using GFramework.Core.Abstractions.architecture;
using GFramework.Core.Abstractions.enums;
using GFramework.Core.Abstractions.rule;
using GFramework.Core.Abstractions.state;
using GFramework.Core.Abstractions.system;
using GFramework.Core.extensions;

namespace GFramework.Core.state;

/// <summary>
/// 上下文感知状态机，继承自StateMachine并实现ISystem接口
/// 该状态机能够感知架构上下文，并在状态切换时发送状态变更事件
/// </summary>
public class ContextAwareStateMachine : StateMachine, ISystem
{
    /// <summary>
    /// 架构上下文对象，用于提供系统运行所需的上下文信息
    /// </summary>
    protected IArchitectureContext Context = null!;

    /// <summary>
    /// 设置架构上下文的方法
    /// </summary>
    /// <param name="context">要设置的架构上下文对象</param>
    public void SetContext(IArchitectureContext context)
    {
        Context = context;
    }

    /// <summary>
    /// 获取当前架构上下文的方法
    /// </summary>
    /// <returns>当前的架构上下文对象</returns>
    public IArchitectureContext GetContext()
    {
        return Context;
    }

    /// <summary>
    /// 处理架构生命周期阶段的方法
    /// </summary>
    /// <param name="phase">当前所处的架构生命周期阶段</param>
    public virtual void OnArchitecturePhase(ArchitecturePhase phase)
    {
    }

    /// <summary>
    /// 初始化方法，在系统启动时调用
    /// 遍历所有状态实例，为实现了IContextAware接口的状态设置上下文
    /// </summary>
    public virtual void Init()
    {
        foreach (var state in States.Values.OfType<IContextAware>())
        {
            state.SetContext(Context);
        }
    }

    /// <summary>
    /// 销毁方法，在系统关闭时调用
    /// </summary>
    public virtual void Destroy()
    {
    }

    /// <summary>
    /// 内部状态切换方法，重写基类方法以添加状态变更事件通知功能
    /// </summary>
    /// <param name="next">要切换到的下一个状态</param>
    protected override void ChangeInternal(IState next)
    {
        var old = Current;
        base.ChangeInternal(next);

        // 发送状态变更事件，通知监听者状态已发生改变
        this.SendEvent(new StateChangedEvent
        {
            OldState = old,
            NewState = Current
        });
    }
}