proper error message if already registered

src/rest/restreg.rs

@@ -21,7 +21,7 @@ async fn register(
     db: &State<DatabaseConnection>,
     register: Form<RegisterForm>,
     user: user::Model,
-) -> Redirect {
+) -> Flash<Redirect> {
     let day = day::Entity::find_by_id(*register.day)
         .one(db.inner())
         .await
@@ -30,22 +30,35 @@ async fn register(
 
     if !(day.open_registration || user.is_cox) {
         log::error!("{} tried to register, even though the user it should not be possible to do so via UI -> manually crafted request?", user.name);
-        return Redirect::to("/");
+        return Flash::error(
+            Redirect::to("/"),
+            "Don't (try to ;)) abuse this system! Incident has been reported...",
+        );
     }
 
     let user = user::Model::find_or_create_user(&register.name, db.inner()).await;
 
     let day = format!("{}", day.day.format("%Y-%m-%d"));
     let trip = trip::ActiveModel {
-        day: Set(day),
+        day: Set(day.clone()),
         user_id: Set(user.id),
         ..Default::default()
     };
 
-    log::info!("{} registered for {:?}", user.name, trip);
-    trip.insert(db.inner()).await.unwrap();
-
-    Redirect::to("/")
+    match trip.insert(db.inner()).await {
+        Ok(_) => {
+            log::info!("{} registered for {:?}", user.name, day);
+            Flash::success(Redirect::to("/"), "Erfolgreich angemeldet!")
+        }
+        Err(_) => {
+            log::warn!(
+                "{} tried to register for {:?}, but is already registered",
+                user.name,
+                day
+            );
+            Flash::error(Redirect::to("/"), "Du bist bereits angemeldet")
+        }
+    }
 }
 
 #[derive(FromForm)]