ls-standard-library/include/ls-std/event/EventManager.hpp

/*
* Author:          Patrick-Christopher Mattulat
* Company:         Lynar Studios
* E-Mail:          webmaster@lynarstudios.com
* Created:         2024-05-16
* Changed:         2024-05-31
*
* */

#ifndef LS_STD_EVENT_MANAGER_HPP
#define LS_STD_EVENT_MANAGER_HPP

#include "Event.hpp"
#include "EventListener.hpp"
#include "EventParameter.hpp"

#include <list>
#include <ls-std/core/Class.hpp>
#include <ls-std/core/definition.hpp>
#include <ls-std/event/type/EventTypes.hpp>
#include <memory>
#include <unordered_map>

namespace ls::std::event::type
{
  using event_listeners = ::std::list<::std::pair<::std::shared_ptr<EventListener>, event_action>>;
  using event_observability_inventory = ::std::unordered_map<::std::string, event_listeners>;
}

namespace ls::std::event
{
  ls_std_class EventManager final : public core::Class
  {
    public:

      explicit EventManager();
      ~EventManager() noexcept override;

      [[nodiscard]] type::listener_id getNextProvisionId() const;
      [[nodiscard]] bool holdsListenerForEvent(type::listener_id _id, const Event &_event);
      void invoke(const Event &_event);
      void invoke(const Event &_event, const EventParameter &_parameter);
      [[nodiscard]] type::listener_id requestListenerId();
      void subscribeListenerForEvent(::std::shared_ptr<EventListener> _listener, const Event &_event, type::event_action _action);
      void unsubscribeListenerForEvent(const ::std::shared_ptr<EventListener> &_listener, const Event &_event);

    private:

      type::event_observability_inventory inventory{};
      type::listener_id provisionId = 1;

      static void _giveListenersParameter(const type::event_listeners &_listeners, const EventParameter &_parameter);
      static void _notifyListeners(const type::event_listeners &_listeners);
      [[nodiscard]] bool _observesEvent(const Event &_event) const;
  };
}

#endif