/*

Copyright (C) 2009 P. L. Lucas
Copyright (C) 2012-2016 Jacob Dawid

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
<http://www.gnu.org/licenses/>.

*/

// Author: P. L. Lucas
// Author: Jacob Dawid <jacob.dawid@cybercatalyst.com>

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

#include "webinfo.h"
#include <QVBoxLayout>
#include <QHBoxLayout>
#include <QApplication>
#include <QClipboard>

#include "file-ops.h"
#include "help.h"
#include "defaults.h"
#include "resource-manager.h"
#include "shortcut-manager.h"


webinfo::webinfo (QWidget *p)
  : QWidget (p)
{
  _font_web = font ();

  QVBoxLayout *vbox_layout = new QVBoxLayout ();
  vbox_layout->setMargin (0);
  setLayout (vbox_layout);

  QHBoxLayout *hbox_layout = new QHBoxLayout ();
  hbox_layout->setMargin (0);
  hbox_layout->setSpacing (0);
  vbox_layout->addLayout (hbox_layout);

  _tab_bar = new webinfo_tab_bar (this);
  _tab_bar->setSizePolicy (QSizePolicy::Preferred,QSizePolicy::Preferred);
  _tab_bar->setExpanding (false);
  _tab_bar->setTabsClosable (true);
#if defined (HAVE_QTABWIDGET_SETMOVABLE)
  _tab_bar->setMovable (true);
#endif
  hbox_layout->addWidget (_tab_bar);

  _zoom_in_button = new QToolButton (this);
  _zoom_in_button->setIcon (resource_manager::icon ("zoom-in"));
  hbox_layout->addWidget (_zoom_in_button);

  _zoom_out_button = new QToolButton (this);
  _zoom_out_button->setIcon (resource_manager::icon ("zoom-out"));
  hbox_layout->addWidget (_zoom_out_button);

  _stacked_widget = new QStackedWidget (this);
  vbox_layout->addWidget (_stacked_widget);

  hbox_layout = new QHBoxLayout ();
  vbox_layout->addLayout (hbox_layout);

  _search_line_edit = new QLineEdit (this);
#if defined (HAVE_SETPLACEHOLDERTEXT)
  _search_line_edit->setPlaceholderText (
    tr ("Type here and press \'Return\' to search"));
#endif
  hbox_layout->addWidget (_search_line_edit);

  _search_check_box = new QCheckBox (tr ("Global search"));
  hbox_layout->addWidget (_search_check_box);

  _close_action = add_action (_tab_bar->get_context_menu (),
        resource_manager::icon ("window-close",false), tr ("&Close"),
        SLOT (request_close_tab (bool)));
  _close_others_action = add_action (_tab_bar->get_context_menu (),
        resource_manager::icon ("window-close",false), tr ("Close &Other Tabs"),
        SLOT (request_close_other_tabs (bool)));
  _close_action->setEnabled (false);
  _close_others_action->setEnabled (false);

  connect (_tab_bar, SIGNAL (tabCloseRequested (int)), this,
           SLOT (close_tab (int)));
  connect (_tab_bar, SIGNAL (currentChanged (int)), this,
           SLOT (current_tab_changed (int)));
  connect (_zoom_in_button, SIGNAL (clicked ()), this, SLOT (zoom_in ()));
  connect (_zoom_out_button, SIGNAL (clicked ()), this, SLOT (zoom_out ()));
  connect (_search_line_edit, SIGNAL (returnPressed ()), this, SLOT (search ()));

  resize (500, 300);
}

// Add an action to a menu or the widget itself
QAction*
webinfo::add_action (QMenu *menu, const QIcon& icon, const QString& text,
                         const char *member)
{
  QAction *a;

  if (menu)
    a = menu->addAction (icon, text, this, member);
  else
    {
      a = new QAction (this);
      connect (a, SIGNAL (triggered ()), this, member);
    }

  addAction (a);  // important for shortcut context
  a->setShortcutContext (Qt::WidgetWithChildrenShortcut);

  return a;
}

// Slot for the close tab action
void
webinfo::request_close_tab (bool)
{
  close_tab (_tab_bar->currentIndex ());
}

// Slot for the close other tabs action
void
webinfo::request_close_other_tabs (bool)
{
  int current = _tab_bar->currentIndex ();

  for (int index = _tab_bar->count ()-1; index >= 0; index--)
  {
    if (current != index)
      close_tab (index);
  }
}

void
webinfo::load_info_file (const QString& info_file)
{
  if (! set_info_path (info_file))
    {
      // Info file does not exist
      _search_check_box->setEnabled (false);
      _search_line_edit->setEnabled (false);

      QTextBrowser *msg = addNewTab (tr ("Error"));
      QString msg_text = QString (
          "<html><body><br><br><center><b>%1</b></center></body></html>").
          arg (tr ("The info file<p>%1<p>or compressed versions do not exist").
          arg (info_file));
      msg->setHtml (msg_text);
    }
}

bool
webinfo::set_info_path (const QString& info_path)
{
  if (_parser.set_info_path (info_path))
    {
      load_node ("Top");
      return true;
    }
  else
    return false;
}

void
webinfo::load_node (const QString& node_name)
{
  // no XREF in the tabs
  QString tab_text = node_name;
  tab_text.replace ("XREF", "");

  //Check if node has been already opened.
  for (int i = 0; i < _tab_bar->count (); i++)
    {
      if (tab_text == _tab_bar->tabText (i))
        {
          _tab_bar->setCurrentIndex (i);
          return;
        }
    }

  QString text = _parser.search_node (node_name);
  int i = _parser.is_ref (node_name);
  _text_browser = addNewTab (tab_text);
  _text_browser->setHtml (_parser.node_text_to_html (text, i - 1, "anchor"));

  if (i != -1)
    {
      _text_browser->scrollToAnchor ("anchor");
    }
}

void
webinfo::link_clicked (const QUrl & link)
{
  QString node = link.toString ();
  if (node.at (0) != '#')
    load_node (node);
  else
    _text_browser->scrollToAnchor (node);
}

void
webinfo::tab_state_changed ()
{
  _close_action->setEnabled (_tab_bar->count () > 1);
  _close_others_action->setEnabled (_tab_bar->count () > 1);
  setFocusProxy (_stacked_widget->currentWidget ());
}

void
webinfo::current_tab_changed (int index)
{
  QVariant tab_data = _tab_bar->tabData (index);
  _text_browser = static_cast<QTextBrowser *> (tab_data.value<void*> ());

  _stacked_widget->setCurrentIndex (_stacked_widget->indexOf (_text_browser));

  if (_text_browser->font () != _font_web)
    {
      _text_browser->setFont (_font_web);
    }

  tab_state_changed ();
}

QTextBrowser *
webinfo::addNewTab (const QString& name)
{
  _text_browser = new QTextBrowser (this);
  _text_browser->setOpenLinks (false);
  _text_browser->show ();

  connect (_text_browser, SIGNAL (anchorClicked (const QUrl &)), this,
           SLOT (link_clicked (const QUrl &)));
  disconnect (_tab_bar, SIGNAL (currentChanged (int)), this,
              SLOT (current_tab_changed (int)));

  int ns = _stacked_widget->addWidget (_text_browser);
  _stacked_widget->setCurrentIndex (ns);

  int nt = _tab_bar->addTab (name);
  _tab_bar->setCurrentIndex (nt);
  QVariant tab_data;
  tab_data.setValue (static_cast<void *> (_text_browser));
  _tab_bar->setTabData (nt, tab_data);

  connect (_tab_bar, SIGNAL (currentChanged (int)), this,
           SLOT (current_tab_changed (int)));

  tab_state_changed ();

  if (_text_browser->font () != _font_web)
    {
      _text_browser->setFont (_font_web);
    }
  return _text_browser;
}

void
webinfo::close_tab (int index)
{
  if (_tab_bar->count () > 1)
    {
      QVariant tab_data = _tab_bar->tabData (index);
      QWidget *w = static_cast<QWidget *> (tab_data.value<void*> ());
      _stacked_widget->removeWidget (w);
      delete w;

      _tab_bar->removeTab (index);
    }

  tab_state_changed ();
}

void
webinfo::load_ref (const QString& ref_name)
{
  QString text = _parser.find_ref (ref_name);
  if (text.length () > 0)
    {
      load_node (text);
    }
  else
    {
      // not found
      load_node ("Top");
    }

  if (_text_browser)
    _text_browser->setFocus ();
}

void
webinfo::search ()
{
  if (_search_line_edit->text ().trimmed ().isEmpty ())
    return;   // do nothing if search field is empty or only has whitespaces

  if (_search_check_box->isChecked ())
    {
      // Global search
      QString results = _parser.global_search (_search_line_edit->text (), 5);
      _text_browser=addNewTab ("Results for: " + _search_line_edit->text ());
      _text_browser->setHtml (results);
    }
  else
    {
      // Local search
      _text_browser->find (_search_line_edit->text ());
    }
}

void
webinfo::zoom_in ()
{
  _font_web.setPointSize (_font_web.pointSize () + 1);
  _text_browser->setFont (_font_web);
}

void
webinfo::zoom_out ()
{
  _font_web.setPointSize (_font_web.pointSize () - 1);
  _text_browser->setFont (_font_web);
}

void
webinfo::copyClipboard ()
{
  if (_search_line_edit->hasFocus () && _search_line_edit->hasSelectedText ())
    {
      QClipboard *clipboard = QApplication::clipboard ();

      clipboard->setText (_search_line_edit->selectedText ());
    }
  if (_text_browser->hasFocus ())
    {
      _text_browser->copy ();
    }
}

void
webinfo::selectAll ()
{
  if (_search_line_edit->hasFocus ())
    {
      _search_line_edit->selectAll ();
    }
  if (_text_browser->hasFocus ())
    {
      _text_browser->selectAll ();
    }
}

void
webinfo::pasteClipboard ()
{
  if (_search_line_edit->hasFocus ())
    {
      QClipboard *clipboard = QApplication::clipboard ();
      QString str = clipboard->text ();
      if (str.length () > 0)
        _search_line_edit->insert (str);
    }
}

void
webinfo::notice_settings (const QSettings*)
{
  shortcut_manager::set_shortcut (_close_action, "editor_file:close");
  shortcut_manager::set_shortcut (_close_others_action, "editor_file:close_other");
}

//
// Functions of the the reimplemented tab bar
//

webinfo_tab_bar::webinfo_tab_bar (QWidget *p) : QTabBar (p)
{
  // prepare the context menu of the tab bar
  _context_menu = new QMenu (this);
}

webinfo_tab_bar::~webinfo_tab_bar ()
{
  delete _context_menu;
}

// Reimplement mouse event for filtering out the desired mouse clicks
void
webinfo_tab_bar::mousePressEvent (QMouseEvent *me)
{
  QPoint click_pos;
  int clicked_idx = -1;

  // detect the tab where the click occured
  for (int i = 0; i < count (); i++)
    {
      click_pos = mapToGlobal (me->pos ());
      if (tabRect (i).contains (mapFromGlobal (click_pos)))
        {
          clicked_idx = i;
          break;
        }
    }

  // If a tab was clicked
  if (clicked_idx >= 0)
    {
      int current_idx = currentIndex ();
      // detect the mouse click
      if ((me->type () == QEvent::MouseButtonDblClick &&
           me->button() == Qt::LeftButton) ||
          (me->type () != QEvent::MouseButtonDblClick &&
           me->button() == Qt::MidButton))
        {
          // Middle click or double click -> close the tab
          // Make the clicked tab the current one and close it
          emit tabCloseRequested (clicked_idx);
          // Was the closed tab before or after the previously current tab?
          // According to the result, use previous index or reduce it by one
          if (current_idx - clicked_idx > 0)
            setCurrentIndex (current_idx - 1);
          else if (current_idx - clicked_idx < 0)
            setCurrentIndex (current_idx);
        }
      else if (me->type () != QEvent::MouseButtonDblClick &&
               me->button() == Qt::RightButton)
        {
          setCurrentIndex (clicked_idx);
          if (! _context_menu->exec (click_pos))
            {
              // No action selected, back to previous tab
              setCurrentIndex (current_idx);
            }
          else
            {
              // Was the possibly only closed tab before or after the
              // previously current tab? According to the result, use previous
              // index or reduce it by one. Also prevent using a too large
              // if other or all files were closed.
              int new_idx = count () - 1;
              if (new_idx > 0)
                {
                  if (current_idx - clicked_idx > 0)
                    new_idx = current_idx - 1;
                  else if (current_idx - clicked_idx < 0)
                    new_idx = current_idx;
                }
              if (new_idx >= 0)
                setCurrentIndex (new_idx);
            }
        }
      else
        {
          // regular handling of the mouse event
          QTabBar::mousePressEvent (me);
        }
    }
  else
    {
      // regular handling of the mouse event
      QTabBar::mousePressEvent (me);
    }
}