////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2011-2022 The Octave Project Developers
//
// See the file COPYRIGHT.md in the top-level directory of this
// distribution or <https://octave.org/copyright/>.
//
// This file is part of Octave.
//
// Octave 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 3 of the License, or
// (at your option) any later version.
//
// Octave 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Octave; see the file COPYING.  If not, see
// <https://www.gnu.org/licenses/>.
//
////////////////////////////////////////////////////////////////////////

#if defined (HAVE_CONFIG_H)
#  include "config.h"
#endif

#include <QApplication>
#include <QClipboard>
#include <QCompleter>
#include <QHBoxLayout>
#include <QHeaderView>
#include <QInputDialog>
#include <QLabel>
#include <QLineEdit>
#include <QMenu>
#include <QMessageBox>
#include <QPushButton>
#include <QSignalMapper>
#include <QVBoxLayout>

#include "gui-preferences-ws.h"
#include "gui-settings.h"
#include "octave-qobject.h"
#include "octave-qtutils.h"
#include "workspace-view.h"

namespace octave
{
  workspace_view::workspace_view (QWidget *p, base_qobject& oct_qobj)
    : octave_dock_widget ("WorkspaceView", p, oct_qobj),
      m_view (new QTableView (this)),
      m_filter_checkbox (new QCheckBox ()),
      m_filter (new QComboBox (this)),
      m_filter_widget (new QWidget (this))
  {
    set_title (tr ("Workspace"));
    setStatusTip (tr ("View the variables in the active workspace."));

    m_filter->setToolTip (tr ("Enter text to filter the workspace"));
    m_filter->setEditable (true);
    m_filter->setMaxCount (ws_max_filter_history.def.toInt ());
    m_filter->setInsertPolicy (QComboBox::NoInsert);
    m_filter->setSizeAdjustPolicy (QComboBox::AdjustToMinimumContentsLengthWithIcon);
    QSizePolicy sizePol (QSizePolicy::Expanding, QSizePolicy::Preferred);
    m_filter->setSizePolicy (sizePol);
    m_filter->completer ()->setCaseSensitivity (Qt::CaseSensitive);

    QLabel *filter_label = new QLabel (tr ("Filter"));

    m_view->setWordWrap (false);
    m_view->setContextMenuPolicy (Qt::CustomContextMenu);
    m_view->setShowGrid (false);
    (m_view->verticalHeader) ()->hide ();
    m_view->setAlternatingRowColors (true);
    m_view_previous_row_count = 0;

    // Set an empty widget, so we can assign a layout to it.
    setWidget (new QWidget (this));

    // Create the layouts
    QHBoxLayout *filter_layout = new QHBoxLayout ();

    filter_layout->addWidget (filter_label);
    filter_layout->addWidget (m_filter_checkbox);
    filter_layout->addWidget (m_filter);
    filter_layout->setMargin (0);

    m_filter_widget->setLayout (filter_layout);

    QVBoxLayout *ws_layout = new QVBoxLayout ();
    ws_layout->addWidget (m_filter_widget);
    ws_layout->addWidget (m_view);
    ws_layout->setSpacing (0);

    gui_settings settings;

    m_filter_shown = settings.value (ws_filter_shown).toBool ();
    m_filter_widget->setVisible (m_filter_shown);

    ws_layout->setMargin (2);

    // Set the empty widget to have our layout.
    widget ()->setLayout (ws_layout);

    // Initialize collapse/expand state of the workspace subcategories.

    //enable sorting (setting column and order after model was set)
    m_view->setSortingEnabled (true);
    // Initialize column order and width of the workspace
    m_view->horizontalHeader ()->restoreState
      (settings.value (ws_column_state.key).toByteArray ());

    // Set header properties for sorting
    m_view->horizontalHeader ()->setSectionsClickable (true);
    m_view->horizontalHeader ()->setSectionsMovable (true);
    m_view->horizontalHeader ()->setSortIndicator (
                                                   settings.value (ws_sort_column).toInt (),
                                                   static_cast<Qt::SortOrder> (settings.value (ws_sort_order).toUInt ()));
    // FIXME: use value<Qt::SortOrder> instead of static cast after
    //        dropping support of Qt 5.4

    m_view->horizontalHeader ()->setSortIndicatorShown (true);

    m_view->horizontalHeader ()->setContextMenuPolicy (Qt::CustomContextMenu);
    connect (m_view->horizontalHeader (),
             &QTableView::customContextMenuRequested,
             this, &workspace_view::header_contextmenu_requested);

    // Init state of the filter
    m_filter->addItems (settings.value (ws_mru_list.key).toStringList ());

    bool filter_state = settings.value (ws_filter_active).toBool ();
    m_filter_checkbox->setChecked (filter_state);
    filter_activate (filter_state);

    // Connect signals and slots.

    connect (m_filter, &QComboBox::editTextChanged,
             this, &workspace_view::filter_update);
    connect (m_filter_checkbox, &QCheckBox::toggled,
             this, &workspace_view::filter_activate);
    connect (m_filter->lineEdit (), &QLineEdit::editingFinished,
             this, &workspace_view::update_filter_history);

    connect (m_view, &QTableView::customContextMenuRequested,
             this, &workspace_view::contextmenu_requested);

    connect (m_view, &QTableView::activated,
             this, &workspace_view::handle_contextmenu_edit);

    if (! p)
      make_window ();
  }

  void workspace_view::setModel (workspace_model *model)
  {
    m_filter_model.setSourceModel (model);
    m_filter_model.setFilterKeyColumn(0);

    m_view->setModel (&m_filter_model);

    // set the sorting after the model is set, it would be ignored otherwise

    gui_settings settings;

    m_view->sortByColumn (
      settings.value (ws_sort_column).toInt (),
      static_cast<Qt::SortOrder> (settings.value (ws_sort_order).toUInt ()));
      // FIXME: use value<Qt::SortOrder> instead of static cast after
      //        dropping support of Qt 5.4

    m_model = model;
  }

  void
  workspace_view::notice_settings (void)
  {
    gui_settings settings;

    m_model->notice_settings (); // update colors of model first

    for (int i = 0; i < ws_columns_shown.length (); i++)
      m_view->setColumnHidden (i + 1, ! settings.value (ws_columns_shown_keys.at (i), true).toBool ());

    QString tool_tip;

    if (settings.value (ws_enable_colors).toBool ()
        && ! settings.value (ws_hide_tool_tips).toBool ())
      {
        tool_tip  = QString (tr ("View the variables in the active workspace.<br>"));
        tool_tip += QString (tr ("Colors for variable attributes:"));

        for (int i = 0; i < ws_colors_count; i++)
          {
            tool_tip +=
              QString (R"(<div style="background-color:%1;color:%2">%3</div>)")
              .arg (m_model->storage_class_color (i).name ())
              .arg (m_model->storage_class_color (i + ws_colors_count).name ())
              .arg (QCoreApplication::translate ("octave::settings_dialog",
                                                 ws_color_names.at (i).toStdString ().data ()));
          }
      }

    setToolTip (tool_tip);
  }

  void
  workspace_view::save_settings (void)
  {
    gui_settings settings;

    settings.setValue (ws_column_state.key,
                       m_view->horizontalHeader ()->saveState ());

    int sort_column = m_view->horizontalHeader ()->sortIndicatorSection ();
    Qt::SortOrder sort_order = m_view->horizontalHeader ()->sortIndicatorOrder ();
    settings.setValue (ws_sort_column.key, sort_column);
    settings.setValue (ws_sort_order.key, sort_order);

    settings.setValue (ws_filter_active.key, m_filter_checkbox->isChecked ());
    settings.setValue (ws_filter_shown.key, m_filter_shown);

    QStringList mru;
    for (int i = 0; i < m_filter->count (); i++)
      mru.append (m_filter->itemText (i));
    settings.setValue (ws_mru_list.key, mru);

    settings.sync ();

    octave_dock_widget::save_settings ();
  }

  void workspace_view::set_filter_focus (bool focus)
  {
    if (focus)
      {
        m_filter->setFocus ();
        setFocusProxy (m_filter);
      }
    else
      {
        m_view->setFocus ();
        setFocusProxy (m_view);
      }
  }

  void
  workspace_view::filter_update (const QString& expression)
  {
    m_filter_model.setFilterWildcard (expression);
    handle_model_changed ();
  }

  void
  workspace_view::filter_activate (bool state)
  {
    m_filter->setEnabled (state);
    m_filter_model.setDynamicSortFilter (state);

    if (state)
      filter_update (m_filter->currentText ());
    else
      filter_update (QString ());

    set_filter_focus (state);
  }

  void
  workspace_view::update_filter_history (void)
  {
    QString text = m_filter->currentText ();   // get current text
    int index = m_filter->findText (text);     // and its actual index

    if (index > -1)
      m_filter->removeItem (index);    // remove if already existing

    m_filter->insertItem (0, text);    // (re)insert at beginning
    m_filter->setCurrentIndex (0);
  }

  void
  workspace_view::header_contextmenu_requested (const QPoint& mpos)
  {
    QMenu menu (this);
    QSignalMapper sig_mapper (this);

    gui_settings settings;

    for (int i = 0; i < ws_columns_shown.length (); i++)
      {
        QAction *action
          = menu.addAction (tr (ws_columns_shown.at (i).toStdString ().data ()),
                            &sig_mapper, SLOT (map ()));
        sig_mapper.setMapping (action, i);
        action->setCheckable (true);
        action->setChecked (settings.value (ws_columns_shown_keys.at (i), true).toBool ());
      }

    // FIXME: We could use
    //
    //   connect (&m_sig_mapper, QOverload<int>::of (&QSignalMapper::mapped),
    //            this, &workspace_view::toggle_header);
    //
    // but referring to QSignalMapper::mapped will generate deprecated
    // function warnings from GCC.  We could also use
    //
    //   connect (&m_sig_mapper, &QSignalMapper::mappedInt,
    //            this, &workspace_view::toggle_header);
    //
    // but the function mappedInt was not introduced until Qt 5.15 so
    // we'll need a feature test.

    connect (&sig_mapper, SIGNAL (mapped (int)),
             this, SLOT (toggle_header (int)));

    menu.exec (m_view->mapToGlobal (mpos));
  }

  void
  workspace_view::toggle_header (int col)
  {
    gui_settings settings;

    QString key = ws_columns_shown_keys.at (col);
    bool shown = settings.value (key, true).toBool ();

    m_view->setColumnHidden (col + 1, shown);

    settings.setValue (key, ! shown);
    settings.sync ();

    octave_dock_widget::save_settings ();
  }

  void
  workspace_view::contextmenu_requested (const QPoint& qpos)
  {
    QMenu menu (this);

    QModelIndex index = m_view->indexAt (qpos);

    // if it isn't Local, Global etc, allow the ctx menu
    if (index.isValid () && index.column () == 0)
      {
        QString var_name = get_var_name (index);

        menu.addAction (tr ("Open in Variable Editor"), this,
                        &workspace_view::handle_contextmenu_edit);

        menu.addAction (tr ("Copy name"), this,
                        &workspace_view::handle_contextmenu_copy);

        menu.addAction (tr ("Copy value"), this,
                        &workspace_view::handle_contextmenu_copy_value);

        QAction *rename
          = menu.addAction (tr ("Rename"), this,
                            &workspace_view::handle_contextmenu_rename);

        // Use m_model here instead of using "m_view->model ()" because
        // that points to the proxy model.
        if (! m_model->is_top_level ())
          {
            rename->setDisabled (true);
            rename->setToolTip (tr ("Only top-level symbols may be renamed"));
          }

        menu.addAction ("Clear " + var_name, this,
                        &workspace_view::handle_contextmenu_clear);

        menu.addSeparator ();

        menu.addAction ("disp (" + var_name + ')', this,
                        &workspace_view::handle_contextmenu_disp);

        menu.addAction ("plot (" + var_name + ')', this,
                        &workspace_view::handle_contextmenu_plot);

        menu.addAction ("stem (" + var_name + ')', this,
                        &workspace_view::handle_contextmenu_stem);

        menu.addSeparator ();

      }

    if (m_filter_shown)
      menu.addAction (tr ("Hide filter"), this,
                      &workspace_view::handle_contextmenu_filter);
    else
      menu.addAction (tr ("Show filter"), this,
                      &workspace_view::handle_contextmenu_filter);

    menu.exec (m_view->mapToGlobal (qpos));
  }

  void
  workspace_view::handle_contextmenu_copy (void)
  {
    QModelIndex index = m_view->currentIndex ();

    if (index.isValid ())
      {
        QString var_name = get_var_name (index);

        QClipboard *clipboard = QApplication::clipboard ();

        clipboard->setText (var_name);
      }
  }

  void
  workspace_view::handle_contextmenu_copy_value (void)
  {
    QModelIndex index = m_view->currentIndex ();

    if (index.isValid ())
      emit copy_variable_value_to_clipboard (get_var_name (index));
  }

  void
  workspace_view::handle_contextmenu_rename (void)
  {
    QModelIndex index = m_view->currentIndex ();

    if (index.isValid ())
      {
        QString var_name = get_var_name (index);

        QInputDialog *inputDialog = new QInputDialog ();

        inputDialog->setOptions (QInputDialog::NoButtons);

        bool ok = false;

        QString new_name
          = inputDialog->getText (nullptr, "Rename Variable", "New name:",
                                  QLineEdit::Normal, var_name, &ok);

        if (ok && ! new_name.isEmpty ())
          emit rename_variable_signal (var_name, new_name);
      }
  }

  void
  workspace_view::handle_contextmenu_edit (void)
  {
    QModelIndex index = m_view->currentIndex ();

    if (index.isValid ())
      emit edit_variable_signal (get_var_name (index));
  }

  void
  workspace_view::handle_contextmenu_clear (void)
  {
    relay_contextmenu_command ("clear", true);
  }

  void
  workspace_view::handle_contextmenu_disp (void)
  {
    relay_contextmenu_command ("disp");
  }

  void
  workspace_view::handle_contextmenu_plot (void)
  {
    relay_contextmenu_command ("figure (); plot");
  }

  void
  workspace_view::handle_contextmenu_stem (void)
  {
    relay_contextmenu_command ("figure (); stem");
  }

  void
  workspace_view::handle_contextmenu_filter (void)
  {
    m_filter_shown = ! m_filter_shown;
    m_filter_widget->setVisible (m_filter_shown);

    set_filter_focus (m_filter_shown && m_filter_checkbox->isChecked ());
  }

  void
  workspace_view::handle_model_changed (void)
  {
    // m_view->resizeRowsToContents ();
    // Just modify those rows that have been added rather than go through
    // the whole list.  For-loop test will handle when number of rows reduced.
    QFontMetrics fm = m_view->fontMetrics ();
    int row_height = fm.height ();
    int new_row_count = m_filter_model.rowCount ();
    for (int i = m_view_previous_row_count; i < new_row_count; i++)
      m_view->setRowHeight (i, row_height);
    m_view_previous_row_count = new_row_count;
  }

  void
  workspace_view::copyClipboard ()
  {
    if (m_view->hasFocus ())
      handle_contextmenu_copy ();
  }

  void
  workspace_view::selectAll ()
  {
    if (m_view->hasFocus ())
      m_view->selectAll ();
  }

  void
  workspace_view::relay_contextmenu_command (const QString& cmdname, bool str)
  {
    QModelIndex index = m_view->currentIndex ();

    if (index.isValid ())
      {
        QString var_name;

        if (str)
          var_name = "\'" + get_var_name (index) + "\'";
        else
          var_name = get_var_name (index);

        emit command_requested (cmdname + " (" + var_name + ");");
      }
  }

  QString
  workspace_view::get_var_name (const QModelIndex& index)
  {
    // We are using a sort model proxy so m_model won't provide the
    // correct ordering.

    QAbstractItemModel *m = m_view->model ();

    QMap<int, QVariant> item_data
      = m->itemData (index.sibling (index.row (), 0));

    return item_data[0].toString ();
  }
}