-module(pgl@internal@scram).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch, inline]).
-define(FILEPATH, "src/pgl/internal/scram.gleam").
-export([client_first/2, get_nonce/1, client_final/4, parse_server_first/2, parse_server_final/1]).
-export_type([server_first/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.

?MODULEDOC(false).

-type server_first() :: {server_first,
        bitstring(),
        bitstring(),
        integer(),
        bitstring()}.

-file("src/pgl/internal/scram.gleam", 26).
?DOC(false).
-spec escape_username(bitstring()) -> {ok, bitstring()} |
    {error, pgl@internal:internal_error()}.
escape_username(User) ->
    _pipe = User,
    _pipe@1 = gleam@bit_array:to_string(_pipe),
    _pipe@3 = gleam@result:replace_error(
        _pipe@1,
        begin
            _pipe@2 = sasl_client_first,
            {protocol_error, _pipe@2, <<"Invalid username"/utf8>>}
        end
    ),
    gleam@result:map(_pipe@3, fun(User@1) -> _pipe@4 = User@1,
            _pipe@5 = gleam@string:replace(
                _pipe@4,
                <<"="/utf8>>,
                <<"=3D"/utf8>>
            ),
            _pipe@6 = gleam@string:replace(
                _pipe@5,
                <<","/utf8>>,
                <<"=2C"/utf8>>
            ),
            gleam_stdlib:identity(_pipe@6) end).

-file("src/pgl/internal/scram.gleam", 16).
?DOC(false).
-spec client_first(bitstring(), bitstring()) -> {ok, bitstring()} |
    {error, pgl@internal:internal_error()}.
client_first(User, Nonce) ->
    gleam@result:map(
        escape_username(User),
        fun(Escaped) ->
            <<"n,,n="/utf8, Escaped/bitstring, ",r="/utf8, Nonce/bitstring>>
        end
    ).

-file("src/pgl/internal/scram.gleam", 41).
?DOC(false).
-spec get_nonce(integer()) -> bitstring().
get_nonce(Num_random_bytes) ->
    _pipe = crypto:strong_rand_bytes(Num_random_bytes),
    _pipe@1 = gleam_stdlib:base64_encode(_pipe, true),
    gleam_stdlib:identity(_pipe@1).

-file("src/pgl/internal/scram.gleam", 196).
?DOC(false).
-spec do_hi(bitstring(), bitstring(), bitstring(), integer()) -> bitstring().
do_hi(Str, U, Hi, I) ->
    case I > 0 of
        false ->
            Hi;

        true ->
            U2 = gleam_crypto_ffi:hmac(U, sha256, Str),
            Hi1 = crypto:exor(Hi, U2),
            do_hi(Str, U2, Hi1, I - 1)
    end.

-file("src/pgl/internal/scram.gleam", 190).
?DOC(false).
-spec hi(bitstring(), bitstring(), integer()) -> bitstring().
hi(Str, Salt, I) ->
    U1 = gleam_crypto_ffi:hmac(
        <<Salt/bitstring, 1:32/integer-big>>,
        sha256,
        Str
    ),
    do_hi(Str, U1, U1, I - 1).

-file("src/pgl/internal/scram.gleam", 47).
?DOC(false).
-spec client_final(server_first(), bitstring(), bitstring(), bitstring()) -> {ok,
        {bitstring(), bitstring()}} |
    {error, pgl@internal:internal_error()}.
client_final(Server_first, Client_nonce, Username, Password) ->
    Channel_binding = <<"c=biws"/utf8>>,
    Nonce = [<<"r="/utf8>>, erlang:element(2, Server_first)],
    _pipe = Password,
    _pipe@1 = pgl@internal@sasl:validate(_pipe),
    _pipe@3 = gleam@result:replace_error(
        _pipe@1,
        begin
            _pipe@2 = sasl_client_final,
            {protocol_error, _pipe@2, <<"Invalid password"/utf8>>}
        end
    ),
    gleam@result:'try'(
        _pipe@3,
        fun(Valid_password) ->
            Salted_password = begin
                _pipe@4 = Valid_password,
                hi(
                    _pipe@4,
                    erlang:element(3, Server_first),
                    erlang:element(4, Server_first)
                )
            end,
            Client_key = gleam_crypto_ffi:hmac(
                <<"Client Key"/utf8>>,
                sha256,
                Salted_password
            ),
            gleam@result:map(
                escape_username(Username),
                fun(Escaped_username) ->
                    Auth_message = begin
                        _pipe@5 = <<"n="/utf8,
                            Escaped_username/bitstring,
                            ",r="/utf8,
                            Client_nonce/bitstring>>,
                        _pipe@6 = gleam@bytes_tree:from_bit_array(_pipe@5),
                        _pipe@7 = gleam@bytes_tree:append(_pipe@6, <<","/utf8>>),
                        _pipe@8 = gleam@bytes_tree:append(
                            _pipe@7,
                            erlang:element(5, Server_first)
                        ),
                        _pipe@9 = gleam@bytes_tree:append(_pipe@8, <<","/utf8>>),
                        _pipe@10 = gleam@bytes_tree:append(
                            _pipe@9,
                            Channel_binding
                        ),
                        _pipe@11 = gleam@bytes_tree:append(
                            _pipe@10,
                            <<","/utf8>>
                        ),
                        _pipe@12 = gleam@list:fold(
                            Nonce,
                            _pipe@11,
                            fun gleam@bytes_tree:append/2
                        ),
                        erlang:list_to_bitstring(_pipe@12)
                    end,
                    Client_signature = begin
                        _pipe@13 = sha256,
                        _pipe@14 = gleam@crypto:hash(_pipe@13, Client_key),
                        gleam_crypto_ffi:hmac(Auth_message, sha256, _pipe@14)
                    end,
                    Encoded_client_proof = begin
                        _pipe@15 = Client_key,
                        _pipe@16 = crypto:exor(_pipe@15, Client_signature),
                        _pipe@17 = gleam_stdlib:base64_encode(_pipe@16, true),
                        gleam_stdlib:identity(_pipe@17)
                    end,
                    Server_signature = begin
                        _pipe@18 = Salted_password,
                        _pipe@19 = gleam_crypto_ffi:hmac(
                            <<"Server Key"/utf8>>,
                            sha256,
                            _pipe@18
                        ),
                        gleam_crypto_ffi:hmac(Auth_message, sha256, _pipe@19)
                    end,
                    Encoded_client_final = begin
                        _pipe@20 = gleam@bytes_tree:new(),
                        _pipe@21 = gleam@bytes_tree:append(
                            _pipe@20,
                            Channel_binding
                        ),
                        _pipe@22 = gleam@bytes_tree:append(
                            _pipe@21,
                            <<","/utf8>>
                        ),
                        _pipe@23 = gleam@list:fold(
                            Nonce,
                            _pipe@22,
                            fun gleam@bytes_tree:append/2
                        ),
                        _pipe@24 = gleam@bytes_tree:append(
                            _pipe@23,
                            <<",p="/utf8>>
                        ),
                        _pipe@25 = gleam@bytes_tree:append(
                            _pipe@24,
                            Encoded_client_proof
                        ),
                        erlang:list_to_bitstring(_pipe@25)
                    end,
                    {Encoded_client_final, Server_signature}
                end
            )
        end
    ).

-file("src/pgl/internal/scram.gleam", 112).
?DOC(false).
-spec parse_server_first(bitstring(), bitstring()) -> {ok, server_first()} |
    {error, pgl@internal:internal_error()}.
parse_server_first(Server_first, Client_nonce) ->
    Parts = begin
        _pipe = gleam@bit_array:to_string(Server_first),
        _pipe@1 = gleam@result:map(
            _pipe,
            fun(_capture) -> gleam@string:split(_capture, <<","/utf8>>) end
        ),
        gleam@result:unwrap(_pipe@1, [])
    end,
    _pipe@2 = case Parts of
        [<<"r="/utf8, Nonce/binary>>,
            <<"s="/utf8, Salt/binary>>,
            <<"i="/utf8, Iters/binary>>] ->
            Nonce@1 = gleam_stdlib:identity(Nonce),
            gleam@result:'try'(
                gleam@bit_array:base64_decode(Salt),
                fun(Salt@1) ->
                    gleam@result:'try'(
                        gleam_stdlib:parse_int(Iters),
                        fun(Iterations) ->
                            gleam@bool:guard(
                                (Iterations < 4096) orelse (Iterations > 100000),
                                {error, nil},
                                fun() ->
                                    Size = erlang:bit_size(Client_nonce),
                                    case Nonce@1 of
                                        <<Prefix:Size/bitstring, _/bitstring>> ->
                                            case Prefix =:= Client_nonce of
                                                true ->
                                                    {ok,
                                                        {server_first,
                                                            Nonce@1,
                                                            Salt@1,
                                                            Iterations,
                                                            Server_first}};

                                                false ->
                                                    {error, nil}
                                            end;

                                        _ ->
                                            {error, nil}
                                    end
                                end
                            )
                        end
                    )
                end
            );

        _ ->
            {error, nil}
    end,
    gleam@result:map_error(
        _pipe@2,
        fun(_) ->
            {protocol_error,
                sasl_server_first,
                <<"Failed to parse server_first"/utf8>>}
        end
    ).

-file("src/pgl/internal/scram.gleam", 152).
?DOC(false).
-spec parse_server_final(bitstring()) -> {ok, bitstring()} |
    {error, pgl@internal:internal_error()}.
parse_server_final(Server_final) ->
    case Server_final of
        <<"v="/utf8, Final/bitstring>> ->
            _pipe = gleam@bit_array:to_string(Final),
            _pipe@1 = gleam@result:map(
                _pipe,
                fun(_capture) -> gleam@string:split(_capture, <<","/utf8>>) end
            ),
            _pipe@2 = gleam@result:'try'(_pipe@1, fun gleam@list:first/1),
            _pipe@3 = gleam@result:'try'(
                _pipe@2,
                fun gleam@bit_array:base64_decode/1
            ),
            gleam@result:map_error(
                _pipe@3,
                fun(_) ->
                    {protocol_error,
                        sasl_server_final,
                        <<"Failed to parse server_final"/utf8>>}
                end
            );

        <<"e="/utf8, Error/bitstring>> ->
            Error_value = begin
                _pipe@4 = gleam@bit_array:to_string(Error),
                gleam@result:unwrap(_pipe@4, <<""/utf8>>)
            end,
            _pipe@5 = {protocol_error,
                sasl_server_error,
                <<<<"Server error: '"/utf8, Error_value/binary>>/binary,
                    "'"/utf8>>},
            {error, _pipe@5};

        _ ->
            _pipe@6 = {protocol_error,
                sasl_server_final,
                <<"Unexpected SASL server final payload"/utf8>>},
            {error, _pipe@6}
    end.