// Find dialog derived from an example from Qt Toolkit (license below (**))

////////////////////////////////////////////////////////////////////////
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// or <https://octave.org/copyright/>.
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////////////////////////////////////////////////////////////////////////

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

#if defined (HAVE_QSCINTILLA)

#include <QApplication>
#include <QCheckBox>
#include <QCheckBox>
#include <QCompleter>
#include <QDesktopWidget>
#include <QDialogButtonBox>
#include <QGridLayout>
#include <QIcon>
#include <QLabel>
#include <QLineEdit>
#include <QMessageBox>
#include <QPushButton>
#include <QVBoxLayout>

#include "find-dialog.h"
#include "gui-preferences-ed.h"
#include "resource-manager.h"
#include "octave-qobject.h"

namespace octave
{
  find_dialog::find_dialog (base_qobject& oct_qobj,
                            octave_dock_widget *ed, QWidget *p)
    : QDialog (p), m_octave_qobj (oct_qobj), m_editor (ed),
      m_in_sel (false), m_sel_beg (-1), m_sel_end (-1)
  {
    setWindowTitle (tr ("Editor: Find and Replace"));
    setWindowIcon (QIcon (":/actions/icons/find.png"));

    m_search_label = new QLabel (tr ("Find &what:"));
    m_search_line_edit = new QComboBox (this);
    m_search_line_edit->setToolTip (tr ("Enter text to search for"));
    m_search_line_edit->setEditable (true);
    m_search_line_edit->setMaxCount (m_mru_length);
    m_search_line_edit->completer ()->setCaseSensitivity (Qt::CaseSensitive);
    m_search_label->setBuddy (m_search_line_edit);

    m_replace_label = new QLabel (tr ("Re&place with:"));
    m_replace_line_edit = new QComboBox (this);
    m_replace_line_edit->setToolTip (tr ("Enter new text replacing search hits"));
    m_replace_line_edit->setEditable (true);
    m_replace_line_edit->setMaxCount (m_mru_length);
    m_replace_line_edit->completer ()->setCaseSensitivity (Qt::CaseSensitive);
    m_replace_label->setBuddy (m_replace_line_edit);

     int width = QFontMetrics (m_search_line_edit->font ()).averageCharWidth();
     m_search_line_edit->setFixedWidth (20*width);
     m_replace_line_edit->setFixedWidth (20*width);

    m_case_check_box = new QCheckBox (tr ("Match &case"));
    m_from_start_check_box = new QCheckBox (tr ("Search from &start"));
    m_wrap_check_box = new QCheckBox (tr ("&Wrap while searching"));
    m_wrap_check_box->setChecked (true);
    m_find_next_button = new QPushButton (tr ("&Find Next"));
    m_find_prev_button = new QPushButton (tr ("Find &Previous"));
    m_replace_button = new QPushButton (tr ("&Replace"));
    m_replace_all_button = new QPushButton (tr ("Replace &All"));

    m_more_button = new QPushButton (tr ("&More..."));
    m_more_button->setCheckable (true);
    m_more_button->setAutoDefault (false);

    m_button_box = new QDialogButtonBox (Qt::Vertical);
    m_button_box->addButton (m_find_next_button, QDialogButtonBox::ActionRole);
    m_button_box->addButton (m_find_prev_button, QDialogButtonBox::ActionRole);
    m_button_box->addButton (m_replace_button, QDialogButtonBox::ActionRole);
    m_button_box->addButton (m_replace_all_button, QDialogButtonBox::ActionRole);
    m_button_box->addButton (m_more_button, QDialogButtonBox::ActionRole);
    m_button_box->addButton (QDialogButtonBox::Close);

    m_extension = new QWidget (this);
    m_whole_words_check_box = new QCheckBox (tr ("&Whole words"));
    m_regex_check_box = new QCheckBox (tr ("Regular E&xpressions"));
    m_backward_check_box = new QCheckBox (tr ("Search &backward"));
    m_search_selection_check_box = new QCheckBox (tr ("Search se&lection"));
    m_search_selection_check_box->setCheckable (true);

    connect (m_find_next_button, &QPushButton::clicked,
             this, &find_dialog::find_next);
    connect (m_find_prev_button, &QPushButton::clicked,
             this, &find_dialog::find_prev);
    connect (m_more_button, &QPushButton::toggled,
             m_extension, &QWidget::setVisible);
    connect (m_replace_button, &QPushButton::clicked,
             this, &find_dialog::replace);
    connect (m_replace_all_button, &QPushButton::clicked,
             this, &find_dialog::replace_all);
    connect (m_backward_check_box, &QCheckBox::stateChanged,
             this, &find_dialog::handle_backward_search_changed);
    connect (m_button_box, &QDialogButtonBox::rejected,
             this, &find_dialog::close);

    connect (m_search_selection_check_box, &QCheckBox::stateChanged,
             this, &find_dialog::handle_sel_search_changed);

    QVBoxLayout *extension_layout = new QVBoxLayout ();
    extension_layout->setMargin (0);
    extension_layout->addWidget (m_whole_words_check_box);
    extension_layout->addWidget (m_backward_check_box);
    extension_layout->addWidget (m_search_selection_check_box);
    m_extension->setLayout (extension_layout);

    QGridLayout *top_left_layout = new QGridLayout;
    top_left_layout->addWidget (m_search_label, 1, 1);
    top_left_layout->addWidget (m_search_line_edit, 1, 2);
    top_left_layout->addWidget (m_replace_label, 2, 1);
    top_left_layout->addWidget (m_replace_line_edit, 2, 2);

    QVBoxLayout *left_layout = new QVBoxLayout;
    left_layout->addLayout (top_left_layout);
    left_layout->insertStretch (1, 5);
    left_layout->addWidget (m_case_check_box);
    left_layout->addWidget (m_from_start_check_box);
    left_layout->addWidget (m_wrap_check_box);
    left_layout->addWidget (m_regex_check_box);

    QGridLayout *main_layout = new QGridLayout;
    main_layout->setSizeConstraint (QLayout::SetFixedSize);
    main_layout->addLayout (left_layout, 0, 0);
    main_layout->addWidget (m_button_box, 0, 1);
    main_layout->addWidget (m_extension, 1, 0);
    setLayout (main_layout);

    m_extension->hide ();
    m_find_next_button->setDefault (true);
    m_find_result_available = false;
    m_rep_all = 0;
    m_rep_active = false;

    // Connect required external signals
    connect (ed, SIGNAL (edit_area_changed (octave_qscintilla *)),
             this, SLOT (update_edit_area (octave_qscintilla *)));

    setWindowModality (Qt::NonModal);

    setAttribute(Qt::WA_ShowWithoutActivating);
    setAttribute(Qt::WA_DeleteOnClose);
  }

  // The edit_area has changed: update relevant data of the file dialog
  void find_dialog::update_edit_area (octave_qscintilla *edit_area)
  {
    m_edit_area = edit_area;
    m_search_selection_check_box->setEnabled (edit_area->hasSelectedText ());

    connect (m_edit_area, SIGNAL (copyAvailable (bool)),
             this,       SLOT (handle_selection_changed (bool)),
             Qt::UniqueConnection);
  }

  void find_dialog::save_settings ()
  {
    resource_manager& rmgr = m_octave_qobj.get_resource_manager ();
    gui_settings *s = rmgr.get_settings ();

    // Save position
    QPoint dlg_pos = pos ();

#if defined (Q_OS_WIN32)
    int y = dlg_pos.y ();
#else
    int y = dlg_pos.y () - geometry ().height () + frameGeometry ().height ();
#endif

    m_last_position = QPoint (dlg_pos.x (), y);

    s->setValue (ed_fdlg_pos.key, m_last_position);

    // Is current search/replace text in the mru list?
    mru_update (m_search_line_edit);
    mru_update (m_replace_line_edit);

    // Store mru lists
    QStringList mru;
    for (int i = 0; i < m_search_line_edit->count (); i++)
      mru.append (m_search_line_edit->itemText (i));
    s->setValue (ed_fdlg_search.key, mru);

    mru.clear ();
    for (int i = 0; i < m_replace_line_edit->count (); i++)
      mru.append (m_replace_line_edit->itemText (i));
    s->setValue (ed_fdlg_replace.key, mru);

    // Store dialog's options
    int opts = 0
               + m_extension->isVisible () * FIND_DLG_MORE
               + m_case_check_box->isChecked () * FIND_DLG_CASE
               + m_from_start_check_box->isChecked () * FIND_DLG_START
               + m_wrap_check_box->isChecked () * FIND_DLG_WRAP
               + m_regex_check_box->isChecked () * FIND_DLG_REGX
               + m_whole_words_check_box->isChecked () * FIND_DLG_WORDS
               + m_backward_check_box->isChecked () * FIND_DLG_BACK
               + m_search_selection_check_box->isChecked () * FIND_DLG_SEL;
    s->setValue (ed_fdlg_opts.key, opts);

    s->sync ();
  }

  void find_dialog::restore_settings (QPoint ed_bottom_right)
  {
    resource_manager& rmgr = m_octave_qobj.get_resource_manager ();
    gui_settings *s = rmgr.get_settings ();

    // Get mru lists for search and replace text
    QStringList mru = s->value (ed_fdlg_search.key).toStringList ();
    while (mru.length () > m_mru_length)
      mru.removeLast ();
    m_search_line_edit->addItems (mru);

    mru = s->value (ed_fdlg_replace.key).toStringList ();
    while (mru.length () > m_mru_length)
      mru.removeLast ();
    m_replace_line_edit->addItems (mru);

    // Get the dialog's options
    int opts = s->value (ed_fdlg_opts.key, ed_fdlg_opts.def).toInt ();

    m_extension->setVisible (FIND_DLG_MORE & opts);
    m_case_check_box->setChecked (FIND_DLG_CASE & opts);
    m_from_start_check_box->setChecked (FIND_DLG_START & opts);
    m_wrap_check_box->setChecked (FIND_DLG_WRAP & opts);
    m_regex_check_box->setChecked (FIND_DLG_REGX & opts);
    m_whole_words_check_box->setChecked (FIND_DLG_WORDS & opts);
    m_backward_check_box->setChecked (FIND_DLG_BACK & opts);
    m_search_selection_check_box->setChecked (FIND_DLG_SEL & opts);

    // Position:  lower right of editor's position
    int xp = ed_bottom_right.x () - sizeHint ().width ();
    int yp = ed_bottom_right.y () - sizeHint ().height ();

    m_last_position = s->value (ed_fdlg_pos.key, QPoint (xp, yp)).toPoint ();
    move (m_last_position);

    if (QApplication::desktop ()->screenNumber (this) == -1)
      {
        // Last used position is not on screen anymore, use default pos.
        m_last_position = QPoint (xp, yp);
        move (m_last_position);

        if (QApplication::desktop ()->screenNumber (this) == -1)
          {
            // Default position is not on screen, last resort
            m_last_position = QPoint (50, 100); // upper left
            move (m_last_position);
          }
      }

  }

  // set text of "search from start" depending on backward search
  void find_dialog::handle_backward_search_changed (int backward)
  {
    if (backward)
      m_from_start_check_box->setText (tr ("Search from end"));
    else
      m_from_start_check_box->setText (tr ("Search from start"));
  }

  // search text has changed: reset the search
  void find_dialog::handle_search_text_changed (void)
  {
    // Return if nothing has changed
    if (m_search_line_edit->currentText () == m_search_line_edit->itemText (0))
      return;

    if (m_search_selection_check_box->isChecked ())
      m_find_result_available = false;

    mru_update (m_search_line_edit);
  }

  // replaced text has changed: reset the search
  void find_dialog::handle_replace_text_changed (void)
  {
    // Return if nothing has changed
    if (m_replace_line_edit->currentText () == m_replace_line_edit->itemText (0))
      return;

    mru_update (m_replace_line_edit);
  }

  // Update the mru list
  void find_dialog::mru_update (QComboBox *mru)
  {
    // Remove possible empty entries from the mru list
    int index;
    while ((index = mru->findText (QString ())) >= 0)
      mru->removeItem (index);

    // Get current text and return if it is empty
    QString text = mru->currentText ();

    if (text.isEmpty ())
      return;

    // Remove occurrences of the current text in the mru list
    while ((index = mru->findText (text)) >= 0)
      mru->removeItem (index);

    // Remove the last entry from the end if the list is full
    if (mru->count () == m_mru_length)
      mru->removeItem (m_mru_length -1);

    // Insert new item at the beginning and set it as current item
    mru->insertItem (0, text);
    mru->setCurrentIndex (0);
  }

  void find_dialog::handle_sel_search_changed (int selected)
  {
    m_from_start_check_box->setEnabled (! selected);
    m_find_result_available = false;
  }

  void find_dialog::handle_selection_changed (bool has_selected)
  {
    if (m_rep_active)
      return;

    m_search_selection_check_box->setEnabled (has_selected);
    m_find_result_available = false;
  }

  // initialize search text with selected text if this is in one single line
  void find_dialog::init_search_text (void)
  {
    if (m_edit_area && m_edit_area->hasSelectedText ())
      {
        int lbeg, lend, cbeg, cend;
        m_edit_area->getSelection (&lbeg, &cbeg, &lend, &cend);
        if (lbeg == lend)
          m_search_line_edit->setCurrentText (m_edit_area->selectedText ());
      }

    // set focus to "Find what" and select all text
    m_search_line_edit->setFocus ();
    m_search_line_edit->lineEdit ()->selectAll ();

    // Default to "find" next time.
    // Otherwise, it defaults to the last action, which may be "replace all".
    m_find_next_button->setDefault (true);
  }

  void find_dialog::find_next (void)
  {
    find (! m_backward_check_box->isChecked ());
  }

  void find_dialog::find_prev (void)
  {
    find (m_backward_check_box->isChecked ());
  }

  void find_dialog::find (bool forward)
  {
    if (! m_edit_area)
      return;

    handle_search_text_changed ();

    // line adn col: -1 means search starts at current position
    int line = -1, col = -1;

    bool do_wrap = m_wrap_check_box->isChecked ();
    bool do_forward = forward;

    // Initialize the selection begin and end if it is the first search
    if (! m_find_result_available)
      {
        if (m_search_selection_check_box->isChecked ()
            && m_edit_area->hasSelectedText ())
          {
            int l1, c1, l2, c2;
            m_edit_area->getSelection (&l1, &c1, &l2, &c2);

            // Store the position of the selection
            m_sel_beg = m_edit_area->positionFromLineIndex (l1, c1);
            m_sel_end = m_edit_area->positionFromLineIndex (l2, c2);
            m_in_sel = true;
          }
        else
          m_in_sel = false;
      }

    // Get the correct line/col for beginning the search
    if (m_rep_all)
      {
        // Replace All
        if (m_rep_all == 1)
          {
            // Start at the beginning of file/sel if it is the first try
            if (m_in_sel)
              m_edit_area->lineIndexFromPosition (m_sel_beg, &line, &col);
            else
              {
                line = 0;
                col = 0;
              }
          }
        do_wrap = false;  // Never wrap when replacing all
      }
    else
      {
        // Normal search (not replace all): calculate start position of
        // search (in file or selection)
        if (m_from_start_check_box->isChecked ()
            || (m_in_sel && (! m_find_result_available)))
          {
            // From the beginning or the end of file/sel
            if (do_forward)
              {
                // From the beginning
                if (m_in_sel)
                  m_edit_area->lineIndexFromPosition (m_sel_beg, &line, &col);
                else
                  {
                    line = 0;
                    col = 0;
                  }
              }
            else
              {
                // From the end
                if (m_in_sel)
                  m_edit_area->lineIndexFromPosition (m_sel_end, &line, &col);
                else
                  {
                    line = m_edit_area->lines () - 1;
                    col  = m_edit_area->text (line).length () - 1;
                    if (col == -1)
                      col = 0;
                  }
              }
          }
        else if (! do_forward)
          {
            // Start from where the cursor is.  Fix QScintilla's cursor
            // positioning
            m_edit_area->getCursorPosition (&line, &col);
            if (m_find_result_available && m_edit_area->hasSelectedText ())
              {
                int currpos = m_edit_area->positionFromLineIndex (line, col);
                currpos -= (m_search_line_edit->currentText ().length ());
                if (currpos < 0)
                  currpos = 0;
                m_edit_area->lineIndexFromPosition (currpos, &line, &col);
              }
          }
      }

    // Do the search
    m_find_result_available
      = m_edit_area->findFirst (m_search_line_edit->currentText (),
                                m_regex_check_box->isChecked (),
                                m_case_check_box->isChecked (),
                                m_whole_words_check_box->isChecked (),
                                do_wrap,
                                do_forward,
                                line, col,
                                true
#if defined (HAVE_QSCI_VERSION_2_6_0)
                                , true
#endif
                               );

    if (m_find_result_available)
      {
        // Search successful: reset search-from-start box and check for
        // the current selection
        m_from_start_check_box->setChecked (0);

        if (m_in_sel)
          {
            m_edit_area->getCursorPosition (&line, &col);
            int pos = m_edit_area->positionFromLineIndex (line, col);

            int l1, c1, l2, c2;
            m_edit_area->lineIndexFromPosition (m_sel_beg, &l1, &c1);
            m_edit_area->lineIndexFromPosition (m_sel_end, &l2, &c2);
            m_edit_area->show_selection_markers (l1, c1, l2, c2);

            // Check if new start position is still within the selection
            m_find_result_available =  pos >= m_sel_beg && pos <= m_sel_end;
          }
      }

    // No more search hits
    if (! m_find_result_available)
      {
        if (m_in_sel)
          {
            // Restore real selection and remove marker for selection
            int l1, c1, l2, c2;
            m_edit_area->lineIndexFromPosition (m_sel_beg, &l1, &c1);
            m_edit_area->lineIndexFromPosition (m_sel_end, &l2, &c2);
            m_edit_area->setSelection (l1, c1, l2, c2);
            m_edit_area->clear_selection_markers ();
          }

        // Display message if not replace all
        if (! m_rep_all)
          no_matches_message ();
      }

  }

  void find_dialog::do_replace (void)
  {
    if (m_edit_area)
      {
        m_rep_active = true;  // changes in selection not made by the user

        m_edit_area->replace (m_replace_line_edit->currentText ());
        if (m_in_sel)
          {
            // Update the length of the selection
            m_sel_end = m_sel_end
                        - m_search_line_edit->currentText ().toUtf8 ().size ()
                        + m_replace_line_edit->currentText ().toUtf8 ().size ();
          }

        m_rep_active = false;
      }
  }

  void find_dialog::replace (void)
  {
    if (m_edit_area)
      {
        handle_replace_text_changed ();

        // Do the replace if we have selected text
        if (m_find_result_available && m_edit_area->hasSelectedText ())
          do_replace ();

        find_next ();
      }
  }

  void find_dialog::replace_all (void)
  {
    int line, col;

    if (m_edit_area)
      {
        handle_replace_text_changed ();

        m_edit_area->getCursorPosition (&line, &col);

        m_rep_all = 1;
        find_next ();  // find first occurrence (forward)

        m_edit_area->beginUndoAction ();
        while (m_find_result_available)   // while search string is found
          {
            do_replace ();
            m_rep_all++;                                          // inc counter
            find_next ();                                        // find next
          }
        m_edit_area->endUndoAction ();

        QMessageBox msg_box (QMessageBox::Information, tr ("Replace Result"),
                             tr ("%1 items replaced").arg (m_rep_all-1),
                             QMessageBox::Ok, this);
        msg_box.exec ();

        m_rep_all = 0;
        m_find_result_available = false;

        if (! m_search_selection_check_box->isChecked ())
          m_edit_area->setCursorPosition (line, col);
      }
  }

  void find_dialog::no_matches_message (void)
  {
    QMessageBox msg_box (QMessageBox::Information, tr ("Find Result"),
                         tr ("No more matches found"), QMessageBox::Ok, this);
    msg_box.exec ();
  }

  void find_dialog::reject ()
  {
    close ();
  }

  void find_dialog::closeEvent (QCloseEvent *e)
  {
    save_settings ();
    e->accept ();
  }

  // Show and hide with (re-)storing position, otherwise there is always
  // a small shift each time the dialog is shown again
  void find_dialog::set_visible (bool visible)
  {
    if (visible)
      {
        show ();
        move (m_last_position);
      }
    else
      {
        m_last_position = pos ();
        hide ();
      }
  }

}
#endif
