/* dzl-properties-group.c
 *
 * Copyright (C) 2017 Christian Hergert <chergert@redhat.com>
 *
 * 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 3 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/>.
 */

#define G_LOG_DOMAIN "dzl-properties-group"

#include "config.h"

#include "dzl-properties-group.h"

/**
 * SECTION:dzl-properties-group
 * @title: DzlPropertiesGroup
 * @short_description: A #GActionGroup of properties on an object
 *
 * This class is a #GActionGroup which provides stateful access to
 * properties in a #GObject. This can be useful when you want to
 * expose properties from a GObject as a #GAction, espectially with
 * use in GtkApplications.
 *
 * Call dzl_properties_group_add_property() to setup the mappings
 * for action-name to property-name for the actions you'd like to
 * add.
 *
 * Not all property types can be supported. What is current supported
 * are properties of type:
 *
 *  %G_TYPE_INT
 *  %G_TYPE_UINT
 *  %G_TYPE_BOOLEAN
 *  %G_TYPE_STRING
 *  %G_TYPE_DOUBLE
 *
 * Since: 3.26
 *
 * Since 3.28 enums are supported by using their enum value nick as
 * a string.
 */

struct _DzlPropertiesGroup
{
  GObject parent_instance;

  /*
   * All subsequent set_object() calls must be this type.
   */
  GType prerequisite;

  /*
   * Weak ref to the object we are monitoring for property changes.
   * We hold both a GWeakRef and a g_object_weak_ref() on the object
   * so that we can get notified of destruction *AND* know when we
   * can safely weak_unref() without invalid pointer user.
   */
  GWeakRef object_ref;

  /*
   * Since the list of mappings are fairly small, we just choose to
   * use an array of all mappings rather than two-hashtables to map
   * from action-name -> property-name and vice versa. Element type
   * is of struct Mapping.
   *
   * The strings in the mapping are intern'd to allow for direct
   * pointer comparison with GParamSpec information.
   */
  GArray *mappings;
};

typedef struct
{
  const gchar        *action_name;
  const GVariantType *param_type;
  const GVariantType *state_type;
  const gchar        *property_name;
  GType               property_type;
  DzlPropertiesFlags  flags : 8;
  guint               can_read : 1;
  guint               can_write : 1;
} Mapping;

enum {
  PROP_0,
  PROP_OBJECT,
  PROP_OBJECT_TYPE,
  N_PROPS
};

static GVariant *
get_action_state (GObject       *object,
                  const Mapping *mapping)
{
  g_auto(GValue) value = G_VALUE_INIT;
  GVariant *ret = NULL;

  g_assert (G_IS_OBJECT (object));
  g_assert (mapping != NULL);

  if (!mapping->can_read)
    return NULL;

  g_value_init (&value, mapping->property_type);
  g_object_get_property (object, mapping->property_name, &value);

  switch (mapping->property_type)
    {
    case G_TYPE_INT:
      ret = g_variant_new_int32 (g_value_get_int (&value));
      break;

    case G_TYPE_UINT:
      ret = g_variant_new_uint32 (g_value_get_uint (&value));
      break;

    case G_TYPE_DOUBLE:
      ret = g_variant_new_double (g_value_get_double (&value));
      break;

    case G_TYPE_STRING:
      if (!g_value_get_string (&value))
        ret = g_variant_new_string ("");
      else
        ret = g_variant_new_string (g_value_get_string (&value));
      break;

    case G_TYPE_BOOLEAN:
      ret = g_variant_new_boolean (g_value_get_boolean (&value));
      break;

    default:
      if (g_type_is_a (mapping->property_type, G_TYPE_ENUM))
        {
          GEnumClass *eclass = g_type_class_ref (mapping->property_type);
          GEnumValue *eval = g_enum_get_value (eclass, g_value_get_enum (&value));

          if (eval != NULL)
            ret = g_variant_new_string (eval->value_nick);

          g_clear_pointer (&eclass, g_type_class_unref);

          break;
        }

      g_assert_not_reached ();
    }

  return g_variant_take_ref (ret);
}

static gboolean
dzl_properties_group_query_action (GActionGroup        *group,
                                   const gchar         *action_name,
                                   gboolean            *enabled,
                                   const GVariantType **param_type,
                                   const GVariantType **state_type,
                                   GVariant           **state_hint,
                                   GVariant           **state)
{
  DzlPropertiesGroup *self = (DzlPropertiesGroup *)group;

  g_assert (DZL_IS_PROPERTIES_GROUP (self));
  g_assert (action_name != NULL);

  for (guint i = 0; i < self->mappings->len; i++)
    {
      const Mapping *mapping = &g_array_index (self->mappings, Mapping, i);

      if (g_strcmp0 (mapping->action_name, action_name) == 0)
        {
          g_autoptr(GObject) object = g_weak_ref_get (&self->object_ref);

          if (enabled)
            *enabled = (object != NULL);

          if (param_type)
            *param_type = mapping->param_type;

          if (state_type)
            *state_type = mapping->state_type;

          if (state_hint)
            *state_hint = NULL;

          if (state)
            {
              if (object)
                *state = get_action_state (object, mapping);
              else
                *state = NULL;
            }

          return TRUE;
        }
    }

  return FALSE;
}

static gchar **
dzl_properties_group_list_actions (GActionGroup *group)
{
  DzlPropertiesGroup *self = (DzlPropertiesGroup *)group;
  GPtrArray *ar;

  g_assert (DZL_IS_PROPERTIES_GROUP (self));

  ar = g_ptr_array_new ();

  for (guint i = 0; i < self->mappings->len; i++)
    {
      const Mapping *mapping = &g_array_index (self->mappings, Mapping, i);

      g_ptr_array_add (ar, g_strdup (mapping->action_name));
    }

  g_ptr_array_add (ar, NULL);

  return (gchar **)g_ptr_array_free (ar, FALSE);
}

static gboolean
dzl_properties_group_has_action (GActionGroup *group,
                                 const gchar  *name)
{
  DzlPropertiesGroup *self = (DzlPropertiesGroup *)group;

  g_assert (DZL_IS_PROPERTIES_GROUP (self));
  g_assert (name != NULL);

  for (guint i = 0; i < self->mappings->len; i++)
    {
      const Mapping *mapping = &g_array_index (self->mappings, Mapping, i);

      if (g_strcmp0 (name, mapping->action_name) == 0)
        return TRUE;
    }

  return FALSE;
}

static gboolean
dzl_properties_group_get_action_enabled (GActionGroup *group,
                                         const gchar  *name)
{
  DzlPropertiesGroup *self = (DzlPropertiesGroup *)group;
  g_autoptr(GObject) object = NULL;

  g_assert (DZL_IS_PROPERTIES_GROUP (self));
  g_assert (name != NULL);

  object = g_weak_ref_get (&self->object_ref);

  return (object != NULL);
}

static const GVariantType *
dzl_properties_group_get_action_parameter_type (GActionGroup *group,
                                                const gchar  *name)
{
  DzlPropertiesGroup *self = (DzlPropertiesGroup *)group;

  g_assert (DZL_IS_PROPERTIES_GROUP (self));
  g_assert (name != NULL);

  for (guint i = 0; i < self->mappings->len; i++)
    {
      const Mapping *mapping = &g_array_index (self->mappings, Mapping, i);

      if (g_strcmp0 (name, mapping->action_name) == 0)
        {
          /* Normal parameter type for boolean actions is NULL. But if
           * we are treating them statefully, where the new state is the
           * activation state, then handle that here.
           */
          if (mapping->property_type == G_TYPE_BOOLEAN &&
              (mapping->flags & DZL_PROPERTIES_FLAGS_STATEFUL_BOOLEANS) != 0)
            return G_VARIANT_TYPE_BOOLEAN;

          return mapping->param_type;
        }
    }

  return NULL;
}

static const GVariantType *
dzl_properties_group_get_action_state_type (GActionGroup *group,
                                            const gchar  *name)
{
  DzlPropertiesGroup *self = (DzlPropertiesGroup *)group;

  g_assert (DZL_IS_PROPERTIES_GROUP (self));
  g_assert (name != NULL);

  for (guint i = 0; i < self->mappings->len; i++)
    {
      const Mapping *mapping = &g_array_index (self->mappings, Mapping, i);

      if (g_strcmp0 (name, mapping->action_name) == 0)
        return mapping->state_type;
    }

  return NULL;
}

static GVariant *
dzl_properties_group_get_action_state_hint (GActionGroup *group,
                                            const gchar  *name)
{
  g_assert (DZL_IS_PROPERTIES_GROUP (group));
  g_assert (name != NULL);

  return NULL;
}

static void
dzl_properties_group_change_action_state (GActionGroup *group,
                                          const gchar  *name,
                                          GVariant     *variant)
{
  DzlPropertiesGroup *self = (DzlPropertiesGroup *)group;
  g_autoptr(GObject) object = NULL;
  const GVariantType *expected;

  g_assert (DZL_IS_PROPERTIES_GROUP (self));
  g_assert (name != NULL);

  expected = dzl_properties_group_get_action_state_type (group, name);

  if (variant == NULL || !g_variant_is_of_type (variant, expected))
    {
      g_warning ("Invalid state for action \"%s\". Expected %s.",
                 name, (const gchar *)expected);
      return;
    }

  object = g_weak_ref_get (&self->object_ref);

  if (object == NULL)
    {
      g_warning ("Attempt to change state of %s after action was disabled",
                 name);
      return;
    }

  for (guint i = 0; i < self->mappings->len; i++)
    {
      const Mapping *mapping = &g_array_index (self->mappings, Mapping, i);

      if (g_strcmp0 (name, mapping->action_name) == 0)
        {
          g_auto(GValue) value = G_VALUE_INIT;

          if (!mapping->can_write)
            {
              g_warning ("property is not writable, ignoring request to change state");
              break;
            }

          switch (mapping->property_type)
            {
            case G_TYPE_INT:
              g_value_init (&value, G_TYPE_INT);
              g_value_set_int (&value, g_variant_get_int32 (variant));
              break;

            case G_TYPE_UINT:
              g_value_init (&value, G_TYPE_UINT);
              g_value_set_uint (&value, g_variant_get_uint32 (variant));
              break;

            case G_TYPE_BOOLEAN:
              g_value_init (&value, G_TYPE_BOOLEAN);
              g_value_set_boolean (&value, g_variant_get_boolean (variant));
              break;

            case G_TYPE_STRING:
              g_value_init (&value, G_TYPE_STRING);
              /* No need to dup the string, its lifetime is longer */
              g_value_set_static_string (&value, g_variant_get_string (variant, NULL));
              break;

            case G_TYPE_DOUBLE:
              g_value_init (&value, G_TYPE_DOUBLE);
              g_value_set_double (&value, g_variant_get_double (variant));
              break;

            default:
              if (g_type_is_a (mapping->property_type, G_TYPE_ENUM))
                {
                  const gchar *str = g_variant_get_string (variant, NULL);
                  GEnumClass *eclass = g_type_class_ref (mapping->property_type);

                  if (eclass != NULL)
                    {
                      GEnumValue *eval = g_enum_get_value_by_nick (eclass, str);

                      if (eval != NULL)
                        {
                          g_value_init (&value, mapping->property_type);
                          g_value_set_enum (&value, eval->value);
                          g_clear_pointer (&eclass, g_type_class_unref);
                          break;
                        }
                    }

                  g_clear_pointer (&eclass, g_type_class_unref);
                  g_warning ("Failed to transform '%s' to %s",
                             str, g_type_name (mapping->property_type));
                  return;
                }

              g_assert_not_reached ();
            }

          g_object_set_property (object, mapping->property_name, &value);

          break;
        }
    }
}

static void
dzl_properties_group_activate_action (GActionGroup *group,
                                      const gchar  *name,
                                      GVariant     *variant)
{
  DzlPropertiesGroup *self = (DzlPropertiesGroup *)group;
  g_autoptr(GObject) object = NULL;

  g_assert (DZL_IS_PROPERTIES_GROUP (self));
  g_assert (name != NULL);

  object = g_weak_ref_get (&self->object_ref);

  if (object == NULL)
    {
      g_warning ("Attempt to activate %s after action was disabled", name);
      return;
    }

  for (guint i = 0; i < self->mappings->len; i++)
    {
      const Mapping *mapping = &g_array_index (self->mappings, Mapping, i);

      if (g_strcmp0 (name, mapping->action_name) == 0)
        {
          if (mapping->property_type == G_TYPE_BOOLEAN &&
              (mapping->flags & DZL_PROPERTIES_FLAGS_STATEFUL_BOOLEANS) == 0)
            {
              gboolean value = FALSE;

              g_object_get (object, mapping->property_name, &value, NULL);
              value = !value;
              g_object_set (object, mapping->property_name, value, NULL);
            }
          else
            {
              dzl_properties_group_change_action_state (group, name, variant);
            }

          break;
        }
    }
}

static void
action_group_iface_init (GActionGroupInterface *iface)
{
  iface->has_action = dzl_properties_group_has_action;
  iface->list_actions = dzl_properties_group_list_actions;
  iface->get_action_enabled = dzl_properties_group_get_action_enabled;
  iface->get_action_parameter_type = dzl_properties_group_get_action_parameter_type;
  iface->get_action_state_type = dzl_properties_group_get_action_state_type;
  iface->get_action_state_hint = dzl_properties_group_get_action_state_hint;
  iface->change_action_state = dzl_properties_group_change_action_state;
  iface->activate_action = dzl_properties_group_activate_action;
  iface->query_action = dzl_properties_group_query_action;
}

G_DEFINE_TYPE_WITH_CODE (DzlPropertiesGroup, dzl_properties_group, G_TYPE_OBJECT,
                         G_IMPLEMENT_INTERFACE (G_TYPE_ACTION_GROUP, action_group_iface_init))

static GParamSpec *properties [N_PROPS];

static void
dzl_properties_group_notify (DzlPropertiesGroup *self,
                             GParamSpec         *pspec,
                             GObject            *object)
{
  g_assert (DZL_IS_PROPERTIES_GROUP (self));
  g_assert (pspec != NULL);
  g_assert (G_IS_OBJECT (object));

  /* mappings is generally quite small, so iterating the array
   * is going to have similar performance to a hashtable lookup
   * plus pointer chaseing.
   */

  for (guint i = 0; i < self->mappings->len; i++)
    {
      const Mapping *mapping = &g_array_index (self->mappings, Mapping, i);

      if (mapping->property_name == pspec->name)
        {
          g_autoptr(GVariant) state = get_action_state (object, mapping);
          g_action_group_action_state_changed (G_ACTION_GROUP (self),
                                               mapping->action_name,
                                               state);
          break;
        }
    }
}

static const GVariantType *
get_param_type_for_type (GType              type,
                         DzlPropertiesFlags flags)
{
  switch (type)
    {
    case G_TYPE_INT:     return G_VARIANT_TYPE_INT32;
    case G_TYPE_UINT:    return G_VARIANT_TYPE_UINT32;
    case G_TYPE_STRING:  return G_VARIANT_TYPE_STRING;
    case G_TYPE_DOUBLE:  return G_VARIANT_TYPE_DOUBLE;

    case G_TYPE_BOOLEAN:
      if (flags & DZL_PROPERTIES_FLAGS_STATEFUL_BOOLEANS)
        return G_VARIANT_TYPE_BOOLEAN;
      return NULL;

    default:
      if (g_type_is_a (type, G_TYPE_ENUM))
        return G_VARIANT_TYPE_STRING;

      g_warning ("%s is not a supported type", g_type_name (type));
      return NULL;
    }
}

static const GVariantType *
get_state_type_for_type (GType type)
{
  switch (type)
    {
    case G_TYPE_INT:     return G_VARIANT_TYPE_INT32;
    case G_TYPE_UINT:    return G_VARIANT_TYPE_UINT32;
    case G_TYPE_BOOLEAN: return G_VARIANT_TYPE_BOOLEAN;
    case G_TYPE_STRING:  return G_VARIANT_TYPE_STRING;
    case G_TYPE_DOUBLE:  return G_VARIANT_TYPE_DOUBLE;

    default:
      if (g_type_is_a (type, G_TYPE_ENUM))
        return G_VARIANT_TYPE_STRING;

      g_warning ("%s is not a supported type", g_type_name (type));
      return NULL;
    }
}

static void
dzl_properties_group_notify_all_disabled (DzlPropertiesGroup *self)
{
  g_assert (DZL_IS_PROPERTIES_GROUP (self));

  for (guint i = 0; i < self->mappings->len; i++)
    {
      const Mapping *mapping = &g_array_index (self->mappings, Mapping, i);
      g_action_group_action_enabled_changed (G_ACTION_GROUP (self),
                                             mapping->action_name,
                                             FALSE);
    }
}

static void
dzl_properties_group_weak_notify (gpointer  data,
                                  GObject  *where_object_was)
{
  DzlPropertiesGroup *self = data;

  g_assert (DZL_IS_PROPERTIES_GROUP (self));

  g_weak_ref_set (&self->object_ref, NULL);

  dzl_properties_group_notify_all_disabled (self);
}

static void
dzl_properties_group_set_object (DzlPropertiesGroup *self,
                                 GObject            *object)
{
  g_autoptr(GObject) old_object = NULL;

  g_assert (DZL_IS_PROPERTIES_GROUP (self));
  g_assert (!object || G_IS_OBJECT (object));

  old_object = g_weak_ref_get (&self->object_ref);

  /* Nothing to do if we aren't changing anything */
  if (object == old_object)
    return;

  if (self->prerequisite == G_TYPE_INVALID && object != NULL)
    self->prerequisite = G_OBJECT_TYPE (object);

  /* Disconnect previous life-cycle tracking */
  if (old_object != NULL)
    {
      g_signal_handlers_disconnect_by_func (old_object,
                                            G_CALLBACK (dzl_properties_group_notify),
                                            self);
      g_object_weak_unref (old_object,
                           dzl_properties_group_weak_notify,
                           self);
      g_weak_ref_set (&self->object_ref, NULL);
    }

  /* Mark all actions as disabled if we lost our object */
  if (object == NULL)
    {
      dzl_properties_group_notify_all_disabled (self);
      return;
    }

  g_signal_connect_object (object,
                           "notify",
                           G_CALLBACK (dzl_properties_group_notify),
                           self,
                           G_CONNECT_SWAPPED);

  /* WeakRef so we can detect 3-rd degree disposal */
  g_weak_ref_set (&self->object_ref, object);

  /* Weak notify so we can get notified of the case */
  g_object_weak_ref (G_OBJECT (object),
                     dzl_properties_group_weak_notify,
                     self);

  /* Emit state changes for all properties */
  for (guint i = 0; i < self->mappings->len; i++)
    {
      const Mapping *mapping = &g_array_index (self->mappings, Mapping, i);
      g_autoptr(GVariant) state = get_action_state (object, mapping);

      g_action_group_action_state_changed (G_ACTION_GROUP (self),
                                           mapping->action_name,
                                           state);
    }
}

static void
dzl_properties_group_finalize (GObject *object)
{
  DzlPropertiesGroup *self = (DzlPropertiesGroup *)object;
  g_autoptr(GObject) weak_obj = NULL;

  weak_obj = g_weak_ref_get (&self->object_ref);

  if (weak_obj != NULL)
    {
      /*
       * No need to disconnect signal handler as we are in finalize and
       * g_signal_connect_object() tracks this for us.
       */
      g_object_weak_unref (weak_obj,
                           dzl_properties_group_weak_notify,
                           self);
    }

  g_weak_ref_clear (&self->object_ref);

  g_clear_pointer (&self->mappings, g_array_unref);

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

static void
dzl_properties_group_get_property (GObject    *object,
                                   guint       prop_id,
                                   GValue     *value,
                                   GParamSpec *pspec)
{
  DzlPropertiesGroup *self = DZL_PROPERTIES_GROUP (object);

  switch (prop_id)
    {
    case PROP_OBJECT:
      g_value_take_object (value, g_weak_ref_get (&self->object_ref));
      break;

    case PROP_OBJECT_TYPE:
      g_value_set_gtype (value, self->prerequisite);
      break;

    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
    }
}

static void
dzl_properties_group_set_property (GObject      *object,
                                   guint         prop_id,
                                   const GValue *value,
                                   GParamSpec   *pspec)
{
  DzlPropertiesGroup *self = DZL_PROPERTIES_GROUP (object);

  switch (prop_id)
    {
    case PROP_OBJECT:
      dzl_properties_group_set_object (self, g_value_get_object (value));
      break;

    case PROP_OBJECT_TYPE:
      if (g_value_get_gtype (value) != G_TYPE_INVALID &&
          g_value_get_gtype (value) != G_TYPE_OBJECT)
        self->prerequisite = g_value_get_gtype (value);
      break;

    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
    }
}

static void
dzl_properties_group_class_init (DzlPropertiesGroupClass *klass)
{
  GObjectClass *object_class = G_OBJECT_CLASS (klass);

  object_class->finalize = dzl_properties_group_finalize;
  object_class->get_property = dzl_properties_group_get_property;
  object_class->set_property = dzl_properties_group_set_property;

  properties [PROP_OBJECT] =
    g_param_spec_object ("object",
                         "Object",
                         "The source object for the properties",
                         G_TYPE_OBJECT,
                         (G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));

  properties [PROP_OBJECT_TYPE] =
    g_param_spec_gtype ("object-type",
                        "Object Type",
                        "A type the object must conform to.",
                        G_TYPE_OBJECT,
                        (G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_STRINGS));

  g_object_class_install_properties (object_class, N_PROPS, properties);
}

static void
dzl_properties_group_init (DzlPropertiesGroup *self)
{
  g_weak_ref_init (&self->object_ref, NULL);

  self->mappings = g_array_new (FALSE, FALSE, sizeof (Mapping));
}

/**
 * dzl_properties_group_new:
 * @object: The object containing the properties
 *
 * This creates a new #DzlPropertiesGroup to create stateful actions
 * around properties in @object.
 *
 * Call dzl_properties_group_add_property() to add a property to
 * action name mapping for this group. Until you've called this,
 * no actions are mapped.
 *
 * Note that #DzlPropertiesGroup only holds a weak reference to
 * @object and therefore you must keep @object alive elsewhere.
 *
 * Returns: (transfer full): A #DzlPropertiesGroup
 *
 * Since: 3.26
 */
DzlPropertiesGroup *
dzl_properties_group_new (GObject *object)
{
  g_return_val_if_fail (G_IS_OBJECT (object), NULL);

  return g_object_new (DZL_TYPE_PROPERTIES_GROUP,
                       "object", object,
                       "object-type", G_OBJECT_TYPE (object),
                       NULL);
}

/**
 * dzl_properties_group_add_property_full:
 * @self: a #DzlPropertiesGroup
 * @name: the name of the action
 * @property_name: the name of the property
 * @flags: optional flags for the action
 *
 * Adds a new stateful action named @name which maps to the underlying
 * property @property_name of #DzlPropertiesGroup:object.
 *
 * Seting @flags allows you to tweak some settings about the action.
 *
 * Since: 3.26
 */
void
dzl_properties_group_add_property_full (DzlPropertiesGroup *self,
                                        const gchar        *name,
                                        const gchar        *property_name,
                                        DzlPropertiesFlags  flags)
{
  GObjectClass *object_class = NULL;
  GParamSpec *pspec;
  Mapping mapping = { 0 };

  g_return_if_fail (DZL_IS_PROPERTIES_GROUP (self));
  g_return_if_fail (name != NULL);
  g_return_if_fail (property_name != NULL);

  if (self->prerequisite == G_TYPE_INVALID)
    {
      g_warning ("Cannot add properties before object has been set.");
      return;
    }

  object_class = g_type_class_ref (self->prerequisite);

  if (object_class == NULL || !G_IS_OBJECT_CLASS (object_class))
    {
      g_warning ("Implausable result for prerequisite, not a GObjectClass");
      goto failure;
    }

  pspec = g_object_class_find_property (object_class, property_name);

  if (pspec == NULL)
    {
      g_warning ("No such property \"%s\" on type %s",
                 property_name, G_OBJECT_CLASS_NAME (object_class));
      goto failure;
    }

  mapping.action_name = g_intern_string (name);
  mapping.param_type = get_param_type_for_type (pspec->value_type, flags);
  mapping.state_type = get_state_type_for_type (pspec->value_type);
  mapping.property_name = pspec->name;
  mapping.property_type = pspec->value_type;
  mapping.flags = flags;
  mapping.can_read = !!(pspec->flags & G_PARAM_READABLE);
  mapping.can_write = !!(pspec->flags & G_PARAM_WRITABLE);

  /* we already warned, ignore this */
  if (mapping.state_type == NULL)
    goto failure;

  g_array_append_val (self->mappings, mapping);

  g_action_group_action_added (G_ACTION_GROUP (self), mapping.action_name);

failure:
  g_clear_pointer (&object_class, g_type_class_unref);
}

/**
 * dzl_properties_group_add_property:
 * @self: a #DzlPropertiesGroup
 * @name: the name of the action
 * @property_name: the name of the property
 *
 * Adds a new stateful action named @name which maps to the underlying
 * property @property_name of #DzlPropertiesGroup:object.
 *
 * Since: 3.26
 */
void
dzl_properties_group_add_property (DzlPropertiesGroup *self,
                                   const gchar        *name,
                                   const gchar        *property_name)
{
  dzl_properties_group_add_property_full (self, name, property_name, 0);
}

/**
 * dzl_properties_group_remove:
 * @self: a #DzlPropertiesGroup
 * @name: the name of the action
 *
 * Removes an action from @self that was previously added with
 * dzl_properties_group_add_property(). @name should match the
 * name parameter to that function.
 *
 * Since: 3.26
 */
void
dzl_properties_group_remove (DzlPropertiesGroup *self,
                             const gchar        *name)
{
  g_return_if_fail (DZL_IS_PROPERTIES_GROUP (self));
  g_return_if_fail (name != NULL);

  name = g_intern_string (name);

  for (guint i = 0; i < self->mappings->len; i++)
    {
      const Mapping *mapping = &g_array_index (self->mappings, Mapping, i);

      if (mapping->action_name == name)
        {
          g_array_remove_index_fast (self->mappings, i);
          g_action_group_action_removed (G_ACTION_GROUP (self), name);
          break;
        }
    }
}

/**
 * dzl_properties_group_add_all_properties:
 * @self: A #DzlPropertiesGroup
 *
 * This function will try to add all properties found on the target
 * instance to the group. Only properties that are supported by the
 * #DzlPropertiesGroup will be added.
 *
 * The action name of all added properties will be identical to their
 * property name.
 *
 * Since: 3.26
 */
void
dzl_properties_group_add_all_properties (DzlPropertiesGroup *self)
{
  g_autofree GParamSpec **pspec = NULL;
  GObjectClass *object_class = NULL;
  guint n_pspec = 0;

  g_return_if_fail (DZL_IS_PROPERTIES_GROUP (self));

  if (self->prerequisite == G_TYPE_INVALID)
    {
      g_warning ("Cannot add properties, no object has been set");
      return;
    }

  object_class = g_type_class_ref (self->prerequisite);

  if (object_class == NULL || !G_IS_OBJECT_CLASS (object_class))
    {
      g_warning ("Implausable result, not a GObjectClass");
      goto failure;
    }

  pspec = g_object_class_list_properties (object_class, &n_pspec);

  for (guint i = 0; i < n_pspec; i++)
    {
      switch (pspec[i]->value_type)
        {
        case G_TYPE_BOOLEAN:
        case G_TYPE_DOUBLE:
        case G_TYPE_INT:
        case G_TYPE_STRING:
        case G_TYPE_UINT:
          dzl_properties_group_add_property (self, pspec[i]->name, pspec[i]->name);
          break;

        default:
          if (g_type_is_a (pspec[i]->value_type, G_TYPE_ENUM))
            dzl_properties_group_add_property (self, pspec[i]->name, pspec[i]->name);
          break;
        }
    }

failure:
  g_clear_pointer (&object_class, g_type_class_unref);
}

/**
 * dzl_properties_group_new_for_type:
 * @object_type: A #GObjectClass based type
 *
 * This creates a new #DzlPropertiesGroup for which the initial object is
 * %NULL.
 *
 * Set @object_type to a type of a class which is a #GObject-based type.
 *
 * Returns: (transfer none): A #DzlPropertiesGroup.
 */
DzlPropertiesGroup *
dzl_properties_group_new_for_type (GType object_type)
{
  g_return_val_if_fail (g_type_is_a (object_type, G_TYPE_OBJECT), NULL);

  return g_object_new (DZL_TYPE_PROPERTIES_GROUP,
                       "object-type", object_type,
                       NULL);
}