using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Runtime.Serialization;
using System.Text;
using System.Threading.Tasks;
using Newtonsoft.Json;

namespace TrainInfomationProviderService.TrainInfo.Entities
{
	public class IndexStorage
	{
		private readonly object _lockObject = new object();

		/// <summary>
		/// 创建 <see cref="IndexStorage" />  的新实例(IndexStorage)
		/// </summary>
		public IndexStorage()
		{
			DateIndices = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
			TrainInfoStorages = new Dictionary<string, TrainInfoStorage>();
		}

		public int Version { get; set; }

		public HashSet<string> DateIndices { get; set; }

		[JsonIgnore]
		public Dictionary<string, TrainInfoStorage> TrainInfoStorages { get; set; }

		[OnDeserialized]
		void Init(StreamingContext ctx)
		{
			lock (_lockObject)
			{
				var dataLoader = new WebDataProvider();
				TrainInfoStorages.Clear();

				var baseDate = DateTime.Now.Date;
				DateIndices = DateIndices.Where(s => s.ToDateTime() >= baseDate).ToHashSet(StringComparer.OrdinalIgnoreCase);
				foreach (var dateIndex in DateIndices.ToArray())
				{
					var data = dataLoader.LoadCache(dateIndex);
					if (data == null)
						DateIndices.Remove(dateIndex);
					else
					{
						data.InitStationTrainData(); 
						TrainInfoStorages.Add(dateIndex, data);
					}
					
				}
			}
		}

		/// <summary>
		/// 移除过时的信息
		/// </summary>
		internal void RemoveOutdateStorage()
		{
			lock (_lockObject)
			{
				var baseDate = DateTime.Now.Date;
				var outdates = DateIndices.Where(s => s.ToDateTime() < baseDate).ToArray();

				Trace.TraceInformation("[TRAIN_INDEX_STORAGE] 正在检查过期数据");
				foreach (var outdate in outdates)
				{
					Trace.TraceInformation("[TRAIN_INDEX_STORAGE] 正在移除过期数据 {0}", outdate);
					DateIndices.Remove(outdate);
					if (TrainInfoStorages.ContainsKey(outdate))
						TrainInfoStorages.Remove(outdate);
					Trace.TraceInformation("[TRAIN_INDEX_STORAGE] 完成移除过期数据 {0}", outdate);
				}
				Trace.TraceInformation("[TRAIN_INDEX_STORAGE] 正在移除过期数据");
			}
		}

	}
}