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

**

** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).

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

**

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

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** No Commercial Usage

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

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** contained in the Technology Preview License Agreement accompanying

** this package.

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** GNU Lesser General Public License Usage

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** 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

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

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

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

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** $QT_END_LICENSE$

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

#include "helpdialog.h"

#include "helpwindow.h"

#include "topicchooser.h"

#include "docuparser.h"

#include "mainwindow.h"

#include "config.h"

#include "tabbedbrowser.h"

#include <QtGui>

#include <QtDebug>

#include <QtCore/QVarLengthArray>

#include <stdlib.h>

#include <limits.h>

QT_BEGIN_NAMESPACE

enum

{

    LinkRole = Qt::UserRole + 1000

};

static bool verifyDirectory(const QString &str)

{

    QFileInfo dirInfo(str);

    if (!dirInfo.exists())

        return QDir().mkdir(str);

    if (!dirInfo.isDir()) {

        qWarning("'%s' exists but is not a directory", str.toLatin1().constData());

        return false;

    }

    return true;

}

struct IndexKeyword {

    IndexKeyword(const QString &kw, const QString &l)

        : keyword(kw), link(l) {}

    IndexKeyword() : keyword(QString()), link(QString()) {}

    bool operator<(const IndexKeyword &ik) const {

        return keyword.toLower() < ik.keyword.toLower();

    }

    bool operator<=(const IndexKeyword &ik) const {

        return keyword.toLower() <= ik.keyword.toLower();

    }

    bool operator>(const IndexKeyword &ik) const {

        return keyword.toLower() > ik.keyword.toLower();

    }

    Q_DUMMY_COMPARISON_OPERATOR(IndexKeyword)

    QString keyword;

    QString link;

};

QDataStream &operator>>(QDataStream &s, IndexKeyword &ik)

{

    s >> ik.keyword;

    s >> ik.link;

    return s;

}

QDataStream &operator<<(QDataStream &s, const IndexKeyword &ik)

{

    s << ik.keyword;

    s << ik.link;

    return s;

}

QValidator::State SearchValidator::validate(QString &str, int &) const

{

    for (int i = 0; i < (int) str.length(); ++i) {

        QChar c = str[i];

        if (!c.isLetterOrNumber() && c != QLatin1Char('\'') && c != QLatin1Char('`')

            && c != QLatin1Char('\"') && c != QLatin1Char(' ') && c != QLatin1Char('-') && c != QLatin1Char('_')

            && c!= QLatin1Char('*'))

            return QValidator::Invalid;

    }

    return QValidator::Acceptable;

}

class IndexListModel: public QStringListModel

{

public:

    IndexListModel(QObject *parent = 0)

        : QStringListModel(parent) {}

    void clear() { contents.clear(); setStringList(QStringList()); }

    QString description(int index) const { return stringList().at(index); }

    QStringList links(int index) const { return contents.values(stringList().at(index)); }

    void addLink(const QString &description, const QString &link) { contents.insert(description, link); }

    void publish() { filter(QString(), QString()); }

    QModelIndex filter(const QString &s, const QString &real);

    virtual Qt::ItemFlags flags(const QModelIndex &index) const

    { return QStringListModel::flags(index) & ~Qt::ItemIsEditable; }

private:

    QMultiMap<QString, QString> contents;

};

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

{

    const QChar *a = as.unicode();

    const QChar *b = bs.unicode();

    if (a == 0)

        return true;

    if (b == 0)

        return false;

    if (a == b)

        return false;

    int l=qMin(as.length(),bs.length());

    while (l-- && QChar::toLower(a->unicode()) == QChar::toLower(b->unicode()))

        a++,b++;

    if (l==-1)

        return (as.length() < bs.length());

    return QChar::toLower(a->unicode()) < QChar::toLower(b->unicode());

}

/**

 * \a real is kinda a hack for the smart search, need a way to match a regexp to an item

 * How would you say the best match for Q.*Wiget is QWidget?

 */

QModelIndex IndexListModel::filter(const QString &s, const QString &real)

{

    QStringList list;

    int goodMatch = -1;

    int perfectMatch = -1;

    if (s.isEmpty())

        perfectMatch = 0;

    const QRegExp regExp(s, Qt::CaseInsensitive);

    QMultiMap<QString, QString>::iterator it = contents.begin();

    QString lastKey;

    for (; it != contents.end(); ++it) {

        if (it.key() == lastKey)

            continue;

        lastKey = it.key();

        const QString key = it.key();

        if (key.contains(regExp) || key.contains(s, Qt::CaseInsensitive)) {

            list.append(key);

            if (perfectMatch == -1 && (key.startsWith(real, Qt::CaseInsensitive))) {

                if (goodMatch == -1)

                    goodMatch = list.count() - 1;

                if (real.length() == key.length()){

                    perfectMatch = list.count() - 1;

                }

            }  else if (perfectMatch > -1 && s == key) {

                perfectMatch = list.count() - 1;

            }

        }

    }

    int bestMatch = perfectMatch;

    if (bestMatch == -1)

        bestMatch = goodMatch;

    bestMatch = qMax(0, bestMatch);

    // sort the new list

    QString match;

    if (bestMatch >= 0 && list.count() > bestMatch)

        match = list[bestMatch];

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

    setStringList(list);

    for (int i = 0; i < list.size(); ++i) {

        if (list.at(i) == match){

            bestMatch = i;

            break;

        }

    }

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

}

HelpNavigationListItem::HelpNavigationListItem(QListWidget *ls, const QString &txt)

    : QListWidgetItem(txt, ls)

{

}

void HelpNavigationListItem::addLink(const QString &link)

{

    QString lnk = HelpDialog::removeAnchorFromLink(link);

    if (linkList.filter(lnk, Qt::CaseInsensitive).count() > 0)

        return;

    linkList << link;

}

HelpDialog::HelpDialog(QWidget *parent, MainWindow *h)

    : QWidget(parent), lwClosed(false), help(h)

{

    ui.setupUi(this);

    ui.listContents->setUniformRowHeights(true);

    ui.listContents->header()->setStretchLastSection(false);

    ui.listContents->header()->setResizeMode(QHeaderView::ResizeToContents);

    ui.listBookmarks->setUniformRowHeights(true);

    ui.listBookmarks->header()->setStretchLastSection(false);

    ui.listBookmarks->header()->setResizeMode(QHeaderView::ResizeToContents);

    indexModel = new IndexListModel(this);

    ui.listIndex->setModel(indexModel);

    ui.listIndex->setLayoutMode(QListView::Batched);

    ui.listBookmarks->setItemHidden(ui.listBookmarks->headerItem(), true);

    ui.listContents->setItemHidden(ui.listContents->headerItem(), true);

    ui.searchButton->setShortcut(QKeySequence(Qt::ALT|Qt::SHIFT|Qt::Key_S));

}

void HelpDialog::initialize()

{

    connect(ui.tabWidget, SIGNAL(currentChanged(int)), this, SLOT(currentTabChanged(int)));

    connect(ui.listContents, SIGNAL(itemActivated(QTreeWidgetItem*,int)), this, SLOT(showTopic(QTreeWidgetItem*)));

    connect(ui.listContents, SIGNAL(customContextMenuRequested(QPoint)), this, SLOT(showTreeItemMenu(QPoint)));

    ui.listContents->viewport()->installEventFilter(this);

    connect(ui.editIndex, SIGNAL(returnPressed()), this, SLOT(showTopic()));

    connect(ui.editIndex, SIGNAL(textEdited(QString)), this, SLOT(searchInIndex(QString)));

    connect(ui.listIndex, SIGNAL(activated(QModelIndex)), this, SLOT(showTopic()));

    connect(ui.listIndex, SIGNAL(customContextMenuRequested(QPoint)), this, SLOT(showIndexItemMenu(QPoint)));

    connect(ui.listBookmarks, SIGNAL(itemActivated(QTreeWidgetItem*,int)), this, SLOT(showTopic(QTreeWidgetItem*)));

    connect(ui.listBookmarks, SIGNAL(customContextMenuRequested(QPoint)), this, SLOT(showTreeItemMenu(QPoint)));

    connect(ui.termsEdit, SIGNAL(textChanged(const QString&)), this, SLOT(updateSearchButton(const QString&)));

    connect(ui.resultBox, SIGNAL(customContextMenuRequested(QPoint)), this, SLOT(showListItemMenu(QPoint)));

    cacheFilesPath = QDir::homePath() + QLatin1String("/.assistant"); //### Find a better location for the dbs

    ui.editIndex->installEventFilter(this);

    ui.framePrepare->hide();

    connect(qApp, SIGNAL(lastWindowClosed()), SLOT(lastWinClosed()));

    ui.termsEdit->setValidator(new SearchValidator(ui.termsEdit));

    actionOpenCurrentTab = new QAction(this);

    actionOpenCurrentTab->setText(tr("Open Link in Current Tab"));

    actionOpenLinkInNewWindow = new QAction(this);

    actionOpenLinkInNewWindow->setText(tr("Open Link in New Window"));

    actionOpenLinkInNewTab = new QAction(this);

    actionOpenLinkInNewTab->setText(tr("Open Link in New Tab"));

    itemPopup = new QMenu(this);

    itemPopup->addAction(actionOpenCurrentTab);

    itemPopup->addAction(actionOpenLinkInNewWindow);

    itemPopup->addAction(actionOpenLinkInNewTab);

    ui.tabWidget->setElideMode(Qt::ElideNone);

    contentList.clear();

    initDoneMsgShown = false;

    fullTextIndex = 0;

    indexDone = false;

    titleMapDone = false;

    contentsInserted = false;

    bookmarksInserted = false;

    setupTitleMap();

}

void HelpDialog::processEvents()

{

    qApp->processEvents(QEventLoop::ExcludeUserInputEvents);

}

void HelpDialog::lastWinClosed()

{

    lwClosed = true;

}

void HelpDialog::removeOldCacheFiles(bool onlyFulltextSearchIndex)

{

    if (!verifyDirectory(cacheFilesPath)) {

        qWarning("Failed to created assistant directory");

        return;

    }

    QString pname = QLatin1String(".") + Config::configuration()->profileName();

    QStringList fileList;

    fileList << QLatin1String("indexdb40.dict")

        << QLatin1String("indexdb40.doc");

    if (!onlyFulltextSearchIndex)

        fileList << QLatin1String("indexdb40") << QLatin1String("contentdb40");

    QStringList::iterator it = fileList.begin();

    for (; it != fileList.end(); ++it) {

      if (QFile::exists(cacheFilesPath + QDir::separator() + *it + pname)) {

            QFile f(cacheFilesPath + QDir::separator() + *it + pname);

            f.remove();

        }

    }

}

void HelpDialog::timerEvent(QTimerEvent *e)

{

    Q_UNUSED(e);

    static int opacity = 255;

    help->setWindowOpacity((opacity-=4)/255.0);

    if (opacity<=0)

        qApp->quit();

}

void HelpDialog::loadIndexFile()

{

    if (indexDone)

        return;

    setCursor(Qt::WaitCursor);

    indexDone = true;

    ui.labelPrepare->setText(tr("Prepare..."));

    ui.framePrepare->show();

    processEvents();

    QProgressBar *bar = ui.progressPrepare;

    bar->setMaximum(100);

    bar->setValue(0);

    keywordDocuments.clear();

    QList<IndexKeyword> lst;

    QFile indexFile(cacheFilesPath + QDir::separator() + QLatin1String("indexdb40.") +

                     Config::configuration()->profileName());

    if (!indexFile.open(QFile::ReadOnly)) {

        buildKeywordDB();

        processEvents();

        if (lwClosed)

            return;

        if (!indexFile.open(QFile::ReadOnly)) {

            QMessageBox::warning(help, tr("Qt Assistant"), tr("Failed to load keyword index file\n"

                                                              "Assistant will not work!"));

#if defined Q_WS_WIN || defined Q_WS_MACX

            startTimer(50);

#endif

            return;

        }

    }

    QDataStream ds(&indexFile);

    quint32 fileAges;

    ds >> fileAges;

    if (fileAges != getFileAges()) {

        indexFile.close();

        buildKeywordDB();

        if (!indexFile.open(QFile::ReadOnly)) {

            QMessageBox::warning(help, tr("Qt Assistant"),

                tr("Cannot open the index file %1").arg(QFileInfo(indexFile).absoluteFilePath()));

            return;

        }

        ds.setDevice(&indexFile);

        ds >> fileAges;

    }

    ds >> lst;

    indexFile.close();

    bar->setValue(bar->maximum());

    processEvents();

    for (int i=0; i<lst.count(); ++i) {

        const IndexKeyword &idx = lst.at(i);

        indexModel->addLink(idx.keyword, idx.link);

        keywordDocuments << HelpDialog::removeAnchorFromLink(idx.link);

    }

    indexModel->publish();

    ui.framePrepare->hide();

    showInitDoneMessage();

    setCursor(Qt::ArrowCursor);

}

quint32 HelpDialog::getFileAges()

{

    QStringList addDocuFiles = Config::configuration()->docFiles();

    QStringList::const_iterator i = addDocuFiles.constBegin();

    quint32 fileAges = 0;

    for (; i != addDocuFiles.constEnd(); ++i) {

        QFileInfo fi(*i);

        if (fi.exists())

            fileAges += fi.lastModified().toTime_t();

    }

    return fileAges;

}

void HelpDialog::buildKeywordDB()

{

    QStringList addDocuFiles = Config::configuration()->docFiles();

    QStringList::iterator i = addDocuFiles.begin();

    // Set up an indeterminate progress bar.

    ui.labelPrepare->setText(tr("Prepare..."));

    ui.progressPrepare->setMaximum(0);

    ui.progressPrepare->setMinimum(0);

    ui.progressPrepare->setValue(0);

    processEvents();

    QList<IndexKeyword> lst;

    quint32 fileAges = 0;

    for (i = addDocuFiles.begin(); i != addDocuFiles.end(); ++i) {

        QFile file(*i);

        if (!file.exists()) {

            QMessageBox::warning(this, tr("Warning"),

                tr("Documentation file %1 does not exist!\n"

                    "Skipping file.").arg(QFileInfo(file).absoluteFilePath()));

            continue;

        }

        fileAges += QFileInfo(file).lastModified().toTime_t();

        DocuParser *handler = DocuParser::createParser(*i);

        bool ok = handler->parse(&file);

        file.close();

        if (!ok){

            QString msg = QString::fromLatin1("In file %1:\n%2")

                          .arg(QFileInfo(file).absoluteFilePath())

                          .arg(handler->errorProtocol());

            QMessageBox::critical(this, tr("Parse Error"), tr(msg.toUtf8()));

            delete handler;

            continue;

        }

        QList<IndexItem*> indLst = handler->getIndexItems();

        int counter = 0;

        foreach (IndexItem *indItem, indLst) {

            QFileInfo fi(indItem->reference);

            lst.append(IndexKeyword(indItem->keyword, indItem->reference));

            if (++counter%100 == 0) {

                if (ui.progressPrepare)

                    ui.progressPrepare->setValue(counter);

                processEvents();

                if (lwClosed) {

                    return;

                }

            }

        }

        delete handler;

    }

    if (!lst.isEmpty())

        qSort(lst);

    QFile indexout(cacheFilesPath + QDir::separator() + QLatin1String("indexdb40.")

      + Config::configuration()->profileName());

    if (verifyDirectory(cacheFilesPath) && indexout.open(QFile::WriteOnly)) {

        QDataStream s(&indexout);

        s << fileAges;

        s << lst;

        indexout.close();

    }

}

void HelpDialog::setupTitleMap()

{

    if (titleMapDone)

        return;

    bool needRebuild = false;

    if (Config::configuration()->profileName() == QLatin1String("default")) {

        const QStringList docuFiles = Config::configuration()->docFiles();

        for (QStringList::ConstIterator it = docuFiles.begin(); it != docuFiles.end(); ++it) {

            if (!QFile::exists(*it)) {

                Config::configuration()->saveProfile(Profile::createDefaultProfile());

                Config::configuration()->loadDefaultProfile();

                needRebuild = true;

                break;

            }

        }

    }

    if (Config::configuration()->docRebuild() || needRebuild) {

        removeOldCacheFiles();

        Config::configuration()->setDocRebuild(false);

        Config::configuration()->saveProfile(Config::configuration()->profile());

    }

    if (contentList.isEmpty())

        getAllContents();

    titleMapDone = true;

    titleMap.clear();

    for (QList<QPair<QString, ContentList> >::Iterator it = contentList.begin(); it != contentList.end(); ++it) {

        ContentList lst = (*it).second;