source: binary-improvements/7dtd-server-fixes/src/CommonMappingFunctions.cs@ 123

using System;
using System.Collections.Generic;
using System.Text.RegularExpressions;
using ManagedSteam.SteamTypes;

public class CommonMappingFunctions
{
        public static ConnectionManager GetConnectionManager ()
        {
                return ConnectionManager.Instance;
        }

        public static GameManager GetGameManager ()
        {
                return GetConnectionManager ().gameManager;
        }

        public static string GetPlayerName (ClientInfo _ci)
        {
                try {
                        int entityId = GetConnectionManager ().mapClientToEntity [_ci.clientId];
                        return GetGameManager ().World.playerEntities.dict [entityId].EntityName;
                } catch (Exception e) {
                        Log.Out ("Error getting player name for ClientInfo: " + e);
                }
                return null;
        }

        public static EntityPlayer GetEntityPlayer (ClientInfo _ci)
        {
                try {
                        int entityId = GetConnectionManager ().mapClientToEntity [_ci.clientId];
                        return GetGameManager ().World.playerEntities.dict [entityId];
                } catch (Exception e) {
                        Log.Out ("Error getting entity player for ClientInfo: " + e);
                }
                return null;
        }

        public static string GetSteamID (ClientInfo _ci)
        {
                return SingletonMonoBehaviour<Authenticator>.Instance.GetPlayerId (GetPlayerName (_ci));
        }

        public static int GetClientID (ClientInfo _ci)
        {
                if (_ci != null) {
                        if (GetConnectionManager ().connectedClients.ContainsKey (_ci.clientId))
                                return _ci.clientId;
                }
                return -1;
        }

        public static int GetEntityID (ClientInfo _ci)
        {
                try {
                        ConnectionManager cm = GetConnectionManager ();

                        if (cm.mapClientToEntity.ContainsKey (_ci.clientId))
                                return cm.mapClientToEntity [_ci.clientId];
                        else
                                return -1;
                } catch (Exception e) {
                        Log.Out ("Error getting entity ID for ClientInfo: " + e);
                }
                return -1;
        }

        public static ClientInfo GetClientInfoFromEntityID (int _entityId)
        {
                try {
                        ConnectionManager cm = GetConnectionManager ();

                        if (cm.mapClientToEntity.ContainsValue (_entityId)) {
                                foreach (KeyValuePair<int, int> kvp in cm.mapClientToEntity) {
                                        if (kvp.Value == _entityId) {
                                                return cm.connectedClients [kvp.Key];
                                        }
                                }
                        }

                        return null;
                } catch (Exception e) {
                        Log.Out ("Error getting ClientInfo for entity ID: " + e);
                }
                return null;
        }

        public static ClientInfo GetClientInfoFromClientID (int _clientId)
        {
                try {
                        ConnectionManager cm = GetConnectionManager ();

                        if (cm.connectedClients.ContainsKey (_clientId))
                                return cm.connectedClients [_clientId];
                        else
                                return null;
                } catch (Exception e) {
                        Log.Out ("Error getting ClientInfo for client ID: " + e);
                }
                return null;
        }

        public static ClientInfo GetClientInfoFromPlayerName (string _playerName, bool ignoreColorcodes)
        {
                try {
                        ConnectionManager cm = GetConnectionManager ();

                        _playerName = _playerName.ToLower ();
                        if (ignoreColorcodes) {
                                _playerName = Regex.Replace (_playerName, "\\[[0-9a-fA-F]{6}\\]", "");
                        }
                        foreach (ClientInfo ci in cm.connectedClients.Values) {
                                string curName = GetPlayerName (ci).ToLower ();
                                if (ignoreColorcodes) {
                                        curName = Regex.Replace (curName, "\\[[0-9a-fA-F]{6}\\]", "");
                                }
                                if (curName.Equals (_playerName)) {
                                        return ci;
                                }
                        }
                } catch (Exception e) {
                        Log.Out ("Error getting ClientInfo for player name: " + e);
                }
                return null;
        }

        public static ClientInfo GetClientInfoFromNameOrID (string _nameOrId, bool ignoreColorcodes)
        {
                try {
                        int entityId = -1;
                        if (int.TryParse (_nameOrId, out entityId)) {
                                ClientInfo ci = GetClientInfoFromEntityID (entityId);
                                if (ci != null)
                                        return ci;
                        }

                        return GetClientInfoFromPlayerName (_nameOrId, ignoreColorcodes);
                } catch (Exception e) {
                        Log.Out ("Error getting ClientInfo for entity ID or player name: " + e);
                }
                return null;
        }

        public static ClientInfo GetClientInfoFromSteamID (string _steamId)
        {
                try {
                        Dictionary<string, object> uToID = Authenticator.Instance.usersToIDs;
                        foreach (KeyValuePair<string, object> kvp in uToID) {
                                string curId = string.Empty + ((SteamID)kvp.Value).AsUInt64;
                                if (curId.Equals (_steamId)) {
                                        return GetClientInfoFromPlayerName (kvp.Key, false);
                                }
                        }
                } catch (Exception e) {
                        Log.Out ("Error getting ClientInfo for steam ID: " + e);
                }
                return null;
        }

}