using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Playables;
using Object = UnityEngine.Object;

/// <summary>
/// 对Timeline中的轨道和GameObject进行随机打乱绑定
/// </summary>
public class TimelineRandomScript : MonoBehaviour
{
    //关联的Timeline的控制器
    public PlayableDirector director;


    private void Awake()
    {
        if (director == null)
        {
            director = GetComponent<PlayableDirector>();
        }
        if (director != null)
        {
            //把自动播放给关掉,担心在播放中时,换对象,会导致异常出现
            director.playOnAwake = false;
        }
    }
    // Start is called before the first frame update   
    private void Start()
    {
        if (director == null)
        {
            director = GetComponent<PlayableDirector>();
        }

        if (director != null)
        {
            List<Object> tracks = new List<Object>();
            List<Object> actors = new List<Object>();
            var e = director.playableAsset.outputs.GetEnumerator();
            while (e.MoveNext())
            {
                tracks.Add(e.Current.sourceObject);
                actors.Add(director.GetGenericBinding(e.Current.sourceObject));
            }

            RandomList(actors);

            for (int i = 0; i < tracks.Count; i++)
            {
                director.SetGenericBinding(tracks[i], actors[i]);
            }
            director.Play();
        }
    }

    //对一个列表进行随机乱序排列
    private void RandomList(List<Object> actors)
    {
        int max = actors.Count;
        for (int i = actors.Count - 1; i >=0; i--)
        {
            int goalIdx = UnityEngine.Random.Range(0, i+1);
            var o = actors[i];
            actors[i] = actors[goalIdx];
            actors[goalIdx] = o;
        }
    }
}