/*
 * Copyright (C) 2023 Red Hat
 *
 * 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, see <http://www.gnu.org/licenses/>.
 */

#include "config.h"

#include "backends/meta-monitor-manager-private.h"
#include "backends/native/meta-backend-native.h"
#include "backends/native/meta-udev.h"
#include "meta-test/meta-context-test.h"
#include "tests/drm-mock/drm-mock.h"

typedef enum _State
{
  INIT,
  PAINTED,
  PRESENTED,
} State;

static MetaContext *test_context;

static void
on_after_paint (ClutterStage     *stage,
                ClutterStageView *view,
                ClutterFrame     *frame,
                State            *state)
{
  *state = PAINTED;
}

static void
on_presented (ClutterStage     *stage,
              ClutterStageView *view,
              ClutterFrameInfo *frame_info,
              State            *state)
{
  if (*state == PAINTED)
    *state = PRESENTED;
}

static void
meta_test_reload (void)
{
  MetaBackend *backend = meta_context_get_backend (test_context);
  MetaMonitorManager *monitor_manager =
    meta_backend_get_monitor_manager (backend);
  ClutterActor *stage = meta_backend_get_stage (backend);
  GList *logical_monitors;
  gulong after_paint_handler_id;
  gulong presented_handler_id;
  g_autoptr (GError) error = NULL;
  State state;

  logical_monitors =
    meta_monitor_manager_get_logical_monitors (monitor_manager);
  g_assert_cmpuint (g_list_length (logical_monitors), ==, 1);

  after_paint_handler_id = g_signal_connect (stage, "after-paint",
                                             G_CALLBACK (on_after_paint),
                                             &state);
  presented_handler_id = g_signal_connect (stage, "presented",
                                           G_CALLBACK (on_presented),
                                           &state);

  state = INIT;
  clutter_actor_queue_redraw (stage);
  while (state < PAINTED)
    g_main_context_iteration (NULL, TRUE);

  meta_monitor_manager_reload (monitor_manager);

  while (state < PRESENTED)
    g_main_context_iteration (NULL, TRUE);

  state = INIT;
  clutter_actor_queue_redraw (stage);
  while (state < PRESENTED)
    g_main_context_iteration (NULL, TRUE);

  g_signal_handler_disconnect (stage, after_paint_handler_id);
  g_signal_handler_disconnect (stage, presented_handler_id);
}

static void
disconnect_connector_filter (gpointer resource,
                             gpointer user_data)
{
  drmModeConnector *drm_connector = resource;

  drm_connector->connection = DRM_MODE_DISCONNECTED;
}

static void
frame_cb (CoglOnscreen  *onscreen,
          CoglFrameEvent frame_event,
          CoglFrameInfo *frame_info,
          void          *user_data)
{
  State *state = user_data;

  if (frame_event == COGL_FRAME_EVENT_SYNC)
    return;

  if (*state == PAINTED)
    *state = PRESENTED;
}

static void
meta_test_disconnect_connect (void)
{
  MetaBackend *backend = meta_context_get_backend (test_context);
  MetaMonitorManager *monitor_manager =
    meta_backend_get_monitor_manager (backend);
  ClutterActor *stage = meta_backend_get_stage (backend);
  MetaUdev *udev = meta_backend_native_get_udev (META_BACKEND_NATIVE (backend));
  g_autolist (GObject) udev_devices = NULL;
  GUdevDevice *udev_device;
  GList *logical_monitors;
  gulong after_paint_handler_id;
  gulong presented_handler_id;
  ClutterStageView *view;
  CoglFramebuffer *onscreen;
  g_autoptr (GError) error = NULL;
  State state;

  udev_devices = meta_udev_list_drm_devices (udev, &error);
  g_assert_cmpuint (g_list_length (udev_devices), ==, 1);
  udev_device = g_list_first (udev_devices)->data;

  logical_monitors =
    meta_monitor_manager_get_logical_monitors (monitor_manager);
  g_assert_cmpuint (g_list_length (logical_monitors), ==, 1);

  after_paint_handler_id = g_signal_connect (stage, "after-paint",
                                             G_CALLBACK (on_after_paint),
                                             &state);
  presented_handler_id = g_signal_connect (stage, "presented",
                                           G_CALLBACK (on_presented),
                                           &state);

  g_debug ("Disconnect during page flip");
  view = clutter_stage_peek_stage_views (CLUTTER_STAGE (stage))->data;
  onscreen = clutter_stage_view_get_onscreen (view);
  g_assert_true (COGL_IS_ONSCREEN (onscreen));
  state = INIT;
  clutter_actor_queue_redraw (stage);
  while (state < PAINTED)
    g_main_context_iteration (NULL, TRUE);
  drm_mock_set_resource_filter (DRM_MOCK_CALL_FILTER_GET_CONNECTOR,
                                disconnect_connector_filter, NULL);
  g_signal_emit_by_name (udev, "hotplug", udev_device);
  logical_monitors =
    meta_monitor_manager_get_logical_monitors (monitor_manager);
  g_assert_cmpuint (g_list_length (logical_monitors), ==, 0);

  g_debug ("Wait until page flip completes");
  cogl_onscreen_add_frame_callback (COGL_ONSCREEN (onscreen),
                                    frame_cb, &state, NULL);
  while (state < PRESENTED)
    g_main_context_iteration (NULL, TRUE);

  g_debug ("Reconnect connector, wait for presented");
  drm_mock_unset_resource_filter (DRM_MOCK_CALL_FILTER_GET_CONNECTOR);
  g_signal_emit_by_name (udev, "hotplug", udev_device);
  logical_monitors =
    meta_monitor_manager_get_logical_monitors (monitor_manager);
  g_assert_cmpuint (g_list_length (logical_monitors), ==, 1);
  state = INIT;
  clutter_actor_queue_redraw (stage);
  while (state < PRESENTED)
    g_main_context_iteration (NULL, TRUE);

  g_debug ("Disconnect after page flip");
  drm_mock_set_resource_filter (DRM_MOCK_CALL_FILTER_GET_CONNECTOR,
                                disconnect_connector_filter, NULL);
  g_signal_emit_by_name (udev, "hotplug", udev_device);
  logical_monitors =
    meta_monitor_manager_get_logical_monitors (monitor_manager);
  g_assert_cmpuint (g_list_length (logical_monitors), ==, 0);
  while (TRUE)
    {
      if (!g_main_context_iteration (NULL, FALSE))
        break;
    }

  g_debug ("Restore");
  drm_mock_unset_resource_filter (DRM_MOCK_CALL_FILTER_GET_CONNECTOR);
  g_signal_emit_by_name (udev, "hotplug", udev_device);
  logical_monitors =
    meta_monitor_manager_get_logical_monitors (monitor_manager);
  g_assert_cmpuint (g_list_length (logical_monitors), ==, 1);

  g_signal_handler_disconnect (stage, after_paint_handler_id);
  g_signal_handler_disconnect (stage, presented_handler_id);
}

static void
init_tests (void)
{
  g_test_add_func ("/hotplug/reload",
                   meta_test_reload);
  g_test_add_func ("/hotplug/disconnect-connect",
                   meta_test_disconnect_connect);
}

int
main (int argc, char *argv[])
{
  g_autoptr (MetaContext) context = NULL;

  context = meta_create_test_context (META_CONTEXT_TEST_TYPE_VKMS,
                                      META_CONTEXT_TEST_FLAG_NO_X11);
  g_assert (meta_context_configure (context, &argc, &argv, NULL));

  init_tests ();

  test_context = context;

  return meta_context_test_run_tests (META_CONTEXT_TEST (context),
                                      META_TEST_RUN_FLAG_NONE);
}