using UnityEngine;
using UnityEditor;
using UnityEngine.Playables;
using System.Collections.Generic;

[ExecuteAlways]
public class EditorTimelinePathTracker : MonoBehaviour
{
    public Color pathColor = Color.green;
    public int maxPoints = 1000;

    private List<Vector3> pathPoints = new List<Vector3>();
    private List<float> timeStamps = new List<float>();
    private Vector3 lastPosition;
    private PlayableDirector director;

    private void OnEnable()
    {
        director = GetComponent<PlayableDirector>();

#if UNITY_EDITOR
        EditorApplication.update += EditorUpdate;
#endif
        pathPoints.Clear();
        timeStamps.Clear();
        lastPosition = transform.position;
        pathPoints.Add(lastPosition);
        timeStamps.Add(GetTimelineTime());
    }

    private void OnDisable()
    {
#if UNITY_EDITOR
        EditorApplication.update -= EditorUpdate;
#endif
    }

    private float GetTimelineTime()
    {
        if (director != null && director.playableGraph.IsValid())
        {
            return (float)director.time;
        }
        return Time.realtimeSinceStartup; // fallback 时间戳
    }

    private float GetTimelineDuration()
    {
        return director != null ? (float)director.duration : -1f;
    }

    private void EditorUpdate()
    {
        if (Application.isPlaying)
            return;

        Vector3 currentPosition = transform.position;
        float currentTime = GetTimelineTime();

        if (Vector3.Distance(currentPosition, lastPosition) > 0.01f)
        {
            lastPosition = currentPosition;
            pathPoints.Add(currentPosition);
            timeStamps.Add(currentTime);

            if (pathPoints.Count > maxPoints)
            {
                pathPoints.RemoveAt(0);
                timeStamps.RemoveAt(0);
            }

            SceneView.RepaintAll();
        }
    }

    private void OnDrawGizmos()
    {
        if (pathPoints == null || pathPoints.Count < 2)
            return;

        float timelineDuration = GetTimelineDuration();
        bool useTimeline = director != null && timelineDuration > 0;

        Gizmos.color = pathColor;
        for (int i = 1; i < pathPoints.Count; i++)
        {
            // 若启用Timeline，仅绘制在时间范围内的轨迹
            if (useTimeline && (timeStamps[i - 1] > timelineDuration || timeStamps[i] > timelineDuration))
                continue;

            Gizmos.DrawLine(pathPoints[i - 1], pathPoints[i]);
        }
    }
}