/* Copyright (C) 2010 The giomm Development Team
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
 */

_CONFIGINCLUDE(giommconfig.h)

#include <glibmm/interface.h>
#include <glibmm/varianttype.h>
#include <gio/gio.h> //To declare g_action_group_get_action_state_type().

_DEFS(giomm,gio)
_PINCLUDE(glibmm/private/interface_p.h)
_PINCLUDE(gio/gio.h)

#ifndef DOXYGEN_SHOULD_SKIP_THIS
typedef struct _GActionGroupInterface GActionGroupInterface;
#endif /* DOXYGEN_SHOULD_SKIP_THIS */

namespace Glib
{

class GIOMM_API VariantBase;
class GIOMM_API VariantContainerBase;
class GIOMM_API VariantType;

}

namespace Gio
{

/** ActionGroup - a group of actions.
 * ActionGroup represents a group of actions.
 *
 * Each action in the group has a unique name (which is a string). All method
 * calls, except list_actions() take the name of an action as an argument.
 *
 * The GActionGroup API is meant to be the 'public' API to the action group.
 * The calls here are exactly the interaction that 'external forces' (eg: UI,
 * incoming D-Bus messages, etc.) are supposed to have with actions.
 * 'Internal' APIs (ie: ones meant only to be accessed by the action group
 * implementation) are found on subclasses. This is why you will find -- for
 * example -- get_action_enabled() but not an equivalent @c set() call.
 *
 * Signals are emitted on the action group in response to state changes on
 * individual actions.
 */
class GIOMM_API ActionGroup : public Glib::Interface
{
  _CLASS_INTERFACE(ActionGroup, GActionGroup, G_ACTION_GROUP, GActionGroupInterface, , , GIOMM_API)

public:
  _WRAP_METHOD(bool has_action(const Glib::ustring& action_name) const, g_action_group_has_action)

#m4 _CONVERSION(`gchar**',`std::vector<Glib::ustring>',`Glib::ArrayHandler<Glib::ustring>::array_to_vector($3, Glib::OWNERSHIP_DEEP)')
  _WRAP_METHOD(std::vector<Glib::ustring> list_actions() const, g_action_group_list_actions)

  //TODO: Add templated method, renaming this to query_action_variant).
  _WRAP_METHOD(bool query_action(const Glib::ustring& action_name, bool& enabled{>>}, Glib::VariantType& parameter_type{>>?}, Glib::VariantBase& state_hint{.>>}, Glib::VariantType& state_type{.>>?}, Glib::VariantBase& state{.>>?}), g_action_group_query_action)

  _WRAP_METHOD(bool get_action_enabled(const Glib::ustring& action_name) const, g_action_group_get_action_enabled)

  _WRAP_METHOD(Glib::VariantType get_action_parameter_type(const Glib::ustring& action_name) const, g_action_group_get_action_parameter_type)
  _WRAP_METHOD(Glib::VariantType get_action_state_type(const Glib::ustring& action_name) const, g_action_group_get_action_state_type)

  //TODO: How do we check for a nullptr Variant?
  /**
   * Requests a hint about the valid range of values for the state of the
   * named action within the action group
   *
   * If a null Variant is returned it either means that the action is not stateful
   * or that there is no hint about the valid range of values for the
   * state of the action.
   *
   * If a ariant array is returned then each item in the array is a
   * possible value for the state.  If Variant pair (ie: two-tuple) is
   * returned then the tuple specifies the inclusive lower and upper bound
   * of valid values for the state.
   *
   * In any case, the information is merely a hint.  It may be possible to
   * have a state value outside of the hinted range and setting a value
   * within the range may fail.
   *
   * @param action_name The name of the action to query.
   * @param value This will be set to the state range hint.
   */
  template <typename T_Value>
  void get_action_state_hint(const Glib::ustring& action_name, T_Value& value) const;

  _WRAP_METHOD(Glib::VariantContainerBase get_action_state_hint_variant(const Glib::ustring& action_name) const, g_action_group_get_action_state_hint)

  //TODO: How do we check for a nullptr Variant?
  /** Queries the current state of the named action within the action group.
   *
   * If the action is not stateful then a null Variant will be returned.  If the
   * action is stateful then the type of the return value is the type
   * given by get_action_state_type().
   *
   * @param action_name The name of the action to query.
   * @param value This will be set to the current state of the action.
   */
  template <typename T_Value>
  void get_action_state(const Glib::ustring& action_name, T_Value& value) const;

  _WRAP_METHOD(Glib::VariantBase get_action_state_variant(const Glib::ustring& action_name) const, g_action_group_get_action_state)

  //TODO: Add templated method, renaming this to change_action_state_variant().
  _WRAP_METHOD(void change_action_state(const Glib::ustring& action_name, const Glib::VariantBase& value), g_action_group_change_action_state)

  //TODO: Add templated method, renaming this to activate_action_variant().
  _WRAP_METHOD(void activate_action(const Glib::ustring& action_name, const Glib::VariantBase& parameter{?}), g_action_group_activate_action)

  _WRAP_METHOD(void action_added(const Glib::ustring& action_name), g_action_group_action_added)
  _WRAP_METHOD(void action_removed(const Glib::ustring& action_name), g_action_group_action_removed)
  _WRAP_METHOD(void action_enabled_changed(const Glib::ustring& action_name, bool enabled), g_action_group_action_enabled_changed)

  //TODO: Add templated method, renaming this to action_state_changed_variant).
  _WRAP_METHOD(void action_state_changed (const Glib::ustring& action_name, const Glib::VariantBase& state), g_action_group_action_state_changed)

  _WRAP_SIGNAL(void action_added(const Glib::ustring& action_name), "action-added", detail_name action_name)
  _WRAP_SIGNAL(void action_enabled_changed(const Glib::ustring& action_name, bool enabled), "action-enabled-changed", detail_name action_name)
  _WRAP_SIGNAL(void action_removed(const Glib::ustring& action_name), "action-removed", detail_name action_name)

#m4 _CONVERSION(`GVariant*', `const Glib::VariantBase&', `Glib::wrap($3, true)')

  _WRAP_SIGNAL(void action_state_changed(const Glib::ustring& action_name, const Glib::VariantBase& value), "action-state-changed", detail_name action_name)

protected:
  _WRAP_VFUNC(bool has_action(const Glib::ustring& name) const, "has_action")

#m4 _CONVERSION(`std::vector<Glib::ustring>',`gchar**',`g_strdupv(const_cast<gchar**>(Glib::ArrayHandler<Glib::ustring>::vector_to_array($3).data()))')
  _WRAP_VFUNC(std::vector<Glib::ustring> list_actions() const, "list_actions")

  _WRAP_VFUNC(bool get_action_enabled(const Glib::ustring& name) const, "get_action_enabled")

#m4 _CONVERSION(`Glib::VariantType',`const GVariantType*',`$3.gobj()')
  _WRAP_VFUNC(Glib::VariantType get_action_parameter_type(const Glib::ustring& name) const, "get_action_parameter_type", keep_return)
  _WRAP_VFUNC(Glib::VariantType get_action_state_type(const Glib::ustring& name) const, "get_action_state_type", keep_return)

  _WRAP_VFUNC(Glib::VariantBase get_action_state_hint(const Glib::ustring& name) const, "get_action_state_hint", refreturn_ctype)
  _WRAP_VFUNC(Glib::VariantBase get_action_state(const Glib::ustring& name) const, "get_action_state", refreturn_ctype)

  _WRAP_VFUNC(void change_action_state(const Glib::ustring& name, const Glib::VariantBase& value), "change_action_state")
  _WRAP_VFUNC(void activate_action(const Glib::ustring& name, const Glib::VariantBase& parameter), "activate_action")
};

template <typename T_Value>
void ActionGroup::get_action_state(const Glib::ustring& action_name, T_Value& value) const
{
  value = T_Value(); //Make sure that it is initialized.

  using type_glib_variant = Glib::Variant<T_Value>;

  g_return_if_fail(
    g_variant_type_equal(g_action_group_get_action_state_type(const_cast<GActionGroup*>(gobj()), action_name.c_str()), type_glib_variant::variant_type().gobj()));

  const auto variantBase = get_action_state_variant(action_name);

  //TODO: Add a bool return instead of letting a std::bad_cast from the cast_dynamic() be thrown up to the caller?
  const auto variantDerived = variantBase.cast_dynamic<type_glib_variant>(variantBase);
  value = variantDerived.get();
}

template <typename T_Value>
void ActionGroup::get_action_state_hint(const Glib::ustring& action_name, T_Value& value) const
{
  value = T_Value(); //Make sure that it is initialized.

  using type_glib_variant = Glib::Variant<T_Value>;

  const auto variantBase = get_action_state_hint_variant(action_name);

  // We can't check the type (a range) that will be returned before getting the range hint.
  g_return_if_fail(
    variantBase.is_of_type(type_glib_variant::variant_type()) );

  const auto variantDerived = variantBase.cast_dynamic<type_glib_variant>(variantBase);
  value = variantDerived.get();
}

} // namespace Gio