/**
 * \file TocWidget.cpp
 * This file is part of LyX, the document processor.
 * Licence details can be found in the file COPYING.
 *
 * \author John Levon
 * \author Abdelrazak Younes
 *
 * Full author contact details are available in file CREDITS.
 */

#include <config.h>

#include "TocWidget.h"

#include "GuiApplication.h"
#include "GuiView.h"
#include "qt_helpers.h"
#include "TocModel.h"
#include "FancyLineEdit.h"

#include "Buffer.h"
#include "BufferView.h"
#include "Cursor.h"
#include "CutAndPaste.h"
#include "FuncRequest.h"
#include "FuncStatus.h"
#include "LyX.h"
#include "Menus.h"
#include "TocBackend.h"

#include "insets/InsetCommand.h"
#include "insets/InsetRef.h"

#include "support/debug.h"
#include "support/lassert.h"

#include <QHeaderView>
#include <QMenu>
#include <QTimer>

#include <vector>

using namespace std;

namespace lyx {
namespace frontend {

TocWidget::TocWidget(GuiView & gui_view, QWidget * parent)
	: QWidget(parent), depth_(0), persistent_(false), keep_expanded_(false),
	  gui_view_(gui_view), timer_(new QTimer(this))
{
	setupUi(this);

	moveOutTB->setIcon(QIcon(getPixmap("images/", "outline-out", "svgz,png")));
	moveInTB->setIcon(QIcon(getPixmap("images/", "outline-in", "svgz,png")));
	moveUpTB->setIcon(QIcon(getPixmap("images/", "outline-up", "svgz,png")));
	moveDownTB->setIcon(QIcon(getPixmap("images/", "outline-down", "svgz,png")));
	updateTB->setIcon(QIcon(getPixmap("images/", "reload", "svgz,png")));

	QSize icon_size = gui_view.iconSize();
	moveOutTB->setIconSize(icon_size);
	moveInTB->setIconSize(icon_size);
	moveUpTB->setIconSize(icon_size);
	moveDownTB->setIconSize(icon_size);
	updateTB->setIconSize(icon_size);
	// update icon size according to gui view
	connect(&gui_view, SIGNAL(iconSizeChanged(QSize)),
		moveOutTB, SLOT(setIconSize(QSize)));
	connect(&gui_view, SIGNAL(iconSizeChanged(QSize)),
		moveInTB, SLOT(setIconSize(QSize)));
	connect(&gui_view, SIGNAL(iconSizeChanged(QSize)),
		moveUpTB, SLOT(setIconSize(QSize)));
	connect(&gui_view, SIGNAL(iconSizeChanged(QSize)),
		moveDownTB, SLOT(setIconSize(QSize)));
	connect(&gui_view, SIGNAL(iconSizeChanged(QSize)),
		updateTB, SLOT(setIconSize(QSize)));

	// avoid flickering
	tocTV->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOn);

	tocTV->showColumn(0);

	// hide the pointless QHeader for now
	// in the future, new columns may appear
	// like labels, bookmarks, etc...
	// tocTV->header()->hide();
	tocTV->header()->setVisible(false);

	// Only one item selected at a time.
	tocTV->setSelectionMode(QAbstractItemView::SingleSelection);

	// The toc types combo won't change its model.
	typeCO->setModel(gui_view_.tocModels().nameModel());

	// The filter bar
	filter_ = new FancyLineEdit(this);
	filter_->setClearButton(true);
	filter_->setPlaceholderText(qt_("All items"));
	filterBarL->addWidget(filter_, 0);
	filterLA->setBuddy(filter_);
	setFocusProxy(filter_);

	// Make sure the buttons are disabled when first shown without a loaded
	// Buffer.
	enableControls(false);

	// make us responsible for the context menu of the tabbar
	setContextMenuPolicy(Qt::CustomContextMenu);
	connect(this, SIGNAL(customContextMenuRequested(const QPoint &)),
		this, SLOT(showContextMenu(const QPoint &)));
	connect(tocTV, SIGNAL(customContextMenuRequested(const QPoint &)),
		this, SLOT(showContextMenu(const QPoint &)));
	connect(filter_, SIGNAL(textEdited(QString)),
		this, SLOT(filterContents()));
	connect(filter_, &FancyLineEdit::downPressed,
		tocTV, [this](){ focusAndHighlight(tocTV); });
	connect(activeFilterCO, SIGNAL(activated(int)),
		this, SLOT(filterContents()));

	// setting the update timer
	timer_->setSingleShot(true);
	connect(timer_, SIGNAL(timeout()), this, SLOT(finishUpdateView()));

	init(QString());
}


void TocWidget::showContextMenu(const QPoint & pos)
{
	std::string name = "context-toc-" + fromqstr(current_type_);
	QMenu * menu = guiApp->menus().menu(toqstr(name), gui_view_);
	if (!menu)
		return;
	menu->exec(mapToGlobal(pos));
}


Inset * TocWidget::itemInset() const
{
	QModelIndex const & index = tocTV->currentIndex();
	TocItem const & item =
		gui_view_.tocModels().currentItem(current_type_, index);
	DocIterator const & dit = item.dit();

	Inset * inset = nullptr;
	if (current_type_ == "label"
		  || current_type_ == "graphics"
		  || current_type_ == "citation"
		  || current_type_ == "child")
		inset = dit.nextInset();

	else if (current_type_ == "branch"
			 || current_type_ == "index"
			 || current_type_ == "change"
			 || current_type_ == "table"
		     || current_type_ == "listing"
		     || current_type_ == "figure")
		inset = &dit.inset();

	return inset;
}


bool TocWidget::getStatus(Cursor & cur, FuncRequest const & cmd,
	FuncStatus & status) const
{
	Inset * inset = itemInset();
	FuncRequest tmpcmd(cmd);

	QModelIndex const & index = tocTV->currentIndex();
	TocItem const & item =
		gui_view_.tocModels().currentItem(current_type_, index);

	switch (cmd.action())
	{
	case LFUN_CHANGE_ACCEPT:
	case LFUN_CHANGE_REJECT:
	case LFUN_OUTLINE_UP:
	case LFUN_OUTLINE_DOWN:
	case LFUN_OUTLINE_IN:
	case LFUN_OUTLINE_OUT:
	case LFUN_SECTION_SELECT:
		status.setEnabled((bool)item.dit());
		return true;

	case LFUN_LABEL_COPY_AS_REFERENCE: {
		// For labels in math, we need to supply the label as a string
		FuncRequest label_copy(LFUN_LABEL_COPY_AS_REFERENCE, item.str());
		if (inset)
			return inset->getStatus(cur, label_copy, status);
		break;
	}

	default:
		if (inset)
			return inset->getStatus(cur, tmpcmd, status);
	}

	return false;
}


void TocWidget::doDispatch(Cursor & cur, FuncRequest const & cmd,
		DispatchResult & dr)
{
	Inset * inset = itemInset();

	QModelIndex const & index = tocTV->currentIndex();
	TocItem const & item =
		gui_view_.tocModels().currentItem(current_type_, index);

	// Start an undo group.
	cur.beginUndoGroup();

	switch (cmd.action())
	{
	case LFUN_CHANGE_ACCEPT:
	case LFUN_CHANGE_REJECT: {
		// The action is almost always LYX_UNKNOWN_ACTION, which will
		// have the effect of moving the cursor to the location of
		// the change. (See TocItem::action.)
		dispatch(item.action());
		// If we do not reset the origin, then the request will be sent back
		// here, and we are in an infinite loop. But we need the dispatch
		// machinery to clean up for us, if the cursor is in an inset that
		// will be deleted. See bug #10316.
		FuncRequest tmpcmd(cmd);
		tmpcmd.setOrigin(FuncRequest::INTERNAL);
		dispatch(tmpcmd);
		dr.forceBufferUpdate();
		break;
	}

	case LFUN_SECTION_SELECT:
		dispatch(item.action());
		cur.dispatch(cmd);
		// necessary to get the selection drawn.
		cur.buffer()->changed(true);
		gui_view_.setFocus();
		break;

	case LFUN_LABEL_COPY_AS_REFERENCE: {
		// For labels in math, we need to supply the label as a string
		FuncRequest label_copy(LFUN_LABEL_COPY_AS_REFERENCE, item.str());
		if (inset)
			inset->dispatch(cur, label_copy);
		break;
	}

	case LFUN_OUTLINE_UP:
	case LFUN_OUTLINE_DOWN:
	case LFUN_OUTLINE_IN:
	case LFUN_OUTLINE_OUT:
		outline(cmd.action());
		break;

	default: {
		FuncRequest tmpcmd(cmd);
		if (inset)
			inset->dispatch(cur, tmpcmd);
	}
	}
	cur.endUndoGroup();
}


void TocWidget::on_tocTV_activated(QModelIndex const & index)
{
	goTo(index);
}


void TocWidget::on_tocTV_pressed(QModelIndex const & index)
{
	DocIterator const & dit = gui_view_.documentBufferView()->cursor();
	keep_expanded_ = gui_view_.tocModels().currentIndex(current_type_, dit) == index;
	Qt::MouseButtons const button = QApplication::mouseButtons();
	if (button & Qt::LeftButton) {
		goTo(index);
		gui_view_.setFocus();
		gui_view_.activateWindow();
	}
}


void TocWidget::on_tocTV_doubleClicked(QModelIndex const &)
{
	keep_expanded_ = true;
}


void TocWidget::goTo(QModelIndex const & index)
{
	LYXERR(Debug::GUI, "goto " << index.row()
		<< ", " << index.column());

	sendDispatch(gui_view_.tocModels().goTo(current_type_, index));
}


void TocWidget::on_updateTB_clicked()
{
	// The backend update can take some time so we disable
	// the controls while waiting.
	enableControls(false);
	gui_view_.currentBufferView()->buffer().updateBuffer();
}


void TocWidget::on_sortCB_stateChanged(int state)
{
	gui_view_.tocModels().sort(current_type_, state == Qt::Checked);
	updateViewNow();
}


void TocWidget::on_persistentCB_stateChanged(int state)
{
	persistent_ = state == Qt::Checked;
}


#if 0
/* FIXME (Ugras 17/11/06):
I have implemented a indexDepth function to get the model indices. In my
opinion, somebody should derive a new qvariant class for tocModelItem
which saves the string data and depth information. That will save the
depth calculation.  */

static int indexDepth(QModelIndex const & index, int depth = -1)
{
	++depth;
	return index.parent() == QModelIndex()
		? depth : indexDepth(index.parent(), depth);
}
#endif

void TocWidget::on_depthSL_valueChanged(int depth)
{
	if (depth == depth_)
		return;
	setTreeDepth(depth);
	gui_view_.setFocus();
}


void TocWidget::setTreeDepth(int depth, bool const maintain_current)
{
	depth_ = depth;
	if (!tocTV->model())
		return;

	if (maintain_current)
		collapseAllOthers(depth);
	else {
		if (depth == 0)
			tocTV->collapseAll();
		else
			tocTV->expandToDepth(depth - 1);
	}
}


void TocWidget::on_typeCO_activated(int index)
{
	if (index == -1)
		return;
	current_type_ = typeCO->itemData(index).toString();
	updateViewNow();
	if (typeCO->hasFocus())
		gui_view_.setFocus();
}


void TocWidget::outline(FuncCode func_code)
{
	QModelIndexList const & list = tocTV->selectionModel()->selectedIndexes();
	if (list.isEmpty())
		return;

	//if another window is active, this attempt will fail,
	//but it will work at least for the second attempt
	gui_view_.activateWindow();

	enableControls(false);
	goTo(list[0]);
	sendDispatch(FuncRequest(func_code));
	enableControls(true);
	gui_view_.setFocus();
}


void TocWidget::sendDispatch(FuncRequest fr)
{
	fr.setViewOrigin(&gui_view_);
	GuiWorkArea * old_wa = gui_view_.currentWorkArea();
	GuiWorkArea * doc_wa = gui_view_.currentMainWorkArea();
	/* The ToC command should be dispatched to the document work area,
	 * not the Adv. Find&Replace (which is the only other know
	 * possibility.
	 */
	if (doc_wa != nullptr && doc_wa != old_wa)
		gui_view_.setCurrentWorkArea(doc_wa);
	DispatchResult const & dr = dispatch(fr);
	/* If the current workarea has not explicitely changed, and the
	 * original one is still visible, let's reset it.
	 */
	if (gui_view_.currentWorkArea() == doc_wa
	     && gui_view_.hasVisibleWorkArea(old_wa)
	     && doc_wa != old_wa)
		gui_view_.setCurrentWorkArea(old_wa);
	if (dr.error())
		gui_view_.message(dr.message());
}


void TocWidget::on_moveUpTB_clicked()
{
	outline(LFUN_OUTLINE_UP);
}


void TocWidget::on_moveDownTB_clicked()
{
	outline(LFUN_OUTLINE_DOWN);
}


void TocWidget::on_moveInTB_clicked()
{
	outline(LFUN_OUTLINE_IN);
}


void TocWidget::on_moveOutTB_clicked()
{
	outline(LFUN_OUTLINE_OUT);
}


void TocWidget::select(QModelIndex const & index)
{
	if (!index.isValid()) {
		LYXERR(Debug::GUI, "TocWidget::select(): QModelIndex is invalid!");
		return;
	}

	tocTV->scrollTo(index);
	tocTV->clearSelection();
	tocTV->setCurrentIndex(index);
}


void TocWidget::enableControls(bool enable)
{
	updateTB->setEnabled(enable);

	if (!canOutline())
		enable = false;

	moveUpTB->setEnabled(enable);
	moveDownTB->setEnabled(enable);
	moveInTB->setEnabled(enable);
	moveOutTB->setEnabled(enable);
}


void TocWidget::updateView()
{
	if (!gui_view_.documentBufferView()) {
		tocTV->setModel(nullptr);
		depthSL->setMaximum(0);
		depthSL->setValue(0);
		setEnabled(false);
		return;
	}
	setEnabled(true);
	bool const is_sortable = isSortable();
	sortCB->setEnabled(is_sortable);
	bool focus = tocTV->hasFocus();
	tocTV->setEnabled(false);
	tocTV->setUpdatesEnabled(false);

	QAbstractItemModel * toc_model =
			gui_view_.tocModels().model(current_type_);
	if (tocTV->model() != toc_model) {
		tocTV->setModel(toc_model);
		tocTV->setEditTriggers(QAbstractItemView::NoEditTriggers);
		setTreeDepth(depth_);
	}

	sortCB->blockSignals(true);
	sortCB->setChecked(is_sortable
		&& gui_view_.tocModels().isSorted(current_type_));
	sortCB->blockSignals(false);

	persistentCB->setEnabled(canNavigate());

	bool controls_enabled = toc_model && toc_model->rowCount() > 0
		&& !gui_view_.documentBufferView()->buffer().isReadonly();
	enableControls(controls_enabled);

	depthSL->setMaximum(gui_view_.tocModels().depth(current_type_));
	depthSL->setValue(depth_);
	tocTV->setEnabled(true);
	tocTV->setUpdatesEnabled(true);
	if (focus)
		tocTV->setFocus();

	// Expensive operations are on a timer.  We finish the update immediately
	// for sparse edition actions, i.e. there was no edition/cursor movement
	// recently, then every 300ms.
	if (!timer_->isActive() && !keep_expanded_) {
		finishUpdateView();
		timer_->start(300);
	}
}


void TocWidget::updateViewNow()
{
	timer_->stop();
	updateView();
}


void TocWidget::finishUpdateView()
{
	// Profiling shows that this is the expensive stuff in the context of typing
	// text and moving with arrows. For bigger operations, this is negligible,
	// and outweighted by TocModels::reset() anyway.
	if (canNavigate()) {
		if (!persistent_ && !keep_expanded_)
			setTreeDepth(depth_, true);
		keep_expanded_ = false;
		persistentCB->setChecked(persistent_);
		// select the item at current cursor location
		if (gui_view_.documentBufferView()) {
			DocIterator const & dit = gui_view_.documentBufferView()->cursor();
			select(gui_view_.tocModels().currentIndex(current_type_, dit));
		}
	}
	filterContents();
}


QModelIndexList TocWidget::getIndices()
{
	QModelIndexList indices = tocTV->model()->match(
		tocTV->model()->index(0, 0),
		Qt::DisplayRole, ".*", -1,
#if QT_VERSION >= QT_VERSION_CHECK(5, 15, 0)
		Qt::MatchFlags(Qt::MatchRegularExpression|Qt::MatchRecursive));
#else
		// deprecated in Qt 5.15.
		Qt::MatchFlags(Qt::MatchRegExp|Qt::MatchRecursive));
#endif
	return indices;
}


void TocWidget::filterContents()
{
	if (!tocTV->model())
		return;

	QModelIndexList indices = getIndices();

	bool const show_active =
		activeFilterCO->currentIndex() != 2;
	bool const show_inactive =
		activeFilterCO->currentIndex() != 1;

	int size = indices.size();
	QString const matchstring = filter_ ? filter_->text() : QString();
	for (int i = 0; i < size; i++) {
		QModelIndex index = indices[i];
		bool matches = index.data().toString().contains(
					matchstring, Qt::CaseInsensitive);
		TocItem const & item =
			gui_view_.tocModels().currentItem(current_type_, index);
		matches &= (show_active && item.isOutput()) || (show_inactive && !item.isOutput());
		tocTV->setRowHidden(index.row(), index.parent(), !matches);
	}
	// recursively unhide parents of unhidden children
	for (int i = size - 1; i >= 0; i--) {
		QModelIndex index = indices[i];
		if (!tocTV->isRowHidden(index.row(), index.parent())
		    && index.parent() != QModelIndex())
			tocTV->setRowHidden(index.parent().row(),
					    index.parent().parent(), false);
	}
}


bool TocWidget::isAncestor(QModelIndex const & ancestor,
			   QModelIndex const & descendant) const
{
	QModelIndex mi = descendant;
	while (true) {
		if (ancestor == mi.parent())
			return true;
		if (mi == QModelIndex())
			return false;
		mi = mi.parent();
	}
	return false;
}


QModelIndex TocWidget::getAncestor(QModelIndex const & descendant) const
{
	QModelIndex mi = descendant;
	while (true) {
		if (mi.parent() == QModelIndex())
			return mi;
		mi = mi.parent();
	}
	return mi;
}


int TocWidget::getItemDepth(QModelIndex const & index_in)
{
	QModelIndex index = index_in;
	int depth = 1;
	while (index.parent().isValid())
	{
		index = index.parent();
		++depth;
	}
	return depth;
}


void TocWidget::collapseAllOthers(int const depth)
{
	if (!tocTV->model())
		return;

	QModelIndexList indices = getIndices();

	int size = indices.size();
	// collapse parents which are not in our ancestry line
	// and which exceed the requested depth
	for (int i = size - 1; i >= 0; i--) {
		QModelIndex index = indices[i];
		if (tocTV->isExpanded(index)
		    && !isAncestor(index, tocTV->currentIndex())
		    && depth < getItemDepth(index))
			tocTV->collapse(index);
	}
}


static QString decodeType(QString const & str)
{
	QString type = str;
	if (type.contains("tableofcontents"))
		type = "tableofcontents";
	else if (type.contains("lstlistoflistings"))
		type = "listing";
	else if (type.contains("floatlist")) {
		if (type.contains("\"figure"))
			type = "figure";
		else if (type.contains("\"table"))
			type = "table";
		else if (type.contains("\"algorithm"))
			type = "algorithm";
	}
	return type;
}


void TocWidget::init(QString const & str)
{
	int new_index;
	if (str.isEmpty())
		new_index = typeCO->findData(current_type_);
	else
		new_index = typeCO->findData(decodeType(str));

	// If everything else fails, settle on the table of contents which is
	// guaranteed to exist.
	if (new_index == -1) {
		current_type_ = "tableofcontents";
		new_index = typeCO->findData(current_type_);
	} else {
		current_type_ = typeCO->itemData(new_index).toString();
	}

	typeCO->blockSignals(true);
	typeCO->setCurrentIndex(new_index);
	typeCO->blockSignals(false);
	updateViewNow();
	setTreeDepth(depth_);
}

} // namespace frontend
} // namespace lyx

#include "moc_TocWidget.cpp"
