/*
 * Copyright (C) 2017 Open Source Robotics Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
*/
#ifndef GZ_GUI_SEARCHMODEL_HH_
#define GZ_GUI_SEARCHMODEL_HH_

#include "gz/gui/Export.hh"
#include "gz/gui/qt.h"

namespace gz::gui
{
  /// \brief Customize the proxy model to display search results.
  ///
  /// Features:
  ///
  /// * This has been tested with QTreeView and QTableView.
  /// * Manages expansion of nested items through DataRole::TO_EXPAND when
  ///   applicable
  /// * Items with DataRole::TYPE == "title" are ignored
  ///
  class GZ_GUI_VISIBLE SearchModel : public QSortFilterProxyModel
  {
    /// \brief Overloaded Qt method. Customize so we accept rows where:
    /// 1. Each of the words can be found in its ancestors or itself, but not
    /// necessarily all words on the same row, or
    /// 2. One of its descendants matches rule 1, or
    /// 3. One of its ancestors matches rule 1.
    ///
    /// For example this structure:
    /// - a
    /// -- b
    /// -- c
    /// --- d
    ///
    /// * A search of "a" will display all rows.
    /// * A search of "b" or "a b" will display "a" and "b".
    /// * A search of "c", "d", "a c", "a d", "a c d" or "c d" will display
    /// "a", "c" and "d".
    /// * A search of "a b c d", "b c" or "b d" will display nothing.
    ///
    /// \param[in] _srcRow Row on the source model.
    /// \param[in] _srcParent Parent on the source model.
    /// \return True if row is accepted.
    public: bool filterAcceptsRow(const int _srcRow,
                                  const QModelIndex &_srcParent) const;

    /// \brief Check if row contains the word on itself.
    /// \param[in] _srcRow Row on the source model.
    /// \param[in] _srcParent Parent on the source model.
    /// \param[in] _word Word to be checked.
    /// \return True if row matches.
    public: bool FilterAcceptsRowItself(const int _srcRow,
                                        const QModelIndex &_srcParent,
                                        const QString &_word) const;

    /// \brief Check if any of the children is fully accepted.
    /// \param[in] _srcRow Row on the source model.
    /// \param[in] _srcParent Parent on the source model.
    /// \return True if any of the children match.
    public: bool HasAcceptedChildren(const int _srcRow,
                                     const QModelIndex &_srcParent) const;

    /// \brief Check if any of the children accepts a specific word.
    /// \param[in] _srcParent Parent on the source model.
    /// \param[in] _word Word to be checked.
    /// \return True if any of the children match.
    public: bool HasChildAcceptsItself(const QModelIndex &_srcParent,
                                       const QString &_word) const;

    /// \brief Set a new search value.
    /// \param[in] _search Full search string.
    public: void SetSearch(const QString &_search);

    /// \brief Full search string.
    public: QString search;
  };
}  // namespace gz::gui
#endif  // GZ_GUI_SEARCHMODEL_HH_
