-module(handler_refresh).
-include("records.hrl").

-export([init/2]).

init(Req, Opts) ->
  handle(Req, Opts).

handle(Req, _Opts) ->
  case cowboy_req:method(Req) of
    <<"POST">> ->
      {ok, Body, Req1} = cowboy_req:read_body(Req),
      case jsx:decode(Body, [return_maps]) of
        #{<<"refresh_token">> := RefreshToken} ->
          case validate_refresh_token(RefreshToken) of
            {ok, UserId} ->
              case core_user:get_by_id(UserId) of
                {ok, User} ->
                  % Генерируем новые токены
                  NewToken = logic_auth:generate_jwt(User#user.id, User#user.role),
                  {NewRefreshToken, ExpiresAt} = logic_auth:generate_refresh_token(User#user.id),

                  % Сохраняем новый refresh token
                  save_refresh_token(User#user.id, NewRefreshToken, ExpiresAt),

                  % Удаляем старый refresh token
                  delete_refresh_token(RefreshToken),

                  Response = #{
                    token => NewToken,
                    refresh_token => NewRefreshToken
                  },
                  send_json(Req1, 200, Response);
                {error, not_found} ->
                  send_error(Req1, 401, <<"User not found">>)
              end;
            {error, expired} ->
              send_error(Req1, 401, <<"Refresh token expired">>);
            {error, invalid} ->
              send_error(Req1, 401, <<"Invalid refresh token">>)
          end;
        _ ->
          send_error(Req1, 400, <<"Missing refresh_token">>)
      end;
    _ ->
      send_error(Req, 405, <<"Method not allowed">>)
  end.

validate_refresh_token(Token) ->
  case get_session_by_token(Token) of
    {ok, Session} ->
      % Проверяем срок действия
      Now = calendar:universal_time(),
      case Session#session.expires_at > Now of
        true -> {ok, Session#session.user_id};
        false -> {error, expired}
      end;
    {error, not_found} ->
      {error, invalid}
  end.

get_session_by_token(Token) ->
  Match = #session{token = Token, type = refresh, _ = '_'},
  case mnesia:dirty_match_object(Match) of
    [] -> {error, not_found};
    [Session] -> {ok, Session}
  end.

save_refresh_token(UserId, Token, ExpiresAt) ->
  Session = #session{
    token = Token,
    user_id = UserId,
    expires_at = ExpiresAt,
    type = refresh
  },
  mnesia:dirty_write(Session).

delete_refresh_token(Token) ->
  Match = #session{token = Token, type = refresh, _ = '_'},
  case mnesia:dirty_match_object(Match) of
    [] -> ok;
    [Session] -> mnesia:dirty_delete_object(Session)
  end.

send_json(Req, Status, Data) ->
  Body = jsx:encode(Data),
  cowboy_req:reply(Status, #{<<"content-type">> => <<"application/json">>}, Body, Req).

send_error(Req, Status, Message) ->
  Body = jsx:encode(#{error => Message}),
  cowboy_req:reply(Status, #{<<"content-type">> => <<"application/json">>}, Body, Req).