using System;
using System.Collections.Generic;
using System.IO;
using System.Net;
using System.Net.Sockets;
using System.Reflection;
using System.Text;
using System.Threading;
using AllocsFixes.FileCache;
using AllocsFixes.NetConnections.Servers.Web.Handlers;
using UnityEngine;

namespace AllocsFixes.NetConnections.Servers.Web {
	public class Web : IConsoleServer {
		private const int GUEST_PERMISSION_LEVEL = 2000;
		public static int handlingCount;
		public static int currentHandlers;
		public static long totalHandlingTime = 0;
		private readonly HttpListener _listener = new HttpListener ();
		private readonly string dataFolder;
		private readonly Dictionary<string, PathHandler> handlers = new Dictionary<string, PathHandler> ();
		private readonly bool useStaticCache;

		public ConnectionHandler connectionHandler;

		public Web () {
			try {
				int webPort = GamePrefs.GetInt (EnumGamePrefs.ControlPanelPort);
				if (webPort < 1 || webPort > 65533) {
					Log.Out ("Webserver not started (ControlPanelPort not within 1-65533)");
					return;
				}

				if (!Directory.Exists (Path.GetDirectoryName (Assembly.GetExecutingAssembly ().Location) +
				                       "/webserver")) {
					Log.Out ("Webserver not started (folder \"webserver\" not found in WebInterface mod folder)");
					return;
				}

				// TODO: Read from config
				useStaticCache = false;

				dataFolder = Path.GetDirectoryName (Assembly.GetExecutingAssembly ().Location) + "/webserver";

				if (!HttpListener.IsSupported) {
					Log.Out ("Webserver not started (needs Windows XP SP2, Server 2003 or later or Mono)");
					return;
				}

				handlers.Add (
					"/index.htm",
					new SimpleRedirectHandler ("/static/index.html"));
				handlers.Add (
					"/favicon.ico",
					new SimpleRedirectHandler ("/static/favicon.ico"));
				handlers.Add (
					"/session/",
					new SessionHandler (
						"/session/",
						dataFolder,
						this)
				);
				handlers.Add (
					"/userstatus",
					new UserStatusHandler ()
				);
				if (useStaticCache) {
					handlers.Add (
						"/static/",
						new StaticHandler (
							"/static/",
							dataFolder,
							new SimpleCache (),
							false)
					);
				} else {
					handlers.Add (
						"/static/",
						new StaticHandler (
							"/static/",
							dataFolder,
							new DirectAccess (),
							false)
					);
				}

				handlers.Add (
					"/itemicons/",
					new ItemIconHandler (
						"/itemicons/",
						true)
				);

				handlers.Add (
					"/map/",
					new StaticHandler (
						"/map/",
						GameUtils.GetSaveGameDir () + "/map",
						MapRendering.MapRendering.GetTileCache (),
						false,
						"web.map")
				);

				handlers.Add (
					"/api/",
					new ApiHandler ("/api/")
				);

				connectionHandler = new ConnectionHandler (this);

				_listener.Prefixes.Add (string.Format ("http://*:{0}/", webPort + 2));
				_listener.Start ();

				SdtdConsole.Instance.RegisterServer (this);

				_listener.BeginGetContext (HandleRequest, _listener);

				Log.Out ("Started Webserver on " + (webPort + 2));
			} catch (Exception e) {
				Log.Out ("Error in Web.ctor: " + e);
			}
		}

		public void Disconnect () {
			try {
				_listener.Stop ();
				_listener.Close ();
			} catch (Exception e) {
				Log.Out ("Error in Web.Disconnect: " + e);
			}
		}

		public void SendLine (string line) {
			connectionHandler.SendLine (line);
		}

		public void SendLog (string text, string trace, LogType type) {
			// Do nothing, handled by LogBuffer internally
		}

		public static bool isSslRedirected (HttpListenerRequest req) {
			string proto = req.Headers ["X-Forwarded-Proto"];
			if (!string.IsNullOrEmpty (proto)) {
				return proto.Equals ("https", StringComparison.OrdinalIgnoreCase);
			}

			return false;
		}

		private void HandleRequest (IAsyncResult result) {
			if (_listener.IsListening) {
				Interlocked.Increment (ref handlingCount);
				Interlocked.Increment (ref currentHandlers);

//				MicroStopwatch msw = new MicroStopwatch ();
				HttpListenerContext ctx = _listener.EndGetContext (result);
				_listener.BeginGetContext (HandleRequest, _listener);
				try {
					HttpListenerRequest request = ctx.Request;
					HttpListenerResponse response = ctx.Response;
					response.SendChunked = false;

					response.ProtocolVersion = new Version ("1.1");

					WebConnection conn;
					int permissionLevel = DoAuthentication (request, out conn);


					//Log.Out ("Login status: conn!=null: {0}, permissionlevel: {1}", conn != null, permissionLevel);


					if (conn != null) {
						Cookie cookie = new Cookie ("sid", conn.SessionID, "/");
						cookie.Expired = false;
						cookie.Expires = new DateTime (2020, 1, 1);
						cookie.HttpOnly = true;
						cookie.Secure = false;
						response.AppendCookie (cookie);
					}

					// No game yet -> fail request
					if (GameManager.Instance.World == null) {
						response.StatusCode = (int) HttpStatusCode.ServiceUnavailable;
						return;
					}

					if (request.Url.AbsolutePath.Length < 2) {
						handlers ["/index.htm"].HandleRequest (request, response, conn, permissionLevel);
						return;
					} else {
						foreach (KeyValuePair<string, PathHandler> kvp in handlers) {
							if (request.Url.AbsolutePath.StartsWith (kvp.Key)) {
								if (!kvp.Value.IsAuthorizedForHandler (conn, permissionLevel)) {
									response.StatusCode = (int) HttpStatusCode.Forbidden;
									if (conn != null) {
										//Log.Out ("Web.HandleRequest: user '{0}' not allowed to access '{1}'", conn.SteamID, kvp.Value.ModuleName);
									}
								} else {
									kvp.Value.HandleRequest (request, response, conn, permissionLevel);
								}

								return;
							}
						}
					}

					// Not really relevant for non-debugging purposes:
					//Log.Out ("Error in Web.HandleRequest(): No handler found for path \"" + request.Url.AbsolutePath + "\"");
					response.StatusCode = (int) HttpStatusCode.NotFound;
				} catch (IOException e) {
					if (e.InnerException is SocketException) {
						Log.Out ("Error in Web.HandleRequest(): Remote host closed connection: " +
						         e.InnerException.Message);
					} else {
						Log.Out ("Error (IO) in Web.HandleRequest(): " + e);
					}
				} catch (Exception e) {
					Log.Out ("Error in Web.HandleRequest(): " + e);
				} finally {
					if (ctx != null && !ctx.Response.SendChunked) {
						ctx.Response.Close ();
					}

//					msw.Stop ();
//					totalHandlingTime += msw.ElapsedMicroseconds;
//					Log.Out ("Web.HandleRequest(): Took {0} µs", msw.ElapsedMicroseconds);
					Interlocked.Decrement (ref currentHandlers);
				}
			}
		}

		private int DoAuthentication (HttpListenerRequest _req, out WebConnection _con) {
			_con = null;

			string sessionId = null;
			if (_req.Cookies ["sid"] != null) {
				sessionId = _req.Cookies ["sid"].Value;
			}

			if (!string.IsNullOrEmpty (sessionId)) {
				WebConnection con = connectionHandler.IsLoggedIn (sessionId, _req.RemoteEndPoint.Address.ToString ());
				if (con != null) {
					_con = con;
					return GameManager.Instance.adminTools.GetAdminToolsClientInfo (_con.SteamID.ToString ())
						.PermissionLevel;
				}
			}

			if (_req.QueryString ["adminuser"] != null && _req.QueryString ["admintoken"] != null) {
				WebPermissions.AdminToken admin = WebPermissions.Instance.GetWebAdmin (_req.QueryString ["adminuser"],
					_req.QueryString ["admintoken"]);
				if (admin != null) {
					return admin.permissionLevel;
				}

				Log.Warning ("Invalid Admintoken used from " + _req.RemoteEndPoint);
			}

			if (_req.Url.AbsolutePath.StartsWith ("/session/verify")) {
				try {
					ulong id = OpenID.Validate (_req);
					if (id > 0) {
						WebConnection con = connectionHandler.LogIn (id, _req.RemoteEndPoint.Address.ToString ());
						_con = con;
						int level = GameManager.Instance.adminTools.GetAdminToolsClientInfo (id.ToString ())
							.PermissionLevel;
						Log.Out ("Steam OpenID login from {0} with ID {1}, permission level {2}",
							_req.RemoteEndPoint.ToString (), con.SteamID, level);
						return level;
					}

					Log.Out ("Steam OpenID login failed from {0}", _req.RemoteEndPoint.ToString ());
				} catch (Exception e) {
					Log.Error ("Error validating login:");
					Log.Exception (e);
				}
			}

			return GUEST_PERMISSION_LEVEL;
		}

		public static void SetResponseTextContent (HttpListenerResponse resp, string text) {
			byte[] buf = Encoding.UTF8.GetBytes (text);
			resp.ContentLength64 = buf.Length;
			resp.ContentType = "text/html";
			resp.ContentEncoding = Encoding.UTF8;
			resp.OutputStream.Write (buf, 0, buf.Length);
		}
	}
}