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

-export([init/2]).

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

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

%% POST /v1/reviews - создание отзыва
create_review(Req) ->
  case handler_auth:authenticate(Req) of
    {ok, UserId, Req1} ->
      {ok, Body, Req2} = cowboy_req:read_body(Req1),
      try jsx:decode(Body, [return_maps]) of
        Decoded when is_map(Decoded) ->
          case Decoded of
            #{<<"target_type">> := TargetTypeBin,
              <<"target_id">> := TargetId,
              <<"rating">> := Rating,
              <<"comment">> := Comment} ->
              TargetType = parse_target_type(TargetTypeBin),
              case logic_review:create_review(UserId, TargetType, TargetId, Rating, Comment) of
                {ok, Review} ->
                  Response = review_to_json(Review),
                  send_json(Req2, 201, Response);
                {error, already_reviewed} ->
                  send_error(Req2, 409, <<"Already reviewed">>);
                {error, cannot_review} ->
                  send_error(Req2, 403, <<"Cannot review this target">>);
                {error, target_not_found} ->
                  send_error(Req2, 404, <<"Target not found">>);
                {error, _} ->
                  send_error(Req2, 500, <<"Internal server error">>)
              end;
            _ ->
              send_error(Req2, 400, <<"Missing required fields">>)
          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.

%% GET /v1/reviews - список отзывов для цели
list_reviews(Req) ->
  case handler_auth:authenticate(Req) of
    {ok, UserId, Req1} ->
      Qs = cowboy_req:parse_qs(Req1),
      case {proplists:get_value(<<"target_type">>, Qs), proplists:get_value(<<"target_id">>, Qs)} of
        {undefined, _} ->
          send_error(Req1, 400, <<"Missing target_type">>);
        {_, undefined} ->
          send_error(Req1, 400, <<"Missing target_id">>);
        {TargetTypeBin, TargetId} ->
          TargetType = parse_target_type(TargetTypeBin),
          case logic_review:list_reviews(UserId, TargetType, TargetId) of
            {ok, Reviews} ->
              Response = [review_to_json(R) || R <- Reviews],
              send_json(Req1, 200, Response);
            {error, _} ->
              send_error(Req1, 500, <<"Internal server error">>)
          end
      end;
    {error, Code, Message, Req1} ->
      send_error(Req1, Code, Message)
  end.

%% Вспомогательные функции
parse_target_type(<<"event">>) -> event;
parse_target_type(<<"calendar">>) -> calendar;
parse_target_type(_) -> undefined.

review_to_json(Review) ->
  #{
    id => Review#review.id,
    user_id => Review#review.user_id,
    target_type => Review#review.target_type,
    target_id => Review#review.target_id,
    rating => Review#review.rating,
    comment => Review#review.comment,
    status => Review#review.status,
    created_at => datetime_to_iso8601(Review#review.created_at),
    updated_at => datetime_to_iso8601(Review#review.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, []}.