Channel add behavior now also returns the same new channel that was just added

! We do this because in order to `get` the channel later we need its id.
Some clients will be updating channel data periodically so this helps to make smaller queries possible

server-api/db/src/channels.rs

@@ -154,5 +154,40 @@ impl FromDB<Channel, Integer> for Channel {
 }
 
 impl Channel {
-    pub async fn add() {}
+    pub async fn add(p: &Pool, name: &str, desc: &str, kind: Integer) -> Response<Self> {
+        //! @returns on success -> Response::Row<Channel>
+        //! @returns on partial success -> Response::Empty
+        //! @returns on failure -> Response::Other
+        if let Ok(conn) = p.get_conn().await {
+            let q = "INSERT INTO channels (name, description, kind) VALUES (:n, :d, :k)";
+            let insert_result = conn.drop_exec(q, params!{
+                "n" => name,
+                "d" => desc,
+                "k" => kind
+            }).await;
+            if let Ok(conn) = insert_result {
+                // This is only kosher because names are enforced as unique by sql
+                let q = "SELECT id FROM channels WHERE name = :name";
+                let fetch_result : Result<(Conn, Option<UBigInt>), SqlError> = 
+                    conn.first_exec(q, params!{"name" => name}).await;
+
+                return match fetch_result {
+                    Ok((_, id_opt)) => {
+                        if let Some(id) = id_opt {
+                            Response::Row(Channel {
+                                id: id,
+                                name: name.into(),
+                                description: Some(desc.into()),
+                                kind: kind
+                            })
+                        }
+                        else { Response::Empty }
+                    },
+                    Err(_) => Response::Empty
+                };
+            }
+            return Response::Other("Could fetch new channel".into());
+        }
+        return Response::Other(no_conn!("db::channels::add"))
+    }
 }