// Copyright (C) 2015 Pier Luigi Fiorini <pierluigi.fiorini@gmail.com>
// Copyright (C) 2016 The Qt Company Ltd.
// Copyright (C) 2016 Pelagicore AG
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only

#include "qeglfskmsgbmintegration_p.h"
#include "qeglfskmsgbmdevice_p.h"
#include "qeglfskmsgbmscreen_p.h"
#include "qeglfskmsgbmcursor_p.h"
#include "qeglfskmsgbmwindow_p.h"
#include "private/qeglfscursor_p.h"

#include <QtCore/QLoggingCategory>
#include <QtCore/QFileSystemWatcher>
#include <QtGui/QScreen>
#include <QtDeviceDiscoverySupport/private/qdevicediscovery_p.h>

#include <gbm.h>

QT_BEGIN_NAMESPACE

QEglFSKmsGbmIntegration::QEglFSKmsGbmIntegration()
{
    qCDebug(qLcEglfsKmsDebug, "New DRM/KMS via GBM integration created");
}

QEglFSKmsGbmIntegration::~QEglFSKmsGbmIntegration()
{
}

#ifndef EGL_EXT_platform_base
typedef EGLDisplay (EGLAPIENTRYP PFNEGLGETPLATFORMDISPLAYEXTPROC) (EGLenum platform, void *native_display, const EGLint *attrib_list);
#endif

#ifndef EGL_PLATFORM_GBM_KHR
#define EGL_PLATFORM_GBM_KHR 0x31D7
#endif

EGLDisplay QEglFSKmsGbmIntegration::createDisplay(EGLNativeDisplayType nativeDisplay)
{
    qCDebug(qLcEglfsKmsDebug, "Querying EGLDisplay");
    EGLDisplay display;

    PFNEGLGETPLATFORMDISPLAYEXTPROC getPlatformDisplay = nullptr;
    const char *extensions = eglQueryString(EGL_NO_DISPLAY, EGL_EXTENSIONS);
    if (extensions && (strstr(extensions, "EGL_KHR_platform_gbm") || strstr(extensions, "EGL_MESA_platform_gbm"))) {
        getPlatformDisplay = reinterpret_cast<PFNEGLGETPLATFORMDISPLAYEXTPROC>(
            eglGetProcAddress("eglGetPlatformDisplayEXT"));
    }

    if (getPlatformDisplay) {
        display = getPlatformDisplay(EGL_PLATFORM_GBM_KHR, nativeDisplay, nullptr);
    } else {
        qCDebug(qLcEglfsKmsDebug, "No eglGetPlatformDisplay for GBM, falling back to eglGetDisplay");
        display = eglGetDisplay(nativeDisplay);
    }

    return display;
}

EGLNativeWindowType QEglFSKmsGbmIntegration::createNativeOffscreenWindow(const QSurfaceFormat &format)
{
    Q_UNUSED(format);
    Q_ASSERT(device());

    gbm_surface *surface = gbm_surface_create(static_cast<QEglFSKmsGbmDevice *>(device())->gbmDevice(),
                                              1, 1,
                                              GBM_FORMAT_XRGB8888,
                                              GBM_BO_USE_RENDERING);

    return reinterpret_cast<EGLNativeWindowType>(surface);
}

void QEglFSKmsGbmIntegration::destroyNativeWindow(EGLNativeWindowType window)
{
    gbm_surface *surface = reinterpret_cast<gbm_surface *>(window);
    gbm_surface_destroy(surface);
}

QPlatformCursor *QEglFSKmsGbmIntegration::createCursor(QPlatformScreen *screen) const
{
#if QT_CONFIG(opengl)
    if (!screenConfig()->hwCursor()) {
        qCDebug(qLcEglfsKmsDebug, "Using plain OpenGL mouse cursor");
        return new QEglFSCursor(screen);
    }
#else
    Q_UNUSED(screen);
#endif
    return nullptr;
}

void QEglFSKmsGbmIntegration::presentBuffer(QPlatformSurface *surface)
{
    QWindow *window = static_cast<QWindow *>(surface->surface());
    QEglFSKmsGbmScreen *screen = static_cast<QEglFSKmsGbmScreen *>(window->screen()->handle());
    screen->flip();
}

QKmsDevice *QEglFSKmsGbmIntegration::createDevice()
{

    m_deviceDiscovery = std::unique_ptr<QDeviceDiscovery>(QDeviceDiscovery::create(QDeviceDiscovery::Device_VideoMask));
    m_kmsConfigWatcher = std::unique_ptr<QFileSystemWatcher>(new QFileSystemWatcher());

    QString path = screenConfig()->devicePath();
    if (!path.isEmpty()) {
        qCDebug(qLcEglfsKmsDebug) << "GBM: Using DRM device" << path << "specified in config file";
    } else {
        const QStringList devices = m_deviceDiscovery->scanConnectedDevices();
        qCDebug(qLcEglfsKmsDebug) << "Found the following video devices:" << devices;

        if (Q_UNLIKELY(devices.isEmpty()))
            qFatal("Could not find DRM device!");

        path = devices.first();
        qCDebug(qLcEglfsKmsDebug) << "Using" << path;
    }

    bool hotreload = !qEnvironmentVariable("QT_QPA_EGLFS_HOTPLUG_ENABLED").isEmpty();
    if (hotreload) {
        qCWarning(qLcEglfsKmsDebug) << "EGLFS/KMS: Hot-Reload on KMS-events enabled, be aware that"
                                    << "this requires actions in UI code for proper functionallity"
                                    << "(e.g. close/open windows on screen's disconnect/connect)";
        QObject::connect(m_deviceDiscovery.get(), &QDeviceDiscovery::deviceChanged,
                         m_deviceDiscovery.get(), [this](const QString &deviceNode) {
                             qCDebug(qLcEglfsKmsDebug) << "KMS device changed:" << deviceNode;
                             m_device->checkConnectedScreens();
                         });
    }

    QString json = qEnvironmentVariable("QT_QPA_EGLFS_KMS_CONFIG");
    if (json.isEmpty())
        json = qEnvironmentVariable("QT_QPA_KMS_CONFIG");

    if (!json.isEmpty()) {
        m_kmsConfigWatcher->addPath(json);
        QObject::connect(m_kmsConfigWatcher.get(), &QFileSystemWatcher::fileChanged,
                         m_kmsConfigWatcher.get(), [this, json]() {
                             qCDebug(qLcEglfsKmsDebug) << "KMS config-file has changed! path:"
                                                       << json;
                             m_screenConfig->refreshConfig();
                             m_device->updateScreens();
                             m_kmsConfigWatcher->addPath(json); // as per QFileSystemWatcher doc we have to re-add
                                                                // the path in case it's a new file
                         });
    }

    return new QEglFSKmsGbmDevice(screenConfig(), path);
}

QEglFSWindow *QEglFSKmsGbmIntegration::createWindow(QWindow *window) const
{
    return new QEglFSKmsGbmWindow(window, this);
}

QT_END_NAMESPACE