using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Security.Policy;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Windows.Forms.VisualStyles;
using FSLib.Network.Http;
using Newtonsoft.Json;

namespace TrainInfomationProviderService.StationInfo
{
	using TrainInfomationProviderService.Web;

	class SameStationManager
	{
		public static Dictionary<string, HashSet<string>> SameStationMap { get; private set; }

		private static Timer _timer;
		internal static string _cacheUrl;

		public static void Init()
		{
			_cacheUrl = PathUtility.Combine(RunTimeContext.DataStorageRoot, "samestation.json");
			SameStationMap = new Dictionary<string, HashSet<string>>(StringComparer.OrdinalIgnoreCase);
			LoadCache();

			if (StationManager.Instance.Storage != null)
			{
				AutoRefreshFromSource();
			}
		}

		static void LoadCache()
		{
			if (!File.Exists(_cacheUrl)) return;

			var list = JsonConvert.DeserializeObject<List<HashSet<string>>>(File.ReadAllText(_cacheUrl));
			foreach (var hashSet in list)
			{
				foreach (var s in hashSet)
				{
					SameStationMap.AddOrUpdate(s, hashSet);
				}
			}
		}

		static void Grabber()
		{
			try
			{
				GrabberFromWeb();
			}
			catch (Exception)
			{

			}

			_timer.Change(new TimeSpan(0, 30, 0), Timeout.InfiniteTimeSpan);
		}

		internal static void Save()
		{
			lock (_cacheUrl)
			{
				File.WriteAllText(_cacheUrl, JsonConvert.SerializeObject(SameStationMap.Values.Distinct().ToArray()));
			}
		}

		internal static void AutoRefreshFromSource()
		{
			var map = SameStationMap;
			if (map == null)
				return;

			var count = map.Count;
			var stations = StationManager.Instance.Storage.StationNameMap.Values.OrderByDescending(s => s.Name.Length).ToList();

			while (stations.Count > 0)
			{
				var st = stations.Last();
				stations.RemoveAt(stations.Count - 1);

				HashSet<string> collection = null;
				for (var i = stations.Count - 1; i >= 0; i--)
				{
					if (stations[i].Name.IndexOf(st.Name) != 0)
						continue;

					(collection ?? (collection = new HashSet<string>(StringComparer.OrdinalIgnoreCase) { st.Code })).Add(stations[i].Code);
					stations.RemoveAt(i);
					i--;
				}
				if (collection != null && collection.Count > 1)
				{
					var curSet = collection.Select(map.GetValue).FirstOrDefault(s => s != null) ?? new HashSet<string>(StringComparer.OrdinalIgnoreCase);
					foreach (var s1 in collection)
					{
						curSet.SafeAdd(s1);
					}

					foreach (var s in collection)
					{
						map.AddOrUpdate(s, curSet);
					}
				}
			}
			if (SameStationMap.Count != count)
			{
				//有变化
				Save();
			}
		}

		private static string _url = "http://service.fishlee.net/ss.json";

		static bool GrabberFromWeb()
		{
			var ctx = new HttpWebClient().Create<string>(HttpMethod.Get, _url).Send();
			if (!ctx.IsValid())
				return false;

			//缓存
			File.WriteAllText(_cacheUrl, ctx.Result);

			var list = JsonConvert.DeserializeObject<List<HashSet<string>>>(File.ReadAllText(_cacheUrl));
			var map = SameStationMap;
			var count = SameStationMap.Count;
			foreach (var hashSet in list)
			{
				var curSet = hashSet.Select(map.GetValue).FirstOrDefault(s => s != null) ?? new HashSet<string>(StringComparer.OrdinalIgnoreCase);
				foreach (var s1 in hashSet)
				{
					curSet.SafeAdd(s1);
				}

				foreach (var s in hashSet)
				{
					map.AddOrUpdate(s, curSet);
				}
			}
			if (SameStationMap.Count != count)
			{
				//有变化
				Save();
			}

			return true;
		}
	}
}