allow trip to be deleted if noone has registered yet

src/model/trip.rs

@@ -50,7 +50,7 @@ WHERE day=?
         ret
     }
 
-    async fn get_all_rower_for_id(db: &SqlitePool, id: i64) -> Vec<Registration> {
+    async fn get_all_rower_for_id(db: &SqlitePool, trip_id: i64) -> Vec<Registration> {
         sqlx::query_as!(
             Registration,
             "
@@ -58,7 +58,7 @@ SELECT
     (SELECT name FROM user WHERE user_trip.user_id = user.id) as name,
     (SELECT created_at FROM user WHERE user_trip.user_id = user.id) as registered_at 
 FROM user_trip WHERE trip_details_id = (SELECT trip_details_id FROM trip WHERE id = ?)",
-            id
+            trip_id
         )
         .fetch_all(db)
         .await
@@ -112,7 +112,7 @@ FROM user_trip WHERE trip_details_id = (SELECT trip_details_id FROM trip WHERE i
         }
     }
 
-    pub async fn delete(db: &SqlitePool, user_id: i64, planned_event_id: i64) {
+    pub async fn delete_by_planned_event_id(db: &SqlitePool, user_id: i64, planned_event_id: i64) {
         let _ = sqlx::query!(
             "DELETE FROM trip WHERE cox_id = ? AND planned_event_id = ?",
             user_id,
@@ -122,9 +122,44 @@ FROM user_trip WHERE trip_details_id = (SELECT trip_details_id FROM trip WHERE i
         .await
         .is_ok();
     }
+
+    pub(crate) async fn delete(
+        db: &SqlitePool,
+        user_id: i64,
+        trip_id: i64,
+    ) -> Result<(), TripDeleteError> {
+        let registered_rower = Self::get_all_rower_for_id(db, trip_id).await;
+        if registered_rower.len() > 0 {
+            return Err(TripDeleteError::SomebodyAlreadyRegistered);
+        }
+
+        let trip_cox = sqlx::query!("SELECT cox_id FROM trip WHERE id = ?", trip_id)
+            .fetch_one(db)
+            .await
+            .unwrap(); //TODO: fixme
+        if trip_cox.cox_id != user_id {
+            return Err(TripDeleteError::NotYourTrip);
+        }
+
+        sqlx::query!(
+            "DELETE FROM trip WHERE cox_id = ? AND id = ?",
+            user_id,
+            trip_id
+        )
+        .execute(db)
+        .await
+        .unwrap(); //TODO: fixme
+
+        Ok(())
+    }
 }
 
 pub enum CoxHelpError {
     AlreadyRegisteredAsRower,
     AlreadyRegisteredAsCox,
 }
+
+pub enum TripDeleteError {
+    SomebodyAlreadyRegistered,
+    NotYourTrip,
+}