using Nettention.Proud;


using ServerCore;
using ServerBase;
using ServerCommon;
using MetaAssets;


namespace GameServer;


public class HostMigrationFactory
{
	public static IHostMigrator createCommonHostMigrator(int battleModeId, GameServerLogic gameServerLogic)
	{
		// battleModeId <- 게임 모드 ID 테이블 참조용
		// TODO: battleModeId를 사용하여 HostMigrationPolicy 생성하는 것으로 변경 예정
		int game_mode_option_data_id = 1;
		var host_migration_policy = createHostMigrationPolicyByMeta(game_mode_option_data_id);

		var net_server = gameServerLogic.getProudNetListener().getNetServer();
		NullReferenceCheckHelper.throwIfNull(net_server, () => $"net_server is null !!!!");
		var host_migration_system = new HostMigrationSystem(net_server, host_migration_policy);
		var host_migrator = new CommonHostMigrator(host_migration_system, gameServerLogic);
		return host_migrator;
	}

	private static HostMigrationPolicy createHostMigrationPolicyByMeta(int gameModeOptionDataId)
	{
		var meta = getMeta(gameModeOptionDataId);
		return new HostMigrationPolicy
		{
			HostKickFpsThreshold = meta.HostKickFpsThreshold,
			HostKickFpsDuration = TimeSpan.FromSeconds(meta.HostKickFpsDuration),
			HostKickPingThreshold = meta.HostKickPingThreshold,
			HostKickPingDuration = TimeSpan.FromSeconds(meta.HostKickPingDuration),
		};

		GameModeOptionMetaData getMeta(int gameModeOptionDataId)
		{
			var game_mode_option_meta_table = MetaData.Instance.Meta.GameModeOptionMetaTable;
			game_mode_option_meta_table.GameModeOptionDataListbyGameModeOptionId.TryGetValue(gameModeOptionDataId,
				out var game_mode_option_meta);
			NullReferenceCheckHelper.throwIfNull(game_mode_option_meta, () => $"game_mode_option_meta is null !!!!");
			return game_mode_option_meta;
		}
	}
}

public class CommonHostMigrator : IHostMigrator
{
	private readonly HostMigrationSystem m_host_migration_system;
	private string m_host_user_guid = string.Empty;
	private readonly GameServerLogic m_game_server_logic;
	private DateTime m_last_loop_time = DateTime.MinValue;
	private readonly TimeSpan m_loop_interval = TimeSpan.FromSeconds(1);

	public HostID SuperPeerHostId => m_host_migration_system.SuperPeerHostId;
	public HostMigrationSystem HostMigrationSystem => m_host_migration_system;

	public CommonHostMigrator(HostMigrationSystem hostMigrationSystem, GameServerLogic gameServerLogic)
	{
		m_host_migration_system = hostMigrationSystem;
		m_game_server_logic = gameServerLogic;
	}

	public (Result, bool) migrateCheck(bool ignoreInterval = false)
	{
		if (!ignoreInterval && isOnMigrationLoopInterval())
		{
			return (new Result(), false);
		}

		var (is_migrated, new_super_peer_id) = m_host_migration_system.migrateCheck();
		if (is_migrated)
		{
			var (result, user_guid) = getUserGuidByHostId(new_super_peer_id);
			if (result.isFail())
			{
				return (result, is_migrated);
			}

			var host_change_success = m_host_migration_system.changeSuperPeerHostId(new_super_peer_id);
			if (!host_change_success)
			{
				return (new Result
				{
					ErrorCode = ServerErrorCode.NotFoundUser, ResultString = "Failed to change super peer."
				}, is_migrated);
			}
			m_host_user_guid = user_guid;
			return (result, is_migrated);
		}
		return (new Result(), false);
	}

	public void setGroupHostId(HostID groupId)
	{
		m_host_migration_system.setGroupHostId(groupId);
	}

	//=================================================================
	// 삭제 예정
	//=================================================================
	public Result defineHost(HostID p2pGroupId = HostID.HostID_None, SuperPeerSelectionPolicy policy = null!, HostID[] excludes = null!)
	{
		// m_host_migration_system.setGroupHostId(p2pGroupId);
		//
		// var (is_migrated, new_super_peer_id) = m_host_migration_system.migrateCheck();
		//
		// if (is_migrated)
		// {
		// 	var (result, user_guid) = getUserGuidByHostId(new_super_peer_id);
		// 	if (result.isFail())
		// 	{
		// 		return result;
		// 	}
		//
		// 	var host_change_success = m_host_migration_system.changeSuperPeerHostId(new_super_peer_id);
		// 	if (!host_change_success)
		// 	{
		// 		return new Result
		// 		{
		// 			ErrorCode = ServerErrorCode.NotFoundUser, ResultString = "Failed to change super peer."
		// 		};
		// 	}
		// 	m_host_user_guid = user_guid;
		// 	return result;
		// }
		return new Result();
	}

	public Result modifyHost(string userGuid)
	{
		var (result, host_id) = getHostIdByUserGuid(userGuid);
		if (result.isFail())
		{
			return result;
		}

		if (m_host_migration_system.changeSuperPeerHostId(host_id))
		{
			m_host_user_guid = userGuid;
			return result;
		}

		return new Result { ErrorCode = ServerErrorCode.NotFoundUser, ResultString = "Failed to change super peer." };
	}

	public Result removeHost()
	{
		m_host_migration_system.changeSuperPeerHostId(HostID.HostID_None);
		m_host_user_guid = string.Empty;
		return new Result();
	}

	public string getHostUserGuid()
	{
		return m_host_user_guid;
	}

	private (Result, string) getUserGuidByHostId(HostID hostId)
	{
		string err_msg;
		var result = new Result();
		if (hostId == HostID.HostID_None)
		{
			err_msg = $"there is not suitable super peer !!!! host_id : {hostId}";
			result.setFail(ServerErrorCode.NotFoundUser, err_msg);
			return (result, string.Empty);
		}

		var session = m_game_server_logic.getProudNetListener().onLookupEntityWithSession((int)hostId);
		if (session is null)
		{
			err_msg = $"session is null!!!! host_id : {hostId}";
			result.setFail(ServerErrorCode.NotFoundUser, err_msg);
			return (result, string.Empty);
		}

		var player = session as Player;
		if (player is null)
		{
			err_msg = $"player is null!!!! host_id : {hostId}";
			result.setFail(ServerErrorCode.NotFoundUser, err_msg);
			return (result, string.Empty);
		}

		return (result, player.getUserGuid());
	}

	private (Result, HostID) getHostIdByUserGuid(string userGuid)
	{
		string err_msg;
		var result = new Result();
		// todo: 임시 다른 방법 모색 - 비용이 비쌀 수 있음
		var session_pair = m_game_server_logic.getProudNetListener()
			.getEntityWithSessions()
			.FirstOrDefault(x => x.Value.getUserGuid() == userGuid);
		var session = session_pair.Value;
		if (session is null)
		{
			err_msg = $"session is null!!!! user_guid : {userGuid}";
			result.setFail(ServerErrorCode.NotFoundUser, err_msg);
			return (result, HostID.HostID_None);
		}

		if (session is not Player player)
		{
			err_msg = $"player is null!!!! user_guid : {userGuid}";
			result.setFail(ServerErrorCode.NotFoundUser, err_msg);
			return (result, HostID.HostID_None);
		}

		return (result, player.getHostId());
	}


	//=================================================================
	// 호스트 마이그레이션 루프 인터벌 중인지 여부
	//=================================================================
	private bool isOnMigrationLoopInterval()
	{
		if (m_last_loop_time == DateTime.MinValue)
		{
			m_last_loop_time = DateTime.UtcNow;
			return false;
		}

		if (m_last_loop_time.Add(m_loop_interval) < DateTime.UtcNow)
		{
			return true;
		}

		m_last_loop_time = DateTime.UtcNow;
		return false;
	}
}