using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Linq;
using System.Runtime.CompilerServices;

namespace AI.Models.Form
{
    /// <summary>
    /// 表单字段条目：schema + 当前值，用于绑定与提交
    /// </summary>
    public class FormFieldEntry : INotifyPropertyChanged
    {
        private string _currentValue = string.Empty;

        public string Id { get; set; } = string.Empty;
        public string Label { get; set; } = string.Empty;
        /// <summary>可选描述/提示</summary>
        public string? Description { get; set; }
        public FormFieldType Type { get; set; }
        public bool Required { get; set; }
        public object? DefaultValue { get; set; }
        public List<string>? Options { get; set; }

        // ----- number -----
        public double? Min { get; set; }
        public double? Max { get; set; }
        public double? Step { get; set; }
        // ----- string -----
        public int? MaxLength { get; set; }
        public string? Placeholder { get; set; }
        // ----- multi-select -----
        public List<string>? DefaultValues { get; set; }
        /// <summary>多选当前选中项（MultiSelect 绑定用）</summary>
        public ObservableCollection<string> SelectedValues { get; } = new ObservableCollection<string>();
        /// <summary>多选选项列表（用于绑定 CheckBox 列表，与 SelectedValues 同步）</summary>
        public ObservableCollection<MultiSelectOptionItem> MultiSelectOptions { get; } = new ObservableCollection<MultiSelectOptionItem>();

        /// <summary>当前输入值（绑定用，提交时按 Type 转换）</summary>
        public string CurrentValue
        {
            get => _currentValue;
            set => SetProperty(ref _currentValue, value);
        }

        public event PropertyChangedEventHandler? PropertyChanged;

        protected void OnPropertyChanged([CallerMemberName] string? propertyName = null) =>
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));

        protected bool SetProperty<T>(ref T field, T value, [CallerMemberName] string? propertyName = null)
        {
            if (EqualityComparer<T>.Default.Equals(field, value))
                return false;
            field = value;
            OnPropertyChanged(propertyName);
            return true;
        }
    }
}