#nullable enable
using System;
using UnityEngine.UIElements;

namespace UVC.UIToolkit
{
    /// <summary>
    /// 열거형 속성 아이템
    /// UTKEnumDropDown을 사용한 열거형 선택
    /// </summary>
    public class UTKEnumPropertyItem : UTKPropertyItemBase<Enum>
    {
        #region Fields
        private UTKEnumDropDown? _enumDropdown;
        private Type _enumType;
        #endregion

        #region Properties
        public override UTKPropertyType PropertyType => UTKPropertyType.Enum;

        /// <summary>열거형 타입</summary>
        public Type EnumType => _enumType;
        #endregion

        #region Constructor
        public UTKEnumPropertyItem(string id, string name, Enum initialValue, bool isReadOnly = false)
            : base(id, name, initialValue ?? throw new ArgumentNullException(nameof(initialValue)))
        {
            _enumType = initialValue.GetType();
            base._isReadOnly = isReadOnly;
        }
        #endregion

        #region Override Methods
        public override VisualElement CreateUI()
        {
            var container = CreateUIFromUxml("UTKEnumPropertyItem");
            if (container == null)
            {
                return CreateUIFallback();
            }

            _enumDropdown = container.Q<UTKEnumDropDown>("enum-dropdown");
            if (_enumDropdown != null)
            {
                _enumDropdown.Init(Value);
                _enumDropdown.IsEnabled = !IsReadOnly;
            }

            return container;
        }

        private VisualElement CreateUIFallback()
        {
            var container = CreateContainer();

            var label = CreateNameLabel();
            container.Add(label);

            var valueContainer = new VisualElement();
            valueContainer.AddToClassList("utk-property-item__value");

            _enumDropdown = new UTKEnumDropDown();
            _enumDropdown.name = "enum-dropdown";
            _enumDropdown.Init(Value);
            _enumDropdown.IsEnabled = !IsReadOnly;
            valueContainer.Add(_enumDropdown);

            container.Add(valueContainer);

            return container;
        }

        public override void BindUI(VisualElement element)
        {
            base.BindUI(element);

            _enumDropdown = element.Q<UTKEnumDropDown>("enum-dropdown");

            if (_enumDropdown != null)
            {
                _enumDropdown.Value = Value;
                _enumDropdown.IsEnabled = !IsReadOnly;
                _enumDropdown.OnValueChanged += OnEnumDropdownChanged;
            }
        }

        public override void UnbindUI(VisualElement element)
        {
            if (_enumDropdown != null)
            {
                _enumDropdown.OnValueChanged -= OnEnumDropdownChanged;
                _enumDropdown = null;
            }

            base.UnbindUI(element);
        }

        public override void RefreshUI()
        {
            if (_enumDropdown != null && _enumDropdown.Value != Value)
            {
                _enumDropdown.Value = Value;
            }
        }

        protected override void UpdateReadOnlyState()
        {
            base.UpdateReadOnlyState();

            if (_enumDropdown != null)
            {
                _enumDropdown.IsEnabled = !IsReadOnly;
            }
        }
        #endregion

        #region Private Methods
        private void OnEnumDropdownChanged(Enum? newValue)
        {
            if (newValue != null)
            {
                Value = newValue;
            }
        }
        #endregion
    }
}