/****************************************************************************
**
** 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.
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** $QT_BEGIN_LICENSE:LGPL$
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** General Public License version 3 as published by the Free Software
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** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 3 requirements
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** 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
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** information to ensure the GNU General Public License requirements will
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****************************************************************************/

#include "surface_factory_qt.h"

#include "gl_context_qt.h"
#include "type_conversion.h"

#include "base/files/file_path.h"
#include "base/native_library.h"
#include "ui/gl/gl_context_egl.h"
#include "ui/gl/gl_implementation.h"
#include "ui/gl/gl_surface.h"
#include "ui/gl/init/gl_initializer.h"
#include "ui/gl/init/gl_factory.h"
#include "ui/ozone/common/gl_ozone_egl.h"

#include <QGuiApplication>

#if defined(USE_OZONE)

#include <EGL/egl.h>

#ifndef QT_LIBDIR_EGL
#define QT_LIBDIR_EGL "/usr/lib"
#endif
#ifndef QT_LIBDIR_GLES2
#define QT_LIBDIR_GLES2 QT_LIBDIR_EGL
#endif

namespace QtWebEngineCore {

class GLOzoneQt : public ui::GLOzoneEGL {
public:
    scoped_refptr<gl::GLSurface> CreateViewGLSurface(gfx::AcceleratedWidget /*window*/) override
    {
        return nullptr;
    }
    scoped_refptr<gl::GLSurface> CreateOffscreenGLSurface(const gfx::Size& /*size*/) override
    {
        return nullptr;
    }

protected:
    // Returns native platform display handle. This is used to obtain the EGL
    // display connection for the native display.
    intptr_t GetNativeDisplay() override;

    // Sets up GL bindings for the native surface.
    bool LoadGLES2Bindings() override;

};

base::NativeLibrary LoadLibrary(const base::FilePath& filename) {
    base::NativeLibraryLoadError error;
    base::NativeLibrary library = base::LoadNativeLibrary(filename, &error);
    if (!library) {
        LOG(ERROR) << "Failed to load " << filename.MaybeAsASCII() << ": " << error.ToString();
        return NULL;
    }
    return library;
}

bool GLOzoneQt::LoadGLES2Bindings()
{
    base::FilePath libEGLPath = QtWebEngineCore::toFilePath(QT_LIBDIR_EGL);
    libEGLPath = libEGLPath.Append("libEGL.so.1");
    base::NativeLibrary eglLibrary = LoadLibrary(libEGLPath);
    if (!eglLibrary)
        return false;

    base::FilePath libGLES2Path = QtWebEngineCore::toFilePath(QT_LIBDIR_GLES2);
    libGLES2Path = libGLES2Path.Append("libGLESv2.so.2");
    base::NativeLibrary gles2Library = LoadLibrary(libGLES2Path);
    if (!gles2Library)
        return false;

    gl::GLGetProcAddressProc get_proc_address = reinterpret_cast<gl::GLGetProcAddressProc>(base::GetFunctionPointerFromNativeLibrary(eglLibrary, "eglGetProcAddress"));
    if (!get_proc_address) {
        LOG(ERROR) << "eglGetProcAddress not found.";
        base::UnloadNativeLibrary(eglLibrary);
        base::UnloadNativeLibrary(gles2Library);
        return false;
    }

    gl::SetGLGetProcAddressProc(get_proc_address);
    gl::AddGLNativeLibrary(eglLibrary);
    gl::AddGLNativeLibrary(gles2Library);
    return true;
}

intptr_t GLOzoneQt::GetNativeDisplay()
{
    static void *display = GLContextHelper::getNativeDisplay();

    if (display)
        return reinterpret_cast<intptr_t>(display);

    return reinterpret_cast<intptr_t>(EGL_DEFAULT_DISPLAY);
}

std::vector<gl::GLImplementation> SurfaceFactoryQt::GetAllowedGLImplementations()
{
    std::vector<gl::GLImplementation> impls;
    impls.push_back(gl::kGLImplementationEGLGLES2);
    return impls;
}

ui::GLOzone* SurfaceFactoryQt::GetGLOzone(gl::GLImplementation implementation)
{
    return new GLOzoneQt();
}

} // namespace QtWebEngineCore

#endif // defined(USE_OZONE)