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

namespace UVC.UIToolkit
{
    /// <summary>
    /// FloatRange 속성 View 클래스입니다.
    /// Min, Max 두 개의 UTKFloatField를 사용하여 실수 범위를 표시/편집합니다.
    /// </summary>
    [UxmlElement]
    public partial class UTKFloatRangePropertyItemView : UTKPropertyItemViewBase, IUTKPropertyItemView<UTKFloatRange>
    {
        #region Fields
        private UTKFloatField? _minField;
        private UTKFloatField? _maxField;

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

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

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

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

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

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

        public UTKFloatRangePropertyItemView(string label, UTKFloatRange value = default) : base()
        {
            _value = value;
            Label = label;
            InitializeUI();
        }

        public UTKFloatRangePropertyItemView(string label, float min, float max) : base()
        {
            _value = new UTKFloatRange(min, max);
            Label = label;
            InitializeUI();
        }
        #endregion

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

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

            // UXML에서 요소 가져오기
            QueryUIElements();

            // 이벤트 등록
            RegisterEvents();

            UpdateValueUI();
            UpdateReadOnlyState();
        }

        private void QueryUIElements()
        {
            _minField = this.Q<UTKFloatField>("min-field");
            _maxField = this.Q<UTKFloatField>("max-field");

            // Fallback: UXML에서 못 찾으면 생성
            if (_valueContainer != null)
            {
                _valueContainer.style.flexDirection = FlexDirection.Row;

                if (_minField == null)
                {
                    _minField = new UTKFloatField { name = "min-field" };
                    _minField.style.flexGrow = 1;
                    _minField.AddToClassList("utk-property-item-view__field");
                    _valueContainer.Add(_minField);

                    var separator = new UTKLabel("~", UTKLabel.LabelSize.Body2);
                    separator.AddToClassList("utk-property-item-view__range-separator");
                    _valueContainer.Add(separator);
                }

                if (_maxField == null)
                {
                    _maxField = new UTKFloatField { name = "max-field" };
                    _maxField.style.flexGrow = 1;
                    _maxField.AddToClassList("utk-property-item-view__field");
                    _valueContainer.Add(_maxField);
                }
            }

            // 초기 값 설정
            if (_minField != null)
            {
                _minField.SetValueWithoutNotify(_value.Min);
                _minField.isReadOnly = IsReadOnly;
            }
            if (_maxField != null)
            {
                _maxField.SetValueWithoutNotify(_value.Max);
                _maxField.isReadOnly = IsReadOnly;
            }
        }

        private void RegisterEvents()
        {
            if (_minField != null)
            {
                _minField.OnValueChanged += OnMinChanged;
            }
            if (_maxField != null)
            {
                _maxField.OnValueChanged += OnMaxChanged;
            }
        }

        private void UnregisterEvents()
        {
            if (_minField != null)
            {
                _minField.OnValueChanged -= OnMinChanged;
            }
            if (_maxField != null)
            {
                _maxField.OnValueChanged -= OnMaxChanged;
            }
        }
        #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 (_minField != null) _minField.isReadOnly = isReadOnly;
            if (_maxField != null) _maxField.isReadOnly = isReadOnly;
        }
        #endregion

        #region Event Handling
        private void OnMinChanged(float newMin)
        {
            var newValue = new UTKFloatRange(newMin, _value.Max);
            if (!_value.Equals(newValue))
            {
                _value = newValue;
                OnValueChanged?.Invoke(newValue);

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

        private void OnMaxChanged(float newMax)
        {
            var newValue = new UTKFloatRange(_value.Min, newMax);
            if (!_value.Equals(newValue))
            {
                _value = newValue;
                OnValueChanged?.Invoke(newValue);

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

        #region Value Update
        private void UpdateValueUI()
        {
            if (_minField != null && !Mathf.Approximately(_minField.Value, _value.Min))
            {
                _minField.SetValueWithoutNotify(_value.Min);
            }

            if (_maxField != null && !Mathf.Approximately(_maxField.Value, _value.Max))
            {
                _maxField.SetValueWithoutNotify(_value.Max);
            }
        }
        #endregion

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

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

            _boundData = data;

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

            data.OnTypedValueChanged += OnDataValueChanged;

            UpdateValueUI();
            UpdateReadOnlyState();
        }

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

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

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

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

                OnValueChanged = null;
                _minField = null;
                _maxField = null;
            }

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