using UnityEngine;
using System.Collections.Generic;

public class ArrowCircleMotion : MonoBehaviour
{
    public Transform targetPoint;              // 圆心
    public float radius = 1f;                  // 半径
    public int arrowCount = 5;                 // 箭头数量
    public GameObject arrowPrefab;             // 箭头预制体
    public float speed = 30f;                  // 旋转速度（度/秒）
    public Vector3 eulerRotation;              // 圆的方向（圆的法线朝向）

    private List<Transform> arrows = new List<Transform>();
    private List<float> angles = new List<float>();
    private Quaternion circleRotation;
    public float modelForwardOffset = -90f; // 若模型默认朝 Y+

    void Start()
    {
        if (!arrowPrefab || !targetPoint) return;

        circleRotation = Quaternion.Euler(eulerRotation);

        for (int i = 0; i < arrowCount; i++)
        {
            GameObject arrow = Instantiate(arrowPrefab, transform);
            arrows.Add(arrow.transform);

            float angle = (360f / arrowCount) * i;
            angles.Add(angle);
        }
    }

    void Update()
    {
        circleRotation = Quaternion.Euler(eulerRotation);

        for (int i = 0; i < arrows.Count; i++)
        {
            // 更新角度
            angles[i] += -speed * Time.deltaTime;
            angles[i] %= 360f;

            float angle = angles[i];
            float selfRotateAngle = angle - 90f;  // 自转角度，给Z轴旋转用（修正模型朝向）

            // 计算位置
            float rad = angle * Mathf.Deg2Rad;
            Vector3 localPos = new Vector3(Mathf.Cos(rad) * radius, Mathf.Sin(rad) * radius, 0f);
            Vector3 worldPos = targetPoint.position + circleRotation * localPos;
            arrows[i].position = worldPos;

            // 速度为负时，箭头绕Z轴旋转180度反向
            if (speed < 0f)
            {
                selfRotateAngle = angle + 90f;
                Quaternion flipRotation = Quaternion.AngleAxis(selfRotateAngle, Vector3.forward);
                arrows[i].rotation = circleRotation * flipRotation;
            }
            else
            {
                selfRotateAngle = angle - 90f;
                // 计算旋转（公转方向 + 自转修正）
                Quaternion zSelfRotation = Quaternion.AngleAxis(selfRotateAngle, Vector3.forward);
                arrows[i].rotation = circleRotation * zSelfRotation;
            }
          
        }
    }
}