using OrderSupportTicket.Models.Api;
using System;
using System.Globalization;
using WPFCommon.Models;

namespace OrderSupportTicket.ViewModels;

/// <summary>
/// 历史工单列表中的单个工单摘要。
/// </summary>
public sealed class WorkOrderSummaryViewModel : BindableBaseEx
{
    private string _appId;
    private string _wechatOrderId;
    private string _status;
    private string _statusText;
    private DateTimeOffset _updatedAt;
    private DateTimeOffset _lastMessageAt;
    private DateTimeOffset? _lastReplyAt;
    private string _lastSenderType;
    private int _unreadCount;
    private bool _hasNewMessage;
    private string _version;

    public WorkOrderSummaryViewModel(WorkOrderSummaryDto dto)
    {
        if (dto == null)
            throw new ArgumentNullException(nameof(dto));
        Apply(dto);
    }

    /// <summary>
    /// 订单所属店铺 APPID。
    /// </summary>
    public string AppId
    {
        get => _appId;
        private set => SetValue(ref _appId, value);
    }

    /// <summary>
    /// 微信订单号，也是客户端使用的工单号。
    /// </summary>
    public string WechatOrderId
    {
        get => _wechatOrderId;
        private set => SetValue(ref _wechatOrderId, value);
    }

    /// <summary>
    /// 工单状态编码。
    /// </summary>
    public string Status
    {
        get => _status;
        private set
        {
            if (SetValue(ref _status, value))
                RaisePropertyChanged(nameof(IsCompleted));
        }
    }

    /// <summary>
    /// 工单状态中文文本。
    /// </summary>
    public string StatusText
    {
        get => _statusText;
        private set => SetValue(ref _statusText, value);
    }

    /// <summary>
    /// 工单最后更新时间。
    /// </summary>
    public DateTimeOffset UpdatedAt
    {
        get => _updatedAt;
        private set
        {
            if (SetValue(ref _updatedAt, value))
                RaisePropertyChanged(nameof(UpdatedAtText));
        }
    }

    /// <summary>
    /// 最近一条公开留言的时间。
    /// </summary>
    public DateTimeOffset LastMessageAt
    {
        get => _lastMessageAt;
        private set => SetValue(ref _lastMessageAt, value);
    }

    /// <summary>
    /// 最近一次客服正式回复时间。
    /// </summary>
    public DateTimeOffset? LastReplyAt
    {
        get => _lastReplyAt;
        private set => SetValue(ref _lastReplyAt, value);
    }

    /// <summary>
    /// 最近一条留言的发送方类型。
    /// </summary>
    public string LastSenderType
    {
        get => _lastSenderType;
        private set
        {
            if (SetValue(ref _lastSenderType, value))
                RaisePropertyChanged(nameof(PreviewText));
        }
    }

    /// <summary>
    /// 当前工单的未读留言数量。
    /// </summary>
    public int UnreadCount
    {
        get => _unreadCount;
        private set => SetValue(ref _unreadCount, value);
    }

    /// <summary>
    /// 本次服务器刷新是否检测到比本地缓存更新的公开消息。
    /// </summary>
    public bool HasNewMessage
    {
        get => _hasNewMessage;
        private set
        {
            if (SetValue(ref _hasNewMessage, value))
                RaisePropertyChanged(nameof(PreviewText));
        }
    }

    /// <summary>
    /// 工单版本号字符串。
    /// </summary>
    public string Version
    {
        get => _version;
        private set => SetValue(ref _version, value);
    }

    /// <summary>
    /// 用于合并工单的 APPID 与订单号组合键。
    /// </summary>
    public string Key => AppId + "|" + WechatOrderId;

    /// <summary>
    /// 工单是否已完结。
    /// </summary>
    public bool IsCompleted =>
        string.Equals(Status, "completed", StringComparison.OrdinalIgnoreCase);

    /// <summary>
    /// 适合列表展示的本地时间文本。
    /// </summary>
    public string UpdatedAtText =>
        UpdatedAt == default
            ? string.Empty
            : UpdatedAt.ToLocalTime().ToString("MM-dd HH:mm", CultureInfo.CurrentCulture);

    /// <summary>
    /// 不读取留言正文时使用的最近动态摘要。
    /// </summary>
    public string PreviewText
    {
        get
        {
            if (HasNewMessage)
                return "有新消息，点击查看";
            if (string.Equals(
                LastSenderType,
                "customer",
                StringComparison.OrdinalIgnoreCase))
            {
                return "客户最近有新留言";
            }
            if (LastReplyAt.HasValue)
                return "客服最近已回复";
            return "暂无公开留言";
        }
    }

    public bool TryApply(WorkOrderSummaryDto dto)
    {
        if (dto == null || !string.Equals(Key, dto.AppId + "|" + dto.WechatOrderId,
                StringComparison.Ordinal))
        {
            return false;
        }

        if (!IsAtLeastCurrentVersion(dto.Version))
            return false;
        Apply(dto);
        return true;
    }

    public void ApplySendResult(string status, string version)
    {
        if (!string.IsNullOrWhiteSpace(status))
        {
            Status = status;
            StatusText = GetStatusText(status);
        }
        if (!string.IsNullOrWhiteSpace(version))
            Version = version;
        UpdatedAt = DateTimeOffset.Now;
        LastMessageAt = UpdatedAt;
        LastSenderType = "customer";
        HasNewMessage = false;
    }

    public void MarkRead()
    {
        UnreadCount = 0;
        HasNewMessage = false;
    }

    /// <summary>
    /// 标记检测到新消息，并确保列表显示未读角标。
    /// </summary>
    public void MarkHasNewMessage()
    {
        HasNewMessage = true;
        if (UnreadCount <= 0)
            UnreadCount = 1;
    }

    private void Apply(WorkOrderSummaryDto dto)
    {
        AppId = dto.AppId;
        WechatOrderId = dto.WechatOrderId;
        Status = dto.Status;
        StatusText = string.IsNullOrWhiteSpace(dto.StatusText)
            ? GetStatusText(dto.Status)
            : dto.StatusText;
        UpdatedAt = ParseTimestamp(dto.UpdatedAt);
        LastMessageAt = ParseTimestamp(dto.LastMessageAt);
        LastReplyAt = ParseNullableTimestamp(dto.LastReplyAt);
        LastSenderType = dto.LastSenderType;
        UnreadCount = Math.Max(0, dto.UnreadCount);
        Version = dto.Version;
    }

    private bool IsAtLeastCurrentVersion(string incomingVersion)
    {
        if (string.IsNullOrWhiteSpace(incomingVersion))
            return true;
        if (!long.TryParse(incomingVersion, out var incoming))
            return true;
        if (!long.TryParse(Version, out var current))
            return true;
        return incoming >= current;
    }

    private static DateTimeOffset ParseTimestamp(string value)
    {
        if (DateTimeOffset.TryParse(
            value,
            CultureInfo.InvariantCulture,
            DateTimeStyles.AssumeUniversal,
            out var parsed))
        {
            return parsed;
        }
        return default;
    }

    private static DateTimeOffset? ParseNullableTimestamp(string value)
    {
        var parsed = ParseTimestamp(value);
        return parsed == default ? (DateTimeOffset?)null : parsed;
    }

    private static string GetStatusText(string status)
    {
        if (string.Equals(status, "waiting_reply", StringComparison.OrdinalIgnoreCase))
            return "待客服回复";
        if (string.Equals(status, "replied", StringComparison.OrdinalIgnoreCase))
            return "客服已回复";
        if (string.Equals(status, "completed", StringComparison.OrdinalIgnoreCase))
            return "已完结";
        return string.IsNullOrWhiteSpace(status) ? "状态未知" : status;
    }
}