-module(bytesize).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch]).

-export([bytes/1, b/1, kb/1, mb/1, gb/1, tb/1, pb/1, kib/1, mib/1, gib/1, tib/1, pib/1, to_string/1, to_string_decimal/1]).
-export_type([byte_size/0, units/0]).

-type byte_size() :: {byte_size, integer()}.

-type units() :: units_decimal | units_binary.

-spec bytes(byte_size()) -> integer().
bytes(Size) ->
    {byte_size, B} = Size,
    B.

-spec to_string_1(float()) -> binary().
to_string_1(N) ->
    X = gleam@float:round(N * 10.0),
    _assert_subject = begin
        _pipe = gleam@int:to_string(X),
        _pipe@1 = gleam@string:reverse(_pipe),
        gleam@string:pop_grapheme(_pipe@1)
    end,
    {ok, {C, Cs}} = case _assert_subject of
        {ok, {_, _}} -> _assert_subject;
        _assert_fail ->
            erlang:error(#{gleam_error => let_assert,
                        message => <<"Assertion pattern match failed"/utf8>>,
                        value => _assert_fail,
                        module => <<"bytesize"/utf8>>,
                        function => <<"to_string_1"/utf8>>,
                        line => 153})
    end,
    <<<<(gleam@string:reverse(Cs))/binary, "."/utf8>>/binary, C/binary>>.

-spec b(integer()) -> byte_size().
b(Size) ->
    {byte_size, Size * 1}.

-spec kb(integer()) -> byte_size().
kb(Size) ->
    {byte_size, Size * 1000}.

-spec mb(integer()) -> byte_size().
mb(Size) ->
    {byte_size, Size * 1000000}.

-spec gb(integer()) -> byte_size().
gb(Size) ->
    {byte_size, Size * 1000000000}.

-spec tb(integer()) -> byte_size().
tb(Size) ->
    {byte_size, Size * 1000000000000}.

-spec pb(integer()) -> byte_size().
pb(Size) ->
    {byte_size, Size * 1000000000000000}.

-spec kib(integer()) -> byte_size().
kib(Size) ->
    {byte_size, Size * 1024}.

-spec mib(integer()) -> byte_size().
mib(Size) ->
    {byte_size, Size * 1048576}.

-spec gib(integer()) -> byte_size().
gib(Size) ->
    {byte_size, Size * 1073741824}.

-spec tib(integer()) -> byte_size().
tib(Size) ->
    {byte_size, Size * 1099511627776}.

-spec pib(integer()) -> byte_size().
pib(Size) ->
    {byte_size, Size * 1125899906842624}.

-spec to_string_units(integer(), units()) -> binary().
to_string_units(Bytes, Units) ->
    {Unit, Unit_base, Unit_suffix} = case Units of
        units_binary ->
            {1024, 6.907755279, <<"iB"/utf8>>};

        units_decimal ->
            {1000, 6.931471806, <<"B"/utf8>>}
    end,
    case Bytes < Unit of
        true ->
            <<(gleam@int:to_string(Bytes))/binary, " B"/utf8>>;

        false ->
            Size = gleam@int:to_float(Bytes),
            Exp = case gleam@float:truncate(case Unit_base of
                    +0.0 -> +0.0;
                    -0.0 -> -0.0;
                    Gleam@denominator -> math:log(Size) / Gleam@denominator
                end) of
                E when E =:= 0 ->
                    1;

                E@1 ->
                    E@1
            end,
            _assert_subject = gleam@int:power(Unit, gleam@int:to_float(Exp)),
            {ok, X} = case _assert_subject of
                {ok, _} -> _assert_subject;
                _assert_fail ->
                    erlang:error(#{gleam_error => let_assert,
                                message => <<"Assertion pattern match failed"/utf8>>,
                                value => _assert_fail,
                                module => <<"bytesize"/utf8>>,
                                function => <<"to_string_units"/utf8>>,
                                line => 130})
            end,
            Unit_prefix = case Exp of
                1 when Units =:= units_decimal ->
                    <<"k"/utf8>>;

                1 ->
                    <<"K"/utf8>>;

                2 ->
                    <<"M"/utf8>>;

                3 ->
                    <<"G"/utf8>>;

                4 ->
                    <<"T"/utf8>>;

                5 ->
                    <<"P"/utf8>>;

                6 ->
                    <<"E"/utf8>>;

                _ ->
                    erlang:error(#{gleam_error => panic,
                            message => <<"exponent too big"/utf8>>,
                            module => <<"bytesize"/utf8>>,
                            function => <<"to_string_units"/utf8>>,
                            line => 139})
            end,
            <<<<<<(to_string_1(case X of
                                +0.0 -> +0.0;
                                -0.0 -> -0.0;
                                Gleam@denominator@1 -> Size / Gleam@denominator@1
                            end))/binary, " "/utf8>>/binary, Unit_prefix/binary>>/binary, Unit_suffix/binary>>
    end.

-spec to_string(byte_size()) -> binary().
to_string(Size) ->
    {byte_size, Bytes} = Size,
    to_string_units(Bytes, units_binary).

-spec to_string_decimal(byte_size()) -> binary().
to_string_decimal(Size) ->
    {byte_size, Bytes} = Size,
    to_string_units(Bytes, units_decimal).