source: binary-improvements/MapRendering/SteamLoginApi.cs@ 497

using System.Net;
using JetBrains.Annotations;
using Webserver;
using Webserver.UrlHandlers;
using Webserver.WebAPI;

namespace AllocsFixes.Web {
        [UsedImplicitly]
        public class SteamLoginApi : AbsWebAPI {
                public override int DefaultPermissionLevel () => 2000;

                private const string pageBasePath = "/legacymap/index.html";

                private const string steamOpenIdVerifyUrl = "verifysteamopenid";
                private const string steamLoginUrl = "loginsteam";
                
                public SteamLoginApi (Webserver.Web _parentWeb) : base(_parentWeb) {
                }

                public override void HandleRequest (RequestContext _context) {
                        if (_context.Request.RemoteEndPoint == null) {
                                WebUtils.WriteText (_context.Response, "No remote endpoint", HttpStatusCode.BadRequest);
                                return;
                        }

                        string subpath = _context.RequestPath;
                        
                        string remoteEndpointString = _context.Request.RemoteEndPoint!.ToString ();
                        
                        if (subpath.StartsWith (steamOpenIdVerifyUrl)) {
                                if (SessionHandler.HandleSteamVerification (ParentWeb.ConnectionHandler, _context, remoteEndpointString)) {
                                        _context.Response.Redirect (pageBasePath);
                                } else {
                                        WebUtils.WriteText (_context.Response, "Login failed", HttpStatusCode.InternalServerError);
                                }
                                return;
                        }
                        
                        if (subpath.StartsWith ("logout")) {
                                SessionHandler.HandleLogout (ParentWeb.ConnectionHandler, _context, pageBasePath);
                                return;
                        }
                        
                        if (subpath.StartsWith (steamLoginUrl)) {
                                string absoluteUrl = _context.Request.Url.AbsolutePath;
                                absoluteUrl = absoluteUrl.Substring (0, absoluteUrl.Length - _context.RequestPath.Length);
                                SessionHandler.HandleSteamLogin (_context, $"{absoluteUrl}{steamOpenIdVerifyUrl}");
                                return;
                        }

                        WebUtils.WriteText (_context.Response, "Invalid path", HttpStatusCode.BadRequest);
                }

        }
}