using System.Collections.Generic;

//============================================================
//支持中文，文件使用UTF-8编码
//@author	JiphuTzu
//@create	20220910
//@company	Umawerse
//
//@description:
//============================================================
namespace Umawerse.FiniteStateMachines
{
    public class FiniteStateMachine
    {
        private Dictionary<StateName, FiniteState> _states;

        private FiniteState _current;

        private StateName _currentName;

        //private Dictionary<>
        public FiniteStateMachine()
        {
            _states = new Dictionary<StateName, FiniteState>();
        }

        public void AddState(FiniteState state)
        {
            _states.Add(state.name, state);
        }

        public void SetState(StateName name, bool force = false)
        {
            if (force)
            {
                _currentName = StateName.none;
                Update();
            }
            _currentName = name;
        }

        public T GetState<T>(StateName name) where T : FiniteState
        {
            if (_states.TryGetValue(name, out var state))
            {
                return state as T;
            }

            return null;
        }

        public StateName Update()
        {
            if (_current == null)
            {
                _states.TryGetValue(_currentName, out _current);
                if (_current != null) _current.Enter();
                else _currentName = StateName.none;
            }
            else if (_current != null)
            {
                if (_current.name == _currentName)
                {
                    _currentName = _current.Update();
                }
                else
                {
                    _current.Exit();
                    _states.TryGetValue(_currentName, out _current);
                    if (_current != null) _current.Enter();
                    else _currentName = StateName.none;
                }
            }

            return _currentName;
        }
    }
}