-module(parse).
-compile(no_auto_import).

-export([int/1, day/1, days/1]).

-spec int(binary()) -> {ok, integer()} | {error, snag:snag()}.
int(S) ->
    _pipe = S,
    _pipe@1 = gleam@int:parse(_pipe),
    gleam@result:replace_error(
        _pipe@1,
        snag:new(
            <<<<"failed to parse \""/utf8, S/binary>>/binary, "\" as int"/utf8>>
        )
    ).

-spec day(binary()) -> {ok, integer()} | {error, snag:snag()}.
day(S) ->
    case int(S) of
        {error, _try} -> {error, _try};
        {ok, I} ->
            case (I > 0) andalso (I < 26) of
                true ->
                    {ok, I};

                false ->
                    _pipe = <<<<<<"invalid day value "/utf8, "'"/utf8>>/binary,
                            S/binary>>/binary,
                        "'"/utf8>>,
                    _pipe@1 = snag:error(_pipe),
                    snag:context(
                        _pipe@1,
                        <<"day must be an integer from 1 to 25"/utf8>>
                    )
            end
    end.

-spec days(list(binary())) -> {ok, list(integer())} | {error, snag:snag()}.
days(L) ->
    case L of
        [] ->
            snag:error(<<"no days selected"/utf8>>);

        _@1 ->
            _pipe = gleam@list:try_map(L, fun day/1),
            snag:context(_pipe, <<"could not map day values to integers"/utf8>>)
    end.