using UnityEngine;

public class VRUIDoorFaceFollow : MonoBehaviour
{
    [SerializeField] private Transform vrCameraTransform;

    [Header("配置・追従パラメータ")]
    [SerializeField] private float forwardDistance = 0.5f;
    [SerializeField] private float heightOffset = -0.1f;
    [SerializeField] private float followSpeed = 5.0f;

    private bool wasActiveLastFrame;

    private void Start()
    {
        if (vrCameraTransform == null && Camera.main != null)
        {
            vrCameraTransform = Camera.main.transform;
        }
    }

    private void LateUpdate()
    {
        if (vrCameraTransform == null) return;

        if (!wasActiveLastFrame)
        {
            SetInitialPosition();
            wasActiveLastFrame = true;
            return;
        }

        SmoothFollowPlayer();
    }

    private void OnDisable()
    {
        wasActiveLastFrame = false;
    }

    private void SetInitialPosition()
    {
        Vector3 targetPosition = vrCameraTransform.position + (vrCameraTransform.forward * forwardDistance);
        targetPosition.y += heightOffset;

        transform.position = targetPosition;
        transform.LookAt(vrCameraTransform.position);
        transform.Rotate(0, 180, 0);
    }

    private void SmoothFollowPlayer()
    {
        Vector3 targetPosition = vrCameraTransform.position + (vrCameraTransform.forward * forwardDistance);
        targetPosition.y += heightOffset;

        transform.position = Vector3.Lerp(transform.position, targetPosition, Time.unscaledDeltaTime * followSpeed);

        Quaternion targetRotation = Quaternion.LookRotation(transform.position - vrCameraTransform.position);
        transform.rotation = Quaternion.Slerp(transform.rotation, targetRotation, Time.unscaledDeltaTime * followSpeed);
    }
}