%%%-------------------------------------------------------------------
%%% @doc Логика специалистов commercial-календаря.
%%% @end
%%%-------------------------------------------------------------------
-module(logic_calendar_specialist).
-include("records.hrl").

-export([list/2, add/5, update/4, remove/3, to_json/1, ensure_owner_specialist/1]).

-spec list(ActorId :: binary(), CalendarId :: binary()) ->
  {ok, [#calendar_specialist{}]} | {error, not_found | access_denied}.
list(ActorId, CalendarId) ->
  case logic_calendar:get_calendar(ActorId, CalendarId) of
    {ok, Cal} ->
      {ok, core_calendar_specialist:list_by_calendar(Cal#calendar.id)};
    Error -> Error
  end.

-spec add(OwnerId :: binary(), CalendarId :: binary(), UserId :: binary(),
    Name :: binary(), Specs :: [binary()]) ->
  {ok, #calendar_specialist{}} |
  {error, not_found | access_denied | not_commercial | user_not_found |
   already_exists | term()}.
add(OwnerId, CalendarId, UserId, Name, Specs) ->
  case require_owner_commercial(OwnerId, CalendarId) of
    {ok, _} ->
      case core_user:get_by_id(UserId) of
        {ok, _} ->
          core_calendar_specialist:create(CalendarId, UserId, Name, Specs);
        {error, _} ->
          {error, user_not_found}
      end;
    Error -> Error
  end.

-spec update(OwnerId :: binary(), CalendarId :: binary(), UserId :: binary(),
    Updates :: [{atom(), term()}]) ->
  {ok, #calendar_specialist{}} | {error, not_found | access_denied | not_commercial | term()}.
update(OwnerId, CalendarId, UserId, Updates) ->
  case require_owner_commercial(OwnerId, CalendarId) of
    {ok, _} ->
      core_calendar_specialist:update(CalendarId, UserId, Updates);
    Error -> Error
  end.

-spec remove(OwnerId :: binary(), CalendarId :: binary(), UserId :: binary()) ->
  ok | {error, not_found | access_denied | not_commercial |
        owner_specialist_protected | term()}.
remove(OwnerId, CalendarId, UserId) ->
  case require_owner_commercial(OwnerId, CalendarId) of
    {ok, #calendar{owner_id = CalOwnerId}} when UserId =:= CalOwnerId ->
      {error, owner_specialist_protected};
    {ok, _} ->
      core_calendar_specialist:delete(CalendarId, UserId);
    Error -> Error
  end.

%% @doc Idempotent: commercial calendar always has a specialist row for owner.
%% Default status=active; name from nickname (else email). No-op if already present.
-spec ensure_owner_specialist(#calendar{}) -> ok | {error, term()}.
ensure_owner_specialist(#calendar{id = CalId, owner_id = OwnerId, type = commercial}) ->
  case core_calendar_specialist:get_by_calendar_and_user(CalId, OwnerId) of
    {ok, _} ->
      ok;
    {error, not_found} ->
      case core_calendar_specialist:create(CalId, OwnerId, owner_display_name(OwnerId), []) of
        {ok, _} -> ok;
        {error, already_exists} -> ok;
        {error, _} = Err -> Err
      end
  end;
ensure_owner_specialist(_) ->
  ok.

-spec to_json(#calendar_specialist{}) -> map().
to_json(S) ->
  #{
    id             => S#calendar_specialist.id,
    calendar_id    => S#calendar_specialist.calendar_id,
    user_id        => S#calendar_specialist.user_id,
    name           => S#calendar_specialist.name,
    specialization => S#calendar_specialist.specialization,
    status         => S#calendar_specialist.status,
    added_at       => handler_utils:datetime_to_iso8601(S#calendar_specialist.added_at),
    updated_at     => handler_utils:datetime_to_iso8601(S#calendar_specialist.updated_at)
  }.

%%%===================================================================
%%% Internal
%%%===================================================================

require_owner_commercial(OwnerId, CalendarId) ->
  case core_calendar:get_by_id(CalendarId) of
    {ok, #calendar{owner_id = OwnerId, type = commercial, status = active} = Cal} ->
      {ok, Cal};
    {ok, #calendar{owner_id = OwnerId, type = personal}} ->
      {error, not_commercial};
    {ok, _} ->
      {error, access_denied};
    Error -> Error
  end.

owner_display_name(OwnerId) ->
  case core_user:get_by_id(OwnerId) of
    {ok, #user{nickname = Nick}} when is_binary(Nick), Nick =/= <<>> ->
      Nick;
    {ok, #user{email = Email}} when is_binary(Email), Email =/= <<>> ->
      Email;
    _ ->
      <<"Owner">>
  end.