hypersig

-module(hypersig@digest).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch, inline]).
-define(FILEPATH, "src/hypersig/digest.gleam").
-export([to_string/1, from_string/1, with_method/2, new/1, verify/2, parse_header/1, verify_header/2]).
-export_type([digest/0]).

-if(?OTP_RELEASE >= 27).
-define(MODULEDOC(Str), -moduledoc(Str)).
-define(DOC(Str), -doc(Str)).
-else.
-define(MODULEDOC(Str), -compile([])).
-define(DOC(Str), -compile([])).
-endif.

-type digest() :: {digest, gleam@crypto:hash_algorithm(), bitstring()}.

-file("src/hypersig/digest.gleam", 19).
-spec method_to_string(gleam@crypto:hash_algorithm()) -> binary().
method_to_string(Alg) ->
    case Alg of
        md5 ->
            <<"md5"/utf8>>;

        sha1 ->
            <<"sha-1"/utf8>>;

        sha224 ->
            <<"sha-224"/utf8>>;

        sha256 ->
            <<"sha-256"/utf8>>;

        sha384 ->
            <<"sha-384"/utf8>>;

        sha512 ->
            <<"sha-512"/utf8>>
    end.

-file("src/hypersig/digest.gleam", 30).
-spec method_from_string(binary()) -> {ok, gleam@crypto:hash_algorithm()} |
    {error, hypersig@error:hyper_error()}.
method_from_string(Alg) ->
    case Alg of
        <<"md5"/utf8>> ->
            {ok, md5};

        <<"sha-1"/utf8>> ->
            {ok, sha1};

        <<"sha-224"/utf8>> ->
            {ok, sha224};

        <<"sha-256"/utf8>> ->
            {ok, sha256};

        <<"sha-384"/utf8>> ->
            {ok, sha384};

        <<"sha-512"/utf8>> ->
            {ok, sha512};

        _ ->
            {error, unsupported_digest}
    end.

-file("src/hypersig/digest.gleam", 44).
-spec to_string(digest()) -> binary().
to_string(Header) ->
    <<<<(method_to_string(erlang:element(2, Header)))/binary, "="/utf8>>/binary,
        (gleam@bit_array:base64_url_encode(erlang:element(3, Header), true))/binary>>.

-file("src/hypersig/digest.gleam", 50).
-spec from_string(binary()) -> {ok, digest()} |
    {error, hypersig@error:hyper_error()}.
from_string(Header) ->
    gleam@result:'try'(
        begin
            _pipe = gleam@string:split_once(Header, <<"="/utf8>>),
            gleam@result:replace_error(_pipe, digest_parse)
        end,
        fun(_use0) ->
            {Method, Digest} = _use0,
            gleam@result:'try'(
                method_from_string(Method),
                fun(Method@1) ->
                    gleam@result:'try'(
                        begin
                            _pipe@1 = gleam@bit_array:base64_url_decode(Digest),
                            gleam@result:replace_error(_pipe@1, digest_parse)
                        end,
                        fun(Digest@1) -> {ok, {digest, Method@1, Digest@1}} end
                    )
                end
            )
        end
    ).

-file("src/hypersig/digest.gleam", 71).
?DOC(" Hashes the data with the given method and creates a Digest object\n").
-spec with_method(gleam@crypto:hash_algorithm(), bitstring()) -> digest().
with_method(Method, Data) ->
    Digest = gleam@crypto:hash(Method, Data),
    {digest, Method, Digest}.

-file("src/hypersig/digest.gleam", 66).
?DOC(" Hashes the data using Sha256 and creates a Digest object\n").
-spec new(bitstring()) -> digest().
new(Data) ->
    with_method(sha256, Data).

-file("src/hypersig/digest.gleam", 78).
?DOC(" Verifies the given digest object matches the given data\n").
-spec verify(digest(), bitstring()) -> boolean().
verify(Digest, Data) ->
    Other = with_method(erlang:element(2, Digest), Data),
    Other =:= Digest.

-file("src/hypersig/digest.gleam", 84).
-spec parse_header(binary()) -> {ok, list(digest())} |
    {error, hypersig@error:hyper_error()}.
parse_header(Header) ->
    _pipe = gleam@string:split(Header, <<","/utf8>>),
    _pipe@1 = gleam@list:map(_pipe, fun from_string/1),
    _pipe@2 = gleam@result:all(_pipe@1),
    gleam@result:replace_error(_pipe@2, digest_parse).

-file("src/hypersig/digest.gleam", 92).
?DOC(" Verify all digests in a given header against the given data\n").
-spec verify_header(list(digest()), bitstring()) -> boolean().
verify_header(Header, Data) ->
    gleam@list:all(Header, fun(_capture) -> verify(_capture, Data) end).