

#include "qcsvmodel.h"
#include "qcsvmodel_p.h"
#include "qcsvreader.h"

#include <QtCore/QMap>
#include <QtCore/QPair>
#include <QtCore/QStringList>
#include <QtCore/QVector>

CsvParser::CsvParser( QObject *parent )
    : QThread( parent ), mDevice( 0 ), mRowCount( 0 ), mColumnCount( 0 ), mCacheCounter( 0 )
{
    mReader = new QCsvReader( this );
}

CsvParser::~CsvParser()
{
    delete mReader;
}

void CsvParser::load( QIODevice *device )
{
    mDevice = device;

    start();
}

void CsvParser::begin()
{
    mCacheCounter = 0;
    mRowCount = 0;
    mColumnCount = 0;
}

void CsvParser::beginLine()
{
    mRowCount++;
}

void CsvParser::field( const QString &data, uint row, uint column )
{
    const int tmp = qMax( mColumnCount, (int)column + 1 );
    if ( tmp != mColumnCount ) {
        mColumnCount = tmp;
        emit columnCountChanged( tmp );
    }

    emit dataChanged( data, row, column );
}

void CsvParser::endLine()
{
    mCacheCounter++;
    if ( mCacheCounter == 50 ) {
        emit rowCountChanged( mRowCount );
        mCacheCounter = 0;
    }
}

void CsvParser::end()
{
    emit rowCountChanged( mRowCount );
    emit ended();
}

void CsvParser::error( const QString & )
{
}

void CsvParser::run()
{
    if ( !mDevice->isOpen() ) {
        mDevice->open( QIODevice::ReadOnly );
    }

    mDevice->reset();
    mReader->read( mDevice );
}

class QCsvModel::Private
{
public:
    Private( QCsvModel *model )
        : mParent( model ), mParser( 0 ),
          mDevice( 0 ), mRowCount( 0 ), mColumnCount( 0 )
    {
    }

    void columnCountChanged( int columns );
    void rowCountChanged( int rows );
    void fieldChanged( const QString &data, int row, int column );
    void finishedLoading();

    QCsvModel *mParent;
    CsvParser *mParser;
    QVector<QString> mFieldIdentifiers;
    QMap< QPair<int, int>, QString> mFields;
    QIODevice *mDevice;

    int mRowCount;
    int mColumnCount;
};

void QCsvModel::Private::columnCountChanged( int columns )
{
    mColumnCount = columns;
    mFieldIdentifiers.resize( columns );
    mFieldIdentifiers[ columns - 1 ] = QLatin1String( "0" );
    emit mParent->layoutChanged();
}

void QCsvModel::Private::rowCountChanged( int rows )
{
    mRowCount = rows;
    emit mParent->layoutChanged();
}

void QCsvModel::Private::fieldChanged( const QString &data, int row, int column )
{
    mFields.insert( QPair<int, int>( row, column ), data );
}

void QCsvModel::Private::finishedLoading()
{
    emit mParent->finishedLoading();
}

QCsvModel::QCsvModel( QObject *parent )
    : QAbstractTableModel( parent ), d( new Private( this ) )
{
    d->mParser = new CsvParser( this );

    connect( d->mParser, SIGNAL(columnCountChanged(int)),
             this, SLOT(columnCountChanged(int)), Qt::QueuedConnection );
    connect( d->mParser, SIGNAL(rowCountChanged(int)),
             this, SLOT(rowCountChanged(int)), Qt::QueuedConnection );
    connect( d->mParser, SIGNAL(dataChanged(QString,int,int)),
             this, SLOT(fieldChanged(QString,int,int)), Qt::QueuedConnection );
    connect( d->mParser, SIGNAL(ended()), this, SLOT(finishedLoading()) );
}

QCsvModel::~QCsvModel()
{
    delete d;
}

bool QCsvModel::load( QIODevice *device )
{
    d->mDevice = device;
    d->mRowCount = 0;
    d->mColumnCount = 0;

    emit layoutChanged();

    d->mParser->load( device );

    return true;
}

void QCsvModel::setTextQuote( const QChar &textQuote )
{
    const bool isRunning = d->mParser->isRunning();

    if ( isRunning ) {
        d->mParser->reader()->terminate();
        d->mParser->wait();
    }

    d->mParser->reader()->setTextQuote( textQuote );

    if ( isRunning ) {
        load( d->mDevice );
    }
}

QChar QCsvModel::textQuote() const
{
    return d->mParser->reader()->textQuote();
}

void QCsvModel::setDelimiter( const QChar &delimiter )
{
    const bool isRunning = d->mParser->isRunning();

    if ( isRunning ) {
        d->mParser->reader()->terminate();
        d->mParser->wait();
    }

    d->mParser->reader()->setDelimiter( delimiter );

    if ( isRunning ) {
        load( d->mDevice );
    }
}

QChar QCsvModel::delimiter() const
{
    return d->mParser->reader()->delimiter();
}

void QCsvModel::setStartRow( uint startRow )
{
    const bool isRunning = d->mParser->isRunning();

    if ( isRunning ) {
        d->mParser->reader()->terminate();
        d->mParser->wait();
    }

    d->mParser->reader()->setStartRow( startRow );

    if ( isRunning ) {
        load( d->mDevice );
    }
}

uint QCsvModel::startRow() const
{
    return d->mParser->reader()->startRow();
}

void QCsvModel::setTextCodec( QTextCodec *textCodec )
{
    const bool isRunning = d->mParser->isRunning();

    if ( isRunning ) {
        d->mParser->reader()->terminate();
        d->mParser->wait();
    }

    d->mParser->reader()->setTextCodec( textCodec );

    if ( isRunning ) {
        load( d->mDevice );
    }
}

QTextCodec *QCsvModel::textCodec() const
{
    return d->mParser->reader()->textCodec();
}

int QCsvModel::columnCount( const QModelIndex &parent ) const
{
    if ( !parent.isValid() ) {
        return d->mColumnCount;
    } else {
        return 0;
    }
}

int QCsvModel::rowCount( const QModelIndex &parent ) const
{
    if ( !parent.isValid() ) {
        return d->mRowCount + 1; // +1 for the header row
    } else {
        return 0;
    }
}

QVariant QCsvModel::data( const QModelIndex &index, int role ) const
{
    if ( !index.isValid() ) {
        return QVariant();
    }

    if ( index.row() == 0 ) {
        if ( index.column() >= d->mFieldIdentifiers.count() ) {
            return QVariant();
        }

        if ( role == Qt::DisplayRole || role == Qt::EditRole ) {
            return d->mFieldIdentifiers.at( index.column() );
        }

        return QVariant();
    }

    const QPair<int, int> pair( index.row() - 1, index.column() );
    if ( !d->mFields.contains( pair ) ) {
        return QVariant();
    }

    const QString data = d->mFields.value( pair );

    if ( role == Qt::DisplayRole ) {
        return data;
    } else {
        return QVariant();
    }
}

bool QCsvModel::setData( const QModelIndex &index, const QVariant &data, int role )
{
    if ( role == Qt::EditRole && index.row() == 0 &&
         index.column() <= d->mFieldIdentifiers.count() ) {
        d->mFieldIdentifiers[ index.column() ] = data.toString();

        emit dataChanged( index, index );
        return true;
    }

    return false;
}

Qt::ItemFlags QCsvModel::flags( const QModelIndex &index ) const
{
    Qt::ItemFlags flags = Qt::ItemIsSelectable | Qt::ItemIsEnabled;
    if ( index.row() == 0 ) {
        flags |= Qt::ItemIsEditable;
    }

    return flags;
}

#include "moc_qcsvmodel.cpp"
#include "moc_qcsvmodel_p.cpp"