#nullable enable
using System;
using System.Collections.Generic;
using System.Linq;
using UnityEngine.UIElements;

namespace UVC.UIToolkit
{
    /// <summary>
    /// 라디오 그룹 속성 아이템
    /// UTKRadioButton 그룹으로 단일 선택
    /// </summary>
    public class UTKRadioPropertyItem : UTKPropertyItemBase<int>
    {
        #region Fields
        private VisualElement? _radioContainer;
        private List<UTKRadioButton> _radioButtons = new();
        private List<string> _choices;
        #endregion

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

        /// <summary>선택 가능한 항목 목록</summary>
        public List<string> Choices
        {
            get => _choices;
            set
            {
                _choices = value ?? new List<string>();
                RebuildRadioButtons();
            }
        }

        /// <summary>현재 선택된 항목의 텍스트</summary>
        public string? SelectedText
        {
            get
            {
                if (Value >= 0 && Value < _choices.Count)
                {
                    return _choices[Value];
                }
                return null;
            }
        }
        #endregion

        #region Constructor
        public UTKRadioPropertyItem(string id, string name, List<string> choices, int selectedIndex = 0)
            : base(id, name, Math.Max(0, Math.Min(selectedIndex, (choices?.Count ?? 1) - 1)))
        {
            _choices = choices ?? new List<string>();
        }

        public UTKRadioPropertyItem(string id, string name, IEnumerable<string> choices, int selectedIndex = 0)
            : this(id, name, choices?.ToList() ?? new List<string>(), selectedIndex)
        {
        }
        #endregion

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

            _radioContainer = container.Q<VisualElement>("radio-container");
            if (_radioContainer != null)
            {
                CreateRadioButtons();
            }

            return container;
        }

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

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

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

            _radioContainer = new VisualElement();
            _radioContainer.name = "radio-container";
            _radioContainer.AddToClassList("utk-property-item__radio-container");
            valueContainer.Add(_radioContainer);

            CreateRadioButtons();

            container.Add(valueContainer);

            return container;
        }

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

            _radioContainer = element.Q<VisualElement>("radio-container");

            if (_radioContainer != null)
            {
                // 기존 라디오 버튼 찾기 또는 새로 생성
                _radioButtons.Clear();
                var existingButtons = _radioContainer.Query<UTKRadioButton>().ToList();

                if (existingButtons.Count == _choices.Count)
                {
                    // 기존 버튼 재사용
                    for (int i = 0; i < existingButtons.Count; i++)
                    {
                        var radio = existingButtons[i];
                        _radioButtons.Add(radio);
                        radio.IsEnabled = !IsReadOnly;

                        int index = i;
                        radio.OnValueChanged += (isChecked) => OnRadioChanged(index, isChecked);
                    }
                }
                else
                {
                    // 새로 생성
                    CreateRadioButtons();
                }

                UpdateSelection();
            }
        }

        public override void UnbindUI(VisualElement element)
        {
            _radioButtons.Clear();
            _radioContainer = null;

            base.UnbindUI(element);
        }

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

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

            foreach (var radio in _radioButtons)
            {
                radio.IsEnabled = !IsReadOnly;
            }
        }
        #endregion

        #region Public Methods
        /// <summary>텍스트로 선택</summary>
        public void SelectByText(string text)
        {
            int index = _choices.IndexOf(text);
            if (index >= 0)
            {
                Value = index;
            }
        }
        #endregion

        #region Private Methods
        private void CreateRadioButtons()
        {
            if (_radioContainer == null) return;

            _radioContainer.Clear();
            _radioButtons.Clear();

            for (int i = 0; i < _choices.Count; i++)
            {
                var radio = new UTKRadioButton(_choices[i]);
                radio.name = $"radio-{i}";
                radio.AddToClassList("utk-property-item__radio");

                int index = i;
                radio.OnValueChanged += (isChecked) => OnRadioChanged(index, isChecked);

                _radioButtons.Add(radio);
                _radioContainer.Add(radio);
            }

            UpdateSelection();
        }

        private void RebuildRadioButtons()
        {
            if (_radioContainer != null)
            {
                CreateRadioButtons();
            }
        }

        private void UpdateSelection()
        {
            for (int i = 0; i < _radioButtons.Count; i++)
            {
                _radioButtons[i].SetChecked(i == Value, false);
            }
        }

        private void OnRadioChanged(int index, bool isChecked)
        {
            if (isChecked && index != Value)
            {
                // 다른 라디오 버튼 해제
                for (int i = 0; i < _radioButtons.Count; i++)
                {
                    if (i != index)
                    {
                        _radioButtons[i].SetChecked(false, false);
                    }
                }

                Value = index;
            }
        }
        #endregion
    }
}