timeago

-module(timeago).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch]).
-define(FILEPATH, "src/timeago.gleam").
-export([time_ago/3]).

-file("src/timeago.gleam", 46).
-spec unit_to_string(gleam@time@duration:unit()) -> binary().
unit_to_string(Unit) ->
    case Unit of
        nanosecond ->
            <<"nanosecond"/utf8>>;

        microsecond ->
            <<"microsecond"/utf8>>;

        millisecond ->
            <<"millisecond"/utf8>>;

        second ->
            <<"second"/utf8>>;

        minute ->
            <<"minute"/utf8>>;

        hour ->
            <<"hour"/utf8>>;

        day ->
            <<"day"/utf8>>;

        week ->
            <<"week"/utf8>>;

        month ->
            <<"month"/utf8>>;

        year ->
            <<"year"/utf8>>
    end.

-file("src/timeago.gleam", 6).
-spec time_ago(
    gleam@time@timestamp:timestamp(),
    gleam@option:option(gleam@time@timestamp:timestamp()),
    gleam@option:option(binary())
) -> binary().
time_ago(Timestamp, Maybe_now, _) ->
    Now = gleam@option:unwrap(Maybe_now, gleam@time@timestamp:system_time()),
    {Amount, Unit} = gleam@time@duration:approximate(
        gleam@time@timestamp:difference(Timestamp, Now)
    ),
    case Unit of
        nanosecond ->
            <<"just now"/utf8>>;

        microsecond ->
            <<"just now"/utf8>>;

        millisecond ->
            <<"just now"/utf8>>;

        _ ->
            Unit_string = unit_to_string(Unit),
            Magnitude = gleam@int:absolute_value(Amount),
            Unit_string_suffix = case Magnitude of
                1 ->
                    <<""/utf8>>;

                _ ->
                    <<"s"/utf8>>
            end,
            case Amount < 0 of
                true ->
                    <<<<<<<<"in "/utf8,
                                    (erlang:integer_to_binary(Magnitude))/binary>>/binary,
                                " "/utf8>>/binary,
                            Unit_string/binary>>/binary,
                        Unit_string_suffix/binary>>;

                false ->
                    <<<<<<<<(erlang:integer_to_binary(Magnitude))/binary,
                                    " "/utf8>>/binary,
                                Unit_string/binary>>/binary,
                            Unit_string_suffix/binary>>/binary,
                        " ago"/utf8>>
            end
    end.