using System;
using System.Diagnostics;
using System.IO;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using MonoTorrent.Client;
using MonoTorrent.Common;
using Launcher.Code.Helper;

namespace Launcher.Code
{
	public static class BackgroundChecks {
		private static bool running;
		public const int BUFFER_SIZE = 4096;

		public static bool MacAllowed() {
			string mac = DataProvider.Mac;
			return DataProvider.LauncherServiceClient.MACAllowed(mac);
		}
		public static bool NewerVersionAvailable() {
			DataProvider.GetMaxVersion();
			return DataProvider.Version < DataProvider.MaxVersion;
		}
		public static TorrentManager GetDownloadForPatch(string s) {
			if(!NewerVersionAvailable())
				return null;
			Torrent torrent = Torrent.Load(s);
			var manager =  new TorrentManager(torrent, DataProvider.DataFilesFolder, DataProvider.StandartTorrentSettings);
			manager.TorrentStateChanged += TorrentStateChanged;
			manager.PieceManager.BlockReceived += TorrentBlockRecieved;
			return manager;
		}

		private static void TorrentBlockRecieved(object sender, BlockEventArgs e) {
			DataProvider.MainWindowInstance.SaveSetProgress(((TorrentManager) sender).Progress);
		}
		public static void SaveTorrentToFile(Stream stream, long version, long length) {
			string torrentPath = GetTorrentPath(version);
			if(File.Exists(torrentPath))
				return;
			int copied = 0;
			byte[] buffer = new byte[BUFFER_SIZE];
			using (var output = File.Create(torrentPath)) {
				while (copied < length) {
					int readed = stream.Read(buffer, 0, buffer.Length);
					output.Write(buffer, 0, readed);
					copied += readed;
				}
				output.Close();
			}
		}

		private static void TorrentStateChanged(object sender, TorrentStateChangedEventArgs e) {
			Trace.WriteLine("Changed torrent state from " + e.OldState + " to " + e.NewState);
			if (e.NewState == TorrentState.Stopped) {
				DataProvider.ClientEngine.Unregister(sender as TorrentManager);
			}
		}

		public static void Start() {
			StartCheckingFiles();
		}
		public static void Stop() {
			
		}

		private static void StartCheckingFiles() {
			Task t = new Task(() => Trace.WriteLine("Starting checking files"));
			t.ContinueWith(CheckFiles);
			t.Start();
		}
		private static void CheckFiles(Task t) {
			Trace.WriteLine("Checking files..");
			Thread.Sleep(500);
			t.ContinueWith(CheckFiles);
		}
		private static string GetTorrentPath() {
			StringBuilder builder = new StringBuilder();
			builder.Append("Fiesta")
				.Append("-")
				.Append(DataProvider.Version)
				.Append(".torrent");
			return Path.Combine(DataProvider.TorrentFilesFolder, builder.ToString());
		}
		public static string GetTorrentPath(long version)
		{
			StringBuilder builder = new StringBuilder();
			builder.Append("Fiesta")
				.Append("-")
				.Append(version)
				.Append(".torrent");
			return Path.Combine(DataProvider.TorrentFilesFolder, builder.ToString());
		}
		
		public static long DownloadTorrent(out Stream stream) {
			string config = "Fiesta";
			Stream output;
			var length = DataProvider.PatcherServiceClient.GetTorrentForVersion(ref DataProvider._v, ref config, out output);
			stream = output;
			return length;
		}
	}
}