using WxOrder.Framework.Commons;
using _29WxOrderWpf.Ctrls.Statistics.Models;
using _29WxOrderWpf.Ctrls.Statistics.Services;
using AllBase.Model.MvvmBaseClasses;
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Input;
using WxOrder.Framework.Commons;

namespace _29WxOrderWpf.Ctrls.Statistics.ViewModels
{
	/// <summary>
	/// 天/周/月周期统计 - 页面 ViewModel（MVVM）。
	/// 通过 PeriodStatisticType 指定统计周期（Day/Week/Month），
	/// 页面统一展示：筛选条件 + 周期×店铺统计表格 + 分页。
	/// </summary>
	public class PeriodRevenueStatisticsViewModel : PropertyNotifyObject
	{
		/// <summary>每页行数</summary>
		private const int PageSize = 50;

		private readonly IShopRevenueStatisticsService _service;
		private readonly PeriodStatisticType _periodType;
		private readonly DelegateCommand _firstPageCommand;
		private readonly DelegateCommand _prevPageCommand;
		private readonly DelegateCommand _nextPageCommand;
		private readonly DelegateCommand _lastPageCommand;

		private ObservableCollection<ShopOption> _selectedShops;
		private ShopRevenueSummary _summary;
		private ObservableCollection<ShopPeriodStatisticsItem> _statistics;
		private List<ShopPeriodStatisticsItem> _allItems = new List<ShopPeriodStatisticsItem>();
		private int _pageIndex = 1;
		private int _totalPages = 1;
		private int _totalCount;
		private string _pagerText = string.Empty;

		/// <summary>是否已完成首次初始化（用于避免页签来回切换时重复初始化、重复查询）</summary>
		private bool _initialized;

		/// <summary>上一次真正生效（并据此计算过日期）的时间范围选项，避免同一个选项被重复应用</summary>
		private TimeRangeOption _appliedTimeRange;

		public PeriodRevenueStatisticsViewModel(PeriodStatisticType periodType)
			: this(periodType, new ShopRevenueStatisticsService())
		{
		}

		public PeriodRevenueStatisticsViewModel(PeriodStatisticType periodType, IShopRevenueStatisticsService service)
		{
			_periodType = periodType;
			_service = service ?? new ShopRevenueStatisticsService();

			PageTitle = GetPageTitle(periodType);
			PeriodColumnHeader = GetPeriodColumnHeader(periodType);

			TimeRangeOptions = new ObservableCollection<TimeRangeOption>(GetTimeRangeOptions(periodType));

			ShopOptions = new ObservableCollection<ShopOption>();

			QueryCommand = new DelegateCommand(async () => await LoadAsync());
			ResetCommand = new DelegateCommand(Reset);
			_firstPageCommand = new DelegateCommand(() => GoToPage(1), () => HasPrevPage);
			_prevPageCommand = new DelegateCommand(() => GoToPage(PageIndex - 1), () => HasPrevPage);
			_nextPageCommand = new DelegateCommand(() => GoToPage(PageIndex + 1), () => HasNextPage);
			_lastPageCommand = new DelegateCommand(() => GoToPage(TotalPages), () => HasNextPage);

		}

		/// <summary>
		/// 页面首次显示时初始化查询条件并加载数据（由外层 TabControl 的选中事件调用）。
		/// 重复调用（在“综合统计 / 天统计 / 周统计 / 月统计”页签之间来回切换）会被忽略：
		/// 否则每次切回来都会把时间范围和店铺重置成默认值，并重新发起一次查询。
		/// 需要刷新数据时点“查询”按钮即可。
		/// </summary>
		public void Init()
		{
			if (_initialized)
				return;

			_initialized = true;
			InitializeAsync();
		}

		#region 页面标题

		/// <summary>页面标题（天统计/周统计/月统计）</summary>
		public string PageTitle { get; }

		/// <summary>周期列表头（日期/周/月份）</summary>
		public string PeriodColumnHeader { get; }

		private static string GetPageTitle(PeriodStatisticType periodType)
		{
			switch (periodType)
			{
				case PeriodStatisticType.Week:
					return "周统计";
				case PeriodStatisticType.Month:
					return "月统计";
				default:
					return "天统计";
			}
		}

		private static string GetPeriodColumnHeader(PeriodStatisticType periodType)
		{
			switch (periodType)
			{
				case PeriodStatisticType.Week:
					return "周";
				case PeriodStatisticType.Month:
					return "月份";
				default:
					return "日期";
			}
		}

		#endregion

		#region 时间范围选项

		/// <summary>按统计周期返回对应的时间范围选项</summary>
		private static List<TimeRangeOption> GetTimeRangeOptions(PeriodStatisticType periodType)
		{
			switch (periodType)
			{
				case PeriodStatisticType.Week:
					return new List<TimeRangeOption>
					{
						new TimeRangeOption { Text = "本周", Value = "week" },
						new TimeRangeOption { Text = "上周", Value = "lastweek" },
						new TimeRangeOption { Text = "最近2周", Value = "last2weeks" },
						new TimeRangeOption { Text = "最近4周", Value = "last4weeks" },
						new TimeRangeOption { Text = "自定义", Value = "custom" }
					};
				case PeriodStatisticType.Month:
					return new List<TimeRangeOption>
					{
						new TimeRangeOption { Text = "本月", Value = "month" },
						new TimeRangeOption { Text = "上月", Value = "lastmonth" },
						new TimeRangeOption { Text = "最近3个月", Value = "last3months" },
						new TimeRangeOption { Text = "最近6个月", Value = "last6months" },
						new TimeRangeOption { Text = "最近12个月", Value = "last12months" },
						new TimeRangeOption { Text = "自定义", Value = "custom" }
					};
				default:
					return new List<TimeRangeOption>
					{
						new TimeRangeOption { Text = "最近5天", Value = "last5" },
						new TimeRangeOption { Text = "最近10天", Value = "last10" },
						new TimeRangeOption { Text = "最近20天", Value = "last20" },
						new TimeRangeOption { Text = "最近30天", Value = "last30" },
						new TimeRangeOption { Text = "自定义", Value = "custom" }
					};
			}
		}

		/// <summary>按统计周期返回默认选中的时间范围值</summary>
		private static string GetDefaultTimeRangeValue(PeriodStatisticType periodType)
		{
			switch (periodType)
			{
				case PeriodStatisticType.Week:
					return "week";
				case PeriodStatisticType.Month:
					return "month";
				default:
					return "last10";
			}
		}

		#endregion

		#region 查询条件

		/// <summary>时间范围选项</summary>
		public ObservableCollection<TimeRangeOption> TimeRangeOptions { get; }

		/// <summary>选中的时间范围</summary>
		public TimeRangeOption SelectedTimeRange
		{
			get { return this.GetValue(x => x.SelectedTimeRange); }
			set
			{
				this.SetValue(x => x.SelectedTimeRange, value);

				// 只有用户真正切换到“另一个”时间范围选项时才重新计算起止日期。
				// 页签切换时下拉框会把同一个选项（甚至先 null 再回写）重放一遍，
				// 若照样重算，就会把用户手工调过的日期覆盖掉（例如自定义区间被改回“本周”）。
				if (value != null && !ReferenceEquals(_appliedTimeRange, value))
				{
					_appliedTimeRange = value;
					ApplyTimeRange();
				}

				OnPropertyChanged(nameof(IsCustomDateRange));
			}
		}

		/// <summary>是否为自定义时间范围</summary>
		public bool IsCustomDateRange
		{
			get { return SelectedTimeRange != null && SelectedTimeRange.Value == "custom"; }
		}

		/// <summary>开始日期</summary>
		public DateTime StartDate
		{
			get { return this.GetValue(x => x.StartDate); }
			set { this.SetValue(x => x.StartDate, value); }
		}

		/// <summary>结束日期</summary>
		public DateTime EndDate
		{
			get { return this.GetValue(x => x.EndDate); }
			set { this.SetValue(x => x.EndDate, value); }
		}

		/// <summary>店铺选项（“全部店铺”由多选控件“全部商铺”表示）</summary>
		public ObservableCollection<ShopOption> ShopOptions { get; }

		/// <summary>选中的店铺（多选，绑定 ShopFilterComboBox.SelectedItems）</summary>
		public ObservableCollection<ShopOption> SelectedShops
		{
			get { return _selectedShops; }
			set
			{
				_selectedShops = value;
				OnPropertyChanged(nameof(SelectedShops));
			}
		}

		#endregion

		#region 统计结果

		/// <summary>汇总卡片数据</summary>
		public ShopRevenueSummary Summary
		{
			get { return _summary; }
			private set
			{
				_summary = value;
				OnPropertyChanged(nameof(Summary));
			}
		}

		/// <summary>当前页的周期×店铺统计表格数据</summary>
		public ObservableCollection<ShopPeriodStatisticsItem> Statistics
		{
			get { return _statistics; }
			private set
			{
				_statistics = value;
				OnPropertyChanged(nameof(Statistics));
			}
		}

		/// <summary>是否正在加载</summary>
		public bool IsLoading
		{
			get { return this.GetValue(x => x.IsLoading); }
			set { this.SetValue(x => x.IsLoading, value); }
		}

		#endregion

		#region 分页

		/// <summary>总行数</summary>
		public int TotalCount
		{
			get { return _totalCount; }
			private set
			{
				_totalCount = value;
				OnPropertyChanged(nameof(TotalCount));
			}
		}

		/// <summary>当前页码（从 1 开始）</summary>
		public int PageIndex
		{
			get { return _pageIndex; }
			private set
			{
				_pageIndex = value;
				OnPropertyChanged(nameof(PageIndex));
			}
		}

		/// <summary>总页数</summary>
		public int TotalPages
		{
			get { return _totalPages; }
			private set
			{
				_totalPages = value;
				OnPropertyChanged(nameof(TotalPages));
			}
		}

		/// <summary>分页提示文本（共 X 条  第 Y / Z 页）</summary>
		public string PagerText
		{
			get { return _pagerText; }
			private set
			{
				_pagerText = value;
				OnPropertyChanged(nameof(PagerText));
			}
		}

		/// <summary>是否有上一页</summary>
		public bool HasPrevPage
		{
			get { return PageIndex > 1; }
		}

		/// <summary>是否有下一页</summary>
		public bool HasNextPage
		{
			get { return PageIndex < TotalPages; }
		}

		/// <summary>是否多页</summary>
		public bool HasMultiplePages
		{
			get { return TotalPages > 1; }
		}

		/// <summary>首页命令</summary>
		public ICommand FirstPageCommand
		{
			get { return _firstPageCommand; }
		}

		/// <summary>上一页命令</summary>
		public ICommand PrevPageCommand
		{
			get { return _prevPageCommand; }
		}

		/// <summary>下一页命令</summary>
		public ICommand NextPageCommand
		{
			get { return _nextPageCommand; }
		}

		/// <summary>末页命令</summary>
		public ICommand LastPageCommand
		{
			get { return _lastPageCommand; }
		}

		/// <summary>跳转到指定页并刷新当前页数据</summary>
		private void GoToPage(int page)
		{
			if (page < 1)
				page = 1;
			if (page > TotalPages)
				page = TotalPages;
			PageIndex = page;
			ApplyPaging();
		}

		/// <summary>按当前页码截取当前页数据并刷新分页状态</summary>
		private void ApplyPaging()
		{
			var pageItems = _allItems
				.Skip((PageIndex - 1) * PageSize)
				.Take(PageSize)
				.ToList();

			Statistics = new ObservableCollection<ShopPeriodStatisticsItem>(pageItems);
			PagerText = string.Format("共 {0} 条   第 {1} / {2} 页", TotalCount, PageIndex, TotalPages);

			OnPropertyChanged(nameof(HasPrevPage));
			OnPropertyChanged(nameof(HasNextPage));
			OnPropertyChanged(nameof(HasMultiplePages));
			_firstPageCommand.RaiseCanExecuteChanged();
			_prevPageCommand.RaiseCanExecuteChanged();
			_nextPageCommand.RaiseCanExecuteChanged();
			_lastPageCommand.RaiseCanExecuteChanged();
		}

		#endregion

		#region 命令

		/// <summary>查询命令</summary>
		public ICommand QueryCommand { get; }

		/// <summary>重置命令</summary>
		public ICommand ResetCommand { get; }

		#endregion

		#region 初始化

		private async void InitializeAsync()
		{
			try
			{
				// 店铺选项（全部店铺由多选控件“全部商铺”表示，不再额外加入“全部店铺”项）
				var shops = await _service.GetShopOptionsAsync();
				foreach (var shop in shops)
					ShopOptions.Add(shop);
				SelectedShops = new ObservableCollection<ShopOption>(ShopOptions);

				// 默认时间范围
				SelectedTimeRange = TimeRangeOptions.FirstOrDefault(t => t.Value == GetDefaultTimeRangeValue(_periodType));
				ApplyTimeRange();

				await LoadAsync();
			}
			catch (Exception ex)
			{
				MessageBox.Show("初始化数据失败：" + ex.Message, "提示", MessageBoxButton.OK, MessageBoxImage.Warning);
			}
		}

		#endregion

		#region 业务逻辑

		/// <summary>根据时间范围选项计算起止日期</summary>
		private void ApplyTimeRange()
		{
			var now = DateTime.Now;
			var today = now.Date;
			var selected = SelectedTimeRange == null ? string.Empty : SelectedTimeRange.Value;
			switch (selected)
			{
				case "last5":
					StartDate = today.AddDays(-4);
					EndDate = now;
					break;
				case "last10":
					StartDate = today.AddDays(-9);
					EndDate = now;
					break;
				case "last20":
					StartDate = today.AddDays(-19);
					EndDate = now;
					break;
				case "last30":
					StartDate = today.AddDays(-29);
					EndDate = now;
					break;
				case "week":
					{
						int diff = today.DayOfWeek == DayOfWeek.Sunday ? 6 : (int)today.DayOfWeek - 1;
						StartDate = today.AddDays(-diff);
						EndDate = now;
					}
					break;
				case "lastweek":
					{
						int diff = today.DayOfWeek == DayOfWeek.Sunday ? 6 : (int)today.DayOfWeek - 1;
						var thisWeekStart = today.AddDays(-diff);
						StartDate = thisWeekStart.AddDays(-7);
						EndDate = thisWeekStart.AddDays(-1).AddHours(23).AddMinutes(59).AddSeconds(59);
					}
					break;
				case "last2weeks":
					StartDate = today.AddDays(-13);
					EndDate = now;
					break;
				case "last4weeks":
					StartDate = today.AddDays(-27);
					EndDate = now;
					break;
				case "month":
					StartDate = new DateTime(today.Year, today.Month, 1);
					EndDate = now;
					break;
				case "lastmonth":
					{
						var firstOfThisMonth = new DateTime(today.Year, today.Month, 1);
						StartDate = firstOfThisMonth.AddMonths(-1);
						EndDate = firstOfThisMonth.AddDays(-1).AddHours(23).AddMinutes(59).AddSeconds(59);
					}
					break;
				case "last3months":
					StartDate = new DateTime(today.Year, today.Month, 1).AddMonths(-2);
					EndDate = now;
					break;
				case "last6months":
					StartDate = new DateTime(today.Year, today.Month, 1).AddMonths(-5);
					EndDate = now;
					break;
				case "last12months":
					StartDate = new DateTime(today.Year, today.Month, 1).AddMonths(-11);
					EndDate = now;
					break;
				default:
					// 自定义：保持用户选择的日期不变
					break;
			}
		}

		/// <summary>
		/// 根据选中店铺生成查询用 ERP 店铺ID 列表（接口 ShopIds 使用 ShopLoginInfo.ErpShopId）：
		/// 未选/全选/选中“全部店铺”时返回空列表（表示全部店铺）。
		/// </summary>
		private List<string> BuildSelectedShopIds()
		{
			var selected = SelectedShops;
			if (selected == null || selected.Count == 0)
				return new List<string>();

			var ids = selected.Select(s => s == null ? string.Empty : s.ErpShopId).ToList();
			if (ids.Any(string.IsNullOrEmpty))
				return new List<string>();

			if (selected.Count >= ShopOptions.Count)
				return new List<string>();

			return ids;
		}

		/// <summary>组装查询参数（起止日期已保证先后顺序）</summary>
		private ShopRevenueStatisticsQuery BuildQuery()
		{
			if (StartDate > EndDate)
			{
				var temp = StartDate;
				StartDate = EndDate;
				EndDate = temp;
			}

			return new ShopRevenueStatisticsQuery
			{
				StartDate = StartDate,
				EndDate = EndDate,
				ShopIds = BuildSelectedShopIds(),
			};
		}

		/// <summary>执行查询，刷新周期统计表格并回到第一页</summary>
		private async Task LoadAsync()
		{
			IsLoading = true;
			try
			{
				var result = await _service.QueryPeriodStatisticsAsync(BuildQuery(), _periodType);
				Summary = result.Summary;
				_allItems = result.Items ?? new List<ShopPeriodStatisticsItem>();
				TotalCount = _allItems.Count;
				TotalPages = TotalCount == 0 ? 1 : (int)Math.Ceiling(TotalCount / (double)PageSize);
				GoToPage(1);
			}
			catch (Exception ex)
			{
				// 查询异常：保留上一次数据，并弹框提示
				MessageBox.Show("查询失败：" + ex.Message, "提示", MessageBoxButton.OK, MessageBoxImage.Warning);
			}
			finally
			{
				IsLoading = false;
			}
		}

		/// <summary>重置查询条件并重新加载</summary>
		private async void Reset()
		{
			SelectedShops = new ObservableCollection<ShopOption>(ShopOptions);
			SelectedTimeRange = TimeRangeOptions.FirstOrDefault(t => t.Value == GetDefaultTimeRangeValue(_periodType));
			ApplyTimeRange();
			await LoadAsync();
		}

		#endregion



		public ICommand ShowOrderListCommand => new AsyncDelegateCommand<string>(ShowOrderList);

		private async Task ShowOrderList(string type)
		{
			var detailType = ParseDetailType(type);
			List<ShopOrderDetailResponse> showList;
			// 明细接口数据量大、耗时长，期间显示页面统一的加载遮罩，避免点了没反应
			IsLoading = true;
			try
			{
				showList = await _service.QueryOrderRowsAsync(BuildQuery(), detailType)
					?? new List<ShopOrderDetailResponse>();
			}
			catch (Exception ex)
			{
				MessageBox.Show("订单明细查询失败：" + ex.Message, "提示", MessageBoxButton.OK, MessageBoxImage.Warning);
				return;
			}
			finally
			{
				IsLoading = false;
			}

			if (showList.Count == 0)
			{
				MessageBox.Show("未查询到符合条件的订单明细。", "提示", MessageBoxButton.OK, MessageBoxImage.Information);
				return;
			}

			new DialogWindow()
			{
				Title = "订单列表",
				Content = new ShowOrderDialogView(showList, detailType, _service),
				DataContext = showList
			}.ShowDialog();
		}

		/// <summary>卡片“明细”按钮参数 → 订单明细类型（对应接口参数 OrderType）</summary>
		private static ShopOrderDetailType ParseDetailType(string type)
		{
			switch (type)
			{
				case "RefundOrderCount":
					return ShopOrderDetailType.Refund; //退款订单
				case "BuyerRefundRemainingAmount":
					return ShopOrderDetailType.BuyerUnrefunded; //买手未退回金额的订单
				default:
					return ShopOrderDetailType.Valid; //有效订单
			}
		}
	}
}