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

namespace UVC.UIToolkit
{
    /// <summary>
    /// 드롭다운 목록 속성 데이터 클래스입니다.
    /// UI는 UTKDropdownPropertyItemView에서 담당합니다.
    /// </summary>
    public class UTKDropdownPropertyItem : UTKPropertyItemBase<string>
    {
        #region Fields
        private List<string> _choices;
        #endregion

        #region Properties
        /// <summary>속성 타입</summary>
        public override UTKPropertyType PropertyType => UTKPropertyType.DropdownList;

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

        #region Constructor
        /// <summary>
        /// 드롭다운 속성을 생성합니다.
        /// </summary>
        /// <param name="id">고유 ID</param>
        /// <param name="name">표시 이름</param>
        /// <param name="choices">선택 항목 목록</param>
        /// <param name="initialValue">초기 선택 값</param>
        /// <param name="isReadOnly">읽기 전용 여부</param>
        public UTKDropdownPropertyItem(string id, string name, List<string> choices, string initialValue = "", bool isReadOnly = false)
            : base(id, name, initialValue)
        {
            _choices = choices ?? new List<string>();

            // initialValue가 choices에 없으면 첫 번째 항목 선택
            if (!string.IsNullOrEmpty(initialValue) && !_choices.Contains(initialValue) && _choices.Count > 0)
            {
                Value = _choices[0];
            }
            IsReadOnly = isReadOnly;
        }

        /// <summary>
        /// 드롭다운 속성을 생성합니다 (인덱스 기반).
        /// </summary>
        /// <param name="id">고유 ID</param>
        /// <param name="name">표시 이름</param>
        /// <param name="choices">선택 항목 목록</param>
        /// <param name="selectedIndex">초기 선택 인덱스</param>
        /// <param name="isReadOnly">읽기 전용 여부</param>
        public UTKDropdownPropertyItem(string id, string name, IEnumerable<string> choices, int selectedIndex = 0, bool isReadOnly = false)
            : base(id, name, string.Empty)
        {
            _choices = choices?.ToList() ?? new List<string>();

            if (_choices.Count > 0 && selectedIndex >= 0 && selectedIndex < _choices.Count)
            {
                Value = _choices[selectedIndex];
            }
            else if (_choices.Count > 0)
            {
                Value = _choices[0];
            }
            IsReadOnly = isReadOnly;
        }
        #endregion

        #region Public Methods
        /// <summary>선택 항목 추가</summary>
        public void AddChoice(string choice)
        {
            if (!_choices.Contains(choice))
            {
                _choices.Add(choice);
            }
        }

        /// <summary>선택 항목 제거</summary>
        public bool RemoveChoice(string choice)
        {
            bool removed = _choices.Remove(choice);
            if (removed && Value == choice && _choices.Count > 0)
            {
                Value = _choices[0];
            }
            return removed;
        }
        #endregion
    }
}