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

namespace UVC.UIToolkit
{
    /// <summary>
    /// Vector2 속성 View 클래스입니다.
    /// UTKVector2Field를 사용하여 Vector2 값을 표시/편집합니다.
    /// </summary>
    [UxmlElement]
    public partial class UTKVector2PropertyItemView : UTKPropertyItemViewBase, IUTKPropertyItemView<Vector2>
    {
        #region Fields
        private UTKVector2Field? _vectorField;

        private Vector2 _value;
        private IUTKPropertyItem<Vector2>? _boundData;
        #endregion

        #region Properties
        protected override string ViewTypeName => "UTKVector2PropertyItemView";

        /// <summary>현재 값</summary>
        public Vector2 Value
        {
            get => _value;
            set
            {
                if (_value != value)
                {
                    _value = value;
                    UpdateValueUI();
                    OnValueChanged?.Invoke(value);

                    if (_boundData != null && _boundData.Value != value)
                    {
                        _boundData.Value = value;
                    }
                }
            }
        }
        #endregion

        #region Events
        public event Action<Vector2>? OnValueChanged;
        #endregion

        #region Constructor
        public UTKVector2PropertyItemView() : base()
        {
            InitializeUI();
        }

        public UTKVector2PropertyItemView(string label, Vector2 value = default) : base()
        {
            _value = value;
            Label = label;
            InitializeUI();
        }
        #endregion

        #region Initialization
        private void InitializeUI()
        {
            AddToClassList("utk-property-item-view");
            AddToClassList("utk-property-item-view--vector2");

            if (!CreateUIFromUxml())
            {
                CreateUIFallback();
            }

            // UXML에서 요소 가져오기
            QueryUIElements();

            // 이벤트 등록
            RegisterEvents();

            UpdateValueUI();
            UpdateReadOnlyState();
        }

        private void QueryUIElements()
        {
            _vectorField = this.Q<UTKVector2Field>("value-field");

            // Fallback: UXML에서 못 찾으면 생성
            if (_valueContainer != null && _vectorField == null)
            {
                _vectorField = new UTKVector2Field
                {
                    name = "value-field",
                    label = ""
                };
                _vectorField.AddToClassList("utk-property-item-view__vector-field");
                _valueContainer.Add(_vectorField);
            }

            // 초기 값 설정
            if (_vectorField != null)
            {
                _vectorField.label = "";
                _vectorField.SetValueWithoutNotify(_value);
                _vectorField.IsReadOnly = IsReadOnly;
            }
        }

        private void RegisterEvents()
        {
            if (_vectorField != null)
            {
                _vectorField.OnValueChanged += OnVectorChanged;
            }
        }

        private void UnregisterEvents()
        {
            if (_vectorField != null)
            {
                _vectorField.OnValueChanged -= OnVectorChanged;
            }
        }
        #endregion

        #region Override Methods
        protected override void CreateValueUI(VisualElement container)
        {
            // UXML/QueryUIElements 기반으로 생성하므로 여기서는 생성하지 않음
        }

        public override void RefreshUI()
        {
            UpdateValueUI();
        }

        protected override void OnReadOnlyStateChanged(bool isReadOnly)
        {
            if (_vectorField != null)
            {
                _vectorField.IsReadOnly = isReadOnly;
            }
        }
        #endregion

        #region Event Handling
        private void OnVectorChanged(Vector2 newValue)
        {
            if (_value != newValue)
            {
                _value = newValue;
                OnValueChanged?.Invoke(newValue);

                if (_boundData != null && _boundData.Value != newValue)
                {
                    _boundData.Value = newValue;
                }
            }
        }
        #endregion

        #region Value Update
        private void UpdateValueUI()
        {
            if (_vectorField != null && _vectorField.Value != _value)
            {
                _vectorField.SetValueWithoutNotify(_value);
            }
        }
        #endregion

        #region Data Binding
        public void Bind(IUTKPropertyItem data)
        {
            if (data is IUTKPropertyItem<Vector2> vectorData)
            {
                Bind(vectorData);
            }
            else
            {
                Debug.LogWarning($"[UTKVector2PropertyItemView] Cannot bind to non-Vector2 data: {data.GetType().Name}");
            }
        }

        public void Bind(IUTKPropertyItem<Vector2> data)
        {
            Unbind();

            _boundData = data;
            BindBase(data);

            Label = data.Name;
            _value = data.Value;
            IsVisible = data.IsVisible;
            TooltipText = data.Tooltip;
            ShowLabel = data.ShowLabel;

            data.OnTypedValueChanged += OnDataValueChanged;

            UpdateValueUI();
            IsReadOnly = data.IsReadOnly;
        }

        public void Unbind()
        {
            if (_boundData != null)
            {
                _boundData.OnTypedValueChanged -= OnDataValueChanged;
                UnbindBase();
                _boundData = null;
            }
        }

        private void OnDataValueChanged(IUTKPropertyItem<Vector2> item, Vector2 oldValue, Vector2 newValue)
        {
            if (_value != newValue)
            {
                _value = newValue;
                UpdateValueUI();
            }
        }
        #endregion

        #region Dispose
        protected override void Dispose(bool disposing)
        {
            if (_disposed) return;

            if (disposing)
            {
                UnregisterEvents();
                Unbind();

                OnValueChanged = null;
                _vectorField = null;
            }

            base.Dispose(disposing);
        }
        #endregion
    }
}