/*
    Copyright (c) 2006-2008 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 "agenttypewidget.h"

#include <KDebug>

#include <QtGui/QApplication>
#include <QtGui/QHBoxLayout>
#include <QtGui/QListView>
#include <QtGui/QPainter>

#include "agentfilterproxymodel.h"
#include "agenttype.h"
#include "agenttypemodel.h"

using namespace Akonadi;

/**
 * @internal
 */
class AgentTypeWidgetDelegate : public QAbstractItemDelegate
{
  public:
    AgentTypeWidgetDelegate( QObject *parent = 0 );

    virtual void paint( QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index ) const;
    virtual QSize sizeHint( const QStyleOptionViewItem &option, const QModelIndex &index ) const;

  private:
    void drawFocus( QPainter*, const QStyleOptionViewItem&, const QRect& ) const;
};


/**
 * @internal
 */
class AgentTypeWidget::Private
{
  public:
    Private( AgentTypeWidget *parent )
      : mParent( parent )
    {
    }

    void currentAgentTypeChanged( const QModelIndex&, const QModelIndex& );

    void typeActivated( const QModelIndex &index )
    {
      if ( index.flags() & (Qt::ItemIsSelectable | Qt::ItemIsEnabled) )
        emit mParent->activated();
    }

    AgentTypeWidget *mParent;
    QListView *mView;
    AgentTypeModel *mModel;
    AgentFilterProxyModel *proxyModel;
};

void AgentTypeWidget::Private::currentAgentTypeChanged( const QModelIndex &currentIndex, const QModelIndex &previousIndex )
{
  AgentType currentType;
  if ( currentIndex.isValid() )
    currentType = currentIndex.data( AgentTypeModel::TypeRole ).value<AgentType>();

  AgentType previousType;
  if ( previousIndex.isValid() )
    previousType = previousIndex.data( AgentTypeModel::TypeRole ).value<AgentType>();

  emit mParent->currentChanged( currentType, previousType );
}

AgentTypeWidget::AgentTypeWidget( QWidget *parent )
  : QWidget( parent ), d( new Private( this ) )
{
  QHBoxLayout *layout = new QHBoxLayout( this );
  layout->setMargin( 0 );

  d->mView = new QListView( this );
  d->mView->setItemDelegate( new AgentTypeWidgetDelegate( d->mView ) );
  d->mView->setVerticalScrollMode( QAbstractItemView::ScrollPerPixel );
  d->mView->setAlternatingRowColors( true );
  layout->addWidget( d->mView );

  d->mModel = new AgentTypeModel( d->mView );
  d->proxyModel = new AgentFilterProxyModel( this );
  d->proxyModel->setSourceModel( d->mModel );
  d->proxyModel->sort( 0 );
  d->mView->setModel( d->proxyModel );

  d->mView->selectionModel()->setCurrentIndex( d->mView->model()->index( 0, 0 ), QItemSelectionModel::Select );
  d->mView->scrollTo( d->mView->model()->index( 0, 0 ) );
  connect( d->mView->selectionModel(), SIGNAL( currentChanged( const QModelIndex&, const QModelIndex& ) ),
           this, SLOT( currentAgentTypeChanged( const QModelIndex&, const QModelIndex& ) ) );
  connect( d->mView, SIGNAL( activated( const QModelIndex& ) ),
           SLOT( typeActivated(QModelIndex) ) );
}

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

AgentType AgentTypeWidget::currentAgentType() const
{
  QItemSelectionModel *selectionModel = d->mView->selectionModel();
  if ( !selectionModel )
    return AgentType();

  QModelIndex index = selectionModel->currentIndex();
  if ( !index.isValid() )
    return AgentType();

  return index.data( AgentTypeModel::TypeRole ).value<AgentType>();
}

AgentFilterProxyModel* AgentTypeWidget::agentFilterProxyModel() const
{
  return d->proxyModel;
}

/**
 * AgentTypeWidgetDelegate
 */

AgentTypeWidgetDelegate::AgentTypeWidgetDelegate( QObject *parent )
 : QAbstractItemDelegate( parent )
{
}

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

  painter->setRenderHint( QPainter::Antialiasing );

  const QString name = index.model()->data( index, Qt::DisplayRole ).toString();
  const QString comment = index.model()->data( index, AgentTypeModel::DescriptionRole ).toString();

  const QVariant data = index.model()->data( index, Qt::DecorationRole );

  QPixmap pixmap;
  if ( data.isValid() && data.type() == QVariant::Icon )
    pixmap = qvariant_cast<QIcon>( data ).pixmap( 64, 64 );

  const QFont oldFont = painter->font();
  QFont boldFont( oldFont );
  boldFont.setBold( true );
  painter->setFont( boldFont );
  QFontMetrics fm = painter->fontMetrics();
  int hn = fm.boundingRect( 0, 0, 0, 0, Qt::AlignLeft, name ).height();
  int wn = fm.boundingRect( 0, 0, 0, 0, Qt::AlignLeft, name ).width();
  painter->setFont( oldFont );

  fm = painter->fontMetrics();
  int hc = fm.boundingRect( 0, 0, 0, 0, Qt::AlignLeft, comment ).height();
  int wc = fm.boundingRect( 0, 0, 0, 0, Qt::AlignLeft, comment ).width();
  int wp = pixmap.width();

  QStyleOptionViewItemV4 opt(option);
  opt.showDecorationSelected = true;
  QApplication::style()->drawPrimitive( QStyle::PE_PanelItemViewItem, &opt, painter );

  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;
  if (option.state & QStyle::State_Selected) {
    painter->setPen(option.palette.color(cg, QPalette::HighlightedText));
  } else {
    painter->setPen(option.palette.color(cg, QPalette::Text));
  }

  QFont font = painter->font();
  painter->setFont(option.font);

  painter->drawPixmap( option.rect.x() + 5, option.rect.y() + 5, pixmap );

  painter->setFont(boldFont);
  if ( !name.isEmpty() )
    painter->drawText( option.rect.x() + 5 + wp + 5, option.rect.y() + 7, wn, hn, Qt::AlignLeft, name );
  painter->setFont(oldFont);

  if ( !comment.isEmpty() )
    painter->drawText( option.rect.x() + 5 + wp + 5, option.rect.y() + 7 + hn, wc, hc, Qt::AlignLeft, comment );

  painter->setPen(pen);

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

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

  const QString name = index.model()->data( index, Qt::DisplayRole ).toString();
  const QString comment = index.model()->data( index, AgentTypeModel::DescriptionRole ).toString();

  QFontMetrics fm = option.fontMetrics;
  int hn = fm.boundingRect( 0, 0, 0, 0, Qt::AlignLeft, name ).height();
  int wn = fm.boundingRect( 0, 0, 0, 0, Qt::AlignLeft, name ).width();
  int hc = fm.boundingRect( 0, 0, 0, 0, Qt::AlignLeft, comment ).height();
  int wc = fm.boundingRect( 0, 0, 0, 0, Qt::AlignLeft, comment ).width();

  int width = 0;
  int height = 0;

  if ( !name.isEmpty() ) {
    height += hn;
    width = qMax( width, wn );
  }

  if ( !comment.isEmpty() ) {
    height += hc;
    width = qMax( width, wc );
  }

  height = qMax( height, 64 ) + 10;
  width += 64 + 15;

  return QSize( width, height );
}

void AgentTypeWidgetDelegate::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);
  }
}

#include "agenttypewidget.moc"
