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

-export([init/2]).

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

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

%% POST /v1/events/:id/bookings - создание бронирования (запись на событие)
create_booking(Req) ->
  case handler_auth:authenticate(Req) of
    {ok, UserId, Req1} ->
      EventId = cowboy_req:binding(id, Req1),
      case logic_booking:create_booking(UserId, EventId) of
        {ok, Booking} ->
          Response = booking_to_json(Booking),
          send_json(Req1, 201, Response);
        {error, already_booked} ->
          send_error(Req1, 409, <<"Already booked">>);
        {error, event_full} ->
          send_error(Req1, 400, <<"Event is full">>);
        {error, event_not_active} ->
          send_error(Req1, 400, <<"Event is not active">>);
        {error, access_denied} ->
          send_error(Req1, 403, <<"Access denied">>);
        {error, not_found} ->
          send_error(Req1, 404, <<"Event not found">>);
        {error, _} ->
          send_error(Req1, 500, <<"Internal server error">>)
      end;
    {error, Code, Message, Req1} ->
      send_error(Req1, Code, Message)
  end.

%% GET /v1/events/:id/bookings - список бронирований события (для владельца)
list_bookings(Req) ->
  case handler_auth:authenticate(Req) of
    {ok, UserId, Req1} ->
      EventId = cowboy_req:binding(id, Req1),
      case logic_booking:list_event_bookings(UserId, EventId) of
        {ok, Bookings} ->
          Response = [booking_to_json(B) || B <- Bookings],
          send_json(Req1, 200, Response);
        {error, access_denied} ->
          send_error(Req1, 403, <<"Access denied">>);
        {error, not_found} ->
          send_error(Req1, 404, <<"Event not found">>);
        {error, _} ->
          send_error(Req1, 500, <<"Internal server error">>)
      end;
    {error, Code, Message, Req1} ->
      send_error(Req1, Code, Message)
  end.

%% Вспомогательные функции
booking_to_json(Booking) ->
  #{
    id => Booking#booking.id,
    event_id => Booking#booking.event_id,
    user_id => Booking#booking.user_id,
    status => Booking#booking.status,
    confirmed_at => case Booking#booking.confirmed_at of
                      undefined -> null;
                      Dt -> datetime_to_iso8601(Dt)
                    end,
    created_at => datetime_to_iso8601(Booking#booking.created_at),
    updated_at => datetime_to_iso8601(Booking#booking.updated_at)
  }.

datetime_to_iso8601({{Year, Month, Day}, {Hour, Minute, Second}}) ->
  iolist_to_binary(io_lib:format("~4..0B-~2..0B-~2..0BT~2..0B:~2..0B:~2..0BZ",
    [Year, Month, Day, Hour, Minute, Second])).

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, []}.