/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */

/*
 * Copyright (C) 2014 Endless Mobile
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * This program 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
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA.
 *
 * Written by:
 *     Jasper St. Pierre <jstpierre@mecheye.net>
 */

#include "config.h"

#include "meta-wayland-buffer.h"

#include <clutter/clutter.h>
#include <cogl/cogl-egl.h>
#include <meta/util.h>

#include "backends/meta-backend-private.h"

enum
{
  RESOURCE_DESTROYED,

  LAST_SIGNAL
};

guint signals[LAST_SIGNAL];

G_DEFINE_TYPE (MetaWaylandBuffer, meta_wayland_buffer, G_TYPE_OBJECT);

static void
meta_wayland_buffer_destroy_handler (struct wl_listener *listener,
                                     void *data)
{
  MetaWaylandBuffer *buffer =
    wl_container_of (listener, buffer, destroy_listener);

  buffer->resource = NULL;
  g_signal_emit (buffer, signals[RESOURCE_DESTROYED], 0);
  g_object_unref (buffer);
}

MetaWaylandBuffer *
meta_wayland_buffer_from_resource (struct wl_resource *resource)
{
  MetaWaylandBuffer *buffer;
  struct wl_listener *listener;

  listener =
    wl_resource_get_destroy_listener (resource,
                                      meta_wayland_buffer_destroy_handler);

  if (listener)
    {
      buffer = wl_container_of (listener, buffer, destroy_listener);
    }
  else
    {
      buffer = g_object_new (META_TYPE_WAYLAND_BUFFER, NULL);

      buffer->resource = resource;
      buffer->destroy_listener.notify = meta_wayland_buffer_destroy_handler;
      wl_resource_add_destroy_listener (resource, &buffer->destroy_listener);
    }

  return buffer;
}

typedef enum _MetaWaylandBufferType
{
  META_WAYLAND_BUFFER_TYPE_UNKNOWN,
  META_WAYLAND_BUFFER_TYPE_SHM,
  META_WAYLAND_BUFFER_TYPE_EGL_IMAGE,
} MetaWaylandBufferType;

static MetaWaylandBufferType
determine_buffer_type (MetaWaylandBuffer *buffer)
{
  EGLint format;
  MetaBackend *backend = meta_get_backend ();
  MetaEgl *egl = meta_backend_get_egl (backend);
  ClutterBackend *clutter_backend = meta_backend_get_clutter_backend (backend);
  CoglContext *cogl_context = clutter_backend_get_cogl_context (clutter_backend);
  EGLDisplay egl_display = cogl_egl_context_get_egl_display (cogl_context);

  if (wl_shm_buffer_get (buffer->resource) != NULL)
    return META_WAYLAND_BUFFER_TYPE_SHM;


  if (meta_egl_query_wayland_buffer (egl, egl_display, buffer->resource,
                                     EGL_TEXTURE_FORMAT, &format,
                                     NULL))
    return META_WAYLAND_BUFFER_TYPE_EGL_IMAGE;

  return META_WAYLAND_BUFFER_TYPE_UNKNOWN;
}

static void
shm_buffer_get_cogl_pixel_format (struct wl_shm_buffer  *shm_buffer,
                                  CoglPixelFormat       *format_out,
                                  CoglTextureComponents *components_out)
{
  CoglPixelFormat format;
  CoglTextureComponents components = COGL_TEXTURE_COMPONENTS_RGBA;

  switch (wl_shm_buffer_get_format (shm_buffer))
    {
#if G_BYTE_ORDER == G_BIG_ENDIAN
    case WL_SHM_FORMAT_ARGB8888:
      format = COGL_PIXEL_FORMAT_ARGB_8888_PRE;
      break;
    case WL_SHM_FORMAT_XRGB8888:
      format = COGL_PIXEL_FORMAT_ARGB_8888;
      components = COGL_TEXTURE_COMPONENTS_RGB;
      break;
#elif G_BYTE_ORDER == G_LITTLE_ENDIAN
    case WL_SHM_FORMAT_ARGB8888:
      format = COGL_PIXEL_FORMAT_BGRA_8888_PRE;
      break;
    case WL_SHM_FORMAT_XRGB8888:
      format = COGL_PIXEL_FORMAT_BGRA_8888;
      components = COGL_TEXTURE_COMPONENTS_RGB;
      break;
#endif
    default:
      g_warn_if_reached ();
      format = COGL_PIXEL_FORMAT_ARGB_8888;
    }

  if (format_out)
    *format_out = format;
  if (components_out)
    *components_out = components;
}

static gboolean
shm_buffer_attach (MetaWaylandBuffer *buffer,
                   GError           **error)
{
  MetaBackend *backend = meta_get_backend ();
  ClutterBackend *clutter_backend = meta_backend_get_clutter_backend (backend);
  CoglContext *cogl_context = clutter_backend_get_cogl_context (clutter_backend);
  struct wl_shm_buffer *shm_buffer;
  int stride, width, height;
  CoglPixelFormat format;
  CoglTextureComponents components;
  CoglBitmap *bitmap;
  CoglTexture *texture;

  if (buffer->texture)
    return TRUE;

  shm_buffer = wl_shm_buffer_get (buffer->resource);
  stride = wl_shm_buffer_get_stride (shm_buffer);
  width = wl_shm_buffer_get_width (shm_buffer);
  height = wl_shm_buffer_get_height (shm_buffer);

  wl_shm_buffer_begin_access (shm_buffer);

  shm_buffer_get_cogl_pixel_format (shm_buffer, &format, &components);

  bitmap = cogl_bitmap_new_for_data (cogl_context,
                                     width, height,
                                     format,
                                     stride,
                                     wl_shm_buffer_get_data (shm_buffer));

  texture = COGL_TEXTURE (cogl_texture_2d_new_from_bitmap (bitmap));
  cogl_texture_set_components (COGL_TEXTURE (texture), components);

  cogl_object_unref (bitmap);

  if (!cogl_texture_allocate (COGL_TEXTURE (texture), error))
    g_clear_pointer (&texture, cogl_object_unref);

  wl_shm_buffer_end_access (shm_buffer);

  buffer->texture = texture;
  buffer->is_y_inverted = TRUE;

  if (!buffer->texture)
    return FALSE;

  return TRUE;
}

static gboolean
egl_image_buffer_attach (MetaWaylandBuffer *buffer,
                         GError           **error)
{
  MetaBackend *backend = meta_get_backend ();
  MetaEgl *egl = meta_backend_get_egl (backend);
  ClutterBackend *clutter_backend = meta_backend_get_clutter_backend (backend);
  CoglContext *cogl_context = clutter_backend_get_cogl_context (clutter_backend);
  EGLDisplay egl_display = cogl_egl_context_get_egl_display (cogl_context);
  EGLContext egl_context = cogl_egl_context_get_egl_context (cogl_context);
  int format, width, height, y_inverted;
  CoglPixelFormat cogl_format;
  EGLImageKHR egl_image;
  CoglTexture2D *texture;

  if (buffer->texture)
    return TRUE;

  if (!meta_egl_query_wayland_buffer (egl, egl_display, buffer->resource,
                                      EGL_TEXTURE_FORMAT, &format,
                                      error))
    return FALSE;

  if (!meta_egl_query_wayland_buffer (egl, egl_display, buffer->resource,
                                      EGL_WIDTH, &width,
                                      error))
    return FALSE;

  if (!meta_egl_query_wayland_buffer (egl, egl_display, buffer->resource,
                                      EGL_HEIGHT, &height,
                                      error))
    return FALSE;

  if (!meta_egl_query_wayland_buffer (egl, egl_display, buffer->resource,
                                      EGL_WAYLAND_Y_INVERTED_WL, &y_inverted,
                                      NULL))
    y_inverted = EGL_TRUE;

  switch (format)
    {
    case EGL_TEXTURE_RGB:
      cogl_format = COGL_PIXEL_FORMAT_RGB_888;
      break;
    case EGL_TEXTURE_RGBA:
      cogl_format = COGL_PIXEL_FORMAT_RGBA_8888_PRE;
      break;
    default:
      g_set_error (error, G_IO_ERROR,
                   G_IO_ERROR_FAILED,
                   "Unsupported buffer format %d", format);
      return FALSE;
    }

  egl_image = meta_egl_create_image (egl, egl_display, egl_context,
                                     EGL_WAYLAND_BUFFER_WL, buffer->resource,
                                     NULL,
                                     error);
  if (egl_image == EGL_NO_IMAGE_KHR)
    return FALSE;

  texture = cogl_egl_texture_2d_new_from_image (cogl_context,
                                                width, height,
                                                cogl_format,
                                                egl_image,
                                                error);

  meta_egl_destroy_image (egl, egl_display, egl_image, NULL);

  if (!texture)
    return FALSE;

  buffer->texture = COGL_TEXTURE (texture);
  buffer->is_y_inverted = !!y_inverted;

  return TRUE;
}

gboolean
meta_wayland_buffer_attach (MetaWaylandBuffer *buffer,
                            GError           **error)
{
  MetaWaylandBufferType buffer_type;

  g_return_val_if_fail (buffer->resource, FALSE);

  buffer_type = determine_buffer_type (buffer);

  switch (buffer_type)
    {
    case META_WAYLAND_BUFFER_TYPE_SHM:
      return shm_buffer_attach (buffer, error);
    case META_WAYLAND_BUFFER_TYPE_EGL_IMAGE:
      return egl_image_buffer_attach (buffer, error);
    case META_WAYLAND_BUFFER_TYPE_UNKNOWN:
      g_set_error (error, G_IO_ERROR,
                   G_IO_ERROR_FAILED,
                   "Unknown buffer type");
      return FALSE;
    }

  g_assert_not_reached ();
}

CoglTexture *
meta_wayland_buffer_get_texture (MetaWaylandBuffer *buffer)
{
  return buffer->texture;
}

gboolean
meta_wayland_buffer_is_y_inverted (MetaWaylandBuffer *buffer)
{
  return buffer->is_y_inverted;
}

static gboolean
process_shm_buffer_damage (MetaWaylandBuffer *buffer,
                           cairo_region_t    *region,
                           GError           **error)
{
  struct wl_shm_buffer *shm_buffer;
  int i, n_rectangles;
  gboolean set_texture_failed = FALSE;

  n_rectangles = cairo_region_num_rectangles (region);

  shm_buffer = wl_shm_buffer_get (buffer->resource);
  wl_shm_buffer_begin_access (shm_buffer);

  for (i = 0; i < n_rectangles; i++)
    {
      const uint8_t *data = wl_shm_buffer_get_data (shm_buffer);
      int32_t stride = wl_shm_buffer_get_stride (shm_buffer);
      CoglPixelFormat format;
      int bpp;
      cairo_rectangle_int_t rect;

      shm_buffer_get_cogl_pixel_format (shm_buffer, &format, NULL);
      bpp = _cogl_pixel_format_get_bytes_per_pixel (format);
      cairo_region_get_rectangle (region, i, &rect);

      if (!_cogl_texture_set_region (buffer->texture,
                                     rect.width, rect.height,
                                     format,
                                     stride,
                                     data + rect.x * bpp + rect.y * stride,
                                     rect.x, rect.y,
                                     0,
                                     error))
        {
          set_texture_failed = TRUE;
          break;
        }
    }

  wl_shm_buffer_end_access (shm_buffer);

  return !set_texture_failed;
}

void
meta_wayland_buffer_process_damage (MetaWaylandBuffer *buffer,
                                    cairo_region_t    *region)
{
  MetaWaylandBufferType buffer_type;
  gboolean res = FALSE;
  GError *error = NULL;

  g_return_if_fail (buffer->resource);

  buffer_type = determine_buffer_type (buffer);

  switch (buffer_type)
    {
    case META_WAYLAND_BUFFER_TYPE_SHM:
      res = process_shm_buffer_damage (buffer, region, &error);
    case META_WAYLAND_BUFFER_TYPE_EGL_IMAGE:
      res = TRUE;
      break;
    case META_WAYLAND_BUFFER_TYPE_UNKNOWN:
      g_set_error (&error, G_IO_ERROR,
                   G_IO_ERROR_FAILED,
                   "Unknown buffer type");
      res = FALSE;
    }

  if (!res)
    {
      g_warning ("Failed to process Wayland buffer damage: %s", error->message);
      g_error_free (error);
    }
}

static void
meta_wayland_buffer_finalize (GObject *object)
{
  MetaWaylandBuffer *buffer = META_WAYLAND_BUFFER (object);

  g_clear_pointer (&buffer->texture, cogl_object_unref);

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

static void
meta_wayland_buffer_init (MetaWaylandBuffer *buffer)
{
}

static void
meta_wayland_buffer_class_init (MetaWaylandBufferClass *klass)
{
  GObjectClass *object_class = G_OBJECT_CLASS (klass);

  object_class->finalize = meta_wayland_buffer_finalize;

  signals[RESOURCE_DESTROYED] = g_signal_new ("resource-destroyed",
                                              G_TYPE_FROM_CLASS (object_class),
                                              G_SIGNAL_RUN_LAST,
                                              0,
                                              NULL, NULL, NULL,
                                              G_TYPE_NONE, 0);
}