/*
    Copyright (C) 2010 Klarälvdalens Datakonsult AB,
        a KDAB Group company, info@kdab.net,
        author Stephen Kelly <stephen@kdab.com>

    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 "breadcrumbnavigationwidget.h"

#include "dynamictreemodel.h"
#include "dynamictreewidget.h"

#include <QSplitter>
#include <QListView>
#include <QTreeView>
#include <QBoxLayout>

#include "kselectionproxymodel.h"
#include "kbreadcrumbselectionmodel.h"

#define SON(object) object->setObjectName(#object)


CurrentItemLabel::CurrentItemLabel(QAbstractItemModel* model, QWidget* parent, Qt::WindowFlags f)
  : QLabel(parent, f), m_model(model)
{
  connect(model, SIGNAL(dataChanged(QModelIndex,QModelIndex)), SLOT(dataChanged(QModelIndex,QModelIndex)));
  connect(model, SIGNAL(rowsInserted(QModelIndex,int,int)), SLOT(rowsInserted(QModelIndex,int,int)));
  connect(model, SIGNAL(rowsRemoved(QModelIndex,int,int)), SLOT(rowsRemoved(QModelIndex,int,int)));
  connect(model, SIGNAL(modelReset()), SLOT(modelReset()));

  if (!m_model->hasChildren())
  {
    setText("No selection");
  }
}

void CurrentItemLabel::dataChanged(const QModelIndex& topLeft, const QModelIndex& bottomRight)
{
  setText(m_model->index(0, 0).data().toString());
}

void CurrentItemLabel::rowsInserted(const QModelIndex& parent, int start, int end)
{
  setText(m_model->index(0, 0).data().toString());
}

void CurrentItemLabel::rowsRemoved(const QModelIndex& parent, int start, int end)
{
  if (!m_model->hasChildren())
  {
    setText("No selection");
    return;
  }
  setText(m_model->index(0, 0).data().toString());
}

void CurrentItemLabel::modelReset()
{
  if (!m_model->hasChildren())
  {
    setText("No selection");
  }
  setText(m_model->index(0, 0).data().toString());
}

KBreadcrumbNavigationProxyModel::KBreadcrumbNavigationProxyModel(QItemSelectionModel* selectionModel, QObject* parent)
  : KSelectionProxyModel(selectionModel, parent)
{

}

QVariant KBreadcrumbNavigationProxyModel::data(const QModelIndex& index, int role) const
{
  if (rowCount() > 2 && index.row() == 0 && role == Qt::DisplayRole)
  {
    QModelIndex sourceIndex = mapToSource(index);
    QStringList dataList;
    while (sourceIndex.isValid())
    {
      dataList.prepend(sourceIndex.data().toString());
      sourceIndex = sourceIndex.parent();
    }
    return dataList.join(" > ");
  }
  return KSelectionProxyModel::data(index, role);
}

void KBreadcrumbNavigationProxyModel::setShowHiddenAscendantData(bool showHiddenAscendantData)
{
  m_showHiddenAscendantData = showHiddenAscendantData;
}

bool KBreadcrumbNavigationProxyModel::showHiddenAscendantData() const
{
  return m_showHiddenAscendantData;
}

KNavigatingProxyModel::KNavigatingProxyModel(QItemSelectionModel* selectionModel, QObject* parent)
  : KSelectionProxyModel(selectionModel, parent), m_selectionModel(selectionModel)
{

}

void KNavigatingProxyModel::setSourceModel(QAbstractItemModel* sourceModel)
{
  connect( m_selectionModel, SIGNAL(selectionChanged(QItemSelection,QItemSelection)),
      SLOT(navigationSelectionChanged(QItemSelection,QItemSelection)) );

  KSelectionProxyModel::setSourceModel(sourceModel);
  updateNavigation();
}

void KNavigatingProxyModel::navigationSelectionChanged(const QItemSelection& selected, const QItemSelection& deselected)
{
  updateNavigation();
}

void KNavigatingProxyModel::updateNavigation()
{
  if (!sourceModel())
    return;

  if (m_selectionModel->selection().isEmpty())
  {
    setFilterBehavior(KSelectionProxyModel::ExactSelection);
    QModelIndex top = sourceModel()->index(0, 0);
    QModelIndex bottom = sourceModel()->index(sourceModel()->rowCount() - 1, 0);

    disconnect( m_selectionModel, SIGNAL(selectionChanged(QItemSelection,QItemSelection)),
        this, SLOT(navigationSelectionChanged(QItemSelection,QItemSelection)) );
    m_selectionModel->select(QItemSelection(top, bottom), QItemSelectionModel::Select);
    connect( m_selectionModel, SIGNAL(selectionChanged(QItemSelection,QItemSelection)),
        SLOT(navigationSelectionChanged(QItemSelection,QItemSelection)) );
  } else if (filterBehavior() != KSelectionProxyModel::ChildrenOfExactSelection) {
    setFilterBehavior(KSelectionProxyModel::ChildrenOfExactSelection);
  }
}

void KNavigatingProxyModel::modelReset()
{
  updateNavigation();
}

QVariant KNavigatingProxyModel::data(const QModelIndex& index, int role) const
{
  if ( role == Qt::DisplayRole && sourceModel()->hasChildren(mapToSource(index)))
  {
    return QString("+ " + KSelectionProxyModel::data(index, role).toString());
  }
  return KSelectionProxyModel::data(index, role);
}


KForwardingItemSelectionModel::KForwardingItemSelectionModel(QAbstractItemModel* model, QItemSelectionModel* selectionModel, QObject *parent)
  : QItemSelectionModel(model, parent), m_selectionModel(selectionModel), m_direction(Forward)
{
  Q_ASSERT(model == selectionModel->model());
  connect(selectionModel, SIGNAL(selectionChanged(QItemSelection,QItemSelection)),
          SLOT(navigationSelectionChanged(QItemSelection,QItemSelection)));
}

KForwardingItemSelectionModel::KForwardingItemSelectionModel(QAbstractItemModel* model, QItemSelectionModel* selectionModel, Direction direction, QObject *parent)
  : QItemSelectionModel(model, parent), m_selectionModel(selectionModel), m_direction(direction)
{
  Q_ASSERT(model == selectionModel->model());
  if (m_direction == Forward)
    connect(selectionModel, SIGNAL(selectionChanged(QItemSelection,QItemSelection)),
            SLOT(navigationSelectionChanged(QItemSelection,QItemSelection)));
}

void KForwardingItemSelectionModel::select(const QModelIndex& index, QItemSelectionModel::SelectionFlags command)
{
  if (m_direction == Reverse)
    m_selectionModel->select(index, command);
  else
    QItemSelectionModel::select(index, command);
}

void KForwardingItemSelectionModel::select(const QItemSelection& selection, QItemSelectionModel::SelectionFlags command)
{
  if (m_direction == Reverse)
    m_selectionModel->select(selection, command);
  else
    QItemSelectionModel::select(selection, command);
}

void KForwardingItemSelectionModel::navigationSelectionChanged(const QItemSelection& selected, const QItemSelection& deselected)
{
  select(selected, ClearAndSelect);
}

BreadcrumbNavigationWidget::BreadcrumbNavigationWidget(QWidget* parent, Qt::WindowFlags f)
  : QWidget(parent, f)
{
  DynamicTreeModel *rootModel = new DynamicTreeModel(this);
  QSplitter *splitter = new QSplitter(this);
  QHBoxLayout *layout = new QHBoxLayout(this);
  layout->addWidget(splitter);

  DynamicTreeWidget *dynamicTree = new DynamicTreeWidget(rootModel, splitter);
  dynamicTree->treeView()->setSelectionMode(QAbstractItemView::SingleSelection);
  dynamicTree->setInitialTree(
    "- 1"
    "- - 2"
    "- - 2"
    "- - - 3"
    "- - - - 4"
    "- - - - - 5"
    "- - 2"
    "- 6"
    "- 6"
    "- 6"
    "- - 7"
    "- - - 8"
    "- - - 8"
    "- - - - 9"
    "- - - - - 10"
    "- - - 8"
    "- - - 8"
    "- - 8"
    "- 16"
    "- - 17"
    "- - - 18"
    "- - - - 19"
    "- - - - - 20");

  QList<QItemSelectionModel*> selectionModelList;

  QSplitter *vSplitter = new QSplitter(Qt::Vertical, splitter);

  QItemSelectionModel *rootSelectionModel = new QItemSelectionModel(rootModel, this);
  SON(rootSelectionModel);

  dynamicTree->treeView()->setSelectionModel(rootSelectionModel);

  KBreadcrumbSelectionModel *breadcrumbOnlyProxySelector2 = new KBreadcrumbSelectionModel(rootSelectionModel, KBreadcrumbSelectionModel::MakeBreadcrumbSelectionInOther, this);
  SON(breadcrumbOnlyProxySelector2);
  breadcrumbOnlyProxySelector2->setActualSelectionIncluded(false);

  KBreadcrumbNavigationProxyModel *breadcrumbNavigationModel = new KBreadcrumbNavigationProxyModel( breadcrumbOnlyProxySelector2, this);
  SON(breadcrumbNavigationModel);
  breadcrumbNavigationModel->setSourceModel( rootModel );
  breadcrumbNavigationModel->setFilterBehavior( KSelectionProxyModel::ExactSelection );

  QListView *breadcrumbView = new QListView(vSplitter);
//   SON(breadcrumbNavigationModel);
  breadcrumbView->setModel(breadcrumbNavigationModel);

  // This shouldn't operate on rootSelectionModel. It should operate on oneway instead?
  KLinkItemSelectionModel *breadcrumbViewSelectionModel = new KLinkItemSelectionModel(breadcrumbNavigationModel, rootSelectionModel, this);
  SON(breadcrumbViewSelectionModel);

  KForwardingItemSelectionModel *oneway2 = new KForwardingItemSelectionModel(breadcrumbNavigationModel, breadcrumbViewSelectionModel, KForwardingItemSelectionModel::Reverse);
  SON(oneway2);

  breadcrumbView->setSelectionModel(oneway2);

  KSelectionProxyModel *currentItemSelectionModel = new KSelectionProxyModel(rootSelectionModel, this);
  currentItemSelectionModel->setFilterBehavior(KSelectionProxyModel::ExactSelection);
  currentItemSelectionModel->setSourceModel(rootModel);
  SON(currentItemSelectionModel);

  CurrentItemLabel *label = new CurrentItemLabel(currentItemSelectionModel, vSplitter);

  QListView *selectionView = new QListView(vSplitter);

  // Need a one-way connection from rootSelectionModel to rootSelectionModel2

  KForwardingItemSelectionModel *oneway = new KForwardingItemSelectionModel(rootModel, rootSelectionModel);

  KNavigatingProxyModel *navigatingProxyModel = new KNavigatingProxyModel(oneway, this);
  SON(navigatingProxyModel);
  navigatingProxyModel->setSourceModel( rootModel );
  selectionView->setModel(navigatingProxyModel);

  KLinkItemSelectionModel *selectedChildrenSelectionModel = new KLinkItemSelectionModel(navigatingProxyModel, rootSelectionModel, this);

  selectionView->setSelectionModel(selectedChildrenSelectionModel);
}