using System;
using System.Security.Cryptography;
using System.Text;

using GamecraftModdingAPI.App;
using GamecraftModdingAPI.Utility;

namespace GamecraftRPC
{
    public static class CallbackUtility
    {
		private const int SALT_BYTE_LENGTH = 256;

		private const string STATE_IN_GAME = "In Game";

		private const string STATE_IN_MENU = "In Menu";

		private const string DEETS_SIM = "Playing ";

		private const string DEETS_BUILD = "Building ";

		private const string DEETS_MENU = null;

		private static RandomNumberGenerator random = RandomNumberGenerator.Create();

		private static long lastUserJoinRequest = 0;

		public static void GameEnter(object sender, GameEventArgs data)
		{
			PresenceUtility.LastGameStart = (ulong)(DateTime.UtcNow.Subtract(new DateTime(1970, 1, 1))).TotalSeconds;
			if (PresenceUtility.IsConnecting && PresenceUtility.Lobby.HasValue)
			{
				PresenceUtility.IsConnecting = false;
				ConnectToGamecraftPeer(PresenceUtility.Lobby.Value);
			}
			else
			{
				Plugin.SetDiscordActivity(
                    state: STATE_IN_GAME,
                    details: DEETS_BUILD + data.GameName,
                    partyMaxSize: 0,
                    partyCurrentSize: 0,
                    start: (long)PresenceUtility.LastGameStart,
                    debug: "GameEnter-API-callback"
                );
				CreateLobby();
			}

		}

		public static void MenuEnter(object sender, MenuEventArgs data)
		{
			if (PresenceUtility.IsConnecting) return;
			PresenceUtility.LastGameStart = 0;
			PresenceUtility.Activity.Timestamps.Start = 0;
			PresenceUtility.Activity.Timestamps.End = 0;
			PresenceUtility.Activity.Party.Id = null;
			PresenceUtility.Activity.Party.Size.CurrentSize = 0;
			PresenceUtility.Activity.Party.Size.MaxSize = 0;
			PresenceUtility.Activity.Details = DEETS_MENU;
			PresenceUtility.Activity.State = STATE_IN_MENU;
			PresenceUtility.Activity.Secrets.Join = null;
			if (PresenceUtility.Lobby.HasValue && Plugin.DiscordRPC != null)
			{
				if (PresenceUtility.IsActivityHost)
				{
					Plugin.DiscordRPC.GetLobbyManager().DeleteLobby(PresenceUtility.Lobby.Value.Id, NobodyCares);
				}
				else
				{
					Plugin.DiscordRPC.GetLobbyManager().DisconnectLobby(PresenceUtility.Lobby.Value.Id, NobodyCares);
				}
				PresenceUtility.Lobby = null;
			}
			PresenceUtility.IsActivityHost = false;
			PresenceUtility.IsServerActive = false;
			Plugin.SetDiscordActivity(PresenceUtility.Activity, debug: "MenuEnter-API-callback");
		}

		public static void SimulationEnter(object sender, GameEventArgs data)
		{
			PresenceUtility.Activity.Details = DEETS_SIM + data.GameName;
			Plugin.SetDiscordActivity(PresenceUtility.Activity, debug: "SimulationEnter-API-callback");
		}

		public static void BuildEnter(object sender, GameEventArgs data)
        {
            PresenceUtility.Activity.Details = DEETS_BUILD + data.GameName;
			Plugin.SetDiscordActivity(PresenceUtility.Activity, debug: "BuildEnter-API-callback");
        }

        private static void CreateLobby()
		{
			if (Plugin.DiscordRPC == null) return;
			Discord.LobbyManager lm = Plugin.DiscordRPC.GetLobbyManager();
			Discord.LobbyTransaction lt = lm.GetLobbyCreateTransaction();
			lt.SetMetadata("steamid", PresenceUtility.SteamId.ToString());
			lt.SetType(Discord.LobbyType.Public);
			lt.SetCapacity(2);
			lm.CreateLobby(lt, SyncActivityLobby);
			PresenceUtility.IsActivityHost = true;
		}

        public static void ActivityJoin(string secret)
		{
			Discord.LobbyManager lm = Plugin.DiscordRPC.GetLobbyManager();
			if (PresenceUtility.Lobby.HasValue)
			{
				lm.DeleteLobby(PresenceUtility.Lobby.Value.Id, NobodyCares);
				PresenceUtility.Lobby = null;
			}
			PresenceUtility.IsActivityHost = false;
            PresenceUtility.IsServerActive = false;
			lm.ConnectLobbyWithActivitySecret(secret, ConnectToGamecraftServerFromLobby);
			lastUserJoinRequest = 0;
			//Logging.MetaLog($"Received activity join");
		}

		public static void ActivityJoinRequest(ref Discord.User user)
        {
			lastUserJoinRequest = user.Id;
            Logging.MetaLog($"Received activity join request from {user.Username}");
        }

		public static void ActivityInvite(Discord.ActivityActionType Type, ref Discord.User user, ref Discord.Activity activity)
		{
			if (Type == Discord.ActivityActionType.Join)
			{
				Logging.MetaLog($"Received invite to join {activity.Secrets.Join} from {user.Username}");
			}
		}

		private static void SyncActivityLobby(Discord.Result result, ref Discord.Lobby lobby)
		{
			Discord.LobbyManager lm = Plugin.DiscordRPC.GetLobbyManager();
			PresenceUtility.Lobby = lobby;
            int lobbySize = lm.MemberCount(lobby.Id);
            Logging.MetaLog($"Lobby {lobby.Id} ({lobbySize}/{lobby.Capacity} players)");
            // TODO sync lobby info to activity
            PresenceUtility.Activity.Secrets.Join = lm.GetLobbyActivitySecret(lobby.Id);
            Logging.MetaLog($"Secret is now {PresenceUtility.Activity.Secrets.Join}");
            PresenceUtility.Activity.Party.Id = lobby.Id.ToString();
			int currentSize = PresenceUtility.PlayerCount > 0 ? (int)PresenceUtility.PlayerCount : lobbySize;
			PresenceUtility.Activity.Party.Size.CurrentSize = currentSize;
			PresenceUtility.Activity.Party.Size.MaxSize = currentSize * 2;
            Plugin.SetDiscordActivity(PresenceUtility.Activity, debug: "SyncActivityLobby-Discord-callback");
		}

		private static void ConnectToGamecraftServerFromLobby(Discord.Result result, ref Discord.Lobby lobby)
		{
			SyncActivityLobby(result, ref lobby);
			Client client = new Client();
			if (client.InMenu)
			{
				PresenceUtility.IsConnecting = true;
				client.MyGames[0].EnterGame();
			}
			else
			{
				ConnectToGamecraftPeer(lobby);
			}
		}

		private static void ConnectToGamecraftPeer(Discord.Lobby lobby)
		{
			Discord.LobbyManager lm = Plugin.DiscordRPC.GetLobbyManager();
            string steamId = lm.GetLobbyMetadataValue(lobby.Id, "steamid");
            Logging.MetaLog($"Joined lobby from request, now joining server hosted by {steamId}");
            GamecraftModdingAPI.Commands.CommandBuilder.Builder()
                                   .Name("ConnectToCreativeServer")
                                   .FromExisting<string>()
                                   .Invoke(steamId);
		}

		public static void DiscordUserJoin(long lobbyId, long userId)
		{
			if (PresenceUtility.IsActivityHost)
			{
				if (!PresenceUtility.IsServerActive)
				{
					Logging.MetaLog("First user connected -- starting server");
					GamecraftModdingAPI.Commands.CommandBuilder.Builder()
								   .Name("StartDefaultServer")
								   .FromExisting()
					               .Invoke();
					PresenceUtility.IsServerActive = true;
				}

			}
		}

		public static void NobodyCares(Discord.Result result)
		{

		}
    }
}