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

using System;
using System.Collections.Generic;
using System.Threading;
using Cysharp.Threading.Tasks;

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

        public TStateEnum CurrentState { get; protected set; }
        public TStateEnum NextState { 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();
        protected TStateMachineContext StateMachineContext { get; }
        
        private readonly SemaphoreSlim _stateLock = new (1, 1);

        public virtual async UniTask SwitchState(TStateEnum nextState)
        {
            await _stateLock.WaitAsync();

            try
            {
                NextState = nextState;

                if (CurrentBaseState != null) await CurrentBaseState.ExitState();

                var newState = States[nextState];
                await newState.EnterState();

                CurrentBaseState = newState;
                CurrentState = nextState;
                NextState = default;

                // Logger
            }
            finally
            {
                _stateLock.Release();
            }
        }
    }
}