-module(glethers@address).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch]).

-export([from_string/1, decoder/1, to_string/1, to_bit_array/1]).
-export_type([address/0, decode_error/0]).

-opaque address() :: {address, binary()}.

-type decode_error() :: not_enough_bytes | non_hex_decimal | incorrect_length.

-spec is_hex_char(binary()) -> boolean().
is_hex_char(Char) ->
    case Char of
        <<"0"/utf8>> ->
            true;

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

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

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

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

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

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

        <<"7"/utf8>> ->
            true;

        <<"8"/utf8>> ->
            true;

        <<"9"/utf8>> ->
            true;

        <<"a"/utf8>> ->
            true;

        <<"b"/utf8>> ->
            true;

        <<"c"/utf8>> ->
            true;

        <<"d"/utf8>> ->
            true;

        <<"e"/utf8>> ->
            true;

        <<"f"/utf8>> ->
            true;

        <<"A"/utf8>> ->
            true;

        <<"B"/utf8>> ->
            true;

        <<"C"/utf8>> ->
            true;

        <<"D"/utf8>> ->
            true;

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

        <<"F"/utf8>> ->
            true;

        _ ->
            false
    end.

-spec from_string(binary()) -> {ok, address()} | {error, decode_error()}.
from_string(Addr) ->
    Address = case Addr of
        <<"0x"/utf8, Value/binary>> ->
            Value;

        Other ->
            Other
    end,
    gleam@bool:guard(
        begin
            _pipe = Address,
            gleam@string:length(_pipe)
        end
        /= 40,
        {error, incorrect_length},
        fun() ->
            gleam@bool:guard(
                begin
                    _pipe@1 = Address,
                    _pipe@2 = gleam@string:to_graphemes(_pipe@1),
                    _pipe@3 = gleam@list:map(_pipe@2, fun is_hex_char/1),
                    gleam@list:any(_pipe@3, fun(Is_hex) -> not Is_hex end)
                end,
                {error, non_hex_decimal},
                fun() -> {ok, {address, Address}} end
            )
        end
    ).

-spec decoder(gleam@dynamic:dynamic_()) -> {ok, address()} |
    {error, list(gleam@dynamic:decode_error())}.
decoder(Value) ->
    gleam@result:'try'(
        (gleam@dynamic:element(1, fun gleam@dynamic:string/1))(Value),
        fun(Str) -> _pipe = from_string(Str),
            gleam@result:map_error(_pipe, fun(_) -> [] end) end
    ).

-spec to_string(address()) -> binary().
to_string(Address) ->
    {address, Addr} = Address,
    <<"0x"/utf8, Addr/binary>>.

-spec to_bit_array(address()) -> bitstring().
to_bit_array(Address) ->
    {address, Addr} = Address,
    _assert_subject = begin
        _pipe = Addr,
        gleam_stdlib:base16_decode(_pipe)
    end,
    {ok, Bytes} = 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 => <<"glethers/address"/utf8>>,
                        function => <<"to_bit_array"/utf8>>,
                        line => 83})
    end,
    <<0:96, Bytes/bitstring>>.