/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the QtWebEngine module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial License Usage
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** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
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** information use the contact form at https://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 3 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL3 included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 3 requirements
** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 2.0 or (at your option) the GNU General
** Public license version 3 or any later version approved by the KDE Free
** Qt Foundation. The licenses are as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
** included in the packaging of this file. Please review the following
** information to ensure the GNU General Public License requirements will
** be met: https://www.gnu.org/licenses/gpl-2.0.html and
** https://www.gnu.org/licenses/gpl-3.0.html.
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** $QT_END_LICENSE$
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****************************************************************************/

#include "qtwebenginecoreglobal_p.h"

#include <QGuiApplication>
#if QT_CONFIG(opengl)
# include <QOpenGLContext>
#ifdef Q_OS_MACOS
#include <sys/types.h>
#include <sys/sysctl.h>
#include <QOffscreenSurface>
#include "macos_context_type_helper.h"
#endif
#endif
#include <QThread>

#if QT_CONFIG(opengl)
QT_BEGIN_NAMESPACE
Q_GUI_EXPORT void qt_gl_set_global_share_context(QOpenGLContext *context);
Q_GUI_EXPORT QOpenGLContext *qt_gl_global_share_context();
QT_END_NAMESPACE
#endif

#if QT_CONFIG(opengl)
#ifdef Q_OS_MACOS
static bool needsOfflineRendererWorkaround()
{
    size_t hwmodelsize = 0;

    if (sysctlbyname("hw.model", nullptr, &hwmodelsize, nullptr, 0) == -1)
        return false;

    char hwmodel[hwmodelsize];
    if (sysctlbyname("hw.model", &hwmodel, &hwmodelsize, nullptr, 0) == -1)
        return false;

    return QString::fromLatin1(hwmodel) == QLatin1String("MacPro6,1");
}
#endif
#endif

namespace QtWebEngineCore {
#if QT_CONFIG(opengl)
static QOpenGLContext *shareContext;

static void deleteShareContext()
{
    if (qt_gl_global_share_context() == shareContext)
        qt_gl_set_global_share_context(nullptr);
    delete shareContext;
    shareContext = 0;
}

#endif
// ### Qt 6: unify this logic and Qt::AA_ShareOpenGLContexts.
// QtWebEngine::initialize was introduced first and meant to be called
// after the QGuiApplication creation, when AA_ShareOpenGLContexts fills
// the same need but the flag has to be set earlier.

Q_WEBENGINECORE_PRIVATE_EXPORT void initialize()
{
#if QT_CONFIG(opengl)
#ifdef Q_OS_WIN32
    qputenv("QT_D3DCREATE_MULTITHREADED", "1");
#endif
#ifdef Q_OS_MACOS
    if (needsOfflineRendererWorkaround())
        qputenv("QT_MAC_PRO_WEBENGINE_WORKAROUND", "1");
#endif
    // No need to override the shared context if QApplication already set one (e.g with Qt::AA_ShareOpenGLContexts).
    if (qt_gl_global_share_context())
        return;

    QCoreApplication *app = QCoreApplication::instance();
    if (!app) {
        qFatal("QtWebEngine::initialize() but no core application instance.");
        return;
    }

    // Bail out silently if the user did not construct a QGuiApplication.
    if (!qobject_cast<QGuiApplication *>(app))
        return;

    if (app->thread() != QThread::currentThread()) {
        qFatal("QtWebEngine::initialize() must be called from the Qt gui thread.");
        return;
    }

    if (shareContext)
        return;

    shareContext = new QOpenGLContext;
    QSurfaceFormat format = QSurfaceFormat::defaultFormat();
//     format.setOption(QSurfaceFormat::ResetNotification);

#ifdef Q_OS_MACOS
    if (format == QSurfaceFormat()) {
        QOpenGLContext testContext;

        // Chromium turns off OpenGL for CoreProfiles with versions < 4.1
        // The newest Mac that only supports 3.3 was released in Mid 2011,
        // so it should be safe to request 4.1, but we still double check it
        // works in order not to set an invalid default surface format.
        format.setVersion(4, 1);
        format.setProfile(QSurfaceFormat::CoreProfile);

        testContext.setFormat(format);
        if (testContext.create()) {
            QOffscreenSurface surface;
            surface.setFormat(format);
            surface.create();

            if (testContext.makeCurrent(&surface)) {
               // The Cocoa QPA integration allows sharing between OpenGL 3.2 and 4.1 contexts,
               // which means even though we requested a 4.1 context, if we only get a 3.2 context,
               // it will still work an Chromium will not black list it.
               if (testContext.format().version() >= qMakePair(3, 2) &&
                   testContext.format().profile() == QSurfaceFormat::CoreProfile &&
                   !isCurrentContextSoftware()) {
                   QSurfaceFormat::setDefaultFormat(format);
               } else {
                   qWarning("The available OpenGL surface format was either not version 3.2 or higher or not a Core Profile.\n"
                            "Chromium on macOS will fall back to software rendering in this case.\n"
                            "Hardware acceleration and features such as WebGL will not be available.");
                   format = QSurfaceFormat::defaultFormat();
               }
               testContext.doneCurrent();
            }
            surface.destroy();
        }
    } else {
        // The user explicitly requested a specific surface format that does not fit Chromium's requirements. Warn them about this.
        if (format.version() < qMakePair(3,2) || format.profile() != QSurfaceFormat::CoreProfile) {
            qWarning("An OpenGL surfcace format was requested that is either not version 3.2 or higher or a not Core Profile.\n"
                    "Chromium on macOS will fall back to software rendering in this case.\n"
                    "Hardware acceleration and features such as WebGL will not be available.");
        }
    }
#endif

    shareContext->setFormat(format);
    shareContext->create();
    qAddPostRoutine(deleteShareContext);
    qt_gl_set_global_share_context(shareContext);

    // Classes like QOpenGLWidget check for the attribute
    app->setAttribute(Qt::AA_ShareOpenGLContexts);
#endif // QT_CONFIG(opengl)
}
} // namespace QtWebEngineCore
