/****************************************************************************
**
** Copyright (C) 2019 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the QtWaylandCompositor module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:GPL$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3 or (at your option) 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.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-3.0.html.
**
** $QT_END_LICENSE$
**
****************************************************************************/

#include "waylandeglstreamintegration.h"
#include "waylandeglstreamcontroller.h"

#include <QtWaylandCompositor/QWaylandCompositor>
#include <QtGui/QGuiApplication>
#include <QtGui/QOpenGLContext>
#include <QtGui/QOpenGLTexture>
#include <QtGui/QOffscreenSurface>

#include <QtEglSupport/private/qeglstreamconvenience_p.h>
#include <qpa/qplatformnativeinterface.h>

#include <QtWaylandCompositor/private/qwaylandcompositor_p.h>
#include <QtWaylandCompositor/private/qwlbuffermanager_p.h>

#include <EGL/egl.h>
#include <EGL/eglext.h>
#include <unistd.h>

#ifndef GL_TEXTURE_EXTERNAL_OES
#define GL_TEXTURE_EXTERNAL_OES     0x8D65
#endif

#ifndef EGL_WAYLAND_BUFFER_WL
#define EGL_WAYLAND_BUFFER_WL       0x31D5
#endif

#ifndef EGL_WAYLAND_EGLSTREAM_WL
#define EGL_WAYLAND_EGLSTREAM_WL    0x334B
#endif

#ifndef EGL_WAYLAND_PLANE_WL
#define EGL_WAYLAND_PLANE_WL        0x31D6
#endif

#ifndef EGL_WAYLAND_Y_INVERTED_WL
#define EGL_WAYLAND_Y_INVERTED_WL   0x31DB
#endif

#ifndef EGL_TEXTURE_RGB
#define EGL_TEXTURE_RGB             0x305D
#endif

#ifndef EGL_TEXTURE_RGBA
#define EGL_TEXTURE_RGBA            0x305E
#endif

#ifndef EGL_TEXTURE_EXTERNAL_WL
#define EGL_TEXTURE_EXTERNAL_WL     0x31DA
#endif

#ifndef EGL_TEXTURE_Y_U_V_WL
#define EGL_TEXTURE_Y_U_V_WL        0x31D7
#endif

#ifndef EGL_TEXTURE_Y_UV_WL
#define EGL_TEXTURE_Y_UV_WL         0x31D8
#endif

#ifndef EGL_TEXTURE_Y_XUXV_WL
#define EGL_TEXTURE_Y_XUXV_WL       0x31D9
#endif

#ifndef EGL_PLATFORM_X11_KHR
#define EGL_PLATFORM_X11_KHR        0x31D5
#endif

QT_BEGIN_NAMESPACE

/* Needed for compatibility with Mesa older than 10.0. */
typedef EGLBoolean (EGLAPIENTRYP PFNEGLQUERYWAYLANDBUFFERWL_compat) (EGLDisplay dpy, struct wl_resource *buffer, EGLint attribute, EGLint *value);

#ifndef EGL_WL_bind_wayland_display
typedef EGLBoolean (EGLAPIENTRYP PFNEGLBINDWAYLANDDISPLAYWL) (EGLDisplay dpy, struct wl_display *display);
typedef EGLBoolean (EGLAPIENTRYP PFNEGLUNBINDWAYLANDDISPLAYWL) (EGLDisplay dpy, struct wl_display *display);
#endif

static const char *
egl_error_string(EGLint code)
{
#define MYERRCODE(x) case x: return #x;
    switch (code) {
    MYERRCODE(EGL_SUCCESS)
    MYERRCODE(EGL_NOT_INITIALIZED)
    MYERRCODE(EGL_BAD_ACCESS)
    MYERRCODE(EGL_BAD_ALLOC)
    MYERRCODE(EGL_BAD_ATTRIBUTE)
    MYERRCODE(EGL_BAD_CONTEXT)
    MYERRCODE(EGL_BAD_CONFIG)
    MYERRCODE(EGL_BAD_CURRENT_SURFACE)
    MYERRCODE(EGL_BAD_DISPLAY)
    MYERRCODE(EGL_BAD_SURFACE)
    MYERRCODE(EGL_BAD_MATCH)
    MYERRCODE(EGL_BAD_PARAMETER)
    MYERRCODE(EGL_BAD_NATIVE_PIXMAP)
    MYERRCODE(EGL_BAD_NATIVE_WINDOW)
    MYERRCODE(EGL_CONTEXT_LOST)
    default:
        return "unknown";
    }
#undef MYERRCODE
}

struct BufferState
{
    BufferState() = default;

    EGLint egl_format = EGL_TEXTURE_EXTERNAL_WL;
    QOpenGLTexture *textures[3] = {};
    EGLStreamKHR egl_stream = EGL_NO_STREAM_KHR;

    bool isYInverted = false;
    QSize size;
};

class WaylandEglStreamClientBufferIntegrationPrivate
{
public:
    WaylandEglStreamClientBufferIntegrationPrivate() = default;

    bool ensureContext();
    bool initEglStream(WaylandEglStreamClientBuffer *buffer, struct ::wl_resource *bufferHandle);
    void handleEglstreamTexture(WaylandEglStreamClientBuffer *buffer);
    void deleteGLTextureWhenPossible(QOpenGLTexture *texture) { orphanedTextures << texture; }
    void deleteOrphanedTextures();

    EGLDisplay egl_display = EGL_NO_DISPLAY;
    bool display_bound = false;
    QOffscreenSurface *offscreenSurface = nullptr;
    QOpenGLContext *localContext = nullptr;
    QVector<QOpenGLTexture *> orphanedTextures;

    WaylandEglStreamController *eglStreamController = nullptr;

    PFNEGLBINDWAYLANDDISPLAYWL egl_bind_wayland_display = nullptr;
    PFNEGLUNBINDWAYLANDDISPLAYWL egl_unbind_wayland_display = nullptr;
    PFNEGLQUERYWAYLANDBUFFERWL_compat egl_query_wayland_buffer = nullptr;

    QEGLStreamConvenience *funcs = nullptr;
    static WaylandEglStreamClientBufferIntegrationPrivate *get(WaylandEglStreamClientBufferIntegration *integration) {
        return shuttingDown ? nullptr : integration->d_ptr.data();
    }

    static bool shuttingDown;
};

bool WaylandEglStreamClientBufferIntegrationPrivate::shuttingDown = false;

void WaylandEglStreamClientBufferIntegrationPrivate::deleteOrphanedTextures()
{
    Q_ASSERT(QOpenGLContext::currentContext());
    qDeleteAll(orphanedTextures);
    orphanedTextures.clear();
}

bool WaylandEglStreamClientBufferIntegrationPrivate::ensureContext()
{
    bool localContextNeeded = false;
    if (!QOpenGLContext::currentContext()) {
        if (!localContext && QOpenGLContext::globalShareContext()) {
            localContext = new QOpenGLContext;
            localContext->setShareContext(QOpenGLContext::globalShareContext());
            localContext->create();
        }
        if (localContext) {
            if (!offscreenSurface) {
                offscreenSurface = new QOffscreenSurface;
                offscreenSurface->setFormat(localContext->format());
                offscreenSurface->create();
            }
            localContext->makeCurrent(offscreenSurface);
            localContextNeeded = true;
        }
    }
    return localContextNeeded;
}


bool WaylandEglStreamClientBufferIntegrationPrivate::initEglStream(WaylandEglStreamClientBuffer *buffer, wl_resource *bufferHandle)
{
    BufferState &state = *buffer->d;
    state.egl_format = EGL_TEXTURE_EXTERNAL_WL;
    state.isYInverted = false;

    EGLNativeFileDescriptorKHR streamFd = EGL_NO_FILE_DESCRIPTOR_KHR;

    if (egl_query_wayland_buffer(egl_display, bufferHandle, EGL_WAYLAND_BUFFER_WL, &streamFd)) {
        state.egl_stream = funcs->create_stream_from_file_descriptor(egl_display, streamFd);
        close(streamFd);
    } else {
        EGLAttrib stream_attribs[] = {
            EGL_WAYLAND_EGLSTREAM_WL, (EGLAttrib)bufferHandle,
            EGL_NONE
        };
        state.egl_stream = funcs->create_stream_attrib_nv(egl_display, stream_attribs);
    }

    if (state.egl_stream == EGL_NO_STREAM_KHR) {
        qWarning("%s:%d: eglCreateStreamFromFileDescriptorKHR failed: 0x%x", Q_FUNC_INFO, __LINE__, eglGetError());
        return false;
    }

    bool usingLocalContext = ensureContext();

    Q_ASSERT(QOpenGLContext::currentContext());

    auto texture = new QOpenGLTexture(static_cast<QOpenGLTexture::Target>(GL_TEXTURE_EXTERNAL_OES));
    texture->create();
    state.textures[0] = texture; // TODO: support multiple planes

    texture->bind();

    auto newStream = funcs->stream_consumer_gltexture(egl_display, state.egl_stream);
    if (usingLocalContext)
        localContext->doneCurrent();

    if (!newStream) {
        EGLint code = eglGetError();
        qWarning() << "Could not initialize EGLStream:" << egl_error_string(code) << hex << (long)code;
        funcs->destroy_stream(egl_display, state.egl_stream);
        state.egl_stream = EGL_NO_STREAM_KHR;
        return false;
    }
    return true;
}

void WaylandEglStreamClientBufferIntegrationPrivate::handleEglstreamTexture(WaylandEglStreamClientBuffer *buffer)
{
    bool usingLocalContext = ensureContext();

    BufferState &state = *buffer->d;
    auto texture = state.textures[0];

    // EGLStream requires calling acquire on every frame.
    texture->bind();
    EGLint stream_state;
    funcs->query_stream(egl_display, state.egl_stream, EGL_STREAM_STATE_KHR, &stream_state);

    if (stream_state == EGL_STREAM_STATE_NEW_FRAME_AVAILABLE_KHR) {
        if (funcs->stream_consumer_acquire(egl_display, state.egl_stream) != EGL_TRUE)
            qWarning("%s:%d: eglStreamConsumerAcquireKHR failed: 0x%x", Q_FUNC_INFO, __LINE__, eglGetError());
    }

    if (usingLocalContext)
        localContext->doneCurrent();
}


WaylandEglStreamClientBufferIntegration::WaylandEglStreamClientBufferIntegration()
    : d_ptr(new WaylandEglStreamClientBufferIntegrationPrivate)
{
}

WaylandEglStreamClientBufferIntegration::~WaylandEglStreamClientBufferIntegration()
{
    WaylandEglStreamClientBufferIntegrationPrivate::shuttingDown = true;
}

void WaylandEglStreamClientBufferIntegration::attachEglStreamConsumer(struct ::wl_resource *wl_surface, struct ::wl_resource *wl_buffer)
{
    Q_D(WaylandEglStreamClientBufferIntegration);
    Q_UNUSED(wl_surface);

    // NOTE: must use getBuffer to create the buffer here, so the buffer will end up in the buffer manager's hash

    auto *bufferManager = QWaylandCompositorPrivate::get(m_compositor)->bufferManager();
    auto *clientBuffer = static_cast<WaylandEglStreamClientBuffer*>(bufferManager->getBuffer(wl_buffer));

    d->initEglStream(clientBuffer, wl_buffer);
}

void WaylandEglStreamClientBufferIntegration::initializeHardware(struct wl_display *display)
{
    Q_D(WaylandEglStreamClientBufferIntegration);

    const bool ignoreBindDisplay = !qgetenv("QT_WAYLAND_IGNORE_BIND_DISPLAY").isEmpty();

    QPlatformNativeInterface *nativeInterface = QGuiApplication::platformNativeInterface();
    if (!nativeInterface) {
        qWarning("QtCompositor: Failed to initialize EGL display. No native platform interface available.");
        return;
    }

    d->egl_display = nativeInterface->nativeResourceForIntegration("EglDisplay");
    if (!d->egl_display) {
        qWarning("QtCompositor: Failed to initialize EGL display. Could not get EglDisplay for window.");
        return;
    }

    const char *extensionString = eglQueryString(d->egl_display, EGL_EXTENSIONS);
    if ((!extensionString || !strstr(extensionString, "EGL_WL_bind_wayland_display")) && !ignoreBindDisplay) {
        qWarning("QtCompositor: Failed to initialize EGL display. There is no EGL_WL_bind_wayland_display extension.");
        return;
    }

    d->egl_bind_wayland_display = reinterpret_cast<PFNEGLBINDWAYLANDDISPLAYWL>(eglGetProcAddress("eglBindWaylandDisplayWL"));
    d->egl_unbind_wayland_display = reinterpret_cast<PFNEGLUNBINDWAYLANDDISPLAYWL>(eglGetProcAddress("eglUnbindWaylandDisplayWL"));
    if ((!d->egl_bind_wayland_display || !d->egl_unbind_wayland_display) && !ignoreBindDisplay) {
        qWarning("QtCompositor: Failed to initialize EGL display. Could not find eglBindWaylandDisplayWL and eglUnbindWaylandDisplayWL.");
        return;
    }

    d->egl_query_wayland_buffer = reinterpret_cast<PFNEGLQUERYWAYLANDBUFFERWL_compat>(eglGetProcAddress("eglQueryWaylandBufferWL"));
    if (!d->egl_query_wayland_buffer) {
        qWarning("QtCompositor: Failed to initialize EGL display. Could not find eglQueryWaylandBufferWL.");
        return;
    }

    if (d->egl_bind_wayland_display && d->egl_unbind_wayland_display) {
        d->display_bound = d->egl_bind_wayland_display(d->egl_display, display);
        if (!d->display_bound) {
            if (!ignoreBindDisplay) {
                qWarning("QtCompositor: Failed to initialize EGL display. Could not bind Wayland display.");
                return;
            } else {
                qWarning("QtCompositor: Could not bind Wayland display. Ignoring.");
            }
        }
    }

    d->eglStreamController = new WaylandEglStreamController(display, this);

    d->funcs = new QEGLStreamConvenience;
    d->funcs->initialize(d->egl_display);
}

QtWayland::ClientBuffer *WaylandEglStreamClientBufferIntegration::createBufferFor(wl_resource *buffer)
{
    if (wl_shm_buffer_get(buffer))
        return nullptr;

    return new WaylandEglStreamClientBuffer(this, buffer);
}


WaylandEglStreamClientBuffer::WaylandEglStreamClientBuffer(WaylandEglStreamClientBufferIntegration *integration, wl_resource *buffer)
    : ClientBuffer(buffer)
    , m_integration(integration)
{
    auto *p = WaylandEglStreamClientBufferIntegrationPrivate::get(m_integration);
    d = new BufferState;
    if (buffer && !wl_shm_buffer_get(buffer)) {
        EGLint width, height;
        p->egl_query_wayland_buffer(p->egl_display, buffer, EGL_WIDTH, &width);
        p->egl_query_wayland_buffer(p->egl_display, buffer, EGL_HEIGHT, &height);
        d->size = QSize(width, height);
    }
}

WaylandEglStreamClientBuffer::~WaylandEglStreamClientBuffer()
{
    auto *p = WaylandEglStreamClientBufferIntegrationPrivate::get(m_integration);

    if (p) {
        if (d->egl_stream)
            p->funcs->destroy_stream(p->egl_display, d->egl_stream);

        for (auto *texture : d->textures)
            p->deleteGLTextureWhenPossible(texture);
    }
    delete d;
}


QWaylandBufferRef::BufferFormatEgl WaylandEglStreamClientBuffer::bufferFormatEgl() const
{
    return QWaylandBufferRef::BufferFormatEgl_EXTERNAL_OES;
}


QSize WaylandEglStreamClientBuffer::size() const
{
    return d->size;
}

QWaylandSurface::Origin WaylandEglStreamClientBuffer::origin() const
{
    return d->isYInverted ? QWaylandSurface::OriginTopLeft : QWaylandSurface::OriginBottomLeft;
}

QOpenGLTexture *WaylandEglStreamClientBuffer::toOpenGlTexture(int plane)
{
    auto *p = WaylandEglStreamClientBufferIntegrationPrivate::get(m_integration);
    // At this point we should have a valid OpenGL context, so it's safe to destroy textures
    p->deleteOrphanedTextures();

    if (!m_buffer)
        return nullptr;

    return d->textures[plane];
}

void WaylandEglStreamClientBuffer::setCommitted(QRegion &damage)
{
    ClientBuffer::setCommitted(damage);
    auto *p = WaylandEglStreamClientBufferIntegrationPrivate::get(m_integration);
    p->handleEglstreamTexture(this);
}

QT_END_NAMESPACE