/****************************************************************************
**
** Copyright (C) 2015 The Qt Company Ltd.
** Contact: http://www.qt.io/licensing
**
** This file is part of Qt Creator.
**
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company.  For licensing terms and
** conditions see http://www.qt.io/terms-conditions.  For further information
** use the contact form at http://www.qt.io/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 or version 3 as published by the Free
** Software Foundation and appearing in the file LICENSE.LGPLv21 and
** LICENSE.LGPLv3 included in the packaging of this file.  Please review the
** following information to ensure the GNU Lesser General Public License
** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, The Qt Company gives you certain additional
** rights.  These rights are described in The Qt Company LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
****************************************************************************/

#include "cppeditoroutline.h"

#include "cppeditor.h"
#include "cppeditorplugin.h"

#include <cpptools/cppmodelmanager.h>

#include <cplusplus/OverviewModel.h>
#include <utils/treeviewcombobox.h>

#include <QSortFilterProxyModel>
#include <QTimer>

/*!
    \class CppEditor::Internal::CppEditorOutline
    \brief A helper class of CppEditorWidget that provides the outline model
           and widget, e.g. for the editor's tool bar.

    \internal

    The caller is responsible for deleting the widget returned by widget().

    \sa CppEditor::Internal::CppEditorWidget
 */

enum { UpdateOutlineIntervalInMs = 500 };

namespace {

class OverviewProxyModel : public QSortFilterProxyModel
{
    Q_OBJECT

public:
    OverviewProxyModel(CPlusPlus::OverviewModel *sourceModel, QObject *parent)
        : QSortFilterProxyModel(parent)
        , m_sourceModel(sourceModel)
    {
        setSourceModel(m_sourceModel);
    }

    bool filterAcceptsRow(int sourceRow,const QModelIndex &sourceParent) const
    {
        // Ignore generated symbols, e.g. by macro expansion (Q_OBJECT)
        const QModelIndex sourceIndex = m_sourceModel->index(sourceRow, 0, sourceParent);
        CPlusPlus::Symbol *symbol = m_sourceModel->symbolFromIndex(sourceIndex);
        if (symbol && symbol->isGenerated())
            return false;

        return QSortFilterProxyModel::filterAcceptsRow(sourceRow, sourceParent);
    }
private:
    CPlusPlus::OverviewModel *m_sourceModel;
};

QTimer *newSingleShotTimer(QObject *parent, int msInternal, const QString &objectName)
{
    QTimer *timer = new QTimer(parent);
    timer->setObjectName(objectName);
    timer->setSingleShot(true);
    timer->setInterval(msInternal);
    return timer;
}

} // anonymous namespace

namespace CppEditor {
namespace Internal {

CppEditorOutline::CppEditorOutline(CppEditorWidget *editorWidget)
    : QObject(editorWidget)
    , m_editorWidget(editorWidget)
    , m_combo(new Utils::TreeViewComboBox)
    , m_model(new CPlusPlus::OverviewModel(this))
    , m_proxyModel(new OverviewProxyModel(m_model, this))
{
    // Set up proxy model
    if (CppEditorPlugin::instance()->sortedOutline())
        m_proxyModel->sort(0, Qt::AscendingOrder);
    else
        m_proxyModel->sort(-1, Qt::AscendingOrder); // don't sort yet, but set column for sortedOutline()
    m_proxyModel->setDynamicSortFilter(true);
    m_proxyModel->setSortCaseSensitivity(Qt::CaseInsensitive);

    // Set up combo box
    m_combo->setModel(m_proxyModel);

    m_combo->setMinimumContentsLength(22);
    QSizePolicy policy = m_combo->sizePolicy();
    policy.setHorizontalPolicy(QSizePolicy::Expanding);
    m_combo->setSizePolicy(policy);
    m_combo->setMaxVisibleItems(40);

    m_combo->setContextMenuPolicy(Qt::ActionsContextMenu);
    m_sortAction = new QAction(tr("Sort Alphabetically"), m_combo);
    m_sortAction->setCheckable(true);
    m_sortAction->setChecked(isSorted());
    connect(m_sortAction, SIGNAL(toggled(bool)),
            CppEditorPlugin::instance(), SLOT(setSortedOutline(bool)));
    m_combo->addAction(m_sortAction);

    connect(m_combo, SIGNAL(activated(int)), this, SLOT(gotoSymbolInEditor()));
    connect(m_combo, SIGNAL(currentIndexChanged(int)), this, SLOT(updateToolTip()));

    // Set up timers
    m_updateTimer = newSingleShotTimer(this, UpdateOutlineIntervalInMs,
                                       QLatin1String("CppEditorOutline::m_updateTimer"));
    connect(m_updateTimer, SIGNAL(timeout()), this, SLOT(updateNow()));

    m_updateIndexTimer = newSingleShotTimer(this, UpdateOutlineIntervalInMs,
                                            QLatin1String("CppEditorOutline::m_updateIndexTimer"));
    connect(m_updateIndexTimer, SIGNAL(timeout()), this, SLOT(updateIndexNow()));
}

void CppEditorOutline::update()
{
    m_updateTimer->start();
}

bool CppEditorOutline::isSorted() const
{
    return m_proxyModel->sortColumn() == 0;
}

void CppEditorOutline::setSorted(bool sort)
{
    if (sort != isSorted()) {
        if (sort)
            m_proxyModel->sort(0, Qt::AscendingOrder);
        else
            m_proxyModel->sort(-1, Qt::AscendingOrder);
        bool block = m_sortAction->blockSignals(true);
        m_sortAction->setChecked(m_proxyModel->sortColumn() == 0);
        m_sortAction->blockSignals(block);
        updateIndexNow();
    }
}

CPlusPlus::OverviewModel *CppEditorOutline::model() const
{
    return m_model;
}

QModelIndex CppEditorOutline::modelIndex()
{
    if (!m_modelIndex.isValid()) {
        int line = 0, column = 0;
        m_editorWidget->convertPosition(m_editorWidget->position(), &line, &column);
        m_modelIndex = indexForPosition(line, column);
        emit modelIndexChanged(m_modelIndex);
    }

    return m_modelIndex;
}

QWidget *CppEditorOutline::widget() const
{
    return m_combo;
}

void CppEditorOutline::updateNow()
{
    CppTools::CppModelManager *cmmi = CppTools::CppModelManager::instance();
    if (!cmmi)
        return;

    const CPlusPlus::Snapshot snapshot = cmmi->snapshot();
    const QString filePath = m_editorWidget->textDocument()->filePath();
    CPlusPlus::Document::Ptr document = snapshot.document(filePath);
    if (!document)
        return;

    if (document->editorRevision() != (unsigned) m_editorWidget->document()->revision()) {
        m_updateTimer->start();
        return;
    }

    m_model->rebuild(document);

    m_combo->view()->expandAll();
    updateIndexNow();
}

void CppEditorOutline::updateIndex()
{
    m_updateIndexTimer->start();
}

void CppEditorOutline::updateIndexNow()
{
    if (!m_model->document())
        return;

    const unsigned revision = m_editorWidget->document()->revision();
    if (m_model->document()->editorRevision() != revision) {
        m_updateIndexTimer->start();
        return;
    }

    m_updateIndexTimer->stop();

    m_modelIndex = QModelIndex(); //invalidate
    QModelIndex comboIndex = modelIndex();

    if (comboIndex.isValid()) {
        bool blocked = m_combo->blockSignals(true);
        m_combo->setCurrentIndex(m_proxyModel->mapFromSource(comboIndex));
        updateToolTip();
        m_combo->blockSignals(blocked);
    }
}

void CppEditorOutline::updateToolTip()
{
    m_combo->setToolTip(m_combo->currentText());
}

void CppEditorOutline::gotoSymbolInEditor()
{
    const QModelIndex modelIndex = m_combo->view()->currentIndex();
    const QModelIndex sourceIndex = m_proxyModel->mapToSource(modelIndex);
    CPlusPlus::Symbol *symbol = m_model->symbolFromIndex(sourceIndex);
    if (!symbol)
        return;

    const TextEditor::TextEditorWidget::Link &link = CppEditorWidget::linkToSymbol(symbol);
    if (!link.hasValidTarget())
        return;

    Core::EditorManager::cutForwardNavigationHistory();
    Core::EditorManager::addCurrentPositionToNavigationHistory();
    m_editorWidget->gotoLine(link.targetLine, link.targetColumn);
    m_editorWidget->activateEditor();
}

QModelIndex CppEditorOutline::indexForPosition(int line, int column,
                                               const QModelIndex &rootIndex) const
{
    QModelIndex lastIndex = rootIndex;

    const int rowCount = m_model->rowCount(rootIndex);
    for (int row = 0; row < rowCount; ++row) {
        const QModelIndex index = m_model->index(row, 0, rootIndex);
        CPlusPlus::Symbol *symbol = m_model->symbolFromIndex(index);
        if (symbol && symbol->line() > unsigned(line))
            break;
        lastIndex = index;
    }

    if (lastIndex != rootIndex) {
        // recurse
        lastIndex = indexForPosition(line, column, lastIndex);
    }

    return lastIndex;
}

} // namespace Internal
} // namespace CppEditor

#include <cppeditoroutline.moc>
