using UnityEngine;

public class BgmGyroRotator : MonoBehaviour
{
    public RectTransform target;
    public float maxRotation = 3f;
    public float rotX = 1f;
    public float rotY = 1f;
    public float rotZ = 0.35f;
    public float smooth = 8f;
    public bool useUnscaled = true;

    private Quaternion baseRotation;
    private bool baseCaptured = false;

    private void Awake()
    {
        if (target == null) target = transform as RectTransform;
        CaptureBase();
    }

    private void OnEnable()
    {
        if (target == null) target = transform as RectTransform;
        CaptureBase();
    }

    private void CaptureBase()
    {
        if (target == null) return;
        baseRotation = target.localRotation;
        baseCaptured = true;
    }

    private void Update()
    {
        if (target == null) return;
        if (!baseCaptured) CaptureBase();

        Vector2 norm = GetMouseNormalized();
        Vector3 delta = new Vector3(-norm.y * maxRotation * rotX,
                                    norm.x * maxRotation * rotY,
                                    norm.x * maxRotation * rotZ);
        Quaternion targetRot = baseRotation * Quaternion.Euler(delta);
        float dt = useUnscaled ? Time.unscaledDeltaTime : Time.deltaTime;
        float t = 1f - Mathf.Exp(-Mathf.Max(0.01f, smooth) * dt);
        target.localRotation = Quaternion.Slerp(target.localRotation, targetRot, t);
    }

    private static Vector2 GetMouseNormalized()
    {
        Vector2 pos = Input.mousePosition;
        if (Screen.width <= 1 || Screen.height <= 1)
            return Vector2.zero;
        float x = (pos.x / Screen.width) * 2f - 1f;
        float y = (pos.y / Screen.height) * 2f - 1f;
        return new Vector2(Mathf.Clamp(x, -1f, 1f), Mathf.Clamp(y, -1f, 1f));
    }
}