#nullable enable
using System;
using UnityEngine;
using UnityEngine.UIElements;

namespace UVC.UIToolkit
{
    /// <summary>
    /// Bounds(경계 상자) 입력 필드 컴포넌트.
    /// Unity BoundsField를 래핑하여 커스텀 스타일을 적용합니다.
    /// 3D 공간에서 객체의 경계를 정의하는 Center(중심점)와 Extents(크기)를 입력받습니다.
    /// </summary>
    /// <remarks>
    /// <para><b>Bounds란?</b></para>
    /// <para>Bounds는 3D 공간에서 축 정렬 경계 상자(AABB)를 나타냅니다.</para>
    /// <para>- Center: 경계 상자의 중심점 (Vector3)</para>
    /// <para>- Extents: 중심에서 각 축 방향으로의 거리 (Vector3), Size의 절반 값</para>
    /// <para>- Size: 경계 상자의 전체 크기 (Extents * 2)</para>
    /// </remarks>
    /// <example>
    /// <para><b>C# 코드에서 사용:</b></para>
    /// <code>
    /// // 기본 Bounds 필드 생성
    /// var boundsField = new UTKBoundsField();
    /// boundsField.label = "충돌 영역";
    ///
    /// // 초기값 설정 (중심점: 0,1,0 / 크기: 2,2,2)
    /// boundsField.Value = new Bounds(
    ///     new Vector3(0, 1, 0),      // center
    ///     new Vector3(2, 2, 2)       // size (extents의 2배)
    /// );
    ///
    /// // 값 변경 이벤트 처리
    /// boundsField.OnValueChanged += (bounds) => {
    ///     Debug.Log($"중심점: {bounds.center}");
    ///     Debug.Log($"크기: {bounds.size}");
    ///     Debug.Log($"최소점: {bounds.min}, 최대점: {bounds.max}");
    /// };
    ///
    /// // 라벨 커스터마이징
    /// boundsField.CenterLabel = "중심";
    /// boundsField.ExtentsLabel = "범위";
    /// boundsField.XLabel = "가로";
    /// boundsField.YLabel = "높이";
    /// boundsField.ZLabel = "깊이";
    ///
    /// // 비활성화
    /// boundsField.IsEnabled = false;
    ///
    /// // 읽기 전용 (사용자가 수정할 수 없음)
    /// var readOnlyField = new UTKBoundsField("고정 경계");
    /// readOnlyField.Value = new Bounds(Vector3.zero, Vector3.one);
    /// readOnlyField.IsReadOnly = true;
    /// </code>
    /// <para><b>UXML에서 사용:</b></para>
    /// <code>
    /// <!-- 네임스페이스 선언 -->
    /// <UXML xmlns:utk="UVC.UIToolkit">
    ///     <!-- 기본 Bounds 필드 -->
    ///     <utk:UTKBoundsField label="경계 영역" />
    ///
    ///     <!-- 커스텀 라벨 -->
    ///     <utk:UTKBoundsField
    ///         label="충돌 박스"
    ///         center-label="위치"
    ///         extents-label="크기" />
    ///
    ///     <!-- 비활성화 -->
    ///     <utk:UTKBoundsField label="비활성화" is-enabled="false" />
    ///
    ///     <!-- 읽기 전용 -->
    ///     <utk:UTKBoundsField label="고정 경계" is-readonly="true" />
    /// </UXML>
    /// </code>
    /// <para><b>실제 활용 예시:</b></para>
    /// <code>
    /// // 게임 오브젝트의 콜라이더 경계 설정
    /// var colliderBounds = new UTKBoundsField("콜라이더 경계");
    /// colliderBounds.OnValueChanged += (bounds) => {
    ///     var boxCollider = targetObject.GetComponent<BoxCollider>();
    ///     if (boxCollider != null)
    ///     {
    ///         boxCollider.center = bounds.center;
    ///         boxCollider.size = bounds.size;
    ///     }
    /// };
    /// </code>
    /// </example>
    [UxmlElement]
    public partial class UTKBoundsField : BoundsField, IDisposable
    {
        #region Constants
        private const string USS_PATH = "UIToolkit/Input/UTKBoundsField";
        #endregion

        #region Fields
        private bool _disposed;
        private bool _isEnabled = true;
        private bool _isReadOnly;
        private string _centerLabel = "Center";
        private string _extentsLabel = "Extents";
        private string _xLabel = "X";
        private string _yLabel = "Y";
        private string _zLabel = "Z";
        #endregion

        #region Events
        /// <summary>값 변경 이벤트</summary>
        public event Action<Bounds>? OnValueChanged;
        #endregion

        #region Properties
        /// <summary>활성화 상태</summary>
        [UxmlAttribute("is-enabled")]
        public bool IsEnabled
        {
            get => _isEnabled;
            set
            {
                _isEnabled = value;
                SetEnabled(value);
                EnableInClassList("utk-boundsfield--disabled", !value);
            }
        }

        /// <summary>현재 값</summary>
        public Bounds Value
        {
            get => value;
            set => this.value = value;
        }

        /// <summary>Center 라벨</summary>
        [UxmlAttribute("center-label")]
        public string CenterLabel
        {
            get => _centerLabel;
            set
            {
                _centerLabel = value;
                UpdateAxisLabels();
            }
        }

        /// <summary>Extents 라벨</summary>
        [UxmlAttribute("extents-label")]
        public string ExtentsLabel
        {
            get => _extentsLabel;
            set
            {
                _extentsLabel = value;
                UpdateAxisLabels();
            }
        }

        /// <summary>X축 라벨</summary>
        [UxmlAttribute("x-label")]
        public string XLabel
        {
            get => _xLabel;
            set
            {
                _xLabel = value;
                UpdateAxisLabels();
            }
        }

        /// <summary>Y축 라벨</summary>
        [UxmlAttribute("y-label")]
        public string YLabel
        {
            get => _yLabel;
            set
            {
                _yLabel = value;
                UpdateAxisLabels();
            }
        }

        /// <summary>Z축 라벨</summary>
        [UxmlAttribute("z-label")]
        public string ZLabel
        {
            get => _zLabel;
            set
            {
                _zLabel = value;
                UpdateAxisLabels();
            }
        }

        /// <summary>읽기 전용 상태</summary>
        [UxmlAttribute("is-readonly")]
        public bool IsReadOnly
        {
            get => _isReadOnly;
            set
            {
                _isReadOnly = value;
                UpdateReadOnlyState();
                EnableInClassList("utk-boundsfield--readonly", value);
            }
        }
        #endregion

        #region Constructor
        public UTKBoundsField() : base()
        {
            UTKThemeManager.Instance.ApplyThemeToElement(this);

            var uss = Resources.Load<StyleSheet>(USS_PATH);
            if (uss != null)
            {
                styleSheets.Add(uss);
            }

            SetupStyles();
            SetupEvents();
            SubscribeToThemeChanges();
        }

        public UTKBoundsField(string label) : this()
        {
            this.label = label;
        }
        #endregion

        #region Setup
        private void SetupStyles()
        {
            AddToClassList("utk-boundsfield");

            // 초기 라벨 설정
            schedule.Execute(() => UpdateAxisLabels());
        }

        private void SetupEvents()
        {
            RegisterCallback<ChangeEvent<Bounds>>(OnFieldValueChanged);
        }

        private void SubscribeToThemeChanges()
        {
            UTKThemeManager.Instance.OnThemeChanged += OnThemeChanged;
            RegisterCallback<DetachFromPanelEvent>(_ =>
            {
                UTKThemeManager.Instance.OnThemeChanged -= OnThemeChanged;
            });
        }

        private void OnThemeChanged(UTKTheme theme)
        {
            UTKThemeManager.Instance.ApplyThemeToElement(this);
        }

        private void UpdateAxisLabels()
        {
            // BoundsField의 내부 Vector3Field들을 찾아서 라벨 변경 (Center, Extents 순서)
            var vector3Fields = this.Query<Vector3Field>().ToList();
            if (vector3Fields.Count >= 2)
            {
                vector3Fields[0].label = _centerLabel;
                vector3Fields[1].label = _extentsLabel;

                // 각 Vector3Field의 내부 FloatField들을 찾아서 X, Y, Z 라벨 변경
                foreach (var vector3Field in vector3Fields)
                {
                    var floatFields = vector3Field.Query<FloatField>().ToList();
                    if (floatFields.Count >= 3)
                    {
                        floatFields[0].label = _xLabel;
                        floatFields[1].label = _yLabel;
                        floatFields[2].label = _zLabel;
                    }
                }
            }
        }

        private void UpdateReadOnlyState()
        {
            // 내부 Vector3Field들의 TextInput을 찾아서 읽기 전용 설정
            var textInputs = this.Query<TextInputBaseField<float>>().ToList();
            foreach (var textInput in textInputs)
            {
                textInput.isReadOnly = _isReadOnly;
            }
        }
        #endregion

        #region Event Handlers
        private void OnFieldValueChanged(ChangeEvent<Bounds> evt)
        {
            OnValueChanged?.Invoke(evt.newValue);
        }
        #endregion

        #region IDisposable
        public void Dispose()
        {
            if (_disposed) return;
            _disposed = true;

            UTKThemeManager.Instance.OnThemeChanged -= OnThemeChanged;
            OnValueChanged = null;
            UnregisterCallback<ChangeEvent<Bounds>>(OnFieldValueChanged);
        }
        #endregion
    }
}