MojSadUnity/Assets/Code/Infrastructure/StateMachine/AbstractStateMachine.cs

using System;
using System.Collections.Generic;
using Code.Infrastructure.EventBus;

namespace Code.Infrastructure.StateMachine
{
    public abstract class AbstractStateMachine<TStateEnum, TStateMachineContext>
        where TStateMachineContext : new()
    {
        protected AbstractStateMachine(TStateMachineContext stateMachineContext )
        {
            StateMachineContext = stateMachineContext; 
        }

        public TStateEnum CurrentState { get; protected set; }
        public BaseState<TStateEnum, TStateMachineContext> CurrentBaseState { get; private set; }
        private BaseState<TStateEnum, TStateMachineContext> _previousBaseState;

        protected Dictionary<TStateEnum, BaseState<TStateEnum, TStateMachineContext>> States = new();
        protected Dictionary<TStateEnum, Type> StatesTypes = new(); 
        public TStateEnum AllowedStates { get; set; }

        protected TStateMachineContext StateMachineContext { get; }
        
        // Костыли 2 шт. для флагового енама в шаблонах 
        protected abstract bool CheckTransitionAllowed(TStateEnum nextState);
        protected abstract void ResetAllowedTransitions();

        // TODO Если в EnterState вызывается ExitState, то будет гарантированная поломка
        public AbstractStateMachine<TStateEnum, TStateMachineContext> SwitchState(TStateEnum nextState)
        {
            if (!CheckTransitionAllowed(nextState) && CurrentBaseState != null)
            {
                return null;
            }

            ResetAllowedTransitions();
            
            _previousBaseState = CurrentBaseState;
            
            CurrentBaseState = States[nextState];

            _previousBaseState?.ExitState();

            CurrentBaseState.EnterState();
            
            CurrentState = nextState;
            
            return this;
        }
    }

    public interface IEnterStateHandle<TState> : IGlobalSubscriber 
    {
        void EnterState();
    }

    public interface IExitStateHandle<TState> : IGlobalSubscriber 
    {
        void ExitState();
    }
}