using System;
using System.Diagnostics;
using System.IO;
using System.Net;
using MonoTorrent;
using MonoTorrent.Client.Encryption;
using MonoTorrent.Common;
using MonoTorrent.Dht;
using MonoTorrent.Dht.Listeners;
using MonoTorrent.Tracker;
using MonoTorrent.Client;
using HttpListener = MonoTorrent.Tracker.Listeners.HttpListener;

namespace PatcherServer.Helper
{
	public static class TrackerHelper {
		public const int CLIENT_PORT = 6666;
		public const int DHT_PORT = 6665;

		public static TorrentSettings StandartTorrentSettings { get; private set; }
		public static EngineSettings ClientSettings { get; private set; }

		private static Tracker tracker;
		private static HttpListener listener;
		private static ClientEngine clientEnginge;

		public static void Initialize() {
				StandartTorrentSettings = new TorrentSettings {
				MaxConnections = 120,
				UploadSlots = 120,
				MaxUploadSpeed = 6000,
				UseDht = true,
				EnablePeerExchange = true,
				InitialSeedingEnabled = true
			};

			ClientSettings = new EngineSettings(DataProvider.PatchfilesFolder, 6666) {
				AllowedEncryption = EncryptionTypes.All,
				GlobalMaxUploadSpeed = 60000,
				GlobalMaxConnections = 10240,
				GlobalMaxHalfOpenConnections = 200
			};

			tracker = new Tracker {
				MinAnnounceInterval = TimeSpan.FromSeconds(10),
				AnnounceInterval = TimeSpan.FromSeconds(30),
				AllowNonCompact = true,
				AllowScrape = true
			};

			clientEnginge = new ClientEngine(ClientSettings);
			DhtListener dhtListener = new DhtListener(new IPEndPoint(IPAddress.Any, DHT_PORT));
			clientEnginge.RegisterDht(new DhtEngine(dhtListener));
			clientEnginge.DhtEngine.Start();
			clientEnginge.ChangeListenEndpoint(new IPEndPoint(IPAddress.Any, CLIENT_PORT));
			clientEnginge.LocalPeerSearchEnabled = true;
			clientEnginge.StartAll();
		}

		public static void Start() {
			listener = new HttpListener(DataProvider.TrackerURL);
			tracker.RegisterListener(listener);
			listener.Start();
		}

		public static void Stop() {
			listener.Stop();
		}

		public static void LoadTorrents() {
			int count = 0;
			foreach (var path in Directory.GetFiles(DataProvider.TorrentfilesFolder)) {
				LoadTorrent(path);
				count ++;
			}
			Trace.WriteLine("Loaded " + count + " torrents.");
		}

		public static void LoadTorrent(string path) {
			Debug.WriteLine("Loaded " + path);
			Torrent torrent = Torrent.Load(path);
			TorrentManager manager = new TorrentManager(torrent, DataProvider.PatchfilesFolder, StandartTorrentSettings);
			manager.TorrentStateChanged += TorrentStateChanged;
			AddToTracker(torrent);
			clientEnginge.Register(manager);
			manager.Start();
			manager.TrackerManager.Announce();
		}

		public static void AddToTracker(Torrent torrent) {
			InfoHashTrackable trackable = new InfoHashTrackable(torrent);
			tracker.Add(trackable);
		}

		private static void TorrentStateChanged(object sender, TorrentStateChangedEventArgs e) {
			Trace.WriteLine("Changed torrent state from " + e.OldState + " to " + e.NewState);
		}

		public static void CreateTorrent(string filePath, string savePath) {
			TorrentCreator creator = new TorrentCreator {
				Comment = "Generated Patch-File torrent.",
				CreatedBy = "skeleten's patch system",
				Publisher = "skeleten's patch system"
			};
			TorrentFileSource source = new TorrentFileSource(filePath);
			AddAnnounces(creator);
			CreateTorrentToFile(creator, savePath, source);
			TorrentManager manager = new TorrentManager(Torrent.Load(savePath), DataProvider.PatchfilesFolder,
			                                            StandartTorrentSettings);
			clientEnginge.Register(manager);
			manager.Start();
		}
		
		private static void AddAnnounces(TorrentCreator creator) {
			RawTrackerTier tracker = new RawTrackerTier();
			tracker.Add(DataProvider.TrackerURL);
			creator.Announces.Add(tracker);
		}

		private static void CreateTorrentToFile(TorrentCreator creator, string path, ITorrentFileSource filesource) {
			FileStream outputStream = File.Exists(path) 
			                          	? new FileStream(path, FileMode.Truncate, FileAccess.ReadWrite) 
			                          	: File.Create(path);
			creator.Create(filesource, outputStream);
		}
	}
}