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>
    /// 散点文件加载卡片的阶段
    /// </summary>
    public enum XyzLoadPhase
    {
        SelectFile = 0,  // 初始：等待用户选择文件
        FileLoaded = 1,  // 文件已加载，显示数据预览 + 列头匹配
        Completed  = 2,  // 列头匹配已确认，摘要已提交
    }

    /// <summary>
    /// 散点文件加载综合卡片：将「打开散点文件」「数据预览」「列头匹配」合并到一张卡片。
    /// 整个业务流程由卡片本身驱动，不需要 AI 参与中间步骤；
    /// 用户确认列头匹配后，统一生成摘要发给 AI。
    /// </summary>
    public class XyzLoadCardMessage : ISpecialMessage, INotifyPropertyChanged
    {
        private XyzLoadPhase _phase = XyzLoadPhase.SelectFile;
        private string _filePath = string.Empty;
        private string _matchButtonLabel = "确认匹配";
        private TableDataMessage? _tablePreview;
        private bool _isLoading;
        private string _statusMessage = string.Empty;

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

        /// <summary>类型名称（用于序列化路由）</summary>
        public string TypeName => "XyzLoadCard";

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

        // ── 阶段控制 ──────────────────────────────────────────────────────────

        public XyzLoadPhase Phase
        {
            get => _phase;
            set
            {
                if (SetProperty(ref _phase, value))
                {
                    OnPropertyChanged(nameof(IsFileInputEnabled));
                    OnPropertyChanged(nameof(ShowLoadButtons));
                    OnPropertyChanged(nameof(HasSubmittedFile));
                    OnPropertyChanged(nameof(ShowPreviewSection));
                    OnPropertyChanged(nameof(ShowMatchSection));
                    OnPropertyChanged(nameof(ShowMatchButton));
                }
            }
        }

        // ── 加载状态 ──────────────────────────────────────────────────────────

        /// <summary>是否正在执行加载（禁用按钮，显示 loading 提示）</summary>
        public bool IsLoading
        {
            get => _isLoading;
            set
            {
                if (SetProperty(ref _isLoading, value))
                {
                    OnPropertyChanged(nameof(ShowLoadButtons));
                    OnPropertyChanged(nameof(IsFileInputEnabled));
                }
            }
        }

        /// <summary>状态提示文案（加载中、错误信息等）</summary>
        public string StatusMessage
        {
            get => _statusMessage;
            set
            {
                SetProperty(ref _statusMessage, value ?? string.Empty);
                OnPropertyChanged(nameof(HasStatusMessage));
            }
        }

        /// <summary>是否有错误提示</summary>
        public bool HasStatusMessage => !string.IsNullOrEmpty(_statusMessage);

        // ── 第一步：选择文件 ─────────────────────────────────────────────────

        /// <summary>文件路径（双向绑定到输入框）</summary>
        public string FilePath
        {
            get => _filePath;
            set => SetProperty(ref _filePath, value ?? string.Empty);
        }

        /// <summary>文件输入框是否可编辑（仅 SelectFile 且非加载中时）</summary>
        public bool IsFileInputEnabled => Phase == XyzLoadPhase.SelectFile && !IsLoading;

        /// <summary>是否显示「选择文件」和「加载」按钮（SelectFile 且非加载中）</summary>
        public bool ShowLoadButtons => Phase == XyzLoadPhase.SelectFile && !IsLoading;

        /// <summary>是否显示正在加载提示</summary>
        public bool ShowLoadingHint => IsLoading;

        /// <summary>文件已提交后显示「已加载」标记</summary>
        public bool HasSubmittedFile => Phase != XyzLoadPhase.SelectFile;

        // ── 第二步：数据预览 ─────────────────────────────────────────────────

        /// <summary>CSV 数据预览（加载后填充）</summary>
        public TableDataMessage? TablePreview
        {
            get => _tablePreview;
            set
            {
                if (SetProperty(ref _tablePreview, value))
                {
                    OnPropertyChanged(nameof(ShowPreviewSection));
                }
            }
        }

        /// <summary>是否显示数据预览区</summary>
        public bool ShowPreviewSection => _tablePreview != null && Phase != XyzLoadPhase.SelectFile;

        // ── 第三步：列头匹配 ─────────────────────────────────────────────────

        /// <summary>列头匹配下拉字段（必需列 → 可用列 ComboBox）</summary>
        public ObservableCollection<FormFieldEntry> ColumnMatchFields { get; } = new();

        /// <summary>列头匹配表单定义（保存 title、submitTarget，用于构建摘要）</summary>
        public FormDefinition? ColumnMatchDefinition { get; set; }

        /// <summary>确认匹配按钮文案</summary>
        public string MatchButtonLabel
        {
            get => _matchButtonLabel;
            set => SetProperty(ref _matchButtonLabel, value);
        }

        /// <summary>是否显示列头匹配区（FileLoaded 阶段且有匹配字段）</summary>
        public bool ShowMatchSection => Phase == XyzLoadPhase.FileLoaded;

        /// <summary>是否显示「确认匹配」按钮（FileLoaded 阶段）</summary>
        public bool ShowMatchButton => Phase == XyzLoadPhase.FileLoaded;

        // ── INotifyPropertyChanged ───────────────────────────────────────────

        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;
        }
    }
}