using System;
using System.IO;
using System.Net;
using sharp.json;
using System.Collections.Generic;
using System.Linq;
namespace sharp.trading.cache
{
	public class HistoryCache
	{
		public static string BaseDataDirectory { get { return Path.Combine(TradingEnvironment.DataDirectory, "cache", "history"); } }
		public static Dictionary<string, HistoryCache> caches = new Dictionary<string, HistoryCache>();

		private static string getCacheName(Market market)
		{
			return Path.Combine(market.Connection.UniqueProviderName, market.PayingSymbol, market.TradedSymbol);
		}
		private static string getCacheDir(Market market)
		{
			return Path.Combine(BaseDataDirectory, getCacheName(market));
		}
		private static bool createIfNotExists(string directoryName)
		{
			if (!Directory.Exists(directoryName))
			{
				Directory.CreateDirectory(directoryName);
				return false;
			}
			return false;
		}

		public static HistoryCache getCache(Market market)
		{
			string cname = getCacheName(market);
			if (!caches.ContainsKey(cname))
			{
				caches[cname] = new HistoryCache(market);
			}
			return caches[cname];
		}

		public string CacheName { get; private set; }
		public string DataDirectory { get; private set; }
		public string HistoricTradesFileName { get; private set; }

		//Dictionary<Int64, HistoricTrade> history = new Dictionary<long, HistoricTrade>();
		SortedSet<HistoricTrade> history = new SortedSet<HistoricTrade>();

		public HistoryCache(Market market){
			CacheName = getCacheName(market);
			DataDirectory = Path.Combine(BaseDataDirectory, CacheName);

			createIfNotExists(DataDirectory);

			HistoricTradesFileName = Path.Combine(DataDirectory, "history.json");

			load();

			// Import Ticks if nothing available
			if (this.history.Count == 0){
				Tick[] ticks = market.getTicks();
				int n = 0;

				foreach (Tick tick in ticks){
					HistoricTrade ht = new HistoricTrade();
					ht.TimeStamp = tick.TimeStamp;
					ht.Price = (tick.CloseAt + tick.OpenAt) / 2;
					ht.Volume = tick.BaseVolume / ht.Price;
					ht.TotalPrice = ht.Price * ht.Volume;
					ht.UniqueID = n++;
					history.Add(ht);
				}

			}


		}

		private void load(){
			if (File.Exists(HistoricTradesFileName)){
				JSON json = JSON.ReadFrom(HistoricTradesFileName);
				foreach (HistoricTrade trade in json.To<HistoricTrade[]>()){
					this.history.Add(trade);
				}
			};
		}
		private void save(){
			lock(this)
			{
				HistoricTrade[] trades = this.history.ToArray();
				JSON json = JSONConverter.From(trades);
				json.WriteTo(HistoricTradesFileName, true);
			}
		}

		public void Update(HistoricTrade[] trades){
			lock (this)
			{
				foreach (HistoricTrade trade in trades)
				{
					if (!history.Contains(trade))
					{
						history.Add(trade);
					}
				}
			}
			save();
		}

		public WeightedAverage calulateWeightedAveragesPerVolume(double volume)
		{
			return calulateWeightedAveragesPerVolume(new double[] { volume })[0];
		}
		public WeightedAverage[] calulateWeightedAveragesPerVolume(double[] volumes)
		{
			WeightedAverage[] averages = new WeightedAverage[volumes.Length];

			for (int n = 0; n<volumes.Length; n++){
				averages[n] = new WeightedAverage("", "");
			}

			lock (this)
			{
				foreach (HistoricTrade trade in this.history)
				{
					int used = 0;

					for (int n = 0; n < volumes.Length; n++)
					{
						if (volumes[n] > 0)
						{
							double v = volumes[n] > trade.Volume ? trade.Volume : volumes[n];
							averages[n].TotalPrice += trade.Price * v;
							averages[n].Volume += v;
							volumes[n] -= v;
							used++;
						}
					}

					if (used == 0)
					{
						break;
					}

				}
			}
			return averages;
		}




		private static void checkDataDirectory(){
			if (!Directory.Exists(BaseDataDirectory)){
				Directory.CreateDirectory(BaseDataDirectory);
			}
		}

	}
}