-module(core_booking).
-include("records.hrl").
-export([create/3, get_by_id/1, list_by_event/1, list_by_user/1, update/2, delete/1]).
-export([count_bookings/0, get_by_event_and_user/2]).
-export([list_all/0]).   % ← добавлено

%% ─────────────────────────────────────────────────────────────────
%% Значения по умолчанию для необязательных полей
%% ─────────────────────────────────────────────────────────────────
-define(DEFAULT_NOTES,         <<>>).
-define(DEFAULT_REMINDER_SENT, false).
-define(DEFAULT_CONFIRMED_AT,  {{1970,1,1},{0,0,0}}).

%%%-------------------------------------------------------------------
%%% @doc Создание бронирования.
%%% @end
%%%-------------------------------------------------------------------
-spec create(EventId :: binary(), UserId :: binary(), Status :: atom()) ->
  {ok, #booking{}} | {error, term()}.
create(EventId, UserId, Status) ->
  Id = infra_utils:generate_id(16),
  Now = calendar:universal_time(),
  Booking = #booking{
    id            = Id,
    event_id      = EventId,
    user_id       = UserId,
    status        = Status,
    notes         = ?DEFAULT_NOTES,
    reminder_sent = ?DEFAULT_REMINDER_SENT,
    confirmed_at  = ?DEFAULT_CONFIRMED_AT,
    created_at    = Now,
    updated_at    = Now
  },
  F = fun() -> mnesia:write(Booking), {ok, Booking} end,
  case mnesia:transaction(F) of
    {atomic, Result} -> Result;
    {aborted, Reason} -> {error, Reason}
  end.

%%%-------------------------------------------------------------------
%%% @doc Получить бронирование по идентификатору.
%%% @end
%%%-------------------------------------------------------------------
-spec get_by_id(Id :: binary()) -> {ok, #booking{}} | {error, not_found}.
get_by_id(Id) ->
  case mnesia:dirty_read(booking, Id) of
    [] -> {error, not_found};
    [Booking] -> {ok, Booking}
  end.

%%%-------------------------------------------------------------------
%%% @doc Список бронирований для события.
%%% @end
%%%-------------------------------------------------------------------
-spec list_by_event(EventId :: binary()) -> {ok, [#booking{}]}.
list_by_event(EventId) ->
  Match = #booking{event_id = EventId, _ = '_'},
  Bookings = mnesia:dirty_match_object(Match),
  {ok, Bookings}.

%%%-------------------------------------------------------------------
%%% @doc Список бронирований пользователя.
%%% @end
%%%-------------------------------------------------------------------
-spec list_by_user(UserId :: binary()) -> {ok, [#booking{}]}.
list_by_user(UserId) ->
  Match = #booking{user_id = UserId, _ = '_'},
  Bookings = mnesia:dirty_match_object(Match),
  {ok, Bookings}.

%%%-------------------------------------------------------------------
%%% @doc Получить все бронирования (административный режим).
%%% @end
%%%-------------------------------------------------------------------
-spec list_all() -> [#booking{}].
list_all() ->
  mnesia:dirty_match_object(#booking{_ = '_'}).

%%%-------------------------------------------------------------------
%%% @doc Обновить поля бронирования.
%%% @end
%%%-------------------------------------------------------------------
-spec update(Id :: binary(), Updates :: [{atom(), term()}]) ->
  {ok, #booking{}} | {error, not_found | term()}.
update(Id, Updates) ->
  F = fun() ->
    case mnesia:read(booking, Id) of
      [] -> {error, not_found};
      [Booking] ->
        UpdatedBooking = apply_updates(Booking, Updates),
        mnesia:write(UpdatedBooking),
        {ok, UpdatedBooking}
    end
      end,
  case mnesia:transaction(F) of
    {atomic, Result} -> Result;
    {aborted, Reason} -> {error, Reason}
  end.

%%%-------------------------------------------------------------------
%%% @doc Удаление бронирования (физическое).
%%% @end
%%%-------------------------------------------------------------------
-spec delete(Id :: binary()) -> ok | {error, not_found}.
delete(Id) ->
  case mnesia:dirty_read(booking, Id) of
    [] -> {error, not_found};
    [_] -> mnesia:dirty_delete(booking, Id), ok
  end.

%%%-------------------------------------------------------------------
%%% @doc Количество бронирований.
%%% @end
%%%-------------------------------------------------------------------
-spec count_bookings() -> non_neg_integer().
count_bookings() ->
  mnesia:table_info(booking, size).

%%%-------------------------------------------------------------------
%%% @doc Получить бронирование по событию и пользователю.
%%% @end
%%%-------------------------------------------------------------------
-spec get_by_event_and_user(EventId :: binary(), UserId :: binary()) ->
  {ok, #booking{}} | {error, not_found}.
get_by_event_and_user(EventId, UserId) ->
  Match = #booking{event_id = EventId, user_id = UserId, _ = '_'},
  case mnesia:dirty_match_object(Match) of
    [] -> {error, not_found};
    [Booking] -> {ok, Booking}
  end.

%%%===================================================================
%%% ВНУТРЕННИЕ ФУНКЦИИ
%%%===================================================================

apply_updates(Booking, Updates) ->
  Updated = lists:foldl(fun({Field, Value}, B) -> set_field(Field, Value, B) end,
    Booking, Updates),
  Updated#booking{updated_at = calendar:universal_time()}.

set_field(status, Value, B)        -> B#booking{status = Value};
set_field(notes, Value, B)         -> B#booking{notes = Value};
set_field(reminder_sent, Value, B) -> B#booking{reminder_sent = Value};
set_field(confirmed_at, Value, B)  -> B#booking{confirmed_at = Value};
set_field(event_id, Value, B)      -> B#booking{event_id = Value};
set_field(user_id, Value, B)       -> B#booking{user_id = Value};
set_field(_, _, B) -> B.