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

namespace UVC.UIToolkit
{
    /// <summary>
    /// Int 속성 View 클래스입니다.
    /// UTKIntegerField, UTKSliderInt, 또는 UTKNumberStepper를 사용하여 int 값을 표시/편집합니다.
    ///
    /// <para><b>사용법 (단독 사용):</b></para>
    /// <code>
    /// // C# 코드에서 생성
    /// var view = new UTKIntPropertyItemView();
    /// view.Label = "수량";
    /// view.Value = 10;
    /// view.UseSlider = true;
    /// view.MinValue = 0;
    /// view.MaxValue = 100;
    /// parent.Add(view);
    ///
    /// // 스테퍼 모드
    /// var stepperView = new UTKIntPropertyItemView();
    /// stepperView.UseStepper = true;
    /// stepperView.Step = 5;
    ///
    /// // UXML에서 사용
    /// &lt;utk:UTKIntPropertyItemView label="수량" value="10" use-slider="true" min-value="0" max-value="100" /&gt;
    /// &lt;utk:UTKIntPropertyItemView label="개수" value="1" use-stepper="true" step="1" /&gt;
    /// </code>
    /// </summary>
    [UxmlElement]
    public partial class UTKIntPropertyItemView : UTKPropertyItemViewBase, IUTKPropertyItemView<int>
    {
        #region Fields
        private UTKIntegerField? _intField;
        private UTKSliderInt? _slider;
        private UTKNumberStepper? _stepper;

        private int _value;
        private int _minValue;
        private int _maxValue = 100;
        private int _step = 1;
        private bool _useSlider;
        private bool _useStepper;

        private IUTKPropertyItem<int>? _boundData;
        #endregion

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

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

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

        /// <summary>최소값 (슬라이더 모드)</summary>
        [UxmlAttribute("min-value")]
        public int MinValue
        {
            get => _minValue;
            set
            {
                _minValue = value;
                if (_slider != null)
                {
                    _slider.lowValue = value;
                }
            }
        }

        /// <summary>최대값 (슬라이더 모드)</summary>
        [UxmlAttribute("max-value")]
        public int MaxValue
        {
            get => _maxValue;
            set
            {
                _maxValue = value;
                if (_slider != null)
                {
                    _slider.highValue = value;
                }
            }
        }

        /// <summary>슬라이더 사용 여부</summary>
        [UxmlAttribute("use-slider")]
        public bool UseSlider
        {
            get => _useSlider;
            set
            {
                if (_useSlider != value)
                {
                    _useSlider = value;
                    if (value) _useStepper = false;
                    UpdateModeClass();
                }
            }
        }

        /// <summary>스테퍼(증감 버튼) 사용 여부</summary>
        [UxmlAttribute("use-stepper")]
        public bool UseStepper
        {
            get => _useStepper;
            set
            {
                if (_useStepper != value)
                {
                    _useStepper = value;
                    if (value) _useSlider = false;
                    UpdateModeClass();
                }
            }
        }

        /// <summary>스테퍼 증감 단위</summary>
        [UxmlAttribute("step")]
        public int Step
        {
            get => _step;
            set
            {
                _step = Math.Max(1, value);
                if (_stepper != null)
                {
                    _stepper.Step = _step;
                }
            }
        }
        #endregion

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

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

        public UTKIntPropertyItemView(string label, int value = 0, bool useSlider = false) : base()
        {
            _value = value;
            _useSlider = useSlider;
            Label = label;
            InitializeUI();
        }

        public UTKIntPropertyItemView(UTKIntPropertyItem item) : base()
        {
            _value = item.Value;
            _minValue = item.MinValue;
            _maxValue = item.MaxValue;
            _useSlider = item.UseSlider;
            _isReadOnly = item.IsReadOnly;

            InitializeUI();
            Bind(item);
        }

        public UTKIntPropertyItemView(string label, int value, int minValue, int maxValue, bool useSlider = true) : base()
        {
            _value = value;
            _minValue = minValue;
            _maxValue = maxValue;
            _useSlider = useSlider;
            Label = label;
            InitializeUI();
        }
        #endregion

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

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

            // UXML에서 요소 가져오기
            QueryUIElements();

            // 이벤트 등록
            RegisterEvents();

            // 슬라이더 클래스 업데이트
            UpdateModeClass();

            UpdateValueUI();
            UpdateReadOnlyState();
        }

        private void QueryUIElements()
        {
            _slider = this.Q<UTKSliderInt>("slider-field");
            _intField = this.Q<UTKIntegerField>("value-field");
            _stepper = this.Q<UTKNumberStepper>("stepper-field");

            // Fallback: UXML에서 못 찾으면 생성
            if (_valueContainer != null)
            {
                if (_slider == null)
                {
                    _slider = new UTKSliderInt("", _minValue, _maxValue, _value)
                    {
                        name = "slider-field"
                    };
                    _slider.AddToClassList("utk-property-item-view__slider");
                    _valueContainer.Insert(0, _slider);
                }

                if (_intField == null)
                {
                    _intField = new UTKIntegerField { name = "value-field" };
                    _intField.AddToClassList("utk-property-item-view__field");
                    _valueContainer.Add(_intField);
                }

                if (_stepper == null)
                {
                    _stepper = new UTKNumberStepper(_minValue, _maxValue, _value, _step, IsReadOnly)
                    {
                        name = "stepper-field"
                    };
                    _stepper.AddToClassList("utk-property-item-view__stepper");
                    _valueContainer.Add(_stepper);
                }
            }

            // 초기 값 설정
            if (_slider != null)
            {
                _slider.lowValue = _minValue;
                _slider.highValue = _maxValue;
                _slider.SetValueWithoutNotify(_value);
            }
            if (_intField != null)
            {
                _intField.SetValueWithoutNotify(_value);
                _intField.isReadOnly = IsReadOnly;
            }
            if (_stepper != null)
            {
                _stepper.MinValue = _minValue;
                _stepper.MaxValue = _maxValue;
                _stepper.Step = _step;
                _stepper.SetValue(_value, false);
                _stepper.IsReadOnly = IsReadOnly;
            }
        }

        private void UpdateModeClass()
        {
            // ReadOnly 상태에서는 무조건 IntegerField만 표시
            if (IsReadOnly)
            {
                RemoveFromClassList("utk-property-item-view--slider");
                RemoveFromClassList("utk-property-item-view--stepper");
                UpdateControlVisibility();
                return;
            }

            // 슬라이더 클래스
            if (_useSlider)
            {
                AddToClassList("utk-property-item-view--slider");
            }
            else
            {
                RemoveFromClassList("utk-property-item-view--slider");
            }

            // 스테퍼 클래스
            if (_useStepper)
            {
                AddToClassList("utk-property-item-view--stepper");
            }
            else
            {
                RemoveFromClassList("utk-property-item-view--stepper");
            }

            UpdateControlVisibility();
        }
        #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 (_intField != null)
            {
                _intField.isReadOnly = isReadOnly;
            }

            if (_slider != null)
            {
                _slider.IsEnabled = !isReadOnly;
            }

            if (_stepper != null)
            {
                _stepper.IsReadOnly = isReadOnly;
            }

            // ReadOnly 상태 변경 시 모드 클래스 업데이트
            UpdateModeClass();
        }
        
        /// <summary>컨트롤 가시성을 업데이트합니다.</summary>
        private void UpdateControlVisibility()
        {
            bool isReadOnlyMode = IsReadOnly;
            bool showSlider = !isReadOnlyMode && _useSlider;
            bool showStepper = !isReadOnlyMode && _useStepper;
            bool showIntField = isReadOnlyMode || (!_useSlider && !_useStepper);

            if (_slider != null)
            {
                _slider.style.display = showSlider ? DisplayStyle.Flex : DisplayStyle.None;
            }

            if (_stepper != null)
            {
                _stepper.style.display = showStepper ? DisplayStyle.Flex : DisplayStyle.None;
            }

            if (_intField != null)
            {
                _intField.style.display = showIntField ? DisplayStyle.Flex : DisplayStyle.None;
            }
        }
        #endregion

        #region Event Handling
        private void RegisterEvents()
        {
            if (_intField != null)
            {
                _intField.OnValueChanged += OnIntFieldChanged;
            }

            if (_slider != null)
            {
                _slider.OnValueChanged += OnSliderChanged;
            }

            if (_stepper != null)
            {
                _stepper.OnValueChanged += OnStepperChanged;
            }
        }

        private void UnregisterEvents()
        {
            if (_intField != null)
            {
                _intField.OnValueChanged -= OnIntFieldChanged;
            }

            if (_slider != null)
            {
                _slider.OnValueChanged -= OnSliderChanged;
            }

            if (_stepper != null)
            {
                _stepper.OnValueChanged -= OnStepperChanged;
            }
        }

        private void OnIntFieldChanged(int newValue)
        {
            int clampedValue = _useSlider ? Mathf.Clamp(newValue, _minValue, _maxValue) : newValue;

            if (_slider != null && _slider.Value != clampedValue)
            {
                _slider.SetValueWithoutNotify(clampedValue);
            }

            if (_intField != null && _intField.Value != clampedValue)
            {
                _intField.SetValueWithoutNotify(clampedValue);
            }

            if (_value != clampedValue)
            {
                _value = clampedValue;
                OnValueChanged?.Invoke(clampedValue);

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

        private void OnSliderChanged(int newValue)
        {
            if (_intField != null && _intField.Value != newValue)
            {
                _intField.SetValueWithoutNotify(newValue);
            }

            if (_value != newValue)
            {
                _value = newValue;
                OnValueChanged?.Invoke(newValue);

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

        private void OnStepperChanged(int 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 (_intField != null && _intField.Value != _value)
            {
                _intField.SetValueWithoutNotify(_value);
            }

            if (_slider != null && _slider.Value != _value)
            {
                _slider.SetValueWithoutNotify(_value);
            }

            if (_stepper != null && _stepper.Value != _value)
            {
                _stepper.SetValue(_value, false);
            }
        }
        #endregion

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

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

            _boundData = data;

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

            if (data is UTKIntPropertyItem intItem)
            {
                _minValue = intItem.MinValue;
                _maxValue = intItem.MaxValue;
                _step = intItem.Step;

                // 모드 변경 확인
                bool modeChanged = false;
                if (_useSlider != intItem.UseSlider)
                {
                    _useSlider = intItem.UseSlider;
                    modeChanged = true;
                }
                if (_useStepper != intItem.UseStepper)
                {
                    _useStepper = intItem.UseStepper;
                    modeChanged = true;
                }
                if (modeChanged)
                {
                    UpdateModeClass();
                }

                // 슬라이더 범위 업데이트
                if (_slider != null)
                {
                    _slider.lowValue = _minValue;
                    _slider.highValue = _maxValue;
                }

                // 스테퍼 설정 업데이트
                if (_stepper != null)
                {
                    _stepper.MinValue = _minValue;
                    _stepper.MaxValue = _maxValue;
                    _stepper.Step = _step;
                }
            }

            data.OnTypedValueChanged += OnDataValueChanged;

            UpdateValueUI();
            UpdateReadOnlyState();
        }

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

        private void OnDataValueChanged(IUTKPropertyItem<int> item, int oldValue, int 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;
                _intField = null;
                _slider = null;
                _stepper?.Dispose();
                _stepper = null;
            }

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