/****************************************************************************

**

** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).

** All rights reserved.

** Contact: Nokia Corporation (qt-info@nokia.com)

**

** This file is part of the Qt Assistant of the Qt Toolkit.

**

** $QT_BEGIN_LICENSE:LGPL$

** No Commercial Usage

** This file contains pre-release code and may not be distributed.

** You may use this file in accordance with the terms and conditions

** contained in the Technology Preview License Agreement accompanying

** this package.

**

** 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 as published by the Free Software

** Foundation and appearing in the file LICENSE.LGPL included in the

** packaging of this file.  Please review the following information to

** ensure the GNU Lesser General Public License version 2.1 requirements

** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.

**

** In addition, as a special exception, Nokia gives you certain additional

** rights.  These rights are described in the Nokia Qt LGPL Exception

** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.

**

** If you have questions regarding the use of this file, please contact

** Nokia at qt-info@nokia.com.

**

**

**

**

**

**

**

**

** $QT_END_LICENSE$

**

****************************************************************************/

#include "qhelpindexwidget.h"

#include "qhelpenginecore.h"

#include "qhelpengine_p.h"

#include "qhelpdbreader_p.h"

#include <QtCore/QThread>

#include <QtCore/QMutex>

#include <QtGui/QListView>

#include <QtGui/QHeaderView>

QT_BEGIN_NAMESPACE

class QHelpIndexProvider : public QThread

{

public:

    QHelpIndexProvider(QHelpEnginePrivate *helpEngine);

    ~QHelpIndexProvider();

    void collectIndices(const QString &customFilterName);

    void stopCollecting();

    QStringList indices() const;

    QList<QHelpDBReader*> activeReaders() const;

    QSet<int> indexIds(QHelpDBReader *reader) const;

private:

    void run();

    QHelpEnginePrivate *m_helpEngine;

    QStringList m_indices;

    QList<QHelpDBReader*> m_activeReaders;

    QMap<QHelpDBReader*, QSet<int> > m_indexIds;

    QStringList m_filterAttributes;

    mutable QMutex m_mutex;

    bool m_abort;

};

class QHelpIndexModelPrivate

{

public:

    QHelpIndexModelPrivate(QHelpEnginePrivate *hE)

    {

        helpEngine = hE;

        indexProvider = new QHelpIndexProvider(helpEngine);

        insertedRows = 0;

    }

    QHelpEnginePrivate *helpEngine;

    QHelpIndexProvider *indexProvider;

    QStringList indices;

    int insertedRows;

    QString currentFilter;

    QList<QHelpDBReader*> activeReaders;

};

static bool caseInsensitiveLessThan(const QString &as, const QString &bs)

{

    return QString::compare(as, bs, Qt::CaseInsensitive) < 0;

}

QHelpIndexProvider::QHelpIndexProvider(QHelpEnginePrivate *helpEngine)

    : QThread(helpEngine)

{

    m_helpEngine = helpEngine;

    m_abort = false;

}

QHelpIndexProvider::~QHelpIndexProvider()

{

    stopCollecting();

}

void QHelpIndexProvider::collectIndices(const QString &customFilterName)

{

    m_mutex.lock();

    m_filterAttributes = m_helpEngine->q->filterAttributes(customFilterName);

    m_mutex.unlock();

    if (!isRunning()) {

        start(LowPriority);

    } else {

        stopCollecting();

        start(LowPriority);

    }

}

void QHelpIndexProvider::stopCollecting()

{

    if (!isRunning())

        return;

    m_mutex.lock();

    m_abort = true;

    m_mutex.unlock();

    wait();

    m_abort = false;

}

QStringList QHelpIndexProvider::indices() const

{

    QMutexLocker lck(&m_mutex);

    return m_indices;

}

QList<QHelpDBReader*> QHelpIndexProvider::activeReaders() const

{

    QMutexLocker lck(&m_mutex);

    return m_activeReaders;

}

QSet<int> QHelpIndexProvider::indexIds(QHelpDBReader *reader) const

{

    QMutexLocker lck(&m_mutex);

    if (m_indexIds.contains(reader))

        return m_indexIds.value(reader);

    return QSet<int>();

}

void QHelpIndexProvider::run()

{

    m_mutex.lock();

    QStringList atts = m_filterAttributes;

    m_indices.clear();

    m_activeReaders.clear();

    QSet<QString> indicesSet;

    m_mutex.unlock();

    foreach (const QString &dbFileName, m_helpEngine->fileNameReaderMap.keys()) {

        m_mutex.lock();

        if (m_abort) {

            m_mutex.unlock();

            return;

        }

        m_mutex.unlock();

        QHelpDBReader reader(dbFileName,

            QHelpGlobal::uniquifyConnectionName(dbFileName +

            QLatin1String("FromIndexProvider"),

            QThread::currentThread()), 0);

        if (!reader.init())

            continue;

        QStringList lst = reader.indicesForFilter(atts);

        if (!lst.isEmpty()) {

            m_mutex.lock();

            foreach (const QString &s, lst)

                indicesSet.insert(s);

            if (m_abort) {

                m_mutex.unlock();

                return;

            }

            QHelpDBReader *orgReader = m_helpEngine->fileNameReaderMap.value(dbFileName);

            m_indexIds.insert(orgReader, reader.indexIds(atts));

            m_activeReaders.append(orgReader);

            m_mutex.unlock();

        }

    }

    m_mutex.lock();

    m_indices = indicesSet.values();

    qSort(m_indices.begin(), m_indices.end(), caseInsensitiveLessThan);

    m_mutex.unlock();

}

/*!

    \class QHelpIndexModel

    \since 4.4

    \inmodule QtHelp

    \brief The QHelpIndexModel class provides a model that

    supplies index keywords to views.

*/

/*!

    \fn void QHelpIndexModel::indexCreationStarted()

    This signal is emitted when the creation of a new index

    has started. The current index is invalid from this

    point on until the signal indexCreated() is emitted.

    \sa isCreatingIndex()

*/

/*!

    \fn void QHelpIndexModel::indexCreated()

    This signal is emitted when the index has been created.

*/

QHelpIndexModel::QHelpIndexModel(QHelpEnginePrivate *helpEngine)

    : QStringListModel(helpEngine)

{

    d = new QHelpIndexModelPrivate(helpEngine);

    connect(d->indexProvider, SIGNAL(finished()), this, SLOT(insertIndices()));

    connect(helpEngine->q, SIGNAL(setupStarted()), this, SLOT(invalidateIndex()));

}

QHelpIndexModel::~QHelpIndexModel()

{

    delete d;

}

void QHelpIndexModel::invalidateIndex(bool onShutDown)

{

    if (onShutDown)

        disconnect(this, SLOT(insertIndices()));

    d->indexProvider->stopCollecting();

    d->indices.clear();

    filter(QString());

}

/*!

    Creates a new index by querying the help system for

    keywords for the specified \a customFilterName.

*/

void QHelpIndexModel::createIndex(const QString &customFilterName)

{

    d->currentFilter = customFilterName;

    d->indexProvider->collectIndices(customFilterName);

    emit indexCreationStarted();

}

void QHelpIndexModel::insertIndices()

{

    d->indices = d->indexProvider->indices();

    d->activeReaders = d->indexProvider->activeReaders();

    QStringList attributes = d->helpEngine->q->filterAttributes(d->currentFilter);

    if (attributes.count() > 1) {

        foreach (QHelpDBReader *r, d->activeReaders)

            r->createAttributesCache(attributes, d->indexProvider->indexIds(r));

    }

    filter(QString());

    emit indexCreated();

}

/*!

    Returns true if the index is currently built up, otherwise

    false.

*/

bool QHelpIndexModel::isCreatingIndex() const

{

    return d->indexProvider->isRunning();

}

/*!

    Returns all hits found for the \a keyword. A hit consists of

    the URL and the document title.

*/

QMap<QString, QUrl> QHelpIndexModel::linksForKeyword(const QString &keyword) const

{

    QMap<QString, QUrl> linkMap;

    QStringList filterAttributes = d->helpEngine->q->filterAttributes(d->currentFilter);

    foreach (QHelpDBReader *reader, d->activeReaders)

        reader->linksForKeyword(keyword, filterAttributes, linkMap);

    return linkMap;

}

/*!

    Filters the indices and returns the model index of the best

    matching keyword. In a first step, only the keywords containing

    \a filter are kept in the model's index list. Analogously, if

    \a wildcard is not empty, only the keywords matched are left

    in the index list. In a second step, the best match is

    determined and its index model returned. When specifying a

    wildcard expression, the \a filter string is used to

    search for the best match.

*/

QModelIndex QHelpIndexModel::filter(const QString &filter, const QString &wildcard)

{

    if (filter.isEmpty()) {

        setStringList(d->indices);

        return index(-1, 0, QModelIndex());

    }

    QStringList lst;

    int goodMatch = -1;

    int perfectMatch = -1;

    if (!wildcard.isEmpty()) {

        QRegExp regExp(wildcard, Qt::CaseInsensitive);

        regExp.setPatternSyntax(QRegExp::Wildcard);

        foreach (const QString &index, d->indices) {

            if (index.contains(regExp)) {

                lst.append(index);

                if (perfectMatch == -1 && index.startsWith(filter, Qt::CaseInsensitive)) {

                    if (goodMatch == -1)

                        goodMatch = lst.count()-1;

                    if (filter.length() == index.length()){

                        perfectMatch = lst.count()-1;

                    }

                } else if (perfectMatch > -1 && index == filter) {

                    perfectMatch = lst.count()-1;

                }

            }

        }

    } else {

        foreach (const QString &index, d->indices) {

            if (index.contains(filter, Qt::CaseInsensitive)) {

                lst.append(index);

                if (perfectMatch == -1 && index.startsWith(filter, Qt::CaseInsensitive)) {

                    if (goodMatch == -1)

                        goodMatch = lst.count()-1;

                    if (filter.length() == index.length()){

                        perfectMatch = lst.count()-1;

                    }

                } else if (perfectMatch > -1 && index == filter) {

                    perfectMatch = lst.count()-1;

                }

            }

        }

    }

    if (perfectMatch == -1)

        perfectMatch = qMax(0, goodMatch);

    setStringList(lst);

    return index(perfectMatch, 0, QModelIndex());

}

/*!

    \class QHelpIndexWidget

    \inmodule QtHelp

    \since 4.4

    \brief The QHelpIndexWidget class provides a list view

    displaying the QHelpIndexModel.

*/

/*!

    \fn void QHelpIndexWidget::linkActivated(const QUrl &link,

        const QString &keyword)

    This signal is emitted when an item is activated and its

    associated \a link should be shown. To know where the link

    belongs to, the \a keyword is given as a second paremeter.

*/

/*!

    \fn void QHelpIndexWidget::linksActivated(const QMap<QString, QUrl> &links,

        const QString &keyword)

    This signal is emitted when the item representing the \a keyword

    is activated and the item has more than one link associated.

    The \a links consist of the document title and their URL.

*/

QHelpIndexWidget::QHelpIndexWidget()

    : QListView(0)

{

    setEditTriggers(QAbstractItemView::NoEditTriggers);

    setUniformItemSizes(true);

    connect(this, SIGNAL(activated(QModelIndex)),

        this, SLOT(showLink(QModelIndex)));

}

void QHelpIndexWidget::showLink(const QModelIndex &index)

{

    if (!index.isValid())

        return;

    QHelpIndexModel *indexModel = qobject_cast<QHelpIndexModel*>(model());

    if (!indexModel)

        return;

    QVariant v = indexModel->data(index, Qt::DisplayRole);

    QString name;

    if (v.isValid())

        name = v.toString();

    QMap<QString, QUrl> links = indexModel->linksForKeyword(name);

    if (links.count() == 1) {

        emit linkActivated(links.constBegin().value(), name);

    } else if (links.count() > 1) {

        emit linksActivated(links, name);

    }

}

/*!

    Activates the current item which will result eventually in

    the emitting of a linkActivated() or linksActivated()

    signal.

*/

void QHelpIndexWidget::activateCurrentItem()

{

    showLink(currentIndex());

}

/*!

    Filters the indices according to \a filter or \a wildcard.

    The item with the best match is set as current item.

    \sa QHelpIndexModel::filter()

*/

void QHelpIndexWidget::filterIndices(const QString &filter, const QString &wildcard)

{

    QHelpIndexModel *indexModel = qobject_cast<QHelpIndexModel*>(model());

    if (!indexModel)

        return;

    QModelIndex idx = indexModel->filter(filter, wildcard);

    if (idx.isValid())

        setCurrentIndex(idx);

}

QT_END_NAMESPACE