#ifndef _FSM_H_
#define _FSM_H_

#include <map>
#include <memory>

#include "IBehaviouralState.hpp"

/// <summary>
///
/// </summary>
/// <typeparam name="TState">IBehaviouralState is the only accepted
/// class.</typeparam>
template <class TState> class FSM {
public:
  template <class... TPState> FSM(TPState &...args) {
    int i = 0;

    ((void)_states.emplace(i++, args), ...);
  }

  /// <summary>
  /// Implement with FSM::act()
  /// </summary>
  void act();

  /// <summary>
  /// Used to check current state.
  /// </summary>
  /// <returns>Current state.</returns>
  std::shared_ptr<TState> &get_state() { return _currentState; }

  /// <summary>
  /// Used to get all states.
  /// </summary>
  /// <returns>Current states.</returns>
  std::map<int, std::shared_ptr<TState>> get_states();

  /// <summary>
  /// Sets current state, calls appropiate functions.
  /// </summary>
  /// <param name="">State to transition into.</param>
  void set_state(std::shared_ptr<TState>);

private:
  std::map<int, std::shared_ptr<TState>> _states;
  std::shared_ptr<TState> _currentState;
};

#endif // _FSM_H_