/***************************************************************************
 *   Copyright (C) 2004-2006 by Albert Astals Cid <tsdgeos@terra.es>       *
 *                                                                         *
 *   This program 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.                                   *
 ***************************************************************************/

// qt/kde includes
#include <qapplication.h>
#include <qdom.h>
#include <qheaderview.h>
#include <QItemDelegate>
#include <qlayout.h>
#include <qstringlist.h>
#include <QTextDocument>
#include <qtreewidget.h>
#include <kicon.h>
#include <klocale.h>
#include <ktreewidgetsearchline.h>

// local includes
#include "toc.h"
#include "core/document.h"
#include "core/page.h"
#include "settings.h"
#include "core/link.h"

#define TOC_SEPARATOR "@@@@@@@@@@"
#define TOC_DELEGATE_INTERNALMARGIN 3

class TOCDelegate : public QItemDelegate
{
    public:
        TOCDelegate( QObject * parent = 0 )
            : QItemDelegate( parent )
        {
        }

    protected:
        virtual void drawDisplay( QPainter *painter, const QStyleOptionViewItem & option, const QRect & rect, const QString & text ) const
        {
            if ( text.indexOf( TOC_SEPARATOR ) == -1 )
            {
                QItemDelegate::drawDisplay( painter, option, rect, text );
                return;
            }
            QString realText = text.section( TOC_SEPARATOR, 1 );
            if ( !Okular::Settings::tocPageColumn() )
            {
                QItemDelegate::drawDisplay( painter, option, rect, realText );
                return;
            }
            QString page = text.section( TOC_SEPARATOR, 0, 0 );
            QTextDocument document;
            document.setPlainText( page );
            document.setDefaultFont( option.font );
            int margindelta = QApplication::style()->pixelMetric( QStyle::PM_FocusFrameHMargin ) + 1;
            int pageRectWidth = (int)document.size().width();
            QRect newRect( rect );
            QRect pageRect( rect );
            pageRect.setWidth( pageRectWidth + 2 * margindelta );
            newRect.setWidth( newRect.width() - pageRectWidth - TOC_DELEGATE_INTERNALMARGIN );
            if ( option.direction == Qt::RightToLeft )
                newRect.translate( pageRectWidth + TOC_DELEGATE_INTERNALMARGIN, 0 );
            else
                pageRect.translate( newRect.width() + TOC_DELEGATE_INTERNALMARGIN - 2 * margindelta, 0 );
            QItemDelegate::drawDisplay( painter, option, newRect, realText );
            QStyleOptionViewItemV2 newoption( option );
            newoption.displayAlignment = ( option.displayAlignment & ~Qt::AlignHorizontal_Mask ) | Qt::AlignRight;
            QItemDelegate::drawDisplay( painter, newoption, pageRect, page );
        }

};

class TOCItem : public QTreeWidgetItem
{
    public:
        TOCItem( QTreeWidget *parent, TOCItem *after, Okular::Document *document, const QDomElement & e )
            : QTreeWidgetItem( parent, after ), m_element( e )
        {
            init( document, e );
        }

        TOCItem( QTreeWidgetItem *parent, TOCItem *after, Okular::Document *document, const QDomElement & e )
            : QTreeWidgetItem( parent, after ), m_element( e )
        {
            init( document, e );
        }

        void init( Okular::Document *document, const QDomElement & e )
        {
            // viewport loading
            if ( e.hasAttribute( "Viewport" ) )
            {
                // if the node has a viewport, set it
                m_viewport = Okular::DocumentViewport( e.attribute( "Viewport" ) );
            }
            else if ( e.hasAttribute( "ViewportName" ) )
            {
                // if the node references a viewport, get the reference and set it
                const QString & page = e.attribute( "ViewportName" );
                QString viewport = document->getMetaData( "NamedViewport", page ).toString();
                if ( !viewport.isNull() )
                    m_viewport = Okular::DocumentViewport( viewport );
            }

            QString text = e.tagName();
            if ( m_viewport.pageNumber != -1 )
                text.prepend( QString::number( m_viewport.pageNumber + 1 ) + TOC_SEPARATOR );
            setText( 0, text );
        }

        const QDomElement & element() const
        {
            return m_element;
        }

        const Okular::DocumentViewport& viewport() const
        {
            return m_viewport;
        }

        void setCurrent( bool selected )
        {
            setIcon( 0, selected ? KIcon( treeWidget()->layoutDirection() == Qt::RightToLeft ? "1leftarrow" : "1rightarrow" ) : QIcon() );
        }

    private:
        QDomElement m_element;
        Okular::DocumentViewport m_viewport;
};

TOC::TOC(QWidget *parent, Okular::Document *document) : QWidget(parent), m_document(document), m_current(0), m_currentPage(-1)
{
    QVBoxLayout *mainlay = new QVBoxLayout( this );
    mainlay->setMargin( 0 );

    QHBoxLayout *searchlay = new QHBoxLayout();
    searchlay->setMargin( 2 );
    searchlay->setSpacing( 2 );
    mainlay->addLayout( searchlay );

    m_searchLine = new KTreeWidgetSearchLine( this );
    searchlay->addWidget( m_searchLine );

    m_treeView = new QTreeWidget( this );
    mainlay->addWidget( m_treeView );
    QStringList cols;
    cols.append( "Topics" );
    m_treeView->setHeaderLabels( cols );
    m_treeView->setSortingEnabled( false );
    m_treeView->setRootIsDecorated( true );
    m_treeView->setAlternatingRowColors( true );
    m_treeView->setItemDelegate( new TOCDelegate( m_treeView ) );
    m_treeView->header()->hide();
    m_treeView->setSelectionBehavior( QAbstractItemView::SelectRows );
    connect( m_treeView, SIGNAL( itemClicked( QTreeWidgetItem *, int ) ), this, SLOT( slotExecuted( QTreeWidgetItem * ) ) );
    connect( m_treeView, SIGNAL( itemActivated( QTreeWidgetItem *, int ) ), this, SLOT( slotExecuted( QTreeWidgetItem * ) ) );
    m_searchLine->addTreeWidget( m_treeView );
}

TOC::~TOC()
{
    m_document->removeObserver( this );
}

uint TOC::observerId() const
{
    return TOC_ID;
}

void TOC::notifySetup( const QVector< Okular::Page * > & /*pages*/, bool documentChanged )
{
    if ( !documentChanged )
        return;

    // clear contents
    m_treeView->clear();
    m_searchLine->clear();
    m_current = 0;
    m_currentPage = -1;

    // request synopsis description (is a dom tree)
    const Okular::DocumentSynopsis * syn = m_document->documentSynopsis();

    // if not present, disable the contents tab
    if ( !syn )
    {
        emit hasTOC( false );
        return;
    }

    // else populate the listview and enable the tab
    addChildren( *syn );
    emit hasTOC( true );
}

void TOC::notifyViewportChanged( bool /*smoothMove*/ )
{
    int newpage = m_document->viewport().pageNumber;
    if ( m_currentPage == newpage )
        return;

    m_currentPage = newpage;

    if ( m_current )
    {
        m_current->setCurrent( false );
        m_current = 0;
    }

    QTreeWidgetItemIterator it( m_treeView );
    while ( (*it) && !m_current )
    {
        TOCItem *tmp = dynamic_cast<TOCItem*>( *it );
        int p = tmp ? tmp->viewport().pageNumber : -1;
        if ( p == newpage )
        {
            m_current = tmp;
            if (m_current)
                m_current->setCurrent( true );
        }
        ++it;
    }
}


void TOC::reparseConfig()
{
    m_treeView->update();
}


void TOC::addChildren( const QDomNode & parentNode, QTreeWidgetItem * parentItem )
{
    // keep track of the current listViewItem
    TOCItem * currentItem = 0;
    QDomNode n = parentNode.firstChild();
    while( !n.isNull() )
    {
        // convert the node to an element (sure it is)
        QDomElement e = n.toElement();

        // insert the entry as top level (listview parented) or 2nd+ level
        if ( !parentItem )
            currentItem = new TOCItem( m_treeView, currentItem, m_document, e );
        else
            currentItem = new TOCItem( parentItem, currentItem, m_document, e );

        // descend recursively and advance to the next node
        if ( e.hasChildNodes() )
            addChildren( n, currentItem );
        n = n.nextSibling();
    }
}

void TOC::slotExecuted( QTreeWidgetItem *i )
{
    TOCItem* tocItem = dynamic_cast<TOCItem*>( i );
    // that filters clicks on [+] that for a strange reason don't seem to be TOCItem*
    if (tocItem == NULL)
        return;
    const QDomElement & e = tocItem->element();

    QString externalFileName = e.attribute( "ExternalFileName" );
    if ( !externalFileName.isEmpty() )
    {
        Okular::LinkGoto link( externalFileName, tocItem->viewport() );
        m_document->processLink( &link );
    }
    else
    {
        m_document->setViewport( tocItem->viewport() );
    }
}

#include "toc.moc"