/*
 * Copyright © 2018 Red Hat, Inc
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library. If not, see <http://www.gnu.org/licenses/>.
 *
 * Authors:
 *       Jan Grulich <jgrulich@redhat.com>
 */

#include "screencast.h"
#include "session.h"
#include "screencaststream.h"
#include "screenchooserdialog.h"
#include "utils.h"

#include <QEventLoop>
#include <QLoggingCategory>
#include <QThread>
#include <QTimer>

#include <QDBusMetaType>
#include <QDBusError>
#include <QDBusArgument>
#include <QDBusConnection>

// KWayland
#include <KWayland/Client/connection_thread.h>
#include <KWayland/Client/event_queue.h>
#include <KWayland/Client/registry.h>
#include <KWayland/Client/output.h>
#include <KWayland/Client/remote_access.h>

// system
#include <fcntl.h>
#include <unistd.h>

Q_LOGGING_CATEGORY(XdgDesktopPortalKdeScreenCast, "xdp-kde-screencast")

Q_DECLARE_METATYPE(ScreenCastPortal::Stream);
Q_DECLARE_METATYPE(ScreenCastPortal::Streams);

const QDBusArgument &operator >> (const QDBusArgument &arg, ScreenCastPortal::Stream &stream)
{
    arg.beginStructure();
    arg >> stream.nodeId;

    arg.beginMap();
    while (!arg.atEnd()) {
        QString key;
        QVariant map;
        arg.beginMapEntry();
        arg >> key >> map;
        arg.endMapEntry();
        stream.map.insert(key, map);
    }
    arg.endMap();
    arg.endStructure();

    return arg;
}

const QDBusArgument &operator << (QDBusArgument &arg, const ScreenCastPortal::Stream &stream)
{
    arg.beginStructure();
    arg << stream.nodeId;
    arg << stream.map;
    arg.endStructure();

    return arg;
}

static const char * formatGLError(GLenum err)
{
    switch(err) {
    case GL_NO_ERROR:
        return "GL_NO_ERROR";
    case GL_INVALID_ENUM:
        return "GL_INVALID_ENUM";
    case GL_INVALID_VALUE:
        return "GL_INVALID_VALUE";
    case GL_INVALID_OPERATION:
        return "GL_INVALID_OPERATION";
    case GL_STACK_OVERFLOW:
        return "GL_STACK_OVERFLOW";
    case GL_STACK_UNDERFLOW:
        return "GL_STACK_UNDERFLOW";
    case GL_OUT_OF_MEMORY:
        return "GL_OUT_OF_MEMORY";
    default:
        return (QLatin1String("0x") + QString::number(err, 16)).toLocal8Bit().constData();
    }
}

// Thank you kscreen
void ScreenCastPortalOutput::setOutputType(const QString &type)
{
    const auto embedded = { QLatin1String("LVDS"),
                                   QLatin1String("IDP"),
                                   QLatin1String("EDP"),
                                   QLatin1String("LCD") };

    for (const QLatin1String &pre : embedded) {
        if (type.toUpper().startsWith(pre)) {
            outputType = OutputType::Laptop;
            return;
        }
    }

    if (type.contains("VGA") || type.contains("DVI") || type.contains("HDMI") || type.contains("Panel") ||
        type.contains("DisplayPort") || type.startsWith("DP") || type.contains("unknown")) {
        outputType = OutputType::Monitor;
    } else if (type.contains("TV")) {
        outputType = OutputType::Television;
    } else {
        outputType = OutputType::Monitor;
    }
}

ScreenCastPortal::ScreenCastPortal(QObject *parent)
    : QDBusAbstractAdaptor(parent)
    , m_eglInitialized(false)
    , m_registryInitialized(false)
    , m_streamingEnabled(false)
    , m_connection(nullptr)
    , m_queue(nullptr)
    , m_registry(nullptr)
    , m_remoteAccessManager(nullptr)
{
    initDrm();
    initWayland();

    qDBusRegisterMetaType<ScreenCastPortal::Stream>();
    qDBusRegisterMetaType<ScreenCastPortal::Streams>();
}

ScreenCastPortal::~ScreenCastPortal()
{
    if (m_remoteAccessManager) {
        m_remoteAccessManager->destroy();
    }

    if (m_drmFd) {
        gbm_device_destroy(m_gbmDevice);
    }

    m_stream->deleteLater();
}

void ScreenCastPortal::createPipeWireStream(const QSize &resolution)
{
    m_stream = new ScreenCastStream(resolution);
    m_stream->init();

    connect(m_stream, &ScreenCastStream::streamReady, this, [] (uint nodeId) {
        qCDebug(XdgDesktopPortalKdeScreenCast) << "Pipewire stream is ready: " << nodeId;
    });

    connect(m_stream, &ScreenCastStream::startStreaming, this, [this] {
        qCDebug(XdgDesktopPortalKdeScreenCast) << "Start streaming";
        m_streamingEnabled = true;

        if (!m_registryInitialized) {
            qCWarning(XdgDesktopPortalKdeScreenCast) << "Cannot start stream because registry is not initialized yet";
            return;
        }
        if (m_registry->hasInterface(KWayland::Client::Registry::Interface::RemoteAccessManager)) {
            KWayland::Client::Registry::AnnouncedInterface interface = m_registry->interface(KWayland::Client::Registry::Interface::RemoteAccessManager);
            if (!interface.name && !interface.version) {
                qCWarning(XdgDesktopPortalKdeScreenCast) << "Cannot start stream because remote access interface is not initialized yet";
                return;
            }
            m_remoteAccessManager = m_registry->createRemoteAccessManager(interface.name, interface.version);
            connect(m_remoteAccessManager, &KWayland::Client::RemoteAccessManager::bufferReady, this, [this] (const void *output, const KWayland::Client::RemoteBuffer * rbuf) {
                Q_UNUSED(output);
                connect(rbuf, &KWayland::Client::RemoteBuffer::parametersObtained, this, [this, rbuf] {
                    processBuffer(rbuf);
                });
            });
        }
    });

    connect(m_stream, &ScreenCastStream::stopStreaming, this, &ScreenCastPortal::stopStreaming);
}

void ScreenCastPortal::initDrm()
{
    m_drmFd = open("/dev/dri/renderD128", O_RDWR);

    if (m_drmFd == -1) {
        qCWarning(XdgDesktopPortalKdeScreenCast) << "Cannot open render node: " << strerror(errno);
        return;
    }

    m_gbmDevice = gbm_create_device(m_drmFd);

    if (!m_gbmDevice) {
        qCWarning(XdgDesktopPortalKdeScreenCast) << "Cannot create GBM device: " << strerror(errno);
        return;
    }

    initEGL();
}

void ScreenCastPortal::initEGL()
{
    // Get the list of client extensions
    const char* clientExtensionsCString = eglQueryString(EGL_NO_DISPLAY, EGL_EXTENSIONS);
    const QByteArray clientExtensionsString = QByteArray::fromRawData(clientExtensionsCString, qstrlen(clientExtensionsCString));
    if (clientExtensionsString.isEmpty()) {
        // If eglQueryString() returned NULL, the implementation doesn't support
        // EGL_EXT_client_extensions. Expect an EGL_BAD_DISPLAY error.
        qCWarning(XdgDesktopPortalKdeScreenCast) << "No client extensions defined! " << formatGLError(eglGetError());
        return;
    }

    m_egl.extensions = clientExtensionsString.split(' ');

    // Use eglGetPlatformDisplayEXT() to get the display pointer
    // if the implementation supports it.
    if (!m_egl.extensions.contains(QByteArrayLiteral("EGL_EXT_platform_base")) ||
            !m_egl.extensions.contains(QByteArrayLiteral("EGL_MESA_platform_gbm"))) {
        qCWarning(XdgDesktopPortalKdeScreenCast) << "One of required EGL extensions is missing";
        return;
    }

    m_egl.display = eglGetPlatformDisplayEXT(EGL_PLATFORM_GBM_MESA, m_gbmDevice, nullptr);

    if (m_egl.display == EGL_NO_DISPLAY) {
        qCWarning(XdgDesktopPortalKdeScreenCast) << "Error during obtaining EGL display: " << formatGLError(eglGetError());
        return;
    }

    EGLint major, minor;
    if (eglInitialize(m_egl.display, &major, &minor) == EGL_FALSE) {
        qCWarning(XdgDesktopPortalKdeScreenCast) << "Error during eglInitialize: " << formatGLError(eglGetError());
        return;
    }

    if (eglBindAPI(EGL_OPENGL_API) == EGL_FALSE) {
        qCWarning(XdgDesktopPortalKdeScreenCast) << "bind OpenGL API failed";
        return;
    }

    m_egl.context = eglCreateContext(m_egl.display, nullptr, EGL_NO_CONTEXT, nullptr);

    if (m_egl.context == EGL_NO_CONTEXT) {
        qCWarning(XdgDesktopPortalKdeScreenCast) << "Couldn't create EGL context: " << formatGLError(eglGetError());
        return;
    }

    qCDebug(XdgDesktopPortalKdeScreenCast) << "Egl initialization succeeded";
    qCDebug(XdgDesktopPortalKdeScreenCast) << QString("EGL version: %1.%2").arg(major).arg(minor);

    m_eglInitialized = true;
}

void ScreenCastPortal::initWayland()
{
    m_thread = new QThread(this);
    m_connection = new KWayland::Client::ConnectionThread;

    connect(m_connection, &KWayland::Client::ConnectionThread::connected, this, &ScreenCastPortal::setupRegistry, Qt::QueuedConnection);
    connect(m_connection, &KWayland::Client::ConnectionThread::connectionDied, this, [this] {
        if (m_queue) {
            delete m_queue;
            m_queue = nullptr;
        }

        m_connection->deleteLater();
        m_connection = nullptr;

        if (m_thread) {
            m_thread->quit();
            if (!m_thread->wait(3000)) {
                m_thread->terminate();
                m_thread->wait();
            }
            delete m_thread;
            m_thread = nullptr;
        }
    });
    connect(m_connection, &KWayland::Client::ConnectionThread::failed, this, [this] {
        m_thread->quit();
        m_thread->wait();
    });

    m_thread->start();
    m_connection->moveToThread(m_thread);
    m_connection->initConnection();
}

uint ScreenCastPortal::CreateSession(const QDBusObjectPath &handle,
                                     const QDBusObjectPath &session_handle,
                                     const QString &app_id,
                                     const QVariantMap &options,
                                     QVariantMap &results)
{
    Q_UNUSED(results)

    qCDebug(XdgDesktopPortalKdeScreenCast) << "CreateSession called with parameters:";
    qCDebug(XdgDesktopPortalKdeScreenCast) << "    handle: " << handle.path();
    qCDebug(XdgDesktopPortalKdeScreenCast) << "    session_handle: " << session_handle.path();
    qCDebug(XdgDesktopPortalKdeScreenCast) << "    app_id: " << app_id;
    qCDebug(XdgDesktopPortalKdeScreenCast) << "    options: " << options;

    QDBusConnection sessionBus = QDBusConnection::sessionBus();
    Session *session = new Session(this, app_id, session_handle.path());
    if (sessionBus.registerVirtualObject(session_handle.path(), session, QDBusConnection::VirtualObjectRegisterOption::SubPath)) {
        connect(session, &Session::closed, [this, session, session_handle] () {
            m_sessionList.remove(session_handle.path());
            QDBusConnection::sessionBus().unregisterObject(session_handle.path());
            session->deleteLater();
            stopStreaming();
        });
        m_sessionList.insert(session_handle.path(), session);
        return 0;
    } else {
        qCDebug(XdgDesktopPortalKdeScreenCast) << sessionBus.lastError().message();
        qCDebug(XdgDesktopPortalKdeScreenCast) << "Failed to register session object: " << session_handle.path();
        session->deleteLater();
        return 2;
    }
}

uint ScreenCastPortal::SelectSources(const QDBusObjectPath &handle,
                                     const QDBusObjectPath &session_handle,
                                     const QString &app_id,
                                     const QVariantMap &options,
                                     QVariantMap &results)
{
    Q_UNUSED(results)

    qCDebug(XdgDesktopPortalKdeScreenCast) << "SelectSource called with parameters:";
    qCDebug(XdgDesktopPortalKdeScreenCast) << "    handle: " << handle.path();
    qCDebug(XdgDesktopPortalKdeScreenCast) << "    session_handle: " << session_handle.path();
    qCDebug(XdgDesktopPortalKdeScreenCast) << "    app_id: " << app_id;
    qCDebug(XdgDesktopPortalKdeScreenCast) << "    options: " << options;

    uint types = Monitor;
    Session *session = nullptr;

    session = m_sessionList.value(session_handle.path());

    if (!session) {
        qCWarning(XdgDesktopPortalKdeScreenCast) << "Tried to select sources on non-existing session " << session_handle.path();
        return 2;
    }

    if (options.contains(QLatin1String("multiple"))) {
        session->setMultipleSources(options.value(QLatin1String("multiple")).toBool());
    }

    if (options.contains(QLatin1String("types"))) {
        types = (SourceType)(options.value(QLatin1String("types")).toUInt());
    }

    if (types == Window) {
        qCWarning(XdgDesktopPortalKdeScreenCast) << "Screen cast of a window is not implemented";
        return 2;
    }

    return 0;
}

uint ScreenCastPortal::Start(const QDBusObjectPath &handle,
                             const QDBusObjectPath &session_handle,
                             const QString &app_id,
                             const QString &parent_window,
                             const QVariantMap &options,
                             QVariantMap &results)
{
    Q_UNUSED(results)

    qCDebug(XdgDesktopPortalKdeScreenCast) << "Start called with parameters:";
    qCDebug(XdgDesktopPortalKdeScreenCast) << "    handle: " << handle.path();
    qCDebug(XdgDesktopPortalKdeScreenCast) << "    session_handle: " << session_handle.path();
    qCDebug(XdgDesktopPortalKdeScreenCast) << "    app_id: " << app_id;
    qCDebug(XdgDesktopPortalKdeScreenCast) << "    parent_window: " << parent_window;
    qCDebug(XdgDesktopPortalKdeScreenCast) << "    options: " << options;

    Session *session = nullptr;
    session = m_sessionList.value(session_handle.path());

    if (!session) {
        qCWarning(XdgDesktopPortalKdeScreenCast) << "Tried to select sources on non-existing session " << session_handle.path();
        return 2;
    }

    if (m_outputMap.isEmpty()) {
        qCWarning(XdgDesktopPortalKdeScreenCast) << "Failed to show dialog as there is no screen to select";
        return 2;
    }

    if (!m_eglInitialized) {
        qCWarning(XdgDesktopPortalKdeScreenCast) << "EGL is not initialized, we are not able to process screen content";
        return 2;
    }

    QScopedPointer<ScreenChooserDialog, QScopedPointerDeleteLater> screenDialog(new ScreenChooserDialog(m_outputMap, session->multipleSources()));
    Utils::setParentWindow(screenDialog.data(), parent_window);

    if (screenDialog->exec()) {
        ScreenCastPortalOutput selectedOutput = m_outputMap.value(screenDialog->selectedScreens().first());

        // Initialize PipeWire
        createPipeWireStream(selectedOutput.resolution);

        // HACK wait for stream to be ready
        bool streamReady = false;
        QEventLoop loop;
        connect(m_stream, &ScreenCastStream::streamReady, this, [&loop, &streamReady] {
            loop.quit();
            streamReady = true;
        });

        QTimer::singleShot(3000, &loop, &QEventLoop::quit);
        loop.exec();

        disconnect(m_stream, &ScreenCastStream::streamReady, this, nullptr);

        if (!streamReady) {
            qCWarning(XdgDesktopPortalKdeScreenCast) << "Pipewire stream is not ready to be streamed";
            return 2;
        }

        // TODO support multiple outputs

        qCDebug(XdgDesktopPortalKdeScreenCast) << "Pipewire node id: " << m_stream->nodeId();

        KWayland::Client::Output *output = new KWayland::Client::Output(this);
        output->setup(m_registry->bindOutput(selectedOutput.waylandOutputName, selectedOutput.waylandOutputVersion));
        m_bindOutputs << output;

        Stream stream;
        stream.nodeId = m_stream->nodeId();
        stream.map = QVariantMap({{QLatin1String("size"), selectedOutput.resolution}});
        results.insert(QLatin1String("streams"), QVariant::fromValue<ScreenCastPortal::Streams>({stream}));

        return 0;
    }

    return 1;
}

void ScreenCastPortal::addOutput(quint32 name, quint32 version)
{
    KWayland::Client::Output *output = new KWayland::Client::Output(this);
    output->setup(m_registry->bindOutput(name, version));

    connect(output, &KWayland::Client::Output::changed, this, [this, name, version, output] () {
        qCDebug(XdgDesktopPortalKdeScreenCast) << "Adding output:";
        qCDebug(XdgDesktopPortalKdeScreenCast) << "    manufacturer: " << output->manufacturer();
        qCDebug(XdgDesktopPortalKdeScreenCast) << "    model: " << output->model();
        qCDebug(XdgDesktopPortalKdeScreenCast) << "    resolution: " << output->pixelSize();

        ScreenCastPortalOutput portalOutput;
        portalOutput.manufacturer = output->manufacturer();
        portalOutput.model = output->model();
        portalOutput.resolution = output->pixelSize();
        portalOutput.waylandOutputName = name;
        portalOutput.waylandOutputVersion = version;
        portalOutput.setOutputType(output->model());

        m_outputMap.insert(name, portalOutput);

        delete output;
    });
}

void ScreenCastPortal::removeOutput(quint32 name)
{
    ScreenCastPortalOutput output = m_outputMap.take(name);
    qCDebug(XdgDesktopPortalKdeScreenCast) << "Removing output:";
    qCDebug(XdgDesktopPortalKdeScreenCast) << "    manufacturer: " << output.manufacturer;
    qCDebug(XdgDesktopPortalKdeScreenCast) << "    model: " << output.model;
}

void ScreenCastPortal::processBuffer(const KWayland::Client::RemoteBuffer* rbuf)
{
    QScopedPointer<const KWayland::Client::RemoteBuffer> guard(rbuf);

    auto gbmHandle = rbuf->fd();
    auto width = rbuf->width();
    auto height = rbuf->height();
    auto stride = rbuf->stride();
    auto format = rbuf->format();

    qCDebug(XdgDesktopPortalKdeScreenCast) << QString("Incoming GBM fd %1, %2x%3, stride %4, fourcc 0x%5").arg(gbmHandle).arg(width).arg(height).arg(stride).arg(QString::number(format, 16));

    if (!m_streamingEnabled) {
        qCDebug(XdgDesktopPortalKdeScreenCast) << "Streaming is disabled";
        close(gbmHandle);
        return;
    }

    if (m_lastFrameTime.isValid() &&
        m_lastFrameTime.msecsTo(QDateTime::currentDateTime()) < (1000 / m_stream->framerate())) {
        close(gbmHandle);
        return;
    }

    if (!gbm_device_is_format_supported(m_gbmDevice, format, GBM_BO_USE_SCANOUT)) {
        qCWarning(XdgDesktopPortalKdeScreenCast) << "Failed to process buffer: GBM format is not supported by device!";
        close(gbmHandle);
        return;
    }

    // import GBM buffer that was passed from KWin
    gbm_import_fd_data importInfo = {gbmHandle, width, height, stride, format};
    gbm_bo *imported = gbm_bo_import(m_gbmDevice, GBM_BO_IMPORT_FD, &importInfo, GBM_BO_USE_SCANOUT);
    if (!imported) {
        qCWarning(XdgDesktopPortalKdeScreenCast) << "Failed to process buffer: Cannot import passed GBM fd - " << strerror(errno);
        close(gbmHandle);
        return;
    }

    // bind context to render thread
    eglMakeCurrent(m_egl.display, EGL_NO_SURFACE, EGL_NO_SURFACE, m_egl.context);

    // create EGL image from imported BO
    EGLImageKHR image = eglCreateImageKHR(m_egl.display, nullptr, EGL_NATIVE_PIXMAP_KHR, imported, nullptr);

    // We can already close gbm handle
    gbm_bo_destroy(imported);
    close(gbmHandle);

    if (image == EGL_NO_IMAGE_KHR) {
        qCWarning(XdgDesktopPortalKdeScreenCast) << "Failed to process buffer: Error creating EGLImageKHR - " << formatGLError(glGetError());
        return;
    }

    // create GL 2D texture for framebuffer
    GLuint texture;
    glGenTextures(1, &texture);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
    glBindTexture(GL_TEXTURE_2D, texture);
    glEGLImageTargetTexture2DOES(GL_TEXTURE_2D, image);

    // bind framebuffer to copy pixels from
    GLuint framebuffer;
    glGenFramebuffers(1, &framebuffer);
    glBindFramebuffer(GL_FRAMEBUFFER, framebuffer);
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture, 0);
    const GLenum status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
    if (status != GL_FRAMEBUFFER_COMPLETE) {
        qCWarning(XdgDesktopPortalKdeScreenCast) << "Failed to process buffer: glCheckFramebufferStatus failed - " << formatGLError(glGetError());
        glDeleteTextures(1, &texture);
        glDeleteFramebuffers(1, &framebuffer);
        eglDestroyImageKHR(m_egl.display, image);
        return;
    }

    auto capture = new QImage(QSize(width, height), QImage::Format_RGBA8888);
    glViewport(0, 0, width, height);
    glGetTexImage(GL_TEXTURE_2D, 0, GL_RGBA, GL_UNSIGNED_BYTE, capture->bits());

    if (m_stream->recordFrame(capture->bits())) {
        m_lastFrameTime = QDateTime::currentDateTime();
    }

    glDeleteTextures(1, &texture);
    glDeleteFramebuffers(1, &framebuffer);
    eglDestroyImageKHR(m_egl.display, image);

    delete capture;
}

void ScreenCastPortal::setupRegistry()
{
    m_queue = new KWayland::Client::EventQueue(this);
    m_queue->setup(m_connection);

    m_registry = new KWayland::Client::Registry(this);

    connect(m_registry, &KWayland::Client::Registry::outputAnnounced, this, &ScreenCastPortal::addOutput);
    connect(m_registry, &KWayland::Client::Registry::outputRemoved, this, &ScreenCastPortal::removeOutput);

    connect(m_registry, &KWayland::Client::Registry::interfacesAnnounced, this, [this] {
        m_registryInitialized = true;
        qCDebug(XdgDesktopPortalKdeScreenCast) << "Registry initialized";
    });

    m_registry->create(m_connection);
    m_registry->setEventQueue(m_queue);
    m_registry->setup();
}

void ScreenCastPortal::stopStreaming()
{
    if (m_streamingEnabled) {
        qCDebug(XdgDesktopPortalKdeScreenCast) << "Stop streaming";
        m_remoteAccessManager->release();
        m_remoteAccessManager->destroy();

        m_streamingEnabled = false;

        qDeleteAll(m_bindOutputs);
        m_bindOutputs.clear();

        delete m_stream;
        m_stream = nullptr;
    }
}
