-module(admin_handler_stats).
-include("records.hrl").
-export([init/2]).
-export([count_users/0, count_calendars/0, count_events/0, count_bookings/0,
  count_reviews/0, count_reports/0, count_tickets/0, count_subscriptions/0]).
-export([is_admin/1]).

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

handle(Req, _Opts) ->
  case cowboy_req:method(Req) of
    <<"GET">> -> get_stats(Req);
    _ -> send_error(Req, 405, <<"Method not allowed">>)
  end.

get_stats(Req) ->
  case handler_auth:authenticate(Req) of
    {ok, AdminId, Req1} ->
      case is_admin(AdminId) of
        true ->
          Stats = #{
            users => count_users(),
            calendars => count_calendars(),
            events => count_events(),
            bookings => count_bookings(),
            reviews => count_reviews(),
            reports => count_reports(),
            tickets => count_tickets(),
            subscriptions => count_subscriptions()
          },
          send_json(Req1, 200, Stats);
        false ->
          send_error(Req1, 403, <<"Admin access required">>)
      end;
    {error, Code, Message, Req1} ->
      send_error(Req1, Code, Message)
  end.

%% Вспомогательные функции
is_admin(UserId) ->
  case core_user:get_by_id(UserId) of
    {ok, User} ->
      Role = User#user.role,
      Role =:= admin orelse Role =:= superadmin orelse
        Role =:= moderator orelse Role =:= support;
    _ -> false
  end.

count_users() -> length(mnesia:dirty_match_object(#user{_ = '_'})).
count_calendars() -> length(mnesia:dirty_match_object(#calendar{_ = '_'})).
count_events() -> length(mnesia:dirty_match_object(#event{is_instance = false, _ = '_'})).
count_bookings() -> length(mnesia:dirty_match_object(#booking{_ = '_'})).
count_reviews() -> length(mnesia:dirty_match_object(#review{_ = '_'})).
count_reports() -> length(mnesia:dirty_match_object(#report{_ = '_'})).
count_tickets() -> length(mnesia:dirty_match_object(#ticket{_ = '_'})).
count_subscriptions() -> length(mnesia:dirty_match_object(#subscription{_ = '_'})).

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

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