using UnityEngine;

namespace WL.UI
{
    /// <summary>
    /// RectTransform 을 기기 Safe Area(노치·홈 인디케이터 제외 영역)에 맞춘다.
    /// HUD 루트 패널에 부착한다.
    /// </summary>
    [RequireComponent(typeof(RectTransform))]
    [DisallowMultipleComponent]
    public class SafeAreaFitter : MonoBehaviour
    {
        [Tooltip("가로 방향에도 Safe Area 를 적용한다")]
        [SerializeField] private bool applyHorizontal = true;
        [Tooltip("세로 방향에도 Safe Area 를 적용한다")]
        [SerializeField] private bool applyVertical = true;

        private RectTransform _rt;
        private Rect _lastSafeArea = new Rect(0f, 0f, 0f, 0f);
        private Vector2Int _lastResolution = Vector2Int.zero;

        private void Awake() { _rt = GetComponent<RectTransform>(); Apply(); }
        private void OnEnable() { Apply(); }

        private void Update()
        {
            if (Screen.safeArea != _lastSafeArea || Screen.width != _lastResolution.x || Screen.height != _lastResolution.y)
                Apply();
        }

        public void Apply()
        {
            if (_rt == null) _rt = GetComponent<RectTransform>();
            if (Screen.width <= 0 || Screen.height <= 0) return;

            Rect safe = Screen.safeArea;
            _lastSafeArea = safe;
            _lastResolution = new Vector2Int(Screen.width, Screen.height);

            Vector2 min = new Vector2(safe.xMin / Screen.width, safe.yMin / Screen.height);
            Vector2 max = new Vector2(safe.xMax / Screen.width, safe.yMax / Screen.height);
            if (!applyHorizontal) { min.x = 0f; max.x = 1f; }
            if (!applyVertical) { min.y = 0f; max.y = 1f; }

            _rt.anchorMin = min;
            _rt.anchorMax = max;
            _rt.offsetMin = Vector2.zero;
            _rt.offsetMax = Vector2.zero;
        }
    }
}