using System;
using System.Collections.Generic;
using UnityEngine;

public class UnityMainThreadDispatcher : MonoBehaviour
{
    private static UnityMainThreadDispatcher _instance;
    private readonly Queue<Action> _actionQueue = new Queue<Action>();

    // 获取单例实例
    public static UnityMainThreadDispatcher Instance
    {
        get
        {
            if (_instance == null)
            {
                // 查找现有实例
                _instance = FindObjectOfType<UnityMainThreadDispatcher>();
                
                // 如果没有实例则创建一个
                if (_instance == null)
                {
                    GameObject obj = new GameObject("UnityMainThreadDispatcher");
                    _instance = obj.AddComponent<UnityMainThreadDispatcher>();
                    DontDestroyOnLoad(obj); // 跨场景保留
                }
            }
            return _instance;
        }
    }

    private void Update()
    {
        // 每帧执行队列中的所有回调（在主线程）
        lock (_actionQueue)
        {
            while (_actionQueue.Count > 0)
            {
                _actionQueue.Dequeue().Invoke();
            }
        }
    }

    // 将行动添加到主线程执行队列
    public void Enqueue(Action action)
    {
        lock (_actionQueue)
        {
            _actionQueue.Enqueue(action);
        }
    }
}