/*
 *  gstvaapiwindow_wayland.c - VA/Wayland window abstraction
 *
 *  Copyright (C) 2012-2013 Intel Corporation
 *    Author: Sreerenj Balachandran <sreerenj.balachandran@intel.com>
 *    Author: Gwenole Beauchesne <gwenole.beauchesne@intel.com>
 *
 *  This library 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 2.1
 *  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, write to the Free
 *  Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 *  Boston, MA 02110-1301 USA
 */

/**
 * SECTION:gstvaapiwindow_wayland
 * @short_description: VA/Wayland window abstraction
 */

#include "sysdeps.h"
#include "gstvaapicompat.h"
#include "gstvaapisurface_priv.h"
#include "gstvaapiwindow_wayland.h"
#include "gstvaapiwindow_priv.h"
#include "gstvaapidisplay_wayland.h"
#include "gstvaapidisplay_wayland_priv.h"
#include "gstvaapiutils.h"
#include "gstvaapifilter.h"
#include "gstvaapisurfacepool.h"

#include <unistd.h>

GST_DEBUG_CATEGORY_EXTERN (gst_debug_vaapi_window);
GST_DEBUG_CATEGORY_EXTERN (gst_debug_vaapi);
#define GST_CAT_DEFAULT gst_debug_vaapi_window

#define GST_VAAPI_WINDOW_WAYLAND_CAST(obj) \
    ((GstVaapiWindowWayland *)(obj))

#define GST_VAAPI_WINDOW_WAYLAND_GET_PRIVATE(obj) \
    gst_vaapi_window_wayland_get_instance_private (GST_VAAPI_WINDOW_WAYLAND_CAST (obj))

#define GST_VAAPI_WINDOW_WAYLAND_GET_CLASS(obj) \
    (G_TYPE_INSTANCE_GET_CLASS ((obj), GST_TYPE_VAAPI_WINDOW_WAYLAND, GstVaapiWindowWaylandClass))

typedef struct _GstVaapiWindowWaylandPrivate GstVaapiWindowWaylandPrivate;
typedef struct _GstVaapiWindowWaylandClass GstVaapiWindowWaylandClass;
typedef struct _FrameState FrameState;

struct _FrameState
{
  GstVaapiWindow *window;
  GstVaapiSurface *surface;
  GstVaapiVideoPool *surface_pool;
  struct wl_callback *callback;
  gboolean done;
};

static FrameState *
frame_state_new (GstVaapiWindow * window)
{
  FrameState *frame;

  frame = g_slice_new (FrameState);
  if (!frame)
    return NULL;

  frame->window = window;
  frame->surface = NULL;
  frame->surface_pool = NULL;
  frame->callback = NULL;
  frame->done = FALSE;
  return frame;
}

static void
frame_state_free (FrameState * frame)
{
  if (!frame)
    return;

  if (frame->surface) {
    if (frame->surface_pool)
      gst_vaapi_video_pool_put_object (frame->surface_pool, frame->surface);
    frame->surface = NULL;
  }
  gst_vaapi_video_pool_replace (&frame->surface_pool, NULL);

  g_clear_pointer (&frame->callback, wl_callback_destroy);
  g_slice_free (FrameState, frame);
}

struct _GstVaapiWindowWaylandPrivate
{
  struct xdg_surface *xdg_surface;
  struct xdg_toplevel *xdg_toplevel;
  struct wl_shell_surface *wl_shell_surface;
  struct wl_surface *surface;
  struct wl_subsurface *video_subsurface;
  struct wl_region *opaque_region;
  struct wl_event_queue *event_queue;
  FrameState *last_frame;
  GstPoll *poll;
  GstPollFD pollfd;
  guint is_shown:1;
  guint fullscreen_on_show:1;
  guint sync_failed:1;
  volatile guint num_frames_pending;
  gint configure_pending;
  gboolean need_vpp;
  gboolean dmabuf_broken;
};

/**
 * GstVaapiWindowWayland:
 *
 * A Wayland window abstraction.
 */
struct _GstVaapiWindowWayland
{
  /*< private > */
  GstVaapiWindow parent_instance;
};

/**
 * GstVaapiWindowWaylandClass:
 *
 * An Wayland Window wrapper class.
 */
struct _GstVaapiWindowWaylandClass
{
  /*< private > */
  GstVaapiWindowClass parent_class;
};

G_DEFINE_TYPE_WITH_PRIVATE (GstVaapiWindowWayland, gst_vaapi_window_wayland,
    GST_TYPE_VAAPI_WINDOW);

/* Object signals */
enum
{
  SIZE_CHANGED,
  N_SIGNALS
};

static guint signals[N_SIGNALS];

static void
handle_xdg_toplevel_configure (void *data, struct xdg_toplevel *xdg_toplevel,
    int32_t width, int32_t height, struct wl_array *states)
{
  GstVaapiWindow *window = GST_VAAPI_WINDOW (data);
  const uint32_t *state;

  GST_DEBUG ("Got XDG-toplevel::reconfigure, [width x height] = [%d x %d]",
      width, height);

  wl_array_for_each (state, states) {
    switch (*state) {
      case XDG_TOPLEVEL_STATE_FULLSCREEN:
      case XDG_TOPLEVEL_STATE_MAXIMIZED:
      case XDG_TOPLEVEL_STATE_RESIZING:
      case XDG_TOPLEVEL_STATE_ACTIVATED:
        break;
    }
  }

  if (width > 0 && height > 0) {
    gst_vaapi_window_set_size (window, width, height);
    g_signal_emit (window, signals[SIZE_CHANGED], 0, width, height);
  }
}

static void
handle_xdg_toplevel_close (void *data, struct xdg_toplevel *xdg_toplevel)
{
}

static const struct xdg_toplevel_listener xdg_toplevel_listener = {
  handle_xdg_toplevel_configure,
  handle_xdg_toplevel_close,
};

static gboolean gst_vaapi_window_wayland_sync (GstVaapiWindow * window);

static gboolean
gst_vaapi_window_wayland_show (GstVaapiWindow * window)
{
  GstVaapiWindowWaylandPrivate *priv =
      GST_VAAPI_WINDOW_WAYLAND_GET_PRIVATE (window);

  if (priv->xdg_surface == NULL) {
    GST_FIXME ("GstVaapiWindowWayland::show() unimplemented for wl_shell");
    return TRUE;
  }

  if (priv->xdg_toplevel != NULL) {
    GST_DEBUG ("XDG toplevel already mapped");
    return TRUE;
  }

  g_atomic_int_set (&priv->configure_pending, 1);
  g_atomic_int_inc (&priv->num_frames_pending);
  /* Create a toplevel window out of it */
  priv->xdg_toplevel = xdg_surface_get_toplevel (priv->xdg_surface);
  g_return_val_if_fail (priv->xdg_toplevel, FALSE);
  xdg_toplevel_set_title (priv->xdg_toplevel, "VA-API Wayland window");
  wl_proxy_set_queue ((struct wl_proxy *) priv->xdg_toplevel,
      priv->event_queue);

  xdg_toplevel_add_listener (priv->xdg_toplevel, &xdg_toplevel_listener,
      window);

  /* Commit the xdg_surface state as top-level window */
  wl_surface_commit (priv->surface);

  return gst_vaapi_window_wayland_sync (window);
}

static gboolean
gst_vaapi_window_wayland_hide (GstVaapiWindow * window)
{
  GstVaapiWindowWaylandPrivate *priv =
      GST_VAAPI_WINDOW_WAYLAND_GET_PRIVATE (window);

  if (priv->xdg_surface == NULL) {
    GST_FIXME ("GstVaapiWindowWayland::hide() unimplemented for wl_shell");
    return TRUE;
  }

  if (priv->xdg_toplevel != NULL) {
    g_clear_pointer (&priv->xdg_toplevel, xdg_toplevel_destroy);
    wl_surface_commit (priv->surface);
  }

  return TRUE;
}

static gboolean
gst_vaapi_window_wayland_sync (GstVaapiWindow * window)
{
  GstVaapiWindowWaylandPrivate *const priv =
      GST_VAAPI_WINDOW_WAYLAND_GET_PRIVATE (window);
  struct wl_display *const wl_display =
      GST_VAAPI_WINDOW_NATIVE_DISPLAY (window);

  if (priv->sync_failed)
    return FALSE;

  if (priv->pollfd.fd < 0) {
    priv->pollfd.fd = wl_display_get_fd (wl_display);
    gst_poll_add_fd (priv->poll, &priv->pollfd);
    gst_poll_fd_ctl_read (priv->poll, &priv->pollfd, TRUE);
  }

  while (g_atomic_int_get (&priv->num_frames_pending) > 0) {
    while (wl_display_prepare_read_queue (wl_display, priv->event_queue) < 0) {
      if (wl_display_dispatch_queue_pending (wl_display, priv->event_queue) < 0)
        goto error;
    }

    if (wl_display_flush (wl_display) < 0)
      goto error;

    if (g_atomic_int_get (&priv->num_frames_pending) == 0) {
      wl_display_cancel_read (wl_display);
      return TRUE;
    }

  again:
    if (gst_poll_wait (priv->poll, GST_CLOCK_TIME_NONE) < 0) {
      int saved_errno = errno;
      if (saved_errno == EAGAIN || saved_errno == EINTR)
        goto again;
      wl_display_cancel_read (wl_display);
      if (saved_errno == EBUSY) /* flushing */
        return FALSE;
      else
        goto error;
    }

    if (wl_display_read_events (wl_display) < 0)
      goto error;
    if (wl_display_dispatch_queue_pending (wl_display, priv->event_queue) < 0)
      goto error;
  }
  return TRUE;

  /* ERRORS */
error:
  {
    priv->sync_failed = TRUE;
    GST_ERROR ("Error on dispatching events: %s", g_strerror (errno));
    return FALSE;
  }
}

static void
handle_ping (void *data, struct wl_shell_surface *wl_shell_surface,
    uint32_t serial)
{
  wl_shell_surface_pong (wl_shell_surface, serial);
}

static void
handle_configure (void *data, struct wl_shell_surface *wl_shell_surface,
    uint32_t edges, int32_t width, int32_t height)
{
}

static void
handle_popup_done (void *data, struct wl_shell_surface *wl_shell_surface)
{
}

static const struct wl_shell_surface_listener shell_surface_listener = {
  handle_ping,
  handle_configure,
  handle_popup_done
};

static void
handle_xdg_surface_configure (void *data, struct xdg_surface *xdg_surface,
    uint32_t serial)
{
  GstVaapiWindow *window = GST_VAAPI_WINDOW (data);
  GstVaapiWindowWaylandPrivate *priv =
      GST_VAAPI_WINDOW_WAYLAND_GET_PRIVATE (window);

  xdg_surface_ack_configure (xdg_surface, serial);
  if (g_atomic_int_compare_and_exchange (&priv->configure_pending, 1, 0))
    g_atomic_int_dec_and_test (&priv->num_frames_pending);
}

static const struct xdg_surface_listener xdg_surface_listener = {
  handle_xdg_surface_configure,
};

static gboolean
gst_vaapi_window_wayland_set_fullscreen (GstVaapiWindow * window,
    gboolean fullscreen)
{
  GstVaapiWindowWaylandPrivate *const priv =
      GST_VAAPI_WINDOW_WAYLAND_GET_PRIVATE (window);

  if (window->use_foreign_window)
    return TRUE;

  if (!priv->is_shown) {
    priv->fullscreen_on_show = fullscreen;
    return TRUE;
  }

  /* XDG-shell */
  if (priv->xdg_toplevel != NULL) {
    if (fullscreen)
      xdg_toplevel_set_fullscreen (priv->xdg_toplevel, NULL);
    else
      xdg_toplevel_unset_fullscreen (priv->xdg_toplevel);
    return TRUE;
  }

  /* wl_shell fallback */
  if (!fullscreen)
    wl_shell_surface_set_toplevel (priv->wl_shell_surface);
  else {
    wl_shell_surface_set_fullscreen (priv->wl_shell_surface,
        WL_SHELL_SURFACE_FULLSCREEN_METHOD_SCALE, 0, NULL);
  }

  return TRUE;
}

static gboolean
gst_vaapi_window_wayland_create (GstVaapiWindow * window,
    guint * width, guint * height)
{
  GstVaapiWindowWaylandPrivate *const priv =
      GST_VAAPI_WINDOW_WAYLAND_GET_PRIVATE (window);
  GstVaapiDisplayWaylandPrivate *const priv_display =
      GST_VAAPI_DISPLAY_WAYLAND_GET_PRIVATE (GST_VAAPI_WINDOW_DISPLAY (window));

  GST_DEBUG ("create window, size %ux%u", *width, *height);

  g_return_val_if_fail (priv_display->compositor != NULL, FALSE);
  g_return_val_if_fail (priv_display->xdg_wm_base || priv_display->wl_shell,
      FALSE);

  GST_VAAPI_WINDOW_LOCK_DISPLAY (window);
  priv->event_queue = wl_display_create_queue (priv_display->wl_display);
  GST_VAAPI_WINDOW_UNLOCK_DISPLAY (window);
  if (!priv->event_queue)
    return FALSE;

  GST_VAAPI_WINDOW_LOCK_DISPLAY (window);
  priv->surface = wl_compositor_create_surface (priv_display->compositor);
  GST_VAAPI_WINDOW_UNLOCK_DISPLAY (window);
  if (!priv->surface)
    return FALSE;
  wl_proxy_set_queue ((struct wl_proxy *) priv->surface, priv->event_queue);

  if (window->use_foreign_window) {
    struct wl_surface *wl_surface;

    if (priv_display->subcompositor) {
      if (GST_VAAPI_SURFACE_ID (window) == VA_INVALID_ID) {
        GST_ERROR ("Invalid window");
        return FALSE;
      }

      wl_surface = (struct wl_surface *) GST_VAAPI_WINDOW_ID (window);
      GST_VAAPI_WINDOW_LOCK_DISPLAY (window);
      priv->video_subsurface =
          wl_subcompositor_get_subsurface (priv_display->subcompositor,
          priv->surface, wl_surface);
      GST_VAAPI_WINDOW_UNLOCK_DISPLAY (window);
      if (!priv->video_subsurface)
        return FALSE;

      wl_proxy_set_queue ((struct wl_proxy *) priv->video_subsurface,
          priv->event_queue);

      wl_subsurface_set_desync (priv->video_subsurface);
    } else {
      GST_ERROR ("Wayland server does not support subsurfaces");
      window->use_foreign_window = FALSE;
    }
    /* Prefer XDG-shell over deprecated wl_shell (if available) */
  } else if (priv_display->xdg_wm_base) {
    /* Create the XDG surface. We make the toplevel on VaapiWindow::show() */
    GST_VAAPI_WINDOW_LOCK_DISPLAY (window);
    priv->xdg_surface = xdg_wm_base_get_xdg_surface (priv_display->xdg_wm_base,
        priv->surface);
    GST_VAAPI_WINDOW_UNLOCK_DISPLAY (window);
    if (!priv->xdg_surface)
      return FALSE;
    wl_proxy_set_queue ((struct wl_proxy *) priv->xdg_surface,
        priv->event_queue);
    xdg_surface_add_listener (priv->xdg_surface, &xdg_surface_listener, window);
  } else {
    /* Fall back to wl_shell */
    GST_VAAPI_WINDOW_LOCK_DISPLAY (window);
    priv->wl_shell_surface = wl_shell_get_shell_surface (priv_display->wl_shell,
        priv->surface);
    GST_VAAPI_WINDOW_UNLOCK_DISPLAY (window);
    if (!priv->wl_shell_surface)
      return FALSE;
    wl_proxy_set_queue ((struct wl_proxy *) priv->wl_shell_surface,
        priv->event_queue);

    wl_shell_surface_add_listener (priv->wl_shell_surface,
        &shell_surface_listener, priv);
    wl_shell_surface_set_toplevel (priv->wl_shell_surface);
  }

  priv->poll = gst_poll_new (TRUE);
  gst_poll_fd_init (&priv->pollfd);

  if (priv->fullscreen_on_show)
    gst_vaapi_window_wayland_set_fullscreen (window, TRUE);

  priv->is_shown = TRUE;

  return TRUE;
}

static void
gst_vaapi_window_wayland_finalize (GObject * object)
{
  GstVaapiWindow *window = GST_VAAPI_WINDOW (object);
  GstVaapiWindowWaylandPrivate *const priv =
      GST_VAAPI_WINDOW_WAYLAND_GET_PRIVATE (window);
  struct wl_display *const wl_display =
      GST_VAAPI_WINDOW_NATIVE_DISPLAY (window);

  /* Make sure that the last wl buffer's callback could be called */
  GST_VAAPI_WINDOW_LOCK_DISPLAY (window);
  if (priv->surface) {
    wl_surface_attach (priv->surface, NULL, 0, 0);
    wl_surface_commit (priv->surface);
    wl_display_flush (wl_display);
  }
  GST_VAAPI_WINDOW_UNLOCK_DISPLAY (window);

  gst_poll_set_flushing (priv->poll, TRUE);

  if (priv->event_queue)
    wl_display_roundtrip_queue (wl_display, priv->event_queue);

  g_clear_pointer (&priv->xdg_surface, xdg_surface_destroy);
  g_clear_pointer (&priv->wl_shell_surface, wl_shell_surface_destroy);
  g_clear_pointer (&priv->video_subsurface, wl_subsurface_destroy);
  g_clear_pointer (&priv->surface, wl_surface_destroy);
  g_clear_pointer (&priv->event_queue, wl_event_queue_destroy);

  gst_poll_free (priv->poll);

  G_OBJECT_CLASS (gst_vaapi_window_wayland_parent_class)->finalize (object);
}

static gboolean
gst_vaapi_window_wayland_resize (GstVaapiWindow * window,
    guint width, guint height)
{
  GstVaapiWindowWaylandPrivate *const priv =
      GST_VAAPI_WINDOW_WAYLAND_GET_PRIVATE (window);
  GstVaapiDisplayWaylandPrivate *const priv_display =
      GST_VAAPI_DISPLAY_WAYLAND_GET_PRIVATE (GST_VAAPI_WINDOW_DISPLAY (window));

  if (window->use_foreign_window)
    return TRUE;

  GST_DEBUG ("resize window, new size %ux%u", width, height);

  if (priv->opaque_region)
    wl_region_destroy (priv->opaque_region);
  GST_VAAPI_WINDOW_LOCK_DISPLAY (window);
  priv->opaque_region = wl_compositor_create_region (priv_display->compositor);
  GST_VAAPI_WINDOW_UNLOCK_DISPLAY (window);
  wl_region_add (priv->opaque_region, 0, 0, width, height);

  return TRUE;
}

void
gst_vaapi_window_wayland_set_render_rect (GstVaapiWindow * window, gint x,
    gint y, gint width, gint height)
{
  GstVaapiWindowWaylandPrivate *const priv =
      GST_VAAPI_WINDOW_WAYLAND_GET_PRIVATE (window);

  if (priv->video_subsurface)
    wl_subsurface_set_position (priv->video_subsurface, x, y);
}

static inline gboolean
frame_done (FrameState * frame)
{
  GstVaapiWindowWaylandPrivate *const priv =
      GST_VAAPI_WINDOW_WAYLAND_GET_PRIVATE (frame->window);

  g_atomic_int_set (&frame->done, TRUE);
  if (g_atomic_pointer_compare_and_exchange (&priv->last_frame, frame, NULL))
    return g_atomic_int_dec_and_test (&priv->num_frames_pending);
  return FALSE;
}

static void
frame_done_callback (void *data, struct wl_callback *callback, uint32_t time)
{
  if (!frame_done (data))
    GST_INFO ("cannot remove last frame because it didn't match or empty");
}

static const struct wl_callback_listener frame_callback_listener = {
  frame_done_callback
};

static void
frame_release_callback (void *data, struct wl_buffer *wl_buffer)
{
  FrameState *const frame = data;

  if (!frame->done)
    if (!frame_done (frame))
      GST_INFO ("cannot remove last frame because it didn't match or empty");
  wl_buffer_destroy (wl_buffer);
  frame_state_free (frame);
}

static const struct wl_buffer_listener frame_buffer_listener = {
  frame_release_callback
};

typedef enum
{
  GST_VAAPI_DMABUF_SUCCESS,
  GST_VAAPI_DMABUF_BAD_FLAGS,
  GST_VAAPI_DMABUF_BAD_FORMAT,
  GST_VAAPI_DMABUF_BAD_MODIFIER,
  GST_VAAPI_DMABUF_NOT_SUPPORTED,
  GST_VAAPI_DMABUF_FLUSH,

} GstVaapiDmabufStatus;

#define DRM_FORMAT_MOD_INVALID 0xffffffffffffff

static GstVaapiDmabufStatus
dmabuf_format_supported (GstVaapiDisplayWaylandPrivate * const priv_display,
    guint format, guint64 modifier)
{
  GArray *formats = priv_display->dmabuf_formats;
  gboolean linear = FALSE;
  gint i;

  for (i = 0; i < formats->len; i++) {
    GstDRMFormat fmt = g_array_index (formats, GstDRMFormat, i);
    if (fmt.format == format && (fmt.modifier == modifier ||
            (fmt.modifier == DRM_FORMAT_MOD_INVALID && modifier == 0)))
      return GST_VAAPI_DMABUF_SUCCESS;
    if (fmt.format == format && (fmt.modifier == 0 ||
            fmt.modifier == DRM_FORMAT_MOD_INVALID))
      linear = TRUE;
  }
  if (linear)
    return GST_VAAPI_DMABUF_BAD_MODIFIER;
  else
    return GST_VAAPI_DMABUF_BAD_FORMAT;
}

GstVideoFormat
check_format (GstVaapiDisplay * const display, gint index,
    GstVideoFormat expect)
{
  GstVaapiDisplayWaylandPrivate *const priv_display =
      GST_VAAPI_DISPLAY_WAYLAND_GET_PRIVATE (display);
  GArray *formats = priv_display->dmabuf_formats;
  GstDRMFormat fmt = g_array_index (formats, GstDRMFormat, index);
  GstVideoFormat format = gst_vaapi_video_format_from_drm_format (fmt.format);
  GstVaapiSurface *surface;

  /* unkown formats should be filtered out in the display */
  g_assert (format != GST_VIDEO_FORMAT_UNKNOWN);

  if ((expect != GST_VIDEO_FORMAT_UNKNOWN) && (format != expect))
    return GST_VIDEO_FORMAT_UNKNOWN;

  surface = gst_vaapi_surface_new_with_format (display, format, 64, 64,
      fmt.modifier == 0 ? GST_VAAPI_SURFACE_ALLOC_FLAG_LINEAR_STORAGE : 0);
  if (!surface)
    return GST_VIDEO_FORMAT_UNKNOWN;

  gst_vaapi_surface_unref (surface);

  return format;
}

GstVideoFormat
choose_next_format (GstVaapiDisplay * const display, gint * next_index)
{
  GstVaapiDisplayWaylandPrivate *const priv_display =
      GST_VAAPI_DISPLAY_WAYLAND_GET_PRIVATE (display);
  GArray *formats = priv_display->dmabuf_formats;
  GstVideoFormat format;
  gint i;

  if (*next_index < 0) {
    *next_index = 0;
    /* try GST_VIDEO_FORMAT_RGBA first */
    for (i = 0; i < formats->len; i++) {
      format = check_format (display, i, GST_VIDEO_FORMAT_RGBA);
      if (format != GST_VIDEO_FORMAT_UNKNOWN)
        return format;
    }
  }

  for (i = *next_index; i < formats->len; i++) {
    format = check_format (display, i, GST_VIDEO_FORMAT_UNKNOWN);
    if (format != GST_VIDEO_FORMAT_UNKNOWN) {
      *next_index = i + 1;
      return format;
    }
  }
  *next_index = formats->len;
  return GST_VIDEO_FORMAT_UNKNOWN;
}

static GstVaapiDmabufStatus
dmabuf_buffer_from_surface (GstVaapiWindow * window, GstVaapiSurface * surface,
    guint va_flags, struct wl_buffer **out_buffer)
{
  GstVaapiDisplay *const display = GST_VAAPI_WINDOW_DISPLAY (window);
  GstVaapiDisplayWaylandPrivate *const priv_display =
      GST_VAAPI_DISPLAY_WAYLAND_GET_PRIVATE (display);
  struct zwp_linux_buffer_params_v1 *params;
  struct wl_buffer *buffer = NULL;
  VADRMPRIMESurfaceDescriptor desc;
  VAStatus status;
  GstVaapiDmabufStatus ret;
  guint format, i, j, plane = 0;

  if (!priv_display->dmabuf)
    return GST_VAAPI_DMABUF_NOT_SUPPORTED;

  if ((va_flags & (VA_TOP_FIELD | VA_BOTTOM_FIELD)) != VA_FRAME_PICTURE)
    return GST_VAAPI_DMABUF_BAD_FLAGS;

  GST_VAAPI_WINDOW_LOCK_DISPLAY (window);
  status = vaExportSurfaceHandle (GST_VAAPI_DISPLAY_VADISPLAY (display),
      GST_VAAPI_SURFACE_ID (surface), VA_SURFACE_ATTRIB_MEM_TYPE_DRM_PRIME_2,
      VA_EXPORT_SURFACE_SEPARATE_LAYERS | VA_EXPORT_SURFACE_READ_ONLY, &desc);
  /* Try again with composed layers, in case the format is supported there */
  if (status == VA_STATUS_ERROR_INVALID_SURFACE)
    status = vaExportSurfaceHandle (GST_VAAPI_DISPLAY_VADISPLAY (display),
        GST_VAAPI_SURFACE_ID (surface), VA_SURFACE_ATTRIB_MEM_TYPE_DRM_PRIME_2,
        VA_EXPORT_SURFACE_COMPOSED_LAYERS | VA_EXPORT_SURFACE_READ_ONLY, &desc);
  GST_VAAPI_WINDOW_UNLOCK_DISPLAY (window);

  if (!vaapi_check_status (status, "vaExportSurfaceHandle()")) {
    if (status == VA_STATUS_ERROR_UNIMPLEMENTED)
      return GST_VAAPI_DMABUF_NOT_SUPPORTED;
    else
      return GST_VAAPI_DMABUF_BAD_FORMAT;
  }

  format = gst_vaapi_drm_format_from_va_fourcc (desc.fourcc);
  params = zwp_linux_dmabuf_v1_create_params (priv_display->dmabuf);
  for (i = 0; i < desc.num_layers; i++) {
    for (j = 0; j < desc.layers[i].num_planes; ++j) {
      gint object = desc.layers[i].object_index[j];
      guint64 modifier = desc.objects[object].drm_format_modifier;

      ret = dmabuf_format_supported (priv_display, format, modifier);
      if (ret != GST_VAAPI_DMABUF_SUCCESS) {
        GST_DEBUG ("skipping unsupported format/modifier %s/0x%"
            G_GINT64_MODIFIER "x", gst_video_format_to_string
            (gst_vaapi_video_format_from_drm_format (format)), modifier);
        goto out;
      }

      zwp_linux_buffer_params_v1_add (params,
          desc.objects[object].fd, plane, desc.layers[i].offset[j],
          desc.layers[i].pitch[j], modifier >> 32,
          modifier & G_GUINT64_CONSTANT (0xffffffff));
      plane++;
    }
  }

  buffer = zwp_linux_buffer_params_v1_create_immed (params, window->width,
      window->height, format, 0);

  if (!buffer)
    ret = GST_VAAPI_DMABUF_NOT_SUPPORTED;

out:
  zwp_linux_buffer_params_v1_destroy (params);

  for (i = 0; i < desc.num_objects; i++)
    close (desc.objects[i].fd);

  *out_buffer = buffer;
  return ret;
}

static gboolean
buffer_from_surface (GstVaapiWindow * window, GstVaapiSurface ** surf,
    const GstVaapiRectangle * src_rect, const GstVaapiRectangle * dst_rect,
    guint flags, struct wl_buffer **buffer)
{
  GstVaapiDisplay *const display = GST_VAAPI_WINDOW_DISPLAY (window);
  GstVaapiWindowWaylandPrivate *const priv =
      GST_VAAPI_WINDOW_WAYLAND_GET_PRIVATE (window);
  GstVaapiSurface *surface;
  GstVaapiDmabufStatus ret;
  guint va_flags;
  VAStatus status;
  gint format_index = -1;

  va_flags = from_GstVaapiSurfaceRenderFlags (flags);

again:
  surface = *surf;
  if (priv->need_vpp) {
    GstVaapiSurface *vpp_surface = NULL;
    if (window->has_vpp) {
      GST_LOG ("VPP: %s <%d, %d, %d, %d> -> %s <%d, %d, %d, %d>",
          gst_video_format_to_string (gst_vaapi_surface_get_format (surface)),
          src_rect->x, src_rect->y, src_rect->width, src_rect->height,
          gst_video_format_to_string (window->surface_pool_format),
          dst_rect->x, dst_rect->y, dst_rect->width, dst_rect->height);
      vpp_surface = gst_vaapi_window_vpp_convert_internal (window, surface,
          src_rect, dst_rect, flags);
    }
    if (G_UNLIKELY (!vpp_surface)) {
      /* Not all formats are supported as destination format during VPP.
         So try again with the next format if VPP fails. */
      GstVideoFormat format = choose_next_format (display, &format_index);
      if ((format != GST_VIDEO_FORMAT_UNKNOWN) && window->has_vpp) {
        GST_DEBUG ("VPP failed. Try again with format %s",
            gst_video_format_to_string (format));
        gst_vaapi_window_set_vpp_format_internal (window, format, 0);
        goto again;
      } else {
        GST_WARNING ("VPP failed. No supported format found.");
        priv->dmabuf_broken = TRUE;
      }
    } else {
      surface = vpp_surface;
      va_flags = VA_FRAME_PICTURE;
    }
  }
  if (!priv->dmabuf_broken) {
    ret = dmabuf_buffer_from_surface (window, surface, va_flags, buffer);
    switch (ret) {
      case GST_VAAPI_DMABUF_SUCCESS:
        goto out;
      case GST_VAAPI_DMABUF_BAD_FLAGS:
        /* FIXME: how should this be handed? */
        break;
      case GST_VAAPI_DMABUF_BAD_FORMAT:{
        /* The Wayland server does not accept the current format or
           vaExportSurfaceHandle() failed. Try again with a different format */
        GstVideoFormat format = choose_next_format (display, &format_index);
        if ((format != GST_VIDEO_FORMAT_UNKNOWN) && window->has_vpp) {
          GST_DEBUG ("Failed to export buffer. Try again with format %s",
              gst_video_format_to_string (format));
          priv->need_vpp = TRUE;
          gst_vaapi_window_set_vpp_format_internal (window, format, 0);
          goto again;
        }
        if (window->has_vpp)
          GST_WARNING ("Failed to export buffer and VPP not supported.");
        else
          GST_WARNING ("Failed to export buffer. No supported format found.");
        priv->dmabuf_broken = TRUE;
        break;
      }
      case GST_VAAPI_DMABUF_BAD_MODIFIER:
        /* The format is supported by the Wayland server but not with the
           current modifier. Try linear instead. */
        if (window->has_vpp) {
          GST_DEBUG ("Modifier rejected by the server. Try linear instead.");
          priv->need_vpp = TRUE;
          gst_vaapi_window_set_vpp_format_internal (window,
              gst_vaapi_surface_get_format (surface),
              GST_VAAPI_SURFACE_ALLOC_FLAG_LINEAR_STORAGE);
          goto again;
        }
        GST_WARNING ("Modifier rejected by the server and VPP not supported.");
        priv->dmabuf_broken = TRUE;
        break;
      case GST_VAAPI_DMABUF_NOT_SUPPORTED:
        GST_DEBUG ("DMABuf protocol not supported");
        priv->dmabuf_broken = TRUE;
        break;
      case GST_VAAPI_DMABUF_FLUSH:
        return FALSE;
    }
  }

  /* DMABuf is not available or does not work. Fall back to the old API.
     There is no format negotiation so stick with NV12  */
  gst_vaapi_window_set_vpp_format_internal (window, GST_VIDEO_FORMAT_NV12, 0);

  GST_VAAPI_WINDOW_LOCK_DISPLAY (window);
  status = vaGetSurfaceBufferWl (GST_VAAPI_DISPLAY_VADISPLAY (display),
      GST_VAAPI_SURFACE_ID (surface),
      va_flags & (VA_TOP_FIELD | VA_BOTTOM_FIELD), buffer);
  GST_VAAPI_WINDOW_UNLOCK_DISPLAY (window);

  if (window->has_vpp && !priv->need_vpp &&
      (status == VA_STATUS_ERROR_FLAG_NOT_SUPPORTED ||
          status == VA_STATUS_ERROR_UNIMPLEMENTED ||
          status == VA_STATUS_ERROR_INVALID_IMAGE_FORMAT)) {
    priv->need_vpp = TRUE;
    goto again;
  }
  if (!vaapi_check_status (status, "vaGetSurfaceBufferWl()"))
    return FALSE;

out:
  *surf = surface;
  return TRUE;
}

static gboolean
gst_vaapi_window_wayland_render (GstVaapiWindow * window,
    GstVaapiSurface * surface,
    const GstVaapiRectangle * src_rect,
    const GstVaapiRectangle * dst_rect, guint flags)
{
  GstVaapiWindowWaylandPrivate *const priv =
      GST_VAAPI_WINDOW_WAYLAND_GET_PRIVATE (window);
  struct wl_display *const wl_display =
      GST_VAAPI_WINDOW_NATIVE_DISPLAY (window);
  struct wl_buffer *buffer;
  FrameState *frame;
  guint width, height;
  gboolean ret;

  /* Skip rendering without valid window size. This can happen with a foreign
     window if the render rectangle is not yet set. */
  if (window->width == 0 || window->height == 0)
    return TRUE;

  /* Check that we don't need to crop source VA surface */
  gst_vaapi_surface_get_size (surface, &width, &height);
  if (src_rect->x != 0 || src_rect->y != 0)
    priv->need_vpp = TRUE;
  if (src_rect->width != width)
    priv->need_vpp = TRUE;

  /* Check that we don't render to a subregion of this window */
  if (dst_rect->x != 0 || dst_rect->y != 0)
    priv->need_vpp = TRUE;
  if (dst_rect->width != window->width || dst_rect->height != window->height)
    priv->need_vpp = TRUE;

  /* Check that the surface has the correct size for the window */
  if (dst_rect->width != src_rect->width ||
      dst_rect->height != src_rect->height)
    priv->need_vpp = TRUE;

  ret = buffer_from_surface (window, &surface, src_rect, dst_rect, flags,
      &buffer);
  if (!ret)
    return FALSE;

  /* if need_vpp is set then the vpp happend */
  if (priv->need_vpp) {
    width = window->width;
    height = window->height;
  }

  /* Wait for the previous frame to complete redraw */
  if (!gst_vaapi_window_wayland_sync (window)) {
    /* Release vpp surface if exists */
    if (priv->need_vpp && window->has_vpp)
      gst_vaapi_video_pool_put_object (window->surface_pool, surface);
    wl_buffer_destroy (buffer);
    return !priv->sync_failed;
  }

  frame = frame_state_new (window);
  if (!frame)
    return FALSE;
  g_atomic_pointer_set (&priv->last_frame, frame);
  g_atomic_int_inc (&priv->num_frames_pending);

  if (priv->need_vpp && window->has_vpp) {
    frame->surface = surface;
    frame->surface_pool = gst_vaapi_video_pool_ref (window->surface_pool);
  }

  /* XXX: attach to the specified target rectangle */
  GST_VAAPI_WINDOW_LOCK_DISPLAY (window);
  wl_surface_attach (priv->surface, buffer, 0, 0);
  wl_surface_damage (priv->surface, 0, 0, width, height);

  if (priv->opaque_region) {
    wl_surface_set_opaque_region (priv->surface, priv->opaque_region);
    wl_region_destroy (priv->opaque_region);
    priv->opaque_region = NULL;
  }

  wl_proxy_set_queue ((struct wl_proxy *) buffer, priv->event_queue);
  wl_buffer_add_listener (buffer, &frame_buffer_listener, frame);

  frame->callback = wl_surface_frame (priv->surface);
  wl_callback_add_listener (frame->callback, &frame_callback_listener, frame);

  wl_surface_commit (priv->surface);
  wl_display_flush (wl_display);
  GST_VAAPI_WINDOW_UNLOCK_DISPLAY (window);
  return TRUE;
}

static gboolean
gst_vaapi_window_wayland_unblock (GstVaapiWindow * window)
{
  GstVaapiWindowWaylandPrivate *const priv =
      GST_VAAPI_WINDOW_WAYLAND_GET_PRIVATE (window);

  gst_poll_set_flushing (priv->poll, TRUE);

  return TRUE;
}

static gboolean
gst_vaapi_window_wayland_unblock_cancel (GstVaapiWindow * window)
{
  GstVaapiWindowWaylandPrivate *const priv =
      GST_VAAPI_WINDOW_WAYLAND_GET_PRIVATE (window);

  gst_poll_set_flushing (priv->poll, FALSE);

  return TRUE;
}

static void
gst_vaapi_window_wayland_class_init (GstVaapiWindowWaylandClass * klass)
{
  GObjectClass *const object_class = G_OBJECT_CLASS (klass);
  GstVaapiWindowClass *const window_class = GST_VAAPI_WINDOW_CLASS (klass);

  object_class->finalize = gst_vaapi_window_wayland_finalize;

  window_class->create = gst_vaapi_window_wayland_create;
  window_class->show = gst_vaapi_window_wayland_show;
  window_class->hide = gst_vaapi_window_wayland_hide;
  window_class->render = gst_vaapi_window_wayland_render;
  window_class->resize = gst_vaapi_window_wayland_resize;
  window_class->set_fullscreen = gst_vaapi_window_wayland_set_fullscreen;
  window_class->unblock = gst_vaapi_window_wayland_unblock;
  window_class->unblock_cancel = gst_vaapi_window_wayland_unblock_cancel;
  window_class->set_render_rect = gst_vaapi_window_wayland_set_render_rect;

  signals[SIZE_CHANGED] = g_signal_new ("size-changed",
      G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST, 0, NULL, NULL, NULL,
      G_TYPE_NONE, 2, G_TYPE_INT, G_TYPE_INT);
}

static void
gst_vaapi_window_wayland_init (GstVaapiWindowWayland * window)
{
}

/**
 * gst_vaapi_window_wayland_new:
 * @display: a #GstVaapiDisplay
 * @width: the requested window width, in pixels
 * @height: the requested windo height, in pixels
 *
 * Creates a window with the specified @width and @height. The window
 * will be attached to the @display and remains invisible to the user
 * until gst_vaapi_window_show() is called.
 *
 * Return value (transfer full): the newly allocated #GstVaapiWindow object
 */
GstVaapiWindow *
gst_vaapi_window_wayland_new (GstVaapiDisplay * display,
    guint width, guint height)
{
  g_return_val_if_fail (GST_VAAPI_IS_DISPLAY_WAYLAND (display), NULL);

  return gst_vaapi_window_new_internal (GST_TYPE_VAAPI_WINDOW_WAYLAND, display,
      GST_VAAPI_ID_INVALID, width, height);
}

/**
 * gst_vaapi_window_wayland_new_with_surface:
 * @display: a #GstVaapiDisplay
 * @wl_surface: a Wayland surface pointer
 *
 * Creates a window with the specified @wl_surface. The window
 * will be attached to the @display and remains invisible to the user
 * until gst_vaapi_window_show() is called.
 *
 * Return value (transfer full): the newly allocated #GstVaapiWindow object
 *
 * Since: 1.18
 */
GstVaapiWindow *
gst_vaapi_window_wayland_new_with_surface (GstVaapiDisplay * display,
    guintptr wl_surface)
{
  g_return_val_if_fail (GST_VAAPI_IS_DISPLAY_WAYLAND (display), NULL);
  g_return_val_if_fail (wl_surface, NULL);

  GST_CAT_DEBUG (gst_debug_vaapi, "new window from surface 0x%"
      G_GINTPTR_MODIFIER "x", wl_surface);

  return gst_vaapi_window_new_internal (GST_TYPE_VAAPI_WINDOW_WAYLAND, display,
      wl_surface, 0, 0);
}