%%%-------------------------------------------------------------------
%%% @doc Тесты клиентского API для отмены вхождения повторяющегося события.
%%%
%%% Покрывает эндпоинты:
%%%   DELETE /v1/events/:id/occurrences/:start_time
%%%
%%% Проверяет:
%%%   - успешную отмену конкретного вхождения
%%%   - ошибку 400 для не-recurring события
%%%   - ошибку 403 при попытке отмены чужим пользователем
%%%   - ошибку 401 без токена
%%% @end
%%%-------------------------------------------------------------------
-module(user_occurrence_cancel_tests).
-include_lib("eunit/include/eunit.hrl").

-export([test/0]).

%%%===================================================================
%%% Главная тестовая функция
%%%===================================================================

-spec test() -> ok.
test() ->
  ct:pal("=== User Occurrence Cancel Tests ==="),
  OwnerToken = api_test_runner:get_user_token(),
  OtherToken = api_test_runner:register_and_login(
    api_test_runner:unique_email(<<"other">>), <<"pass">>),

  % Создаём календарь и повторяющееся событие
  CalId = api_test_runner:create_calendar(OwnerToken, #{title => <<"OccCancel">>}),
  #{<<"id">> := RecurringId} = api_test_runner:client_post(
    <<"/v1/calendars/", CalId/binary, "/events">>, OwnerToken,
    #{title      => <<"Weekly Standup">>,
      start_time => <<"2026-06-01T10:00:00Z">>,
      duration   => 30,
      recurrence => #{freq => <<"WEEKLY">>, interval => 1}}),

  % Получаем вхождения (ответ – список карт)
  OccPath = <<"/v1/events/", RecurringId/binary, "/occurrences?from=2026-06-01T00:00:00Z&to=2026-06-30T00:00:00Z">>,
  Occurrences = api_test_runner:client_get(OccPath, OwnerToken),
  ?assert(is_list(Occurrences)),
  ?assert(length(Occurrences) >= 1),
  #{<<"start_time">> := FirstStart} = hd(Occurrences),

  test_cancel_occurrence(OwnerToken, RecurringId, FirstStart),
  test_cancel_occurrence_on_single_event(OwnerToken, CalId),
  test_cancel_occurrence_forbidden(OtherToken, RecurringId, FirstStart),
  test_cancel_occurrence_unauthorized(RecurringId, FirstStart),

  ct:pal("=== All user occurrence cancel tests passed ==="),
  ok.

%%%===================================================================
%%% Тестовые функции
%%%===================================================================

%% @doc Успешная отмена вхождения: 200 OK.
-spec test_cancel_occurrence(binary(), binary(), binary()) -> ok.
test_cancel_occurrence(Token, EventId, StartTime) ->
  ct:pal("  TEST: Cancel occurrence"),
  Path = <<"/v1/events/", EventId/binary, "/occurrences/", StartTime/binary>>,
  Resp = api_test_runner:client_request(delete, Path, Token),
  {ok, 200, _, Body} = Resp,
  #{<<"status">> := Status} = jsx:decode(list_to_binary(Body), [return_maps]),
  ?assertEqual(<<"cancelled">>, Status),
  ct:pal("    OK: occurrence cancelled").

%% @doc Попытка отменить вхождение для одиночного события: 400.
-spec test_cancel_occurrence_on_single_event(binary(), binary()) -> ok.
test_cancel_occurrence_on_single_event(Token, CalId) ->
  ct:pal("  TEST: Cancel occurrence on non-recurring event"),
  #{<<"id">> := SingleId} = api_test_runner:client_post(
    <<"/v1/calendars/", CalId/binary, "/events">>, Token,
    #{title      => <<"Single">>,
      start_time => <<"2026-06-02T10:00:00Z">>,
      duration   => 30}),
  Path = <<"/v1/events/", SingleId/binary, "/occurrences/2026-06-02T10:00:00Z">>,
  Resp = api_test_runner:client_request(delete, Path, Token),
  ?assertMatch({ok, 400, _, _}, Resp),
  ct:pal("    OK: got 400").

%% @doc Попытка отмены чужим пользователем: 403.
-spec test_cancel_occurrence_forbidden(binary(), binary(), binary()) -> ok.
test_cancel_occurrence_forbidden(OtherToken, EventId, StartTime) ->
  ct:pal("  TEST: Cancel occurrence by non-owner"),
  Path = <<"/v1/events/", EventId/binary, "/occurrences/", StartTime/binary>>,
  Resp = api_test_runner:client_request(delete, Path, OtherToken),
  ?assertMatch({ok, 403, _, _}, Resp),
  ct:pal("    OK: got 403").

%% @doc Запрос без токена: 401.
-spec test_cancel_occurrence_unauthorized(binary(), binary()) -> ok.
test_cancel_occurrence_unauthorized(EventId, StartTime) ->
  ct:pal("  TEST: Cancel occurrence without token"),
  Path = <<"/v1/events/", EventId/binary, "/occurrences/", StartTime/binary>>,
  Resp = api_test_runner:client_request(delete, Path, <<>>),
  ?assertMatch({ok, 401, _, _}, Resp),
  ct:pal("    OK: got 401").