glethers

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

-export([from_bit_array/1, to_bit_array/1, hash_message/1]).
-export_type([hash/0]).

-opaque hash() :: {hash, bitstring()}.

-spec from_bit_array(bitstring()) -> {ok, hash()} | {error, binary()}.
from_bit_array(Hash) ->
    case erlang:byte_size(Hash) =:= 32 of
        true ->
            {ok, {hash, Hash}};

        false ->
            {error, <<"Invalid bit array length"/utf8>>}
    end.

-spec to_bit_array(hash()) -> bitstring().
to_bit_array(Hash) ->
    {hash, Hash@1} = Hash,
    Hash@1.

-spec hash_message(binary()) -> hash().
hash_message(Message) ->
    Message_prefix_bit_array = begin
        _pipe = <<"\x{0019}Ethereum Signed Message:\n"/utf8>>,
        gleam_stdlib:identity(_pipe)
    end,
    Message_length = begin
        _pipe@1 = gleam@string:length(Message),
        _pipe@2 = gleam@int:to_string(_pipe@1),
        gleam_stdlib:identity(_pipe@2)
    end,
    Utf8_message = begin
        _pipe@3 = Message,
        gleam_stdlib:identity(_pipe@3)
    end,
    {hash,
        'Elixir.ExKeccak':hash_256(
            gleam_stdlib:bit_array_concat(
                [Message_prefix_bit_array, Message_length, Utf8_message]
            )
        )}.