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

-export([init/2]).

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

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

%% GET /v1/calendars/:id - получение календаря
get_calendar(Req) ->
  case handler_auth:authenticate(Req) of
    {ok, UserId, Req1} ->
      CalendarId = cowboy_req:binding(id, Req1),
      case logic_calendar:get_calendar(UserId, CalendarId) of
        {ok, Calendar} ->
          Response = calendar_to_json(Calendar),
          send_json(Req1, 200, Response);
        {error, access_denied} ->
          send_error(Req1, 403, <<"Access denied">>);
        {error, not_found} ->
          send_error(Req1, 404, <<"Calendar not found">>);
        {error, _} ->
          send_error(Req1, 500, <<"Internal server error">>)
      end;
    {error, Code, Message, Req1} ->
      send_error(Req1, Code, Message)
  end.

%% PUT /v1/calendars/:id - обновление календаря
update_calendar(Req) ->
  case handler_auth:authenticate(Req) of
    {ok, UserId, Req1} ->
      CalendarId = cowboy_req:binding(id, Req1),
      {ok, Body, Req2} = cowboy_req:read_body(Req1),
      try jsx:decode(Body, [return_maps]) of
        UpdatesMap when is_map(UpdatesMap) ->
          Updates = maps:to_list(UpdatesMap),
          case logic_calendar:update_calendar(UserId, CalendarId, Updates) of
            {ok, Calendar} ->
              Response = calendar_to_json(Calendar),
              send_json(Req2, 200, Response);
            {error, access_denied} ->
              send_error(Req2, 403, <<"Access denied">>);
            {error, not_found} ->
              send_error(Req2, 404, <<"Calendar not found">>);
            {error, _} ->
              send_error(Req2, 500, <<"Internal server error">>)
          end;
        _ ->
          send_error(Req2, 400, <<"Invalid JSON">>)
      catch
        _:_ ->
          send_error(Req2, 400, <<"Invalid JSON format">>)
      end;
    {error, Code, Message, Req1} ->
      send_error(Req1, Code, Message)
  end.

%% DELETE /v1/calendars/:id - удаление календаря
delete_calendar(Req) ->
  case handler_auth:authenticate(Req) of
    {ok, UserId, Req1} ->
      CalendarId = cowboy_req:binding(id, Req1),
      case logic_calendar:delete_calendar(UserId, CalendarId) of
        {ok, _} ->
          send_json(Req1, 200, #{status => <<"deleted">>});
        {error, access_denied} ->
          send_error(Req1, 403, <<"Access denied">>);
        {error, not_found} ->
          send_error(Req1, 404, <<"Calendar not found">>);
        {error, _} ->
          send_error(Req1, 500, <<"Internal server error">>)
      end;
    {error, Code, Message, Req1} ->
      send_error(Req1, Code, Message)
  end.

%% Вспомогательные функции
calendar_to_json(Calendar) ->
  #{
    id => Calendar#calendar.id,
    owner_id => Calendar#calendar.owner_id,
    title => Calendar#calendar.title,
    description => Calendar#calendar.description,
    tags => Calendar#calendar.tags,
    type => Calendar#calendar.type,
    confirmation => confirmation_to_json(Calendar#calendar.confirmation),
    rating_avg => Calendar#calendar.rating_avg,
    rating_count => Calendar#calendar.rating_count,
    status => Calendar#calendar.status,
    created_at => Calendar#calendar.created_at,
    updated_at => Calendar#calendar.updated_at
  }.

confirmation_to_json(auto) -> <<"auto">>;
confirmation_to_json(manual) -> <<"manual">>;
confirmation_to_json({timeout, N}) -> #{<<"timeout">> => N}.

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, []}.