using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Runtime.CompilerServices;
using AI.Models.Form;

namespace AI.Models.SpecialMessages
{
    /// <summary>
    /// 表单请求特殊消息 - 在聊天流中显示可填写的表单
    /// </summary>
    public class FormRequestMessage : ISpecialMessage, INotifyPropertyChanged
    {
        private string _submitLabel = "提交";

        /// <summary>消息唯一标识符</summary>
        public string Id { get; set; } = Guid.NewGuid().ToString();

        /// <summary>类型名称</summary>
        public string TypeName => "Form";

        /// <summary>不需要实时更新</summary>
        public bool IsLive => false;

        /// <summary>表单定义（只读）</summary>
        public FormDefinition Definition { get; }

        /// <summary>带当前值的字段列表，用于绑定与提交</summary>
        public ObservableCollection<FormFieldEntry> FieldsWithValues { get; } = new ObservableCollection<FormFieldEntry>();

        /// <summary>提交按钮文案（可从 Definition 覆盖）</summary>
        public string SubmitLabel
        {
            get => _submitLabel;
            set => SetProperty(ref _submitLabel, value);
        }

        public FormRequestMessage(FormDefinition definition)
        {
            Definition = definition ?? throw new ArgumentNullException(nameof(definition));
            _submitLabel = definition.SubmitLabel;

            foreach (var f in definition.Fields)
            {
                var entry = new FormFieldEntry
                {
                    Id = f.Id,
                    Label = f.Label,
                    Description = f.Description,
                    Type = f.Type,
                    Required = f.Required,
                    DefaultValue = f.DefaultValue,
                    Options = f.Options,
                    Min = f.Min,
                    Max = f.Max,
                    Step = f.Step,
                    MaxLength = f.MaxLength,
                    Placeholder = f.Placeholder,
                    DefaultValues = f.DefaultValues != null ? new List<string>(f.DefaultValues) : null,
                    CurrentValue = f.DefaultValue?.ToString() ?? string.Empty,
                };
                if (f.Type == FormFieldType.MultiSelect)
                {
                    if (f.DefaultValues != null && f.DefaultValues.Count > 0)
                    {
                        foreach (var v in f.DefaultValues)
                            entry.SelectedValues.Add(v);
                    }
                    else if (f.DefaultValue is System.Collections.IEnumerable en && f.DefaultValue is not string)
                    {
                        foreach (var v in en)
                            entry.SelectedValues.Add(v?.ToString() ?? string.Empty);
                    }
                    else if (f.DefaultValue is string defStr && !string.IsNullOrEmpty(defStr))
                    {
                        foreach (var v in defStr.Split(',', StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries))
                            entry.SelectedValues.Add(v);
                    }
                    if (f.Options != null)
                    {
                        foreach (var opt in f.Options)
                            entry.MultiSelectOptions.Add(new MultiSelectOptionItem(entry, opt, entry.SelectedValues.Contains(opt)));
                    }
                }
                FieldsWithValues.Add(entry);
            }
        }

        /// <summary>收集当前值，用于提交。Key 为字段 Id，Value 为对象（按 Type 转换）</summary>
        public Dictionary<string, object> GetValues()
        {
            var dict = new Dictionary<string, object>(StringComparer.OrdinalIgnoreCase);
            foreach (var entry in FieldsWithValues)
            {
                var raw = entry.CurrentValue?.Trim() ?? string.Empty;
                object value = entry.Type switch
                {
                    FormFieldType.Number => double.TryParse(raw, out var n) ? n : 0d,
                    FormFieldType.Boolean => raw is "1" or "true" or "True" or "yes" or "是",
                    FormFieldType.Json => raw,
                    FormFieldType.MultiSelect => entry.SelectedValues.Count > 0
                        ? new List<string>(entry.SelectedValues)
                        : (object)raw.Split(',', StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries).ToList(),
                    _ => raw,
                };
                dict[entry.Id] = value;
            }
            return dict;
        }

        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;
        }
    }
}