/*=========================================================================

   Program: ParaView
   Module:    pqFavoritesDialog.cxx

   Copyright (c) 2005-2008 Sandia Corporation, Kitware Inc.
   All rights reserved.

   ParaView is a free software; you can redistribute it and/or modify it
   under the terms of the ParaView license version 1.2.

   See License_v1.2.txt for the full ParaView license.
   A copy of this license can be obtained by contacting
   Kitware Inc.
   28 Corporate Drive
   Clifton Park, NY 12065
   USA

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR
CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

=========================================================================*/

// self
#include "pqFavoritesDialog.h"
#include "ui_pqFavoritesDialog.h"

// Qt
#include <QDropEvent>
#include <QHeaderView>
#include <QSet>
#include <QShortcut>
#include <QStringList>

// pqCore
#include "pqApplicationCore.h"
#include "pqSettings.h"

namespace
{
//----------------------------------------------------------------------------
bool isItemCategory(QTreeWidgetItem* item)
{
  return item->data(0, Qt::UserRole).toBool();
}

//----------------------------------------------------------------------------
void ensureUniqueCategoryName(QTreeWidgetItem* parent, QTreeWidgetItem* item, int v = 0)
{
  QString itemText = item->text(0);
  for (int i = 0; parent && i < parent->childCount(); i++)
  {
    QTreeWidgetItem* child = parent->child(i);
    if (child != item && isItemCategory(child) && child->text(0) == itemText)
    {
      QRegExp rx("(.*)_([0-9]+)");
      int p = rx.indexIn(itemText);
      if (p > -1)
      {
        itemText = rx.cap(1);
        v = rx.cap(2).toInt();
      }
      item->setText(0, QString("%1_%2").arg(itemText, QString::number(v + 1)));
      ensureUniqueCategoryName(parent, item, v + 1);
      break;
    }
  }
}

//----------------------------------------------------------------------------
void ensureUniqueCategoryName(QTreeWidget* w, QTreeWidgetItem* item, int v = 0)
{
  QTreeWidgetItem* parent = item->parent() ? item->parent() : w->invisibleRootItem();
  ensureUniqueCategoryName(parent, item, v);
}

//----------------------------------------------------------------------------
QTreeWidgetItem* createItem(QTreeWidgetItem* parent, const QString& name, bool isCategory,
  const QString& proxyName = "", QTreeWidgetItem* preceding = nullptr, bool allowDuplicated = false)
{
  if (name.isEmpty())
  {
    return nullptr;
  }
  for (int i = 0; !allowDuplicated && i < parent->childCount(); i++)
  {
    QTreeWidgetItem* child = parent->child(i);
    if (isItemCategory(child) == isCategory && child->text(0) == name)
    {
      return child;
    }
  }

  if (preceding == nullptr)
  {
    preceding = parent->child(parent->childCount() - 1);
  }

  QTreeWidgetItem* item = new QTreeWidgetItem(parent, preceding, QTreeWidgetItem::UserType);
  Qt::ItemFlags itemFlags =
    Qt::ItemIsSelectable | Qt::ItemIsUserCheckable | Qt::ItemIsEnabled | Qt::ItemIsDragEnabled;

  if (isCategory)
  {
    itemFlags |= Qt::ItemIsEditable | Qt::ItemIsDropEnabled;
    QFont f = item->font(0);
    f.setItalic(true);
    item->setFont(0, f);
    item->setChildIndicatorPolicy(QTreeWidgetItem::ShowIndicator);
    item->setExpanded(true);
  }

  item->setText(0, name);
  item->setData(0, Qt::UserRole, QVariant(isCategory));
  item->setData(0, Qt::UserRole + 1, proxyName);
  item->setFlags(itemFlags);

  return item;
}

//----------------------------------------------------------------------------
void removeTreeViewItemRec(
  QTreeWidgetItem* item, QSet<QTreeWidgetItem*>& deletedItems, bool parentIsDeleted = false)
{
  if (!deletedItems.contains(item))
  {
    deletedItems.insert(item);
    for (int i = 0; i < item->childCount(); i++)
    {
      removeTreeViewItemRec(item->child(i), deletedItems, true);
    }
    if (!parentIsDeleted)
    {
      delete item;
    }
  }
}

//----------------------------------------------------------------------------
void fetchTreeViewItemRec(QTreeWidget* widget, QTreeWidgetItem* item,
  QSet<QTreeWidgetItem*>& aboveItems, QSet<QTreeWidgetItem*>& belowItems)
{
  aboveItems.insert(widget->itemAbove(item));
  belowItems.insert(widget->itemBelow(item));
  for (int i = 0; i < item->childCount(); i++)
  {
    fetchTreeViewItemRec(widget, item->child(i), aboveItems, belowItems);
  }
}
}

//----------------------------------------------------------------------------
pqFavoritesDialog::pqFavoritesDialog(const QVariant& filtersList, QWidget* p)
  : Superclass(p)
  , Ui(new Ui::pqFavoritesDialog())
{
  this->Ui->setupUi(this);

  this->Ui->availableFilters->setAcceptDrops(false);
  this->Ui->availableFilters->sortByColumn(0, Qt::AscendingOrder);
  this->Ui->availableFilters->setHeaderLabels(QStringList() << QString("Name"));

  QObject::connect(this->Ui->addCategory, SIGNAL(released()), this, SLOT(createCategory()));
  QObject::connect(
    this->Ui->removeFavorite, SIGNAL(released()), this, SLOT(onRemoveFavoritePressed()));
  QShortcut* shortcut = new QShortcut(QKeySequence(Qt::Key_Delete), this->Ui->favorites);
  QObject::connect(shortcut, SIGNAL(activated()), this, SLOT(onRemoveFavoritePressed()));

  this->Ui->favorites->setHeaderLabels(QStringList() << QString("Name"));
  this->Ui->favorites->viewport()->installEventFilter(this);
  QObject::connect(this->Ui->addFavorite, SIGNAL(released()), this, SLOT(onAddFavoritePressed()));
  QObject::connect(this->Ui->favorites, SIGNAL(itemChanged(QTreeWidgetItem*, int)), this,
    SLOT(onItemChanged(QTreeWidgetItem*, int)));
  QObject::connect(
    this->Ui->searchBox, SIGNAL(textChanged(QString)), this, SLOT(onSearchTextChanged(QString)));

  this->connect(this, SIGNAL(accepted()), SLOT(onAccepted()));

  this->populateFiltersTree(filtersList);
  this->populateFavoritesTree();
}

//----------------------------------------------------------------------------
pqFavoritesDialog::~pqFavoritesDialog()
{
}

//----------------------------------------------------------------------------
void pqFavoritesDialog::onSearchTextChanged(QString pattern)
{
  auto* root = this->Ui->availableFilters->invisibleRootItem();
  for (int i = 0; i < root->childCount(); i++)
  {
    auto* item = root->child(i);
    if (pattern == "")
    {
      item->setHidden(false);
    }
    else
    {
      item->setHidden(!item->text(0).contains(pattern, Qt::CaseInsensitive));
    }
  }
}

//----------------------------------------------------------------------------
bool pqFavoritesDialog::eventFilter(QObject* object, QEvent* event)
{
  if (event->type() == QEvent::Drop)
  {
    auto* dropEvent = static_cast<QDropEvent*>(event);
    auto* sourceTreeView = dynamic_cast<QTreeWidget*>(dropEvent->source());
    auto* destItem = this->Ui->favorites->itemAt(dropEvent->pos());
    QTreeWidgetItem* categoryItem = nullptr;
    if (destItem)
    {
      bool onItem = this->Ui->favorites->isDropOnItem();
      categoryItem = onItem ? destItem : destItem->parent();
    }
    if (categoryItem == nullptr)
    {
      categoryItem = this->Ui->favorites->invisibleRootItem();
    }
    else
    {
      categoryItem->setExpanded(true);
    }

    for (auto* item : sourceTreeView->selectedItems())
    {
      for (int i = 0; i < categoryItem->childCount(); i++)
      {
        auto* child = categoryItem->child(i);
        if (child != item && !::isItemCategory(child) && !::isItemCategory(item) &&
          child->text(0) == item->text(0))
        {
          // This item already exists at this level, skip it!
          dropEvent->setDropAction(Qt::IgnoreAction);
          event->ignore();
          return true;
        }
      }
    }
    for (auto* item : sourceTreeView->selectedItems())
    {
      if (::isItemCategory(item))
      {
        ::ensureUniqueCategoryName(categoryItem, item);
      }
    }
  }

  return QDialog::eventFilter(object, event);
}

//----------------------------------------------------------------------------
void pqFavoritesDialog::populateFavoritesTree()
{
  this->Ui->favorites->clear();
  pqSettings* settings = pqApplicationCore::instance()->settings();
  QString key = QStringLiteral("favorites.ParaViewFilters/");
  if (settings->contains(key))
  {
    QString settingValue = settings->value(key).toString();
    QStringList bmList = settingValue.split("|", QString::SkipEmptyParts);
    for (QString bm : bmList)
    {
      QStringList bmPath = bm.split(";", QString::SkipEmptyParts);
      if (bmPath.size() >= 2)
      {
        QString group = bmPath.takeFirst();
        bool isCategory = group.compare("categories") == 0;
        QString proxyName = isCategory ? "" : bmPath.takeLast();
        QString displayName = bmPath.takeLast();

        QTreeWidgetItem* root = this->Ui->favorites->invisibleRootItem();
        for (const QString& category : bmPath)
        {
          root = ::createItem(root, category, true);
        }
        ::createItem(root, displayName, isCategory, proxyName);
      }
    }
  }
  this->Ui->favorites->resizeColumnToContents(0);
}

//----------------------------------------------------------------------------
void pqFavoritesDialog::populateFiltersTree(const QVariant& filtersList)
{
  this->Ui->availableFilters->clear();
  QSequentialIterable iterableList = filtersList.value<QSequentialIterable>();

  for (const QVariant& variant : iterableList)
  {
    if (variant.canConvert<QStringList>())
    {
      QStringList filter = variant.toStringList();
      ::createItem(
        this->Ui->availableFilters->invisibleRootItem(), filter.at(0), false, filter.at(1));
    }
  }
  this->Ui->availableFilters->resizeColumnToContents(0);
}

//----------------------------------------------------------------------------
void pqFavoritesDialog::onItemChanged(QTreeWidgetItem* item, int)
{
  if (::isItemCategory(item))
  {
    // Ensure unicity of categories
    ::ensureUniqueCategoryName(this->Ui->favorites, item);
  }
  else
  {
    // ensure that item that are not categories have drop disabled
    if (item->flags() & Qt::ItemIsDropEnabled)
    {
      item->setFlags(item->flags() & ~(Qt::ItemIsDropEnabled));
    }
  }
  this->Ui->favorites->scrollToItem(item);
  this->Ui->favorites->setCurrentItem(item);
}

//----------------------------------------------------------------------------
QTreeWidgetItem* pqFavoritesDialog::getSelectedCategory()
{
  QTreeWidgetItem* item = this->Ui->favorites->invisibleRootItem();
  if (!this->Ui->favorites->selectedItems().isEmpty())
  {
    item = this->Ui->favorites->selectedItems().first();
    if (!::isItemCategory(item))
    {
      item = item->parent();
    }
  }

  return item;
}

//----------------------------------------------------------------------------
void pqFavoritesDialog::createCategory()
{
  QTreeWidgetItem* root = this->getSelectedCategory() ? this->getSelectedCategory()
                                                      : this->Ui->favorites->invisibleRootItem();
  QTreeWidgetItem* precedingItem = nullptr;
  if (!this->Ui->favorites->selectedItems().isEmpty() &&
    !::isItemCategory(this->Ui->favorites->selectedItems().first()))
  {
    precedingItem = this->Ui->favorites->selectedItems().first();
  }

  QTreeWidgetItem* newItem =
    ::createItem(root, QStringLiteral("New Category"), true, "", precedingItem, true);
  this->Ui->favorites->scrollToItem(newItem);
  this->Ui->favorites->setCurrentItem(newItem);
  this->Ui->favorites->editItem(newItem, 0);
  this->Ui->favorites->resizeColumnToContents(0);
}

//----------------------------------------------------------------------------
void pqFavoritesDialog::onRemoveFavoritePressed()
{
  QSet<QTreeWidgetItem *> deletedItems, aboveItems, belowItems;
  QList<QTreeWidgetItem*> selected = this->Ui->favorites->selectedItems();
  if (selected.size() == 0)
  {
    return;
  }

  // Fetch all items that are above and below the selected items
  for (auto* item : selected)
  {
    ::fetchTreeViewItemRec(this->Ui->favorites, item, aboveItems, belowItems);
  }
  // Remove the selected items recursively

  for (auto* item : selected)
  {
    ::removeTreeViewItemRec(item, deletedItems);
  }
  // deleteItems contains all the removed item. We add the null pointer
  // as aboveItems and belowItems might contains the null pointer.
  deletedItems.insert(nullptr);
  // Select the/a below item if it exists otherwise, select the/a above one.
  // We remove all the deleted items from those sets to make sure we select
  // an item that is still alive. Note: on sparsed multiple selection, the
  // selection is not predictive, it might occurs around any of the selected
  // element, not the one with the highest row id.
  belowItems = belowItems.subtract(deletedItems);
  if (belowItems.count() == 0)
  {
    belowItems = aboveItems.subtract(deletedItems);
  }
  if (belowItems.count() != 0)
  {
    auto* item = *belowItems.begin();
    this->Ui->favorites->scrollToItem(item);
    this->Ui->favorites->setCurrentItem(item);
  }

  this->Ui->favorites->resizeColumnToContents(0);
}

//----------------------------------------------------------------------------
void pqFavoritesDialog::onAddFavoritePressed()
{
  QTreeWidgetItem* root = this->getSelectedCategory() ? this->getSelectedCategory()
                                                      : this->Ui->favorites->invisibleRootItem();
  QTreeWidgetItem* precedingItem = nullptr;
  if (!this->Ui->favorites->selectedItems().isEmpty() &&
    !::isItemCategory(this->Ui->favorites->selectedItems().first()))
  {
    precedingItem = this->Ui->favorites->selectedItems().first();
  }

  for (auto item : this->Ui->availableFilters->selectedItems())
  {
    auto* qitem = ::createItem(
      root, item->text(0), false, item->data(0, Qt::UserRole + 1).toString(), precedingItem);

    this->Ui->favorites->scrollToItem(qitem);
  }

  root->setExpanded(true);
  this->Ui->favorites->resizeColumnToContents(0);
}

//----------------------------------------------------------------------------
void pqFavoritesDialog::onAccepted()
{
  QTreeWidgetItem* item = this->Ui->favorites->invisibleRootItem();
  QString value;
  value = this->populateSettingsValue(value, item);
  pqSettings* settings = pqApplicationCore::instance()->settings();
  QString key = QStringLiteral("favorites.ParaViewFilters/");
  settings->setValue(key, value);
}

//----------------------------------------------------------------------------
QString pqFavoritesDialog::populateSettingsValue(const QString& value, QTreeWidgetItem* item)
{
  QString newValue;
  for (auto child : item->takeChildren())
  {
    if (child->childCount() > 0)
    {
      QString currentPath = QString("%1;%2").arg(value).arg(child->text(0));
      newValue += this->populateSettingsValue(currentPath, child);
    }
    else
    {
      QString group =
        ::isItemCategory(child) ? QStringLiteral("categories") : QStringLiteral("filters");
      QString proxyName = child->data(0, Qt::UserRole + 1).toString();
      newValue += QString("%1;%2;%3;%4|")
                    .arg(group)
                    .arg(value)
                    .arg(child->text(0))
                    .arg(child->data(0, Qt::UserRole + 1).toString());
    }
  }
  return newValue;
}
