/*
 * GStreamer Wayland video sink
 *
 * Copyright (C) 2011 Intel Corporation
 * Copyright (C) 2011 Sreerenj Balachandran <sreerenj.balachandran@intel.com>
 * Copyright (C) 2012 Wim Taymans <wim.taymans@gmail.com>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the Free
 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/**
 * SECTION:element-waylandsink
 *
 *  The waylandsink is creating its own window and render the decoded video frames to that.
 *  Setup the Wayland environment as described in
 *  <ulink url="http://wayland.freedesktop.org/building.html">Wayland</ulink> home page.
 *  The current implementaion is based on weston compositor.
 *
 * <refsect2>
 * <title>Example pipelines</title>
 * |[
 * gst-launch -v videotestsrc ! waylandsink
 * ]| test the video rendering in wayland
 * </refsect2>
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include "gstwaylandsink.h"

/* signals */
enum
{
  SIGNAL_0,
  SIGNAL_FRAME_READY,
  LAST_SIGNAL
};

/* Properties */
enum
{
  PROP_0,
  PROP_WAYLAND_DISPLAY
};

GST_DEBUG_CATEGORY (gstwayland_debug);
#define GST_CAT_DEFAULT gstwayland_debug

static GstStaticPadTemplate sink_template = GST_STATIC_PAD_TEMPLATE ("sink",
    GST_PAD_SINK,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS ("video/x-raw, "
        "format = (string) BGRA, "
        "framerate = (fraction) [ 0, MAX ], "
        "width = (int) [ 1, MAX ], " "height = (int) [ 1, MAX ] "));

/*Fixme: Add more interfaces */
#define gst_wayland_sink_parent_class parent_class
G_DEFINE_TYPE (GstWaylandSink, gst_wayland_sink, GST_TYPE_VIDEO_SINK);

/* wl metadata */
GType
gst_wl_meta_api_get_type (void)
{
  static volatile GType type;
  static const gchar *tags[] =
      { "memory", "size", "colorspace", "orientation", NULL };

  if (g_once_init_enter (&type)) {
    GType _type = gst_meta_api_type_register ("GstWlMetaAPI", tags);
    g_once_init_leave (&type, _type);
  }
  return type;
}

static void
gst_wl_meta_free (GstWlMeta * meta, GstBuffer * buffer)
{
  gst_object_unref (meta->sink);
  munmap (meta->data, meta->size);
  wl_buffer_destroy (meta->wbuffer);
}

const GstMetaInfo *
gst_wl_meta_get_info (void)
{
  static const GstMetaInfo *wl_meta_info = NULL;

  if (wl_meta_info == NULL) {
    wl_meta_info =
        gst_meta_register (GST_WL_META_API_TYPE, "GstWlMeta",
        sizeof (GstWlMeta), (GstMetaInitFunction) NULL,
        (GstMetaFreeFunction) gst_wl_meta_free,
        (GstMetaTransformFunction) NULL);
  }
  return wl_meta_info;
}

static void gst_wayland_sink_get_property (GObject * object,
    guint prop_id, GValue * value, GParamSpec * pspec);
static void gst_wayland_sink_set_property (GObject * object,
    guint prop_id, const GValue * value, GParamSpec * pspec);
static void gst_wayland_sink_finalize (GObject * object);
static GstCaps *gst_wayland_sink_get_caps (GstBaseSink * bsink,
    GstCaps * filter);
static gboolean gst_wayland_sink_set_caps (GstBaseSink * bsink, GstCaps * caps);
static gboolean gst_wayland_sink_start (GstBaseSink * bsink);
static gboolean gst_wayland_sink_stop (GstBaseSink * bsink);
static gboolean gst_wayland_sink_preroll (GstBaseSink * bsink,
    GstBuffer * buffer);
static gboolean gst_wayland_sink_render (GstBaseSink * bsink,
    GstBuffer * buffer);

static int event_mask_update (uint32_t mask, void *data);
static struct display *create_display (void);
static void display_handle_global (struct wl_display *display, uint32_t id,
    const char *interface, uint32_t version, void *data);
static void redraw (void *data, struct wl_callback *callback, uint32_t time);
static void create_window (GstWaylandSink * sink, struct display *display,
    int width, int height);

static void
gst_wayland_sink_class_init (GstWaylandSinkClass * klass)
{
  GObjectClass *gobject_class;
  GstElementClass *gstelement_class;
  GstBaseSinkClass *gstbasesink_class;

  gobject_class = (GObjectClass *) klass;
  gstelement_class = (GstElementClass *) klass;
  gstbasesink_class = (GstBaseSinkClass *) klass;

  gobject_class->set_property = gst_wayland_sink_set_property;
  gobject_class->get_property = gst_wayland_sink_get_property;
  gobject_class->finalize = GST_DEBUG_FUNCPTR (gst_wayland_sink_finalize);

  gst_element_class_add_pad_template (gstelement_class,
      gst_static_pad_template_get (&sink_template));

  gst_element_class_set_details_simple (gstelement_class,
      "wayland video sink", "Sink/Video",
      "Output to wayland surface",
      "Sreerenj Balachandran <sreerenj.balachandran@intel.com>");

  gstbasesink_class->get_caps = GST_DEBUG_FUNCPTR (gst_wayland_sink_get_caps);
  gstbasesink_class->set_caps = GST_DEBUG_FUNCPTR (gst_wayland_sink_set_caps);
  gstbasesink_class->start = GST_DEBUG_FUNCPTR (gst_wayland_sink_start);
  gstbasesink_class->stop = GST_DEBUG_FUNCPTR (gst_wayland_sink_stop);
  gstbasesink_class->preroll = GST_DEBUG_FUNCPTR (gst_wayland_sink_preroll);
  gstbasesink_class->render = GST_DEBUG_FUNCPTR (gst_wayland_sink_render);

  g_object_class_install_property (gobject_class, PROP_WAYLAND_DISPLAY,
      g_param_spec_pointer ("wayland-display", "Wayland Display",
          "Wayland  Display handle created by the application ",
          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
}

static void
gst_wayland_sink_init (GstWaylandSink * sink)
{
  sink->render_busy = FALSE;
  sink->display = NULL;
  sink->window = NULL;

  g_mutex_init (&sink->wayland_lock);
}

static void
gst_wayland_sink_get_property (GObject * object,
    guint prop_id, GValue * value, GParamSpec * pspec)
{
  GstWaylandSink *sink = GST_WAYLAND_SINK (object);

  switch (prop_id) {
    case PROP_WAYLAND_DISPLAY:
      g_value_set_pointer (value, sink->display);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

static void
gst_wayland_sink_set_property (GObject * object,
    guint prop_id, const GValue * value, GParamSpec * pspec)
{
  GstWaylandSink *sink = GST_WAYLAND_SINK (object);

  switch (prop_id) {
    case PROP_WAYLAND_DISPLAY:
      sink->display = g_value_get_pointer (value);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

static void
destroy_display (struct display *display)
{
  if (display->shm)
    wl_shm_destroy (display->shm);

  if (display->shell)
    wl_shell_destroy (display->shell);

  if (display->compositor)
    wl_compositor_destroy (display->compositor);

  wl_display_flush (display->display);
  wl_display_destroy (display->display);
  free (display);
}

static void
destroy_window (struct window *window)
{
  if (window->shell_surface)
    wl_shell_surface_destroy (window->shell_surface);
  if (window->surface)
    wl_surface_destroy (window->surface);
  free (window);
}

static void
gst_wayland_sink_finalize (GObject * object)
{
  GstWaylandSink *sink = GST_WAYLAND_SINK (object);

  GST_DEBUG_OBJECT (sink, "Finalizing the sink..");

  if (sink->window)
    destroy_window (sink->window);
  if (sink->display)
    destroy_display (sink->display);

  g_mutex_clear (&sink->wayland_lock);

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

static GstCaps *
gst_wayland_sink_get_caps (GstBaseSink * bsink, GstCaps * filter)
{
  return gst_static_pad_template_get_caps (&sink_template);
}

static int
event_mask_update (uint32_t mask, void *data)
{
  struct display *d = data;

  d->mask = mask;

  return 0;
}

static void
shm_format (void *data, struct wl_shm *wl_shm, uint32_t format)
{
  struct display *d = data;

  d->formats |= (1 << format);
}

struct wl_shm_listener shm_listenter = {
  shm_format
};

static void
display_handle_global (struct wl_display *display, uint32_t id,
    const char *interface, uint32_t version, void *data)
{
  struct display *d = data;

  if (strcmp (interface, "wl_compositor") == 0) {
    d->compositor = wl_display_bind (display, id, &wl_compositor_interface);
  } else if (strcmp (interface, "wl_shell") == 0) {
    d->shell = wl_display_bind (display, id, &wl_shell_interface);
  } else if (strcmp (interface, "wl_shm") == 0) {
    d->shm = wl_display_bind (display, id, &wl_shm_interface);
    wl_shm_add_listener (d->shm, &shm_listenter, d);
  }

}

static struct display *
create_display (void)
{
  struct display *display;

  display = malloc (sizeof *display);
  display->display = wl_display_connect (NULL);
  assert (display->display);

  wl_display_add_global_listener (display->display,
      display_handle_global, display);

  wl_display_iterate (display->display, WL_DISPLAY_READABLE);
  wl_display_roundtrip (display->display);

  if (!(display->formats & (1 << WL_SHM_FORMAT_XRGB8888))) {
    GST_ERROR ("WL_SHM_FORMAT_XRGB32 not available");
    return NULL;
  }

  wl_display_get_fd (display->display, event_mask_update, display);

  return display;
}

static GstBuffer *
wayland_buffer_create (GstWaylandSink * sink)
{
  char filename[1024];
  int fd, size, stride;
  static void *data;
  static int init = 0;
  GstBuffer *buffer;
  GstWlMeta *wmeta;

  GST_DEBUG_OBJECT (sink, "Creating wayland-shm buffers");

  snprintf (filename, 256, "%s-%d-%s", "/tmp/wayland-shm", init++, "XXXXXX");

  fd = mkstemp (filename);
  if (fd < 0) {
    GST_ERROR_OBJECT (sink, "open %s failed:", filename);
    return NULL;
  }

  stride = sink->video_width * 4;
  size = stride * sink->video_height;

  if (ftruncate (fd, size) < 0) {
    GST_ERROR_OBJECT (sink, "ftruncate failed:");
    close (fd);
    return NULL;
  }

  data = mmap (NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
  unlink (filename);
  if (data == MAP_FAILED) {
    GST_ELEMENT_ERROR (sink, LIBRARY, SHUTDOWN, (NULL),
        ("mmap() failed: %s", strerror (errno)));
    close (fd);
    return NULL;
  }

  buffer = gst_buffer_new ();

  wmeta = (GstWlMeta *) gst_buffer_add_meta (buffer, GST_WL_META_INFO, NULL);
  wmeta->sink = gst_object_ref (sink);
  wmeta->wbuffer = wl_shm_create_buffer (sink->display->shm, fd,
      sink->video_width, sink->video_height, stride, WL_SHM_FORMAT_XRGB8888);
  wmeta->data = data;
  wmeta->size = size;

  close (fd);

  gst_buffer_append_memory (buffer,
      gst_memory_new_wrapped (GST_MEMORY_FLAG_NO_SHARE, data,
          size, 0, size, NULL, NULL));

  return buffer;
}

static gboolean
gst_wayland_sink_set_caps (GstBaseSink * bsink, GstCaps * caps)
{
  GstWaylandSink *sink = GST_WAYLAND_SINK (bsink);
  const GstStructure *structure;
  gboolean ret = TRUE;

  GST_LOG_OBJECT (sink, "set caps %" GST_PTR_FORMAT, caps);

  structure = gst_caps_get_structure (caps, 0);

  ret &= gst_structure_get_int (structure, "width", &sink->video_width);
  ret &= gst_structure_get_int (structure, "height", &sink->video_height);

  if (!ret)
    return FALSE;

  return TRUE;
}

static const struct wl_callback_listener frame_listener;

static void
redraw (void *data, struct wl_callback *callback, uint32_t time)
{

  GstWaylandSink *sink = (GstWaylandSink *) data;

  sink->render_busy = FALSE;
}

static void
create_window (GstWaylandSink * sink, struct display *display, int width,
    int height)
{
  struct window *window;

  if (sink->window)
    return;

  g_mutex_lock (&sink->wayland_lock);

  window = malloc (sizeof *window);
  window->display = display;
  window->width = width;
  window->height = height;
  window->surface = wl_compositor_create_surface (display->compositor);

  window->shell_surface = wl_shell_get_shell_surface (display->shell,
      window->surface);
  /* wl_shell_surface_set_toplevel (window->shell_surface); */
#ifdef WL_SHELL_SURFACE_FULLSCREEN_METHOD_DEFAULT
  wl_shell_surface_set_fullscreen (window->shell_surface,
      WL_SHELL_SURFACE_FULLSCREEN_METHOD_DEFAULT, 0, NULL);
#endif

  sink->window = window;

  g_mutex_unlock (&sink->wayland_lock);
}

static gboolean
gst_wayland_sink_start (GstBaseSink * bsink)
{
  GstWaylandSink *sink = (GstWaylandSink *) bsink;
  gboolean result = TRUE;

  GST_DEBUG_OBJECT (sink, "start");

  if (!sink->display)
    sink->display = create_display ();

  return result;
}

static gboolean
gst_wayland_sink_stop (GstBaseSink * bsink)
{
  GstWaylandSink *sink = (GstWaylandSink *) bsink;

  GST_DEBUG_OBJECT (sink, "stop");

  return TRUE;
}

static GstFlowReturn
gst_wayland_sink_preroll (GstBaseSink * bsink, GstBuffer * buffer)
{
  GST_DEBUG_OBJECT (bsink, "preroll buffer %p", buffer);
  return gst_wayland_sink_render (bsink, buffer);
}

static GstFlowReturn
gst_wayland_sink_render (GstBaseSink * bsink, GstBuffer * buffer)
{
  GstWaylandSink *sink = GST_WAYLAND_SINK (bsink);
  GstVideoRectangle src, dst, res;
  GstBuffer *to_render;
  GstWlMeta *meta;

  GST_LOG_OBJECT (sink, "render buffer %p" GST_TIME_FORMAT, buffer);

  if (!sink->window)
    create_window (sink, sink->display, sink->video_width, sink->video_height);

  if (sink->render_busy)
    goto was_busy;

  meta = gst_buffer_get_wl_meta (buffer);

  if (meta && meta->sink == sink) {
    GST_LOG_OBJECT (sink, "buffer %p from our pool, writing directly", buffer);
    to_render = buffer;
  } else {
    GstMapInfo src;

    GST_LOG_OBJECT (sink, "buffer %p not from our pool, copying", buffer);

    to_render = wayland_buffer_create (sink);

    gst_buffer_map (buffer, &src, GST_MAP_READ);
    gst_buffer_fill (to_render, 0, src.data, src.size);
    gst_buffer_unmap (buffer, &src);

    meta = gst_buffer_get_wl_meta (to_render);
  }

  src.w = sink->video_width;
  src.h = sink->video_height;
  dst.w = sink->window->width;
  dst.h = sink->window->height;

  gst_video_sink_center_rect (src, dst, &res, FALSE);

  sink->render_busy = TRUE;

  wl_buffer_damage (meta->wbuffer, 0, 0, res.w, res.h);
  wl_surface_attach (sink->window->surface, meta->wbuffer, 0, 0);
  wl_surface_damage (sink->window->surface, 0, 0, res.w, res.h);

  if (sink->callback)
    wl_callback_destroy (sink->callback);

  sink->callback = wl_surface_frame (sink->window->surface);
  wl_callback_add_listener (sink->callback, &frame_listener, sink);
  wl_display_iterate (sink->display->display, sink->display->mask);

  if (buffer != to_render)
    gst_buffer_unref (to_render);

  return GST_FLOW_OK;

was_busy:
  {
    GST_LOG_OBJECT (sink,
        "Waiting to get the signal from compositor to render the next frame..");
    return GST_FLOW_OK;
  }
}

static const struct wl_callback_listener frame_listener = {
  redraw
};

static gboolean
plugin_init (GstPlugin * plugin)
{
  GST_DEBUG_CATEGORY_INIT (gstwayland_debug, "waylandsink", 0,
      " wayland video sink");

  return gst_element_register (plugin, "waylandsink", GST_RANK_MARGINAL,
      GST_TYPE_WAYLAND_SINK);
}

GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
    GST_VERSION_MINOR,
    waylandsink,
    "Wayland Video Sink", plugin_init, VERSION, "LGPL", GST_PACKAGE_NAME,
    GST_PACKAGE_ORIGIN)