validate.erl

login(_DbConn, req#{body = <<>>}) ->
  {error, "No body provided"};
login(DbConn, req#{body = ReqJsonStr}) ->
  case json:parse(ReqJsonStr) of
    {error, Reason} -> 
      {error, Reason};
    {ok, ReqJson} ->
      case validate_and_decode_login_request(ReqJson) of
        {error, Reason} ->
          {error, Reason};
        {ok, #login_request{username = Username, password = Password}} ->
          case db.find_user(DbConn, Username) of
            {error, Reason} ->
              {error, Reason};
            {ok, #user_details{hashed_password = HashedPassword}} ->
              case does_password_match(HashedPassword, Password) of
                {error, Reason} ->
                  {error, Reason};
                {ok, false} ->
                  {error, "Invalid username or password"}
                {ok, true} ->
                  case jwt.generate_token(Username) of
                    {error, Reason} ->
                      {error, Reason};
                    {ok, jwtToken} ->
                      {ok, 200, json:encode([{"token", jwtToken}])}
                  end
              end
          end
      end
  end.