/*
 * Wayland Support
 *
 * Copyright (C) 2012,2013 Intel Corporation
 *
 * 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.
 */

#include <config.h>

#include <clutter/clutter.h>
#include <clutter/wayland/clutter-wayland-compositor.h>
#include <clutter/wayland/clutter-wayland-surface.h>

#include <glib.h>
#include <sys/time.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <stdlib.h>
#include <sys/wait.h>
#include <fcntl.h>
#include <unistd.h>

#include <wayland-server.h>

#include "backends/meta-backend.h"

#include "meta-wayland-private.h"
#include "meta-xwayland-private.h"
#include "meta-window-actor-private.h"
#include "meta-wayland-seat.h"
#include "meta-wayland-keyboard.h"
#include "meta-wayland-pointer.h"
#include "meta-wayland-outputs.h"
#include "meta-wayland-data-device.h"
#include "meta-cursor-tracker-private.h"
#include "display-private.h"
#include "window-private.h"
#include <meta/types.h>
#include <meta/main.h>
#include "frame.h"

static MetaWaylandCompositor _meta_wayland_compositor;

MetaWaylandCompositor *
meta_wayland_compositor_get_default (void)
{
  return &_meta_wayland_compositor;
}

static guint32
get_time (void)
{
  struct timeval tv;
  gettimeofday (&tv, NULL);
  return tv.tv_sec * 1000 + tv.tv_usec / 1000;
}

static gboolean
wayland_event_source_prepare (GSource *base, int *timeout)
{
  WaylandEventSource *source = (WaylandEventSource *)base;

  *timeout = -1;

  wl_display_flush_clients (source->display);

  return FALSE;
}

static gboolean
wayland_event_source_check (GSource *base)
{
  WaylandEventSource *source = (WaylandEventSource *)base;
  return source->pfd.revents;
}

static gboolean
wayland_event_source_dispatch (GSource *base,
                               GSourceFunc callback,
                               void *data)
{
  WaylandEventSource *source = (WaylandEventSource *)base;
  struct wl_event_loop *loop = wl_display_get_event_loop (source->display);

  wl_event_loop_dispatch (loop, 0);

  return TRUE;
}

static GSourceFuncs wayland_event_source_funcs =
{
  wayland_event_source_prepare,
  wayland_event_source_check,
  wayland_event_source_dispatch,
  NULL
};

static GSource *
wayland_event_source_new (struct wl_display *display)
{
  WaylandEventSource *source;
  struct wl_event_loop *loop = wl_display_get_event_loop (display);

  source = (WaylandEventSource *) g_source_new (&wayland_event_source_funcs,
                                                sizeof (WaylandEventSource));
  source->display = display;
  source->pfd.fd = wl_event_loop_get_fd (loop);
  source->pfd.events = G_IO_IN | G_IO_ERR;
  g_source_add_poll (&source->source, &source->pfd);

  return &source->source;
}

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

  wl_signal_emit (&buffer->destroy_signal, buffer);
  g_slice_free (MetaWaylandBuffer, buffer);
}

void
meta_wayland_buffer_ref (MetaWaylandBuffer *buffer)
{
  buffer->ref_count++;
}

void
meta_wayland_buffer_unref (MetaWaylandBuffer *buffer)
{
  buffer->ref_count--;
  if (buffer->ref_count == 0)
    {
      g_clear_pointer (&buffer->texture, cogl_object_unref);
      wl_resource_queue_event (buffer->resource, WL_BUFFER_RELEASE);
    }
}

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_slice_new0 (MetaWaylandBuffer);

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

  return buffer;
}

void
meta_wayland_compositor_set_input_focus (MetaWaylandCompositor *compositor,
                                         MetaWindow            *window)
{
  MetaWaylandSurface *surface = window ? window->surface : NULL;

  meta_wayland_seat_set_input_focus (compositor->seat, surface);
}

void
meta_wayland_compositor_repick (MetaWaylandCompositor *compositor)
{
  meta_wayland_seat_repick (compositor->seat);
}

static void
wl_compositor_create_surface (struct wl_client *client,
                              struct wl_resource *resource,
                              guint32 id)
{
  MetaWaylandCompositor *compositor = wl_resource_get_user_data (resource);

  meta_wayland_surface_create (compositor, client, resource, id);
}

static void
wl_region_destroy (struct wl_client *client,
                   struct wl_resource *resource)
{
  wl_resource_destroy (resource);
}

static void
wl_region_add (struct wl_client *client,
               struct wl_resource *resource,
               gint32 x,
               gint32 y,
               gint32 width,
               gint32 height)
{
  MetaWaylandRegion *region = wl_resource_get_user_data (resource);
  cairo_rectangle_int_t rectangle = { x, y, width, height };

  cairo_region_union_rectangle (region->region, &rectangle);
}

static void
wl_region_subtract (struct wl_client *client,
                    struct wl_resource *resource,
                    gint32 x,
                    gint32 y,
                    gint32 width,
                    gint32 height)
{
  MetaWaylandRegion *region = wl_resource_get_user_data (resource);
  cairo_rectangle_int_t rectangle = { x, y, width, height };

  cairo_region_subtract_rectangle (region->region, &rectangle);
}

static const struct wl_region_interface meta_wayland_region_interface = {
  wl_region_destroy,
  wl_region_add,
  wl_region_subtract
};

static void
meta_wayland_region_resource_destroy_cb (struct wl_resource *resource)
{
  MetaWaylandRegion *region = wl_resource_get_user_data (resource);

  cairo_region_destroy (region->region);
  g_slice_free (MetaWaylandRegion, region);
}

static void
wl_compositor_create_region (struct wl_client *client,
                             struct wl_resource *compositor_resource,
                             uint32_t id)
{
  MetaWaylandRegion *region = g_slice_new0 (MetaWaylandRegion);

  region->resource = wl_resource_create (client, &wl_region_interface, wl_resource_get_version (compositor_resource), id);
  wl_resource_set_implementation (region->resource, &meta_wayland_region_interface, region, meta_wayland_region_resource_destroy_cb);

  region->region = cairo_region_create ();
}

const static struct wl_compositor_interface meta_wayland_compositor_interface = {
  wl_compositor_create_surface,
  wl_compositor_create_region
};

void
meta_wayland_compositor_paint_finished (MetaWaylandCompositor *compositor)
{
  while (!wl_list_empty (&compositor->frame_callbacks))
    {
      MetaWaylandFrameCallback *callback =
        wl_container_of (compositor->frame_callbacks.next, callback, link);

      wl_callback_send_done (callback->resource, get_time ());
      wl_resource_destroy (callback->resource);
    }
}

static void
compositor_bind (struct wl_client *client,
		 void *data,
                 guint32 version,
                 guint32 id)
{
  MetaWaylandCompositor *compositor = data;
  struct wl_resource *resource;

  resource = wl_resource_create (client, &wl_compositor_interface, version, id);
  wl_resource_set_implementation (resource, &meta_wayland_compositor_interface, compositor, NULL);
}

/**
 * meta_wayland_compositor_update:
 * @compositor: the #MetaWaylandCompositor instance
 * @event: the #ClutterEvent used to update @seat's state
 *
 * This is used to update display server state like updating cursor
 * position and keeping track of buttons and keys pressed. It must be
 * called for all input events coming from the underlying devices.
 */
void
meta_wayland_compositor_update (MetaWaylandCompositor *compositor,
                                const ClutterEvent    *event)
{
  meta_wayland_seat_update (compositor->seat, event);
}

/**
 * meta_wayland_compositor_handle_event:
 * @compositor: the #MetaWaylandCompositor instance
 * @event: the #ClutterEvent to be sent
 *
 * This method sends events to the focused wayland client, if any.
 *
 * Return value: whether @event was sent to a wayland client.
 */
gboolean
meta_wayland_compositor_handle_event (MetaWaylandCompositor *compositor,
                                      const ClutterEvent    *event)
{
  return meta_wayland_seat_handle_event (compositor->seat, event);
}

static void
set_gnome_env (const char *name,
	       const char *value)
{
  GDBusConnection *session_bus;
  GError *error = NULL;

  setenv (name, value, TRUE);

  session_bus = g_bus_get_sync (G_BUS_TYPE_SESSION, NULL, NULL);
  g_assert (session_bus);

  g_dbus_connection_call_sync (session_bus,
			       "org.gnome.SessionManager",
			       "/org/gnome/SessionManager",
			       "org.gnome.SessionManager",
			       "Setenv",
			       g_variant_new ("(ss)", name, value),
			       NULL,
			       G_DBUS_CALL_FLAGS_NO_AUTO_START,
			       -1, NULL, &error);
  if (error)
    {
      if (g_strcmp0 (g_dbus_error_get_remote_error (error), "org.gnome.SessionManager.NotInInitialization") != 0)
        meta_warning ("Failed to set environment variable %s for gnome-session: %s\n", name, error->message);

      g_error_free (error);
    }
}

static void
meta_wayland_log_func (const char *fmt,
                       va_list     arg)
{
  char *str = g_strdup_vprintf (fmt, arg);
  g_warning ("WL: %s", str);
  g_free (str);
}

void
meta_wayland_init (void)
{
  MetaWaylandCompositor *compositor = &_meta_wayland_compositor;
  GSource *wayland_event_source;

  memset (compositor, 0, sizeof (MetaWaylandCompositor));

  compositor->wayland_display = wl_display_create ();
  if (compositor->wayland_display == NULL)
    g_error ("failed to create wayland display");

  wl_display_init_shm (compositor->wayland_display);
  wl_log_set_handler_server(meta_wayland_log_func);

  wl_list_init (&compositor->frame_callbacks);

  if (!wl_global_create (compositor->wayland_display,
			 &wl_compositor_interface,
			 META_WL_COMPOSITOR_VERSION,
			 compositor, compositor_bind))
    g_error ("Failed to register wayland compositor object");

  wayland_event_source = wayland_event_source_new (compositor->wayland_display);

  /* XXX: Here we are setting the wayland event source to have a
   * slightly lower priority than the X event source, because we are
   * much more likely to get confused being told about surface changes
   * relating to X clients when we don't know what's happened to them
   * according to the X protocol.
   *
   * At some point we could perhaps try and get the X protocol proxied
   * over the wayland protocol so that we don't have to worry about
   * synchronizing the two command streams. */
  g_source_set_priority (wayland_event_source, GDK_PRIORITY_EVENTS + 1);
  g_source_attach (wayland_event_source, NULL);
  clutter_wayland_set_compositor_display (compositor->wayland_display);

  meta_clutter_init ();

  meta_wayland_outputs_init (compositor);
  meta_wayland_data_device_manager_init (compositor);
  meta_wayland_shell_init (compositor);
  meta_wayland_seat_init (compositor);

  /* FIXME: find the first free name instead */
  compositor->display_name = wl_display_add_socket_auto (compositor->wayland_display);
  if (compositor->display_name == NULL)
    g_error ("Failed to create socket");

  /* XXX: It's important that we only try and start xwayland after we
   * have initialized EGL because EGL implements the "wl_drm"
   * interface which xwayland requires to determine what drm device
   * name it should use.
   *
   * By waiting until we've shown the stage above we ensure that the
   * underlying GL resources for the surface have also been allocated
   * and so EGL must be initialized by this point.
   */

  if (!meta_xwayland_start (&compositor->xwayland_manager, compositor->wayland_display))
    g_error ("Failed to start X Wayland");

  set_gnome_env ("DISPLAY", compositor->xwayland_manager.display_name);
  set_gnome_env ("WAYLAND_DISPLAY", compositor->display_name);
}

void
meta_wayland_finalize (void)
{
  MetaWaylandCompositor *compositor;

  compositor = meta_wayland_compositor_get_default ();

  meta_xwayland_stop (&compositor->xwayland_manager);
}