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

namespace UVC.UIToolkit
{
    /// <summary>
    /// 버튼 속성 View 클래스입니다.
    /// UTKButton을 표시하고 클릭 시 Action 이름을 이벤트로 전달합니다.
    /// </summary>
    [UxmlElement]
    public partial class UTKButtonItemView : UTKPropertyItemViewBase, IUTKPropertyItemView<string>
    {
        #region Fields
        private UTKButton? _button;
        private IUTKPropertyItem<string>? _boundData;
        #endregion

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

        /// <summary>값 변경 이벤트 (IUTKPropertyItemView 인터페이스 구현)</summary>
        public event Action<string>? OnValueChanged;

        /// <summary>버튼 클릭 이벤트</summary>
        public event Action<string>? OnButtonClicked;

        /// <summary>액션 이름 (현재 Value)</summary>
        public string Value
        {
            get => _boundData?.Value ?? "";
            set
            {
                if (_boundData != null)
                {
                    _boundData.Value = value;
                }
            }
        }
        #endregion

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

        public UTKButtonItemView(UTKButtonItem data) : this()
        {
            Bind(data);
        }
        #endregion

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

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

            QueryUIElements();
        }

        private void QueryUIElements()
        {
            if (_valueContainer == null) return;

            _button = this.Q<UTKButton>("button-field");
            if (_button == null)
            {
                _button = new UTKButton { name = "button-field" };
                _button.AddToClassList("utk-property-item-view__button");
                _valueContainer.Add(_button);
            }

            // 버튼 클릭 이벤트 등록
            _button.OnClicked += OnButtonClickedInternal;
        }
        #endregion

        #region Override Methods
        protected override void CreateValueUI(VisualElement container)
        {
            // Fallback: UXML 로드 실패 시 코드로 생성
            _button = new UTKButton { name = "button-field" };
            _button.AddToClassList("utk-property-item-view__button");
            container.Add(_button);

            _button.OnClicked += OnButtonClickedInternal;
        }

        public override void RefreshUI()
        {
            // 버튼은 정적이므로 별도 갱신 불필요
        }

        protected override void OnReadOnlyStateChanged(bool isReadOnly)
        {
            // 버튼은 ReadOnly 개념이 적용되지 않으므로 IsEnabled로 제어
            if (_button != null)
            {
                _button.IsEnabled = !isReadOnly;
            }
        }
        #endregion

        #region Event Handling
        private void OnButtonClickedInternal()
        {
            if (_boundData is UTKButtonItem buttonItem)
            {
                OnButtonClicked?.Invoke(buttonItem.ActionName);
            }
        }
        #endregion

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

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

            _boundData = data;

            // 라벨 텍스트 설정
            if (_labelElement != null)
            {
                _labelElement.Text = data.DisplayName;
            }

            // UTKButtonItem 설정 적용
            if (data is UTKButtonItem buttonItem && _button != null)
            {
                _button.Text = buttonItem.Text;
                _button.Icon = buttonItem.Icon;
                _button.IconSize = buttonItem.IconSize;
                _button.Variant = buttonItem.Variant;
                _button.Size = buttonItem.Size;
                _button.IconOnly = buttonItem.IconOnly;

                if (buttonItem.BackgroundColor.HasValue)
                {
                    _button.BackgroundColor = buttonItem.BackgroundColor;
                }

                if (buttonItem.BorderWidth >= 0)
                {
                    _button.BorderWidth = buttonItem.BorderWidth;
                }

                _button.IsEnabled = !buttonItem.IsReadOnly;

                // 라벨 표시 여부 제어
                if (_labelElement != null)
                {
                    if (buttonItem.ShowLabel)
                    {
                        _labelElement.style.display = DisplayStyle.Flex;
                        RemoveFromClassList("utk-property-item-view--button-no-label");
                    }
                    else
                    {
                        _labelElement.style.display = DisplayStyle.None;
                        AddToClassList("utk-property-item-view--button-no-label");
                    }
                }
            }

            IsReadOnly = data.IsReadOnly;
            IsVisible = data.IsVisible;
            TooltipText = data.Tooltip;
        }

        public void Unbind()
        {
            if (_boundData != null)
            {
                _boundData = null;
            }
        }
        #endregion

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

            if (disposing)
            {
                if (_button != null)
                {
                    _button.OnClicked -= OnButtonClickedInternal;
                    _button.Dispose();
                }

                Unbind();
                OnValueChanged = null;
                OnButtonClicked = null;
                _button = null;
            }

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