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Assets/BITKit/Core/StateMachine/AsyncStateMachine.cs

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+using System;
+using System.Collections.Generic;
+using System.Threading;
+using Cysharp.Threading.Tasks;
+using Microsoft.Extensions.DependencyInjection;
+using Random = UnityEngine.Random;
+
+namespace BITKit.StateMachine
+{
+    /// <summary>
+    /// 动态异步状态机
+    /// </summary>
+    /// <typeparam name="T">异步状态</typeparam>
+    public class AsyncStateMachine<T>:IStateMachine<T> ,IDisposable where T  : class, IStateAsync
+    {
+        private readonly IServiceProvider _serviceProvider;
+        public AsyncStateMachine(IServiceProvider serviceProvider)
+        {
+            _serviceProvider = serviceProvider;
+        }
+        public AsyncStateMachine()
+        {
+            _serviceProvider = new ServiceCollection().BuildServiceProvider();
+        }
+
+        public bool Enabled { get; set; } = true;
+        public T CurrentState { get;private set; }
+        public T NextOrCurrentState => _nextTargetState.IfNotAllow(CurrentState);
+        private T _nextState;
+        public event Action<T, T> OnStateChanging;
+        public event Action<T, T> OnStateChanged;
+        public event Action<T> OnStateRegistered;
+        public IReadOnlyDictionary<int, T> Dictionary => _dictionary;
+        public event Action<T> OnStateUnRegistered;
+        public IDictionary<Type, T> StateDictionary { get; } = new Dictionary<Type, T>();
+        public readonly ValidHandle IsBusy=new();
+        private readonly CancellationTokenSource _cancellationTokenSource=new();
+        private readonly Dictionary<int, T> _dictionary = new();
+        private readonly Optional<T> _nextTargetState = new();
+        public async void Initialize()
+        {
+            await IsBusy;
+            if(_cancellationTokenSource.IsCancellationRequested)return;
+            using var _ = IsBusy.GetHandle();
+            foreach (var (_,value) in StateDictionary)
+            {
+                await value.InitializeAsync();
+                value.Initialize();
+            }
+        }
+
+
+        public async void UpdateState(float deltaTime)
+        {
+            if (CurrentState is null) return;
+            using var _ = IsBusy.GetHandle();
+            await CurrentState.OnStateUpdateAsync(deltaTime);
+            CurrentState.OnStateUpdate(deltaTime);
+        }
+
+
+        public async void DisposeState()
+        {
+            await IsBusy;
+            if(_cancellationTokenSource.IsCancellationRequested)return;
+            if (CurrentState is null) return;
+            using var _ = IsBusy.GetHandle();
+            await CurrentState.OnStateExitAsync(CurrentState, null);
+            if(_cancellationTokenSource.IsCancellationRequested)return;
+            CurrentState.OnStateExit(CurrentState, null);
+            CurrentState = null;
+        }
+
+        public T TransitionState<TState>() where TState : T
+        {
+            T nextState;
+            foreach (var (type, value) in Dictionary)
+            {
+                if ((typeof(TState) == value.GetType()) is false) continue;
+                
+                nextState = value;
+                
+                TransitionState(nextState);
+                return nextState;
+            }
+            nextState = _serviceProvider.GetRequiredService<TState>();
+
+            return  TransitionState(nextState);;
+        }
+
+        public async UniTask TransitionStateAsync(T nextState)
+        {
+            if (nextState is not null)
+            {
+                if (nextState.Identifier == 0)
+                {
+                    nextState.Identifier = nextState.GetHashCode();
+                }
+            }
+            if (Equals(nextState, CurrentState)) return;
+            if(_nextTargetState.Allow && Equals(_nextTargetState.Value,nextState))return;
+            if (_nextTargetState.Allow)
+            {
+                _nextTargetState.Value = nextState;
+                return;
+            }
+            _nextTargetState.SetValueThenAllow(nextState);
+            await IsBusy;
+            if(_cancellationTokenSource.IsCancellationRequested)return;
+            using var _ = IsBusy.GetHandle();
+            OnStateChanging?.Invoke(CurrentState,nextState);
+            if (_dictionary.TryAdd(nextState.Identifier, nextState))
+            {
+                await nextState.InitializeAsync();
+                if(_cancellationTokenSource.IsCancellationRequested)return;
+                nextState.Initialize();
+            }
+            if (CurrentState is not null)
+            {
+                CurrentState.Enabled = false;
+                await CurrentState.OnStateExitAsync(CurrentState, nextState);
+                if(_cancellationTokenSource.IsCancellationRequested)return;
+                CurrentState.OnStateExit(CurrentState,nextState);
+            }
+
+            var tempState = CurrentState;
+            CurrentState = _nextTargetState.Value;
+            _nextTargetState.Clear();
+            nextState.Enabled = true;
+            await nextState.OnStateEntryAsync(tempState);
+            if(_cancellationTokenSource.IsCancellationRequested)return;
+            nextState.OnStateEntry(tempState);
+           OnStateChanged?.Invoke(tempState,nextState);
+    
+        }
+        public T TransitionState(T nextState)
+        {
+            TransitionStateAsync(nextState).Forget();
+            return nextState;
+        }
+
+        public async void UnRegister(T newState)
+        {
+            if (newState is null) return;
+            if (Dictionary.ContainsKey(newState.Identifier) is false) return;
+            _dictionary.Remove(newState.Identifier);
+
+            if (Equals(CurrentState, newState))
+            {
+                await CurrentState.OnStateExitAsync(CurrentState, null);
+                CurrentState.OnStateExit(CurrentState, null);
+                if (CurrentState is IAsyncDisposable asyncDisposable)
+                {
+                    await asyncDisposable.DisposeAsync();
+                }
+                if (CurrentState is IDisposable disposable)
+                {
+                    disposable.Dispose();
+                }
+                CurrentState = null;
+            }
+            
+            OnStateUnRegistered?.Invoke(newState);
+        }
+        public void Dispose()
+        {
+            if(_isDisposed)return;
+            _cancellationTokenSource.Cancel();
+            _cancellationTokenSource.Dispose();
+            _isDisposed = true;
+        }
+
+        private bool _isDisposed;
+    }
+
+}