fix login with email

src/user.ml

@@ -164,18 +164,7 @@ let get_nick user_id =
   Ok nick
 
 let login ~login ~password request =
-  if is_banished login then Error "YOU ARE BANISHED"
-  else
-    let* user_id =
-      match Db.find_opt Q.get_user_id_from_nick login with
-      | Error e -> Error (Format.sprintf "db error: %s" (Caqti_error.show e))
-      | Ok None -> (
-        match Db.find_opt Q.get_user_id_from_email login with
-        | Error e -> Error (Format.sprintf "db error: %s" (Caqti_error.show e))
-        | Ok None -> Error "wrong login"
-        | Ok (Some user_id) -> Ok user_id )
-      | Ok (Some user_id) -> Ok user_id
-    in
+  let try_password user_id =
     let^ good_password = Db.find Q.get_password user_id in
     if Bcrypt.verify password (Bcrypt.hash_of_string good_password) then
       let _unit_lwt = Dream.invalidate_session request in
@@ -183,7 +172,21 @@ let login ~login ~password request =
       let* nick = get_nick user_id in
       let _unit_lwt = Dream.put_session "nick" nick request in
       Ok ()
+    else if is_banished login then Error "YOU ARE BANISHED"
     else Error "wrong password"
+  in
+
+  let^ id_from_nick = Db.find_opt Q.get_user_id_from_nick login in
+  let^ id_from_email = Db.find_opt Q.get_user_id_from_email login in
+  let user_id_list = List.filter_map Fun.id [ id_from_nick; id_from_email ] in
+  match user_id_list with
+  | [] -> Error "Invalid login"
+  | [ id ] -> try_password id
+  | [ id_1; id_2 ] -> (
+    match try_password id_1 with
+    | Ok () -> Ok ()
+    | Error _e -> try_password id_2 )
+  | _to_many_ids -> assert false
 
 let valid_nick nick =
   String.length nick < 64