source: binary-improvements/MapRendering/Web/Handlers/ApiHandler.cs@ 326

using System;
using System.Collections.Generic;
using System.Net;
using System.Reflection;
using AllocsFixes.NetConnections.Servers.Web.API;

namespace AllocsFixes.NetConnections.Servers.Web.Handlers {
        public class ApiHandler : PathHandler {
                private readonly Dictionary<string, WebAPI> apis = new CaseInsensitiveStringDictionary<WebAPI> ();
                private readonly string staticPart;

                public ApiHandler (string staticPart, string moduleName = null) : base (moduleName) {
                        this.staticPart = staticPart;

                        foreach (Type t in Assembly.GetExecutingAssembly ().GetTypes ()) {
                                if (!t.IsAbstract && t.IsSubclassOf (typeof (WebAPI))) {
                                        ConstructorInfo ctor = t.GetConstructor (new Type [0]);
                                        if (ctor != null) {
                                                WebAPI apiInstance = (WebAPI) ctor.Invoke (new object [0]);
                                                addApi (apiInstance.Name, apiInstance);
                                        }
                                }
                        }

                        // Add dummy types
                        Type dummy_t = typeof (Null);
                        ConstructorInfo dummy_ctor = dummy_t.GetConstructor (new Type [0]);
                        if (dummy_ctor != null) {
                                WebAPI dummy_apiInstance = (WebAPI) dummy_ctor.Invoke (new object[0]);

                                // Permissions that don't map to a real API
                                addApi ("viewallclaims", dummy_apiInstance);
                                addApi ("viewallplayers", dummy_apiInstance);
                        }
                }

                private void addApi (string _apiName, WebAPI _api) {
                        apis.Add (_apiName, _api);
                        WebPermissions.Instance.AddKnownModule ("webapi." + _apiName, _api.DefaultPermissionLevel ());
                }

                public override void HandleRequest (HttpListenerRequest req, HttpListenerResponse resp, WebConnection user,
                        int permissionLevel) {
                        string apiName = req.Url.AbsolutePath.Remove (0, staticPart.Length);
                        if (!AuthorizeForCommand (apiName, user, permissionLevel)) {
                                resp.StatusCode = (int) HttpStatusCode.Forbidden;
                                if (user != null) {
                                        //Log.Out ("ApiHandler: user '{0}' not allowed to execute '{1}'", user.SteamID, apiName);
                                }

                                return;
                        }

                        WebAPI api;
                        if (apis.TryGetValue (apiName, out api)) {
                                try {
                                        api.HandleRequest (req, resp, user, permissionLevel);
                                        return;
                                } catch (Exception e) {
                                        Log.Error ("Error in ApiHandler.HandleRequest(): Handler {0} threw an exception:", api.Name);
                                        Log.Exception (e);
                                        resp.StatusCode = (int) HttpStatusCode.InternalServerError;
                                        return;
                                }
                        }
                        
                        Log.Out ("Error in ApiHandler.HandleRequest(): No handler found for API \"" + apiName + "\"");
                        resp.StatusCode = (int) HttpStatusCode.NotFound;
                }

                private bool AuthorizeForCommand (string apiName, WebConnection user, int permissionLevel) {
                        return WebPermissions.Instance.ModuleAllowedWithLevel ("webapi." + apiName, permissionLevel);
                }
        }
}