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", 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()),
    {Seconds, Nanoseconds} = gleam@time@duration:to_seconds_and_nanoseconds(
        gleam@time@timestamp:difference(Timestamp, Now)
    ),
    Diff = case (Seconds < 0) andalso (Nanoseconds > 0) of
        true ->
            Seconds + 1;

        false ->
            Seconds
    end,
    case Diff of
        0 ->
            <<"just now"/utf8>>;

        _ ->
            Diff_magnitude = gleam@int:absolute_value(Diff),
            {Amount, Unit} = case Diff_magnitude of
                N when N < 60 ->
                    {N, <<"second"/utf8>>};

                N@1 when N@1 < 3600 ->
                    {N@1 div 60, <<"minute"/utf8>>};

                N@2 when N@2 < 86400 ->
                    {N@2 div 3600, <<"hour"/utf8>>};

                N@3 when N@3 < 2635200 ->
                    {N@3 div 86400, <<"day"/utf8>>};

                N@4 when N@4 < 31536000 ->
                    {N@4 div 2635200, <<"month"/utf8>>};

                N@5 ->
                    {N@5 div 31536000, <<"year"/utf8>>}
            end,
            Unit_suffix = case Amount of
                1 ->
                    <<""/utf8>>;

                _ ->
                    <<"s"/utf8>>
            end,
            case Diff < 0 of
                true ->
                    <<<<<<<<"in "/utf8,
                                    (erlang:integer_to_binary(Amount))/binary>>/binary,
                                " "/utf8>>/binary,
                            Unit/binary>>/binary,
                        Unit_suffix/binary>>;

                false ->
                    <<<<<<<<(erlang:integer_to_binary(Amount))/binary,
                                    " "/utf8>>/binary,
                                Unit/binary>>/binary,
                            Unit_suffix/binary>>/binary,
                        " ago"/utf8>>
            end
    end.