source: binary-improvements/MapRendering/API/GetPlayersLocation.cs

using System.Collections.Generic;
using AllocsFixes.PersistentData;
using JetBrains.Annotations;
using Utf8Json;
using Webserver;
using Webserver.Permissions;
using Webserver.WebAPI;

namespace AllocsFixes.WebAPIs {
        [UsedImplicitly]
        public class GetPlayersLocation : AbsWebAPI {
                private static readonly byte[] jsonKeySteamId = JsonWriter.GetEncodedPropertyNameWithBeginObject ("steamid");
                private static readonly byte[] jsonKeyCrossPlatformId = JsonWriter.GetEncodedPropertyNameWithPrefixValueSeparator ("crossplatformid");
                private static readonly byte[] jsonKeyName = JsonWriter.GetEncodedPropertyNameWithPrefixValueSeparator ("name");
                private static readonly byte[] jsonKeyOnline = JsonWriter.GetEncodedPropertyNameWithPrefixValueSeparator ("online");
                private static readonly byte[] jsonKeyPosition = JsonWriter.GetEncodedPropertyNameWithPrefixValueSeparator ("position");

                public override void HandleRequest (RequestContext _context) {
                        AdminTools admTools = GameManager.Instance.adminTools;
                        PlatformUserIdentifierAbs userId = _context.Connection?.UserId;

                        bool listOffline = false;
                        if (_context.Request.QueryString ["offline"] != null) {
                                bool.TryParse (_context.Request.QueryString ["offline"], out listOffline);
                        }

                        bool bViewAll = PermissionUtils.CanViewAllPlayers (_context.PermissionLevel);

                        JsonWriter writer = new JsonWriter ();
                        
                        writer.WriteBeginArray ();
                        
                        bool first = true;

                        Players playersList = PersistentContainer.Instance.Players;

                        foreach (KeyValuePair<PlatformUserIdentifierAbs, Player> kvp in playersList.Dict) {
                                if (admTools != null) {
                                        if (admTools.Blacklist.IsBanned (kvp.Key, out _, out _)) {
                                                continue;
                                        }
                                }

                                Player p = kvp.Value;

                                if (listOffline || p.IsOnline) {
                                        if (bViewAll || p.InternalId.Equals (userId)) {

                                                if (!first) {
                                                        writer.WriteValueSeparator ();
                                                }

                                                first = false;
                                
                                                writer.WriteRaw (jsonKeySteamId);
                                                writer.WriteString (kvp.Value.PlatformId.CombinedString);
                                
                                                writer.WriteRaw (jsonKeyCrossPlatformId);
                                                writer.WriteString (kvp.Value.CrossPlatformId?.CombinedString ?? "");
                                
                                                writer.WriteRaw (jsonKeyName);
                                                writer.WriteString (p.Name);
                                
                                                writer.WriteRaw (jsonKeyOnline);
                                                writer.WriteBoolean (p.IsOnline);
                                
                                                writer.WriteRaw (jsonKeyPosition);
                                                JsonCommons.WriteVector3I (ref writer, p.LastPosition);
                                
                                                writer.WriteEndObject ();
                                        }
                                }
                        }
                        
                        writer.WriteEndArray ();
                        
                        WebUtils.WriteJsonData (_context.Response, ref writer);
                }
        }
}