Add dummy logout endpoint

bin/matrixoidc.dart

@@ -35,7 +35,8 @@ void main(List<String> argsRaw) async {
               )
               ..get("/userinfo", apiHelper.userinfoHandler)
               ..get("/bridge", apiHelper.bridgeHandler)
-              ..post("/login", apiHelper.handleLogin)
+              ..post("/login", apiHelper.loginHandler)
+              ..post("/logout", apiHelper.logoutHandler)
               ..post("/token", apiHelper.tokenHandler))
             .call,
       );

lib/helpers/api_helper.dart

@@ -12,7 +12,7 @@ class ApiHelper {
   final Ref ref;
   ApiHelper(this.ref);
 
-  Future<Response> handleLogin(Request request) async {
+  Future<Response> loginHandler(Request request) async {
     final body = await request.readAsString();
     final data = Uri.splitQueryString(body);
 
@@ -157,6 +157,9 @@ class ApiHelper {
     }
   }
 
+  Future<Response> logoutHandler(Request request) async =>
+      Response.ok("Log out is not currently implemented");
+
   Response openidConfiguration(_) {
     final settings = ref.read(SettingsController.provider)!;
     return Response.ok(
@@ -165,6 +168,7 @@ class ApiHelper {
         "authorization_endpoint": settings.authorizeEndpoint,
         "token_endpoint": "${settings.issuer}/token",
         "userinfo_endpoint": "${settings.issuer}/userinfo",
+        "end_session_endpoint": "${settings.issuer}/logout",
         "response_types_supported": ["code"],
         "subject_types_supported": ["public"],
         "id_token_signing_alg_values_supported": ["HS256"],