using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Net;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading;
using System.Threading.Tasks;
using System.Web.Caching;
using System.Web.Hosting;
using FSLib.Network.Http;
using Newtonsoft.Json;
using TrainInfomationProviderService.StationInfo.Entities;

namespace TrainInfomationProviderService.StationInfo
{
	/// <summary>
	/// </summary>
	public class StationManager
	{
		private static readonly object _lockObject = new object();
		private static StationManager _stationManager;

		public static StationManager Instance
		{
			get
			{
				if (_stationManager == null)
				{
					lock (_lockObject)
					{
						if (_stationManager == null)
						{
							_stationManager = new StationManager();
						}
					}
				}

				return _stationManager;
			}
		}

		/// <summary>
		/// 创建 <see cref="StationManager" />  的新实例(StationManager)
		/// </summary>
		public StationManager()
		{
			Trace.TraceInformation("[STATION] 车站管理器对象已新建");
		}


		private string _dataFilePath;

		/// <summary>
		/// 仓库
		/// </summary>
		public StationStorage Storage
		{
			get
			{
				return _storage;
			}
		}

		public void Init()
		{
			Trace.TraceInformation("[STATION] 正在初始化");

			_dataFilePath = PathUtility.Combine(RunTimeContext.DataStorageRoot, "stations.json");
			Trace.TraceInformation("[STATION] 目标缓存文件路径：{0}", _dataFilePath);

			//if (RunTimeContext.IsWeb)
			//{
			//	Trace.TraceInformation("[STATION] WEB模式");

			//	InitWeb();
			//}
			//else
			//{
			Trace.TraceInformation("[STATION] 服务模式");
			InitService();
			//}
		}

		#region web环境

		///// <summary>
		///// web环境初始化
		///// </summary>
		//void InitWeb()
		//{
		//	Trace.TraceInformation("[STATION] 初始化WEB模式");
		//	LoadCache();
		//}

		//void LoadCache()
		//{
		//	Trace.TraceInformation("[STATION] 正在检查缓存刷新");
		//	_storage = null;
		//	if (File.Exists(_dataFilePath))
		//	{
		//		Trace.TraceInformation("[STATION] 正在加载缓存");
		//		_storage = JsonConvert.DeserializeObject<StationStorage>(File.ReadAllText(_dataFilePath));
		//		Trace.TraceInformation("[STATION] 缓存加载完成");
		//	}

		//	if (Storage != null)
		//	{
		//		Trace.TraceInformation("[STATION] 正在加入HttpRuntime缓存");
		//		HostingEnvironment.Cache.Add("_12306stations", Storage, new CacheDependency(_dataFilePath),
		//			Cache.NoAbsoluteExpiration, Cache.NoSlidingExpiration, CacheItemPriority.High,
		//			(_1, _2, _3) =>
		//			{
		//				Trace.TraceInformation("[STATION] HttpRuntime缓存已被清除，原因：{0}，正在重新加载", _3);
		//				LoadCache();
		//			});
		//		Trace.TraceInformation("[STATION] HttpRuntime缓存加入完成");
		//	}
		//}


		#endregion

		#region 服务模式

		private Timer _checkStationTimer;
		private StationStorage _storage;

		/// <summary>
		/// 服务模式初始化
		/// </summary>
		void InitService()
		{
			if (_dataFilePath.AsFileInfo().Exists)
			{
				Trace.TraceInformation("[STATION] 正在加载文件缓存数据");
				_storage = JsonConvert.DeserializeObject<StationStorage>(File.ReadAllText(_dataFilePath));
				Trace.TraceInformation("[STATION] 文件缓存数据加载完成");
			}
			var lastestVersion = GetLatestVersionFromWeb();
			var needUpdate = _storage == null || _storage.Version < lastestVersion;
			Trace.TraceInformation("[STATION] 最新版本：{0}", lastestVersion);

			if (needUpdate)
			{
				Trace.TraceInformation("[STATION] 正在刷新缓存");
				RefreshStationInfo(lastestVersion);
				SameStationManager.AutoRefreshFromSource();
				Trace.TraceInformation("[STATION] 缓存数据已刷新");
			}
			_checkStationTimer = new Timer(_ => CheckStationVersion(), null, new TimeSpan(0, 30, 0), Timeout.InfiniteTimeSpan);
		}

		void RefreshStationInfo(int version)
		{
			Trace.TraceInformation("[STATION] 正在获得最新车站信息");
			var html = new HttpClient().Create(HttpMethod.Get, "https://kyfw.12306.cn/otn/resources/js/framework/station_name.js", null, null, "").Send();
			if (!html.IsValid())
			{
				Trace.TraceError("[STATION] 车站信息获得失败。错误：{0}", html.Exception);

				return;
			}
			Trace.TraceInformation("[STATION] 正在分析车站信息");

			var mcs = Regex.Matches(html.Result, @"@([^\|]+)\|([^\|]+)\|([^\|]+)\|([^\|]+)\|([^\|]+)\|(\d+)");
			var result = new List<StationDetailInfo>(mcs.Count);
			foreach (Match mc in mcs)
			{
				var s = new StationDetailInfo()
				{
					Code = mc.GetGroupValue(3),
					Name = mc.GetGroupValue(2),
					Py = mc.GetGroupValue(5),
					PyFull = mc.GetGroupValue(4),
					Sort = mc.GetGroupValue(6).ToInt32()
				};
				result.Add(s);
			}
			_storage = new StationStorage(version, result);
			Trace.TraceInformation("[STATION] 车站信息分析完成，{0} 车站。正在缓存车站信息", result.Count);

			//save
			File.WriteAllText(_dataFilePath, JsonConvert.SerializeObject(Storage));
			Trace.TraceInformation("[STATION] 车站信息缓存完成。目标文件 {0}", _dataFilePath);
		}

		void CheckStationVersion()
		{
			var lastestVersion = GetLatestVersionFromWeb();
			if (Storage == null || Storage.Version < lastestVersion)
			{
				RefreshStationInfo(lastestVersion);
			}
			_checkStationTimer.Change(new TimeSpan(0, 30, 0), Timeout.InfiniteTimeSpan);
		}

		/// <summary>
		/// 从网络加载最新的版本号
		/// </summary>
		/// <returns></returns>
		public int GetLatestVersionFromWeb()
		{
			var ctx = new HttpClient().Create<string>(HttpMethod.Get, "https://kyfw.12306.cn/otn/leftTicket/init", "https://kyfw.12306.cn/otn/leftTicket/init").Send();
			if (!ctx.IsValid())
				return 0;

			var version = (int)(Regex.Match(ctx.Result, @"station_name\.js\?station_version=([\d\.]+)").GetGroupValue(1).ToSingle() * 100000);

			return version;
		}


		#endregion
	}
}