using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using TrainInfomationProviderService.StationInfo;
using TrainInfomationProviderService.StationInfo.Entities;

namespace TrainInfomationProviderService.TrainInfo.Entities
{
	using System.Text.RegularExpressions;

	public class TrainLineSegment
	{
		StationDetailInfo _toStation;
		StationDetailInfo _fromStation;
		TimeSpan? _elapsedTime;

		public Train Train { get; private set; }

		public TrainStop From { get; private set; }

		public TrainStop To { get; private set; }

		public bool IsBegin
		{
			get { return From.Arrive == null; }
		}

		public bool IsEnd
		{
			get { return To.Left == null; }
		}

		public StationDetailInfo FromStation
		{
			get
			{
				if (_fromStation == null)
					_fromStation = StationManager.Instance.Storage.Stations.GetValue(From.Code);
				return _fromStation;
			}
		}

		public StationDetailInfo ToStation
		{
			get
			{
				if (_toStation == null)
					_toStation = StationManager.Instance.Storage.Stations.GetValue(To.Code);
				return _toStation;
			}
		}

		/// <summary>
		/// 历时
		/// </summary>
		public TimeSpan ElapsedTime => _elapsedTime ?? TimeSpan.Zero;

		int? _calculatedMinutesBase;

		/// <summary>
		/// 进行时间对比的基础分钟数
		/// </summary>
		public int CalculatedMinutesBase
		{
			get
			{
				if (_calculatedMinutesBase == null)
				{
					var minutes = ElapsedTime.TotalMinutes;

					_calculatedMinutesBase = Utility.CalculateTimeForCompare(Train.TrainClass, minutes);
				}
				return _calculatedMinutesBase ?? 0;
			}
		}

		/// <summary>
		/// 创建 <see cref="TrainLineSegment" />  的新实例(TrainLineSegment)
		/// </summary>
		/// <param name="train"></param>
		/// <param name="from"></param>
		/// <param name="to"></param>
		public TrainLineSegment(Train train, TrainStop from, TrainStop to, DateTime baseDate)
		{
			Train = train;
			From = from;
			To = to;

			_left = baseDate.Date.Add(from.Left.Value.AddDays(-from.Left.Value.Days));
			if (_left < baseDate)
				_left = _left.AddDays(1);
			//_arrive = _left.Add(to.Arrive.Value - from.Left.Value);

			//计算历时
			var stopList = train.TrainStops.SkipWhile(s => s != From).TakeWhile(s => s != to).Concat(new[] { to }).ToArray();
			var ts = TimeSpan.Zero;
			var classL = Regex.IsMatch(train.Code, @"^(K[456]\d{3})$", RegexOptions.IgnoreCase);
			for (int i = 1; i < stopList.Length; i++)
			{
				var elpTime = (stopList[i].Arrive ?? TimeSpan.Zero) - (stopList[i - 1].Left ?? TimeSpan.Zero);
				if (elpTime.TotalMinutes < 60 && classL)
					elpTime = elpTime.AddHours(24);
				ts += elpTime;
				if (i < stopList.Length - 1)
					ts += stopList[i].StopTime;
			}
			_elapsedTime = ts;
			_arrive = (_left + ts).Date.Add(to.Arrive.Value);
		}

		DateTime _left, _arrive;

		public DateTime LeftTime
		{
			get { return _left; }
		}

		public DateTime ArriveTime
		{
			get { return _arrive; }
		}
	}
}