refactor(state): 重构状态机实现以支持状态历史记录和线程安全

- 在销毁时添加当前状态退出和所有状态清理逻辑
- 向IStateMachine接口添加状态检查、获取、历史记录等新方法
- 实现线程安全的状态机，添加锁保护并发访问
- 添加状态历史记录功能，支持最大历史数量限制
- 实现GoBack状态回退功能和状态转换验证
- 添加状态切换前后的回调方法
- 在注销状态时从历史记录中移除相关引用
- 添加Unregister方法中的状态转换验证逻辑

GFramework.Core.Abstractions/state/IStateMachine.cs

@@ -1,4 +1,7 @@
-namespace GFramework.Core.Abstractions.state;
+using System;
+using System.Collections.Generic;
+
+namespace GFramework.Core.Abstractions.state;
 
 /// <summary>
 /// 状态机接口，用于管理状态的注册、切换和验证
@@ -34,4 +37,47 @@ public interface IStateMachine
     /// </summary>
     /// <typeparam name="T">要切换到的状态类型，必须实现IState接口</typeparam>
     void ChangeTo<T>() where T : IState;
+
+    /// <summary>
+    /// 检查指定类型的状态是否已注册
+    /// </summary>
+    /// <typeparam name="T">要检查的状态类型</typeparam>
+    /// <returns>如果状态已注册则返回true，否则返回false</returns>
+    bool IsRegistered<T>() where T : IState;
+
+    /// <summary>
+    /// 获取指定类型的已注册状态实例
+    /// </summary>
+    /// <typeparam name="T">要获取的状态类型</typeparam>
+    /// <returns>如果状态存在则返回对应实例，否则返回null</returns>
+    T? GetState<T>() where T : class, IState;
+
+    /// <summary>
+    /// 获取所有已注册状态的类型集合
+    /// </summary>
+    /// <returns>包含所有已注册状态类型的枚举器</returns>
+    IEnumerable<Type> GetRegisteredStateTypes();
+
+    /// <summary>
+    /// 获取上一个状态
+    /// </summary>
+    /// <returns>如果历史记录存在则返回上一个状态，否则返回null</returns>
+    IState? GetPreviousState();
+
+    /// <summary>
+    /// 获取状态历史记录
+    /// </summary>
+    /// <returns>状态历史记录的只读副本</returns>
+    IReadOnlyList<IState> GetStateHistory();
+
+    /// <summary>
+    /// 回退到上一个状态
+    /// </summary>
+    /// <returns>如果成功回退则返回true，否则返回false</returns>
+    bool GoBack();
+
+    /// <summary>
+    /// 清空状态历史记录
+    /// </summary>
+    void ClearHistory();
 }

GFramework.Core.Tests/tests/SyncArchitectureTests.cs

@@ -1,4 +1,5 @@
-using GFramework.Core.Abstractions.enums;
+using System;
+using GFramework.Core.Abstractions.enums;
 using GFramework.Core.architecture;
 using GFramework.Core.Tests.architecture;
 using GFramework.Core.Tests.events;

GFramework.Core/state/ContextAwareStateMachine.cs

@@ -61,6 +61,20 @@ public class ContextAwareStateMachine : StateMachine, ISystem
     /// </summary>
     public virtual void Destroy()
     {
+        // 退出当前状态
+        if (Current != null)
+        {
+            Current.OnExit(null);
+            Current = null;
+        }
+
+        // 清理所有状态
+        foreach (var state in States.Values.OfType<IDisposable>())
+        {
+            state.Dispose();
+        }
+
+        States.Clear();
     }
 
     /// <summary>

GFramework.Core/state/StateMachine.cs

@@ -5,8 +5,11 @@ namespace GFramework.Core.state;
 /// <summary>
 /// 状态机实现类，用于管理状态的注册、切换和生命周期
 /// </summary>
-public class StateMachine : IStateMachine
+public class StateMachine(int maxHistorySize = 10) : IStateMachine
 {
+    private readonly object _lock = new();
+    private readonly Stack<IState> _stateHistory = new();
+
     /// <summary>
     /// 存储所有已注册状态的字典，键为状态类型，值为状态实例
     /// </summary>
@@ -15,14 +18,19 @@ public class StateMachine : IStateMachine
     /// <summary>
     /// 获取当前激活的状态
     /// </summary>
-    public IState? Current { get; private set; }
+    public IState? Current { get; protected set; }
 
     /// <summary>
     /// 注册一个状态到状态机中
     /// </summary>
     /// <param name="state">要注册的状态实例</param>
     public void Register(IState state)
-        => States[state.GetType()] = state;
+    {
+        lock (_lock)
+        {
+            States[state.GetType()] = state;
+        }
+    }
 
     /// <summary>
     /// 从状态机中注销指定类型的状态
@@ -30,17 +38,28 @@ public class StateMachine : IStateMachine
     /// <typeparam name="T">要注销的状态类型</typeparam>
     public void Unregister<T>() where T : IState
     {
-        var type = typeof(T);
-        if (!States.TryGetValue(type, out var state)) return;
-
-        // 如果当前状态是要注销的状态，则先执行退出逻辑
-        if (Current == state)
+        lock (_lock)
         {
-            Current.OnExit(null);
-            Current = null;
-        }
+            var type = typeof(T);
+            if (!States.TryGetValue(type, out var state)) return;
 
-        States.Remove(type);
+            // 如果当前状态是要注销的状态，则先执行退出逻辑
+            if (Current == state)
+            {
+                Current.OnExit(null);
+                Current = null;
+            }
+
+            // 从历史记录中移除该状态的所有引用
+            var tempStack = new Stack<IState>(_stateHistory.Reverse());
+            _stateHistory.Clear();
+            foreach (var historyState in tempStack.Where(s => s != state))
+            {
+                _stateHistory.Push(historyState);
+            }
+
+            States.Remove(type);
+        }
     }
 
     /// <summary>
@@ -63,10 +82,117 @@ public class StateMachine : IStateMachine
     /// <exception cref="InvalidOperationException">当目标状态未注册时抛出</exception>
     public void ChangeTo<T>() where T : IState
     {
-        if (!States.TryGetValue(typeof(T), out var target))
-            throw new InvalidOperationException("State not registered.");
+        lock (_lock)
+        {
+            // 检查目标状态是否已注册
+            if (!States.TryGetValue(typeof(T), out var target))
+                throw new InvalidOperationException("State not registered.");
 
-        ChangeInternal(target);
+            // 验证当前状态是否可以转换到目标状态
+            if (Current != null && !Current.CanTransitionTo(target))
+                throw new InvalidOperationException(
+                    $"Cannot transition from {Current.GetType().Name} to {typeof(T).Name}");
+
+            ChangeInternal(target);
+        }
+    }
+
+    /// <summary>
+    /// 检查指定类型的状态是否已注册
+    /// </summary>
+    /// <typeparam name="T">要检查的状态类型</typeparam>
+    /// <returns>如果状态已注册则返回true，否则返回false</returns>
+    public bool IsRegistered<T>() where T : IState => States.ContainsKey(typeof(T));
+
+    /// <summary>
+    /// 获取指定类型的已注册状态实例
+    /// </summary>
+    /// <typeparam name="T">要获取的状态类型</typeparam>
+    /// <returns>如果状态存在则返回对应实例，否则返回null</returns>
+    public T? GetState<T>() where T : class, IState => States.TryGetValue(typeof(T), out var state) ? state as T : null;
+
+    /// <summary>
+    /// 获取所有已注册状态的类型集合
+    /// </summary>
+    /// <returns>包含所有已注册状态类型的枚举器</returns>
+    public IEnumerable<Type> GetRegisteredStateTypes() => States.Keys;
+
+    /// <summary>
+    /// 获取上一个状态
+    /// </summary>
+    /// <returns>如果历史记录存在则返回上一个状态，否则返回null</returns>
+    public IState? GetPreviousState()
+    {
+        lock (_lock)
+        {
+            return _stateHistory.Count > 0 ? _stateHistory.Peek() : null;
+        }
+    }
+
+    /// <summary>
+    /// 获取状态历史记录
+    /// </summary>
+    /// <returns>状态历史记录的只读副本，从最近到最远排序</returns>
+    public IReadOnlyList<IState> GetStateHistory()
+    {
+        lock (_lock)
+        {
+            return _stateHistory.ToList().AsReadOnly();
+        }
+    }
+
+    /// <summary>
+    /// 回退到上一个状态
+    /// </summary>
+    /// <returns>如果成功回退则返回true，否则返回false</returns>
+    public bool GoBack()
+    {
+        lock (_lock)
+        {
+            if (_stateHistory.Count == 0) return false;
+
+            var previousState = _stateHistory.Pop();
+
+            // 检查上一个状态是否仍然注册
+            if (!States.ContainsValue(previousState))
+            {
+                // 如果状态已被注销，继续尝试更早的状态
+                return GoBack();
+            }
+
+            // 回退时不添加到历史记录
+            ChangeInternalWithoutHistory(previousState);
+            return true;
+        }
+    }
+
+    /// <summary>
+    /// 清空状态历史记录
+    /// </summary>
+    public void ClearHistory()
+    {
+        lock (_lock)
+        {
+            _stateHistory.Clear();
+        }
+    }
+
+    /// <summary>
+    /// 内部状态切换方法（不记录历史），用于回退操作
+    /// </summary>
+    /// <param name="next">下一个状态实例</param>
+    protected virtual void ChangeInternalWithoutHistory(IState next)
+    {
+        if (Current == next) return;
+
+        var old = Current;
+        OnStateChanging(old, next);
+
+        old?.OnExit(next);
+        Current = next;
+        Current.OnEnter(old);
+
+        OnStateChanged(old, Current);
     }
 
     /// <summary>
@@ -75,13 +201,68 @@ public class StateMachine : IStateMachine
     /// <param name="next">下一个状态实例</param>
     protected virtual void ChangeInternal(IState next)
     {
+        // 检查是否为相同状态，避免不必要的切换
         if (Current == next) return;
-        if (Current != null && !Current.CanTransitionTo(next)) return;
+
+        // 验证当前状态是否允许切换到目标状态
+        if (Current != null && !Current.CanTransitionTo(next))
+        {
+            OnTransitionRejected(Current, next);
+            return;
+        }
 
         var old = Current;
-        old?.OnExit(next);
+        OnStateChanging(old, next);
 
+        // 将当前状态添加到历史记录
+        if (Current != null)
+        {
+            _stateHistory.Push(Current);
+
+            // 限制历史记录大小
+            if (_stateHistory.Count > maxHistorySize)
+            {
+                // 移除最旧的记录（栈底元素）
+                var tempStack = new Stack<IState>(_stateHistory.Reverse().Skip(1));
+                _stateHistory.Clear();
+                foreach (var state in tempStack.Reverse())
+                {
+                    _stateHistory.Push(state);
+                }
+            }
+        }
+
+        old?.OnExit(next);
         Current = next;
         Current.OnEnter(old);
+
+        OnStateChanged(old, Current);
+    }
+
+    /// <summary>
+    /// 当状态转换被拒绝时的回调方法
+    /// </summary>
+    /// <param name="from">源状态</param>
+    /// <param name="to">目标状态</param>
+    protected virtual void OnTransitionRejected(IState from, IState to)
+    {
+    }
+
+    /// <summary>
+    /// 当状态即将发生改变时的回调方法
+    /// </summary>
+    /// <param name="from">源状态</param>
+    /// <param name="to">目标状态</param>
+    protected virtual void OnStateChanging(IState? from, IState to)
+    {
+    }
+
+    /// <summary>
+    /// 当状态改变完成后的回调方法
+    /// </summary>
+    /// <param name="from">源状态</param>
+    /// <param name="to">目标状态</param>
+    protected virtual void OnStateChanged(IState? from, IState? to)
+    {
     }
 }