/****************************************************************************
**
** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** 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
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** use the contact form at http://qt.digia.com/contact-us.
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** 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.
**
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****************************************************************************/

#include "localhelpmanager.h"

#include "bookmarkmanager.h"
#include "helpconstants.h"
#include "helpviewer.h"

#include <app/app_version.h>
#include <coreplugin/helpmanager.h>

#include <QMutexLocker>

#include <QHelpEngine>

using namespace Help::Internal;

static LocalHelpManager *m_instance = 0;

QMutex LocalHelpManager::m_guiMutex;
QHelpEngine* LocalHelpManager::m_guiEngine = 0;

QMutex LocalHelpManager::m_bkmarkMutex;
BookmarkManager* LocalHelpManager::m_bookmarkManager = 0;

LocalHelpManager::LocalHelpManager(QObject *parent)
    : QObject(parent)
    , m_guiNeedsSetup(true)
    , m_needsCollectionFile(true)
{
    m_instance = this;
    qRegisterMetaType<Help::Internal::LocalHelpManager::HelpData>("Help::Internal::LocalHelpManager::HelpData");
}

LocalHelpManager::~LocalHelpManager()
{
    if (m_bookmarkManager) {
        m_bookmarkManager->saveBookmarks();
        delete m_bookmarkManager;
        m_bookmarkManager = 0;
    }

    delete m_guiEngine;
    m_guiEngine = 0;
}

LocalHelpManager *LocalHelpManager::instance()
{
    return m_instance;
}

void LocalHelpManager::setupGuiHelpEngine()
{
    if (m_needsCollectionFile) {
        m_needsCollectionFile = false;
        helpEngine().setCollectionFile(Core::HelpManager::collectionFilePath());
    }

    if (m_guiNeedsSetup) {
        m_guiNeedsSetup = false;
        helpEngine().setupData();
    }
}

void LocalHelpManager::setEngineNeedsUpdate()
{
    m_guiNeedsSetup = true;
}

QHelpEngine &LocalHelpManager::helpEngine()
{
    if (!m_guiEngine) {
        QMutexLocker _(&m_guiMutex);
        if (!m_guiEngine) {
            m_guiEngine = new QHelpEngine(QString());
            m_guiEngine->setAutoSaveFilter(false);
        }
    }
    return *m_guiEngine;
}

BookmarkManager& LocalHelpManager::bookmarkManager()
{
    if (!m_bookmarkManager) {
        QMutexLocker _(&m_bkmarkMutex);
        if (!m_bookmarkManager) {
            m_bookmarkManager = new BookmarkManager;
            m_bookmarkManager->setupBookmarkModels();
            const QString &url = QString::fromLatin1("qthelp://org.qt-project.qtcreator."
                "%1%2%3/doc/index.html").arg(IDE_VERSION_MAJOR).arg(IDE_VERSION_MINOR)
                .arg(IDE_VERSION_RELEASE);
            helpEngine().setCustomValue(QLatin1String("DefaultHomePage"), url);
        }
    }
    return *m_bookmarkManager;
}

QVariant LocalHelpManager::engineFontSettings()
{
    return helpEngine().customValue(Constants::FontKey, QVariant());
}

/*!
 * Checks if the string does contain a scheme, and if that scheme is a "sensible" scheme for
 * opening in a internal or external browser (qthelp, about, file, http, https).
 * This is necessary to avoid trying to open e.g. "Foo::bar" in a external browser.
 */
bool LocalHelpManager::isValidUrl(const QString &link)
{
    QUrl url(link);
    if (!url.isValid())
        return false;
    const QString scheme = url.scheme();
    return (scheme == QLatin1String("qthelp")
            || scheme == QLatin1String("about")
            || scheme == QLatin1String("file")
            || scheme == QLatin1String("http")
            || scheme == QLatin1String("https"));
}

QByteArray LocalHelpManager::loadErrorMessage(const QUrl &url, const QString &errorString)
{
    const char g_htmlPage[] =
        "<html>"
        "<head>"
        "<meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">"
        "<title>%1</title>"
        "<style>"
        "body {padding: 3em 0em; background: #eeeeee;}"
        "hr {color: lightgray; width: 100%;}"
        "img {float: left; opacity: .8;}"
        "#box {background: white; border: 1px solid lightgray; width: 600px; padding: 60px; margin: auto;}"
        "h1 {font-size: 130%; font-weight: bold; border-bottom: 1px solid lightgray; margin-left: 48px;}"
        "h2 {font-size: 100%; font-weight: normal; border-bottom: 1px solid lightgray; margin-left: 48px;}"
        "p {font-size: 90%; margin-left: 48px;}"
        "</style>"
        "</head>"
        "<body>"
        "<div id=\"box\">"
        "<img "
            "src=\"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAACA"
            "AAAAgCAYAAABzenr0AAAABHNCSVQICAgIfAhkiAAAAAlwSFlzAAAOxAAADsQBlSsOGwAABnxJREFUWIXtlltsHGcVx3/fzO7MXuy92X"
            "ux17u+Jb61bEMiCk0INCjw0AckEIaHcH2oH5CSoChQAq0s8RJD5SYbiFOrUlOqEOChlSioREIlqkJoKwFKSoNQktpxUpqNE3vXu/ZeZ"
            "me+j4e1gwKRYruK+sKRPmk0M+ec3/mf78w38H/7kE2sx2lyctLdGov9UNWd6nxh/tTIyMi59QJo63Fyu8V2Xbj3BkPxgyB2jY6OrisO"
            "gGutDtlstsMwA8eDQT2k6zeIxZJ7pHTOAyfWA7Bmcp/Ps8frjadrpVdxl/fh92uGxxv5zvj4c5H7DnDs2JGHg8HEtwVzpFtPkOrNIRa"
            "OEo13b/H7nb33FWB4eFj3+0Pf9/nCfo/9SwYfyZPcYBFtfR0PF4i0pB8fGxt74L4B7NixYzgYbP+8pr1Hf8/vbt/PbC8i55+nra2rLR"
            "Rq2ccaJ2tVABMTB8OBQORHkUhCN8on6NlSgyqNBcRjf8VUfybVObTr2Z89+5m1AKxqCoQIPR6Ndm6U9hk6U68xObGFy5fDCF3i8+p87"
            "QtvUpw6SrjjRbMQjjyRzWb/tHfv3tpqYt9TgSNHjgwkEqn9rVETd+UknQ/UuPDPzSwsbiW/8DDTMw+RuxGhK30ZNX+Szp6hnVKyazXJ"
            "7wkwOjqqBQKBfX39mahV/iPtqbdQSsfrKaNpJQRFFPNoCJIb6tTnXqG3s1WkuzbuHx8/lvzAAJFIZHt7csNXS6VrhGSWzqE6utCQdpn"
            "S4hILxQUKhTl0HLCb6eud5tLZJ9m27dODTU3a7g8EkM1mzZaW6NOZTMZbn/85HT03oBrGrrqxnUUKhQL5fIFSsQhOHWqSlrBEVH5PMf"
            "cWfYObvnX06NHMugF0Xf96Kt2/eebKadqDv6GpyQt1ExTYtSXm5uYpFheQTg0NBywLaet0x3P86+2nyTz4kZjfH9g/PDysrxlgfHw8m"
            "WhLPdnf36OX33+enqEyWH6wNXB0apUSxeIijqPweHRM3Qa7hqxZtEQcguo1Lr05wcDQli9u3br1c2sGCATCBwcGtqSnL75MV/Qs1P1I"
            "S0DVwcm7mL+VY3p6itnZG1TKizjlReyiRb1Sp1aGnpjF/KVjdHUl/G3J9A8mJyeDqwY4fPjwg9FY22MuvYQ9e5Ku7iK1fJFK/jrVfA6"
            "rmKeYv0m1MksudxPHqSJrNtYiOEvglIA6JIxrXHz9x/T2bfqktOWXVgUwMjLiDgTChwcGMi1X//4Mgx2nWcpZVAtlrJLEXgLdAc/y5y"
            "scaaEt3oqhg6oDFuCAbUNn3KJ85TgsTRFrT313fHz8rmN5B0Amk3ksGks9emX6DeL6r/C5JHUblA1IUA64dAg1A7jw+lswDROhGs+Ro"
            "GTjfSWhOzDH7Pmf0tbR1+/1evfcDeD2wXHo0KFQazTxRnf30MDSlVE+2vEKblOiHGAlgQJNwcwMXL0OHi8EfZAMgccA6TQS44CU4BZw"
            "4ZpBpesgNf/mhZl339m5e/fuv9xVAZ+v6alYYsPAws3TdHhfxTBlQ1ansVQdlAVaHWwH3s3B2XcMbuUh6AVpLbfBBsdpqGXVob3ZoTr"
            "za0LB1mBTU/P3/lsBfbn6rnBL4pDHsJvdxeP0xqYQQt2WdQVCo9GCiZfgqefc/ONGBunp5KHke/iNRtVyRa1lfX0eRaV4k/myl6bkIx"
            "s//rFN50+dOnXxDgWam4PPBEPxdnvxNCn/GTxeHU0YaJobTdMQukDXwK2D0GE6B+AmnQ5T1zspWwZuE4ThQne70U0D3TRwmW6EYdARd"
            "9BmX8aj2UZzKPrE2NjY7bF0TUxkPxEIhD/rVC8T4W/0DaawLAO3oxrlKIVSEqEa16ZLsv+bkoow8IYNPjV4nWRHEpfPxFMXKARCY3nj"
            "NDZZc0xScIpMT/2C1uSubeVS4RvAEQDxwgsv/iGeSO9Uxd8Ss15CKeM/0qsVLRsB1XJQF1C2oFJx8HkFLl1Hoa/kBHHnb5EANN2mUI0"
            "i0we4tehcnZme2XHgwL4pl9BELBJpwhv/MoKvAAKBhtAEQghMj4nhNjE9Xlwu13J1opFAgFpOKh0bq26Dgmp5iZpVQ0qJUgolGyomhI"
            "atNMRcvj176Ce9wJQrd/39M+WlpY5are66PRQaaKIhpSY0BHqjKpfAtVKbaEAoANXAsFEoe7ltOEipaHROoZRCAEIooZS8fO7cuUsr6"
            "gDc89i8D/b2h5Dzf+3fzO2jy1yqBcAAAAAASUVORK5CYII=\""
            "width=\"32\" height=\"32\"/>"
        "<h1>%2</h1>"
        "<h2>%3</h2>"
        "%4"
        "</div>"
        "</body>"
        "</html>";

    // some of the values we will replace %1...6 inside the former html
    const QString g_percent1 = QCoreApplication::translate("Help", "Error loading page");
    // percent2 will be the error details
    // percent3 will be the url of the page we got the error from
    const QString g_percent4 = QCoreApplication::translate("Help", "<p>Check that you have the corresponding "
        "documentation set installed.</p>");

    return QString::fromLatin1(g_htmlPage).arg(g_percent1, errorString,
                QCoreApplication::translate("Help", "Error loading: %1").arg(url.toString()),
                g_percent4).toUtf8();
}

LocalHelpManager::HelpData LocalHelpManager::helpData(const QUrl &url)
{
    HelpData data;
    const QHelpEngineCore &engine = helpEngine();

    data.resolvedUrl = engine.findFile(url);
    if (data.resolvedUrl.isValid()) {
        data.data = engine.fileData(data.resolvedUrl);
        data.mimeType = HelpViewer::mimeFromUrl(data.resolvedUrl);
        if (data.mimeType.isEmpty())
            data.mimeType = QLatin1String("application/octet-stream");
    } else {
        data.data = loadErrorMessage(url, QCoreApplication::translate(
                                         "Help", "The page could not be found"));
        data.mimeType = QLatin1String("text/html");
    }
    return data;
}