fix: message notification deletion

src/database/notifications.rs

@@ -0,0 +1,26 @@
+use super::DataManager;
+use oiseau::{params, query_row};
+use tetratto_core::model::{Error, Result};
+
+impl DataManager {
+    /// Get the number of notifications a user has for the given tag.
+    pub async fn get_notifications_count_by_tag(&self, user: usize, tag: &str) -> Result<usize> {
+        let conn = match self.0.connect().await {
+            Ok(c) => c,
+            Err(e) => return Err(Error::DatabaseConnection(e.to_string())),
+        };
+
+        let res = query_row!(
+            &conn,
+            "SELECT COUNT(*)::int FROM notifications WHERE owner = $1 AND tag = $2",
+            params![&(user as i64), &tag],
+            |x| { Ok(x.get::<usize, i32>(0)) }
+        );
+
+        if let Err(e) = res {
+            return Err(Error::DatabaseError(e.to_string()));
+        }
+
+        Ok(res.unwrap() as usize)
+    }
+}