/***************************************************************************
 *   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.                                   *
 ***************************************************************************/

#include "toc.h"

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

// local includes
#include "pageitemdelegate.h"
#include "core/action.h"
#include "core/document.h"
#include "core/page.h"

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

        TOCItem( QTreeWidgetItem *parent, TOCItem *after, Okular::Document *document, const QDomElement & e )
            : QTreeWidgetItem( parent, after )
        {
            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->metaData( "NamedViewport", page ).toString();
                if ( !viewport.isNull() )
                    m_viewport = Okular::DocumentViewport( viewport );
            }

            if ( m_viewport.isValid() )
            {
                setData( 0, PageItemDelegate::PageRole, QString::number( m_viewport.pageNumber + 1 ) );
                QString label = document->page( m_viewport.pageNumber )->label();
                if ( !label.isEmpty() )
                    setData( 0, PageItemDelegate::PageLabelRole, label );
            }
            m_extFileName = e.attribute( "ExternalFileName" );
            setText( 0, e.tagName() );
        }

        QString externalFileName() const
        {
            return m_extFileName;
        }

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

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

    private:
        Okular::DocumentViewport m_viewport;
        QString m_extFileName;
};

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 PageItemDelegate( 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 );

        // open/keep close the item
        bool isOpen = false;
        if ( e.hasAttribute( "Open" ) )
            isOpen = QVariant( e.attribute( "Open" ) ).toBool();
        currentItem->setExpanded( isOpen );

        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;

    QString externalFileName = tocItem->externalFileName();
    if ( !externalFileName.isEmpty() )
    {
        Okular::GotoAction action( externalFileName, tocItem->viewport() );
        m_document->processAction( &action );
    }
    else
    {
        m_document->setViewport( tocItem->viewport() );
    }
}

#include "toc.moc"