/*
    This file is part of the KDE Libraries

    Copyright (C) 2006 Tobias Koenig (tokoe@kde.org)
    Copyright (C) 2007 Rafael Fernández López (ereslibre@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 "kpageview_p.h"

#include <QtGui/QApplication>
#include <QtGui/QHeaderView>
#include <QtGui/QPainter>
#include <QtGui/QTextLayout>
#include <QtGui/QVBoxLayout>

#include <kdialog.h>
#include <kiconloader.h>
#include <kglobalsettings.h>

using namespace KDEPrivate;

/**
 * KPagePlainView
 */

KPagePlainView::KPagePlainView( QWidget *parent )
 : QAbstractItemView( parent )
{
  hide();
}

QModelIndex KPagePlainView::indexAt( const QPoint& ) const
{
  return QModelIndex();
}

void KPagePlainView::scrollTo( const QModelIndex&, ScrollHint )
{
}

QRect KPagePlainView::visualRect( const QModelIndex& ) const
{
  return QRect();
}

QModelIndex KPagePlainView::moveCursor( QAbstractItemView::CursorAction, Qt::KeyboardModifiers )
{
  return QModelIndex();
}

int KPagePlainView::horizontalOffset() const
{
  return 0;
}

int KPagePlainView::verticalOffset() const
{
  return 0;
}

bool KPagePlainView::isIndexHidden( const QModelIndex& ) const
{
  return false;
}

void KPagePlainView::setSelection( const QRect&, QFlags<QItemSelectionModel::SelectionFlag> )
{
}

QRegion KPagePlainView::visualRegionForSelection( const QItemSelection& ) const
{
  return QRegion();
}


/**
 * KPageListView
 */

KPageListView::KPageListView( QWidget *parent )
 : QListView( parent )
{
  setViewMode( QListView::ListMode );
  setMovement( QListView::Static );
  setVerticalScrollMode( QListView::ScrollPerPixel );

  QFont boldFont( font() );
  boldFont.setBold( true );
  setFont( boldFont );

  setItemDelegate( new KPageListViewDelegate( this ) );
}

KPageListView::~KPageListView()
{
}

void KPageListView::setModel( QAbstractItemModel *model )
{
/*
  KPageListViewProxy *proxy = new KPageListViewProxy( this );
  proxy->setSourceModel( model );
  proxy->rebuildMap();

  connect( model, SIGNAL(layoutChanged()), proxy, SLOT(rebuildMap()) );
*/
  connect( model, SIGNAL(layoutChanged()), this, SLOT(updateWidth()) );

//  QListView::setModel( proxy );
  QListView::setModel( model );

  // Set our own selection model, which won't allow our current selection to be cleared
  setSelectionModel( new KDEPrivate::SelectionModel( model, this ) );

  updateWidth();
}

void KPageListView::updateWidth()
{
  if ( !model() )
    return;

  int rows = model()->rowCount();

  int width = 0;
  for ( int i = 0; i < rows; ++i )
    width = qMax( width, sizeHintForIndex( model()->index( i, 0 ) ).width() );

  setFixedWidth( width + 25 );
}


/**
 * KPageTreeView
 */

KPageTreeView::KPageTreeView( QWidget *parent )
 : QTreeView( parent )
{
  header()->hide();
}

void KPageTreeView::setModel( QAbstractItemModel *model )
{
  connect( model, SIGNAL(layoutChanged()), this, SLOT(updateWidth()) );

  QTreeView::setModel( model );

  // Set our own selection model, which won't allow our current selection to be cleared
  setSelectionModel( new KDEPrivate::SelectionModel( model, this ) );

  updateWidth();
}

void KPageTreeView::updateWidth()
{
  if ( !model() )
    return;

  int columns = model()->columnCount();
  
  expandItems();

  int width = 0;
  for ( int i = 0; i < columns; ++i ) {
    resizeColumnToContents( i );
    width = qMax( width, sizeHintForColumn( i ) );
  }

  setFixedWidth( width + 25 );
}

void KPageTreeView::expandItems( const QModelIndex &index )
{
  setExpanded( index, true );

  const int count = model()->rowCount( index );
  for ( int i = 0; i < count; ++i )
    expandItems( model()->index( i, 0, index ) );
}


/**
 * KPageTabbedView
 */

KPageTabbedView::KPageTabbedView( QWidget *parent )
  : QAbstractItemView( parent )
{
  // hide the viewport of the QAbstractScrollArea
  const QList<QWidget*> list = findChildren<QWidget*>();
  for ( int i = 0; i < list.count(); ++i )
    list[ i ]->hide();

  setFrameShape( NoFrame );

  QVBoxLayout *layout = new QVBoxLayout( this );
  layout->setMargin( 0 );

  mTabWidget = new QTabWidget( this );
  connect( mTabWidget, SIGNAL(currentChanged(int)), this, SLOT(currentPageChanged(int)) );

  layout->addWidget( mTabWidget );
}

KPageTabbedView::~KPageTabbedView()
{
  if (model()) {
    for ( int i = 0; i < mTabWidget->count(); ++i ) {
        QWidget *page = qvariant_cast<QWidget*>( model()->data( model()->index( i, 0 ), KPageView::WidgetRole ) );

        if (page) {
            page->setVisible(false);
            page->setParent(0); // reparent our children before they are deleted
        }
    }
  }
}

void KPageTabbedView::setModel( QAbstractItemModel *model )
{
  QAbstractItemView::setModel( model );

  connect( model, SIGNAL(layoutChanged()), this, SLOT(layoutChanged()) );

  layoutChanged();
}

QModelIndex KPageTabbedView::indexAt( const QPoint& ) const
{
  if ( model() )
    return model()->index( 0, 0 );
  else
    return QModelIndex();
}

void KPageTabbedView::scrollTo( const QModelIndex &index, ScrollHint )
{
  if ( !index.isValid() )
    return;

  mTabWidget->setCurrentIndex( index.row() );
}

QRect KPageTabbedView::visualRect( const QModelIndex& ) const
{
  return QRect();
}

QSize KPageTabbedView::minimumSizeHint() const
{
  return mTabWidget->minimumSizeHint();
}

QModelIndex KPageTabbedView::moveCursor(QAbstractItemView::CursorAction, Qt::KeyboardModifiers)
{
  return QModelIndex();
}

int KPageTabbedView::horizontalOffset() const
{
  return 0;
}

int KPageTabbedView::verticalOffset() const
{
  return 0;
}

bool KPageTabbedView::isIndexHidden( const QModelIndex &index ) const
{
  return ( mTabWidget->currentIndex() != index.row() );
}

void KPageTabbedView::setSelection( const QRect&, QFlags<QItemSelectionModel::SelectionFlag> )
{
}

QRegion KPageTabbedView::visualRegionForSelection( const QItemSelection& ) const
{
  return QRegion();
}

void KPageTabbedView::currentPageChanged( int index )
{
  if ( !model() )
    return;

  QModelIndex modelIndex = model()->index( index, 0 );

  selectionModel()->setCurrentIndex( modelIndex, QItemSelectionModel::ClearAndSelect );
}

void KPageTabbedView::layoutChanged()
{
  // save old position
  int pos = mTabWidget->currentIndex();

  // clear tab bar
  int count = mTabWidget->count();
  for ( int i = 0; i < count; ++i ) {
    mTabWidget->removeTab( 0 );
  }

  if ( !model() )
    return;

  // add new tabs
  for ( int i = 0; i < model()->rowCount(); ++i ) {
    const QString title = model()->data( model()->index( i, 0 ) ).toString();
    const QIcon icon = model()->data( model()->index( i, 0 ), Qt::DecorationRole ).value<QIcon>();
    QWidget *page = qvariant_cast<QWidget*>( model()->data( model()->index( i, 0 ), KPageView::WidgetRole ) );
    if (page) {
        QWidget *widget = new QWidget(this);
        QVBoxLayout *layout = new QVBoxLayout(widget);
        widget->setLayout(layout);
        layout->addWidget(page);
        page->setVisible(true);
        mTabWidget->addTab( widget, icon, title );
    }
  }

  mTabWidget->setCurrentIndex( pos );
}

void KPageTabbedView::dataChanged( const QModelIndex &index, const QModelIndex& )
{
  if ( !index.isValid() )
    return;

  if ( index.row() < 0 || index.row() >= mTabWidget->count() )
    return;

  const QString title = model()->data( index ).toString();
  const QIcon icon = model()->data( index, Qt::DecorationRole ).value<QIcon>();

  mTabWidget->setTabText( index.row(), title );
  mTabWidget->setTabIcon( index.row(), icon );
}

/**
 * KPageListViewDelegate
 */

KPageListViewDelegate::KPageListViewDelegate( QObject *parent )
 : QAbstractItemDelegate( parent )
{
    mIconSize = KIconLoader::global()->currentSize( KIconLoader::Dialog );

    connect(KGlobalSettings::self(), SIGNAL(iconChanged(int)), this, SLOT(iconSettingsChanged(int)) );
}

void KPageListViewDelegate::iconSettingsChanged( int group )
{
    if ( group == KIconLoader::Dialog ) {
        const int iconSize = KIconLoader::global()->currentSize( KIconLoader::Dialog );
        if ( mIconSize != iconSize ) {
            mIconSize = iconSize;
            emit sizeHintChanged( QModelIndex() );
        }
    }
}

static int layoutText(QTextLayout *layout, int maxWidth)
{
    qreal height = 0;
    int textWidth = 0;
    layout->beginLayout();
    while (true) {
        QTextLine line = layout->createLine();
        if (!line.isValid()) {
            break;
        }
        line.setLineWidth(maxWidth);
        line.setPosition(QPointF(0, height));
        height += line.height();
        textWidth = qMax(textWidth, qRound(line.naturalTextWidth() + 0.5));
    }
    layout->endLayout();
    return textWidth;
}

void KPageListViewDelegate::paint( QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index ) const
{
  if ( !index.isValid() )
    return;

  const QString text = index.model()->data( index, Qt::DisplayRole ).toString();
  const QIcon icon = index.model()->data( index, Qt::DecorationRole ).value<QIcon>();
  const QPixmap pixmap = icon.pixmap( mIconSize, mIconSize );

  QFontMetrics fm = painter->fontMetrics();
  int wp = pixmap.width();
  int hp = pixmap.height();

  QTextLayout iconTextLayout( text, option.font );
  QTextOption textOption( Qt::AlignHCenter );
  iconTextLayout.setTextOption( textOption );
  int maxWidth = qMax( 3 * wp, 8 * fm.height() );
  layoutText( &iconTextLayout, maxWidth );

  QPen pen = painter->pen();
  QPalette::ColorGroup cg = option.state & QStyle::State_Enabled
                            ? QPalette::Normal : QPalette::Disabled;
  if ( cg == QPalette::Normal && !(option.state & QStyle::State_Active) )
    cg = QPalette::Inactive;

  QStyleOptionViewItemV4 opt(option);
  opt.showDecorationSelected = true;
  QStyle *style = opt.widget ? opt.widget->style() : QApplication::style();
  style->drawPrimitive(QStyle::PE_PanelItemViewItem, &opt, painter, opt.widget);
  if ( option.state & QStyle::State_Selected ) {
    painter->setPen( option.palette.color( cg, QPalette::HighlightedText ) );
  } else {
    painter->setPen( option.palette.color( cg, QPalette::Text ) );
  }

  painter->drawPixmap( option.rect.x() + (option.rect.width()/2)-(wp/2), option.rect.y() + 5, pixmap );
  if ( !text.isEmpty() )
    iconTextLayout.draw( painter, QPoint( option.rect.x() + (option.rect.width()/2)-(maxWidth/2), option.rect.y() + hp+7 ) );

  painter->setPen( pen );

  drawFocus( painter, option, option.rect );
}

QSize KPageListViewDelegate::sizeHint( const QStyleOptionViewItem &option, const QModelIndex &index ) const
{
  if ( !index.isValid() )
    return QSize( 0, 0 );

  const QString text = index.model()->data( index, Qt::DisplayRole ).toString();
  const QIcon icon = index.model()->data( index, Qt::DecorationRole ).value<QIcon>();
  const QPixmap pixmap = icon.pixmap( mIconSize, mIconSize );

  QFontMetrics fm = option.fontMetrics;
  int gap = fm.height();
  int wp = pixmap.width();
  int hp = pixmap.height();

  if ( hp == 0 ) {
    /**
     * No pixmap loaded yet, we'll use the default icon size in this case.
     */
    hp = mIconSize;
    wp = mIconSize;
  }

  QTextLayout iconTextLayout( text, option.font );
  int wt = layoutText( &iconTextLayout, qMax( 3 * wp, 8 * fm.height() ) );
  int ht = iconTextLayout.boundingRect().height();

  int width, height;
  if ( text.isEmpty() )
    height = hp;
  else
    height = hp + ht + 10;

  width = qMax( wt, wp ) + gap;

  return QSize( width, height );
}

void KPageListViewDelegate::drawFocus( QPainter *painter, const QStyleOptionViewItem &option, const QRect &rect ) const
{
  if (option.state & QStyle::State_HasFocus) {
    QStyleOptionFocusRect o;
    o.QStyleOption::operator=(option);
    o.rect = rect;
    o.state |= QStyle::State_KeyboardFocusChange;
    QPalette::ColorGroup cg = (option.state & QStyle::State_Enabled)
                              ? QPalette::Normal : QPalette::Disabled;
    o.backgroundColor = option.palette.color( cg, (option.state & QStyle::State_Selected)
                                              ? QPalette::Highlight : QPalette::Background );
    QApplication::style()->drawPrimitive( QStyle::PE_FrameFocusRect, &o, painter );
  }
}


/**
 * KPageListViewProxy
 */

KPageListViewProxy::KPageListViewProxy( QObject *parent )
 : QAbstractProxyModel( parent )
{
}

KPageListViewProxy::~KPageListViewProxy()
{
}

int KPageListViewProxy::rowCount( const QModelIndex& ) const
{
  return mList.count();
}

int KPageListViewProxy::columnCount( const QModelIndex& ) const
{
  return 1;
}

QModelIndex KPageListViewProxy::index( int row, int column, const QModelIndex& ) const
{
  if ( column > 1 || row >= mList.count() )
    return QModelIndex();
  else
    return createIndex( row, column, mList[ row ].internalPointer() );
}

QModelIndex KPageListViewProxy::parent( const QModelIndex& ) const
{
  return QModelIndex();
}

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

  if ( index.row() >= mList.count() )
    return QVariant();

  return sourceModel()->data( mList[ index.row() ], role );
}

QModelIndex KPageListViewProxy::mapFromSource( const QModelIndex &index ) const
{
  if ( !index.isValid() )
    return QModelIndex();

  for ( int i = 0; i < mList.count(); ++i ) {
    if ( mList[ i ] == index )
      return createIndex( i, 0, index.internalPointer() );
  }

  return QModelIndex();
}

QModelIndex KPageListViewProxy::mapToSource( const QModelIndex &index ) const
{
  if ( !index.isValid() )
    return QModelIndex();

  return mList[ index.row() ];
}

void KPageListViewProxy::rebuildMap()
{
  mList.clear();

  const QAbstractItemModel *model = sourceModel();
  if ( !model )
    return;

  for ( int i = 0; i < model->rowCount(); ++i ) {
    addMapEntry( model->index( i, 0 ) );
  }

  for ( int i = 0; i < mList.count(); ++i )
    qDebug( "%d:0 -> %d:%d", i, mList[ i ].row(), mList[ i ].column() );

  emit layoutChanged();
}

void KPageListViewProxy::addMapEntry( const QModelIndex &index )
{
  if ( sourceModel()->rowCount( index ) == 0 ) {
    mList.append( index );
  } else {
    const int count = sourceModel()->rowCount( index );
    for ( int i = 0; i < count; ++i )
      addMapEntry( sourceModel()->index( i, 0, index ) );
  }
}

SelectionModel::SelectionModel( QAbstractItemModel *model, QObject *parent )
  : QItemSelectionModel( model, parent )
{
}

void SelectionModel::clear()
{
  // Don't allow the current selection to be cleared
}

void SelectionModel::select( const QModelIndex &index, QItemSelectionModel::SelectionFlags command )
{
  // Don't allow the current selection to be cleared
  if ( !index.isValid() && ( command & QItemSelectionModel::Clear ) ) {
    return;
  }
  QItemSelectionModel::select( index, command );
}

void SelectionModel::select( const QItemSelection &selection, QItemSelectionModel::SelectionFlags command )
{
  // Don't allow the current selection to be cleared
  if ( !selection.count() && ( command & QItemSelectionModel::Clear ) ) {
    return;
  }
  QItemSelectionModel::select( selection, command );
}

#include "moc_kpageview_p.cpp"