daemon: add support for getting messages from db

kordophone-db/src/repository.rs

@@ -207,6 +207,21 @@ impl<'a> Repository<'a> {
         Ok(result)
     }
 
+    pub fn get_last_message_for_conversation(&mut self, conversation_guid: &str) -> Result<Option<Message>> {
+        use crate::schema::messages::dsl::*;
+        use crate::schema::conversation_messages::dsl::*;
+
+        let message_record = conversation_messages
+            .filter(conversation_id.eq(conversation_guid))
+            .inner_join(messages)
+            .select(MessageRecord::as_select())
+            .order_by(schema::messages::date.desc())
+            .first::<MessageRecord>(self.connection)
+            .optional()?;
+
+        Ok(message_record.map(|r| r.into()))
+    }
+
     // Helper function to get the last inserted row ID
     // This is a workaround since the Sqlite backend doesn't support `RETURNING`
     // Huge caveat with this is that it depends on whatever the last insert was, prevents concurrent inserts.

kordophone-db/src/tests/mod.rs

@@ -310,6 +310,10 @@ async fn test_insert_messages_batch() {
                 ),
             }
         }
+
+        // Make sure the last message is the last one we inserted
+        let last_message = repository.get_last_message_for_conversation(&conversation_id).unwrap().unwrap();
+        assert_eq!(last_message.id, message4.id);
     })
     .await;
 }