Implement initial login functionality

pkg/httpx/json.go

@@ -10,17 +10,11 @@ func JSON[T any](f func(r *http.Request) (T, error)) JSONHandler[T] {
 	return JSONHandler[T](f)
 }
 
-// JSONHandler implements [http.Handler] by returning values as json to the caller.
-// In case of an error, a generic "internal server error" message is returned.
-type JSONHandler[T any] func(r *http.Request) (T, error)
-
-// ServeHTTP calls j(r) and returns json
-func (j JSONHandler[T]) ServeHTTP(w http.ResponseWriter, r *http.Request) {
-	// call the function
-	result, err := j(r)
-
+// WriteJSON writes a JSON response of type T to w.
+// If an error occured, writes an error response instead.
+func WriteJSON[T any](result T, err error, w http.ResponseWriter, r *http.Request) {
 	// handle any errors
-	if jsonInterceptor.Intercept(w, r, err) {
+	if JSONInterceptor.Intercept(w, r, err) {
 		return
 	}
 
@@ -29,3 +23,13 @@ func (j JSONHandler[T]) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	w.WriteHeader(http.StatusOK)
 	json.NewEncoder(w).Encode(result)
 }
+
+// JSONHandler implements [http.Handler] by returning values as json to the caller.
+// In case of an error, a generic "internal server error" message is returned.
+type JSONHandler[T any] func(r *http.Request) (T, error)
+
+// ServeHTTP calls j(r) and returns json
+func (j JSONHandler[T]) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	result, err := j(r)
+	WriteJSON(result, err, w, r)
+}