-module(dove@response).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function]).

-export([decode/1]).
-export_type([decode_result/0]).

-type decode_result() :: more |
    {eoh, binary()} |
    {header, {binary(), binary()}, binary()} |
    {status_line, {{integer(), integer()}, integer(), binary()}, binary()}.

-spec decode_headers(binary(), list({binary(), binary()})) -> {ok,
        {list({binary(), binary()}), binary()}} |
    {error, dove@error:error()}.
decode_headers(Binary, Storage) ->
    gleam@result:then(
        begin
            _pipe = dove_ffi:decode_header(Binary),
            gleam@result:replace_error(_pipe, invalid_header)
        end,
        fun(Result) -> case Result of
                {eoh, Rest} ->
                    {ok, {Storage, Rest}};

                {header, Header, Rest@1} ->
                    decode_headers(Rest@1, gleam@list:append(Storage, [Header]));

                more ->
                    {error, more_needed};

                {status_line, _, _} ->
                    {error, wrong_packet_type}
            end end
    ).

-spec decode(binary()) -> {ok,
        {{integer(), list({binary(), binary()}), gleam@option:option(binary())},
            binary()}} |
    {error, dove@error:error()}.
decode(Response) ->
    case dove_ffi:decode_status_line(Response) of
        {ok, {status_line, {_, Status, _}, Rest}} ->
            gleam@result:then(
                decode_headers(Rest, []),
                fun(_use0) ->
                    {Headers, Rest@1} = _use0,
                    case begin
                        _pipe = gleam@list:key_find(
                            Headers,
                            <<"content-length"/utf8>>
                        ),
                        _pipe@1 = gleam@result:map(_pipe, fun gleam@int:parse/1),
                        gleam@result:flatten(_pipe@1)
                    end of
                        {ok, 0} ->
                            {ok, {{Status, Headers, none}, Rest@1}};

                        {error, nil} ->
                            {ok, {{Status, Headers, none}, Rest@1}};

                        {ok, Length} ->
                            Body = gleam@string:slice(Rest@1, 0, Length),
                            Rest@2 = gleam@string:slice(
                                Rest@1,
                                Length,
                                gleam@string:length(Rest@1)
                            ),
                            {ok, {{Status, Headers, {some, Body}}, Rest@2}}
                    end
                end
            );

        {ok, more} ->
            {error, more_needed};

        {error, nil} ->
            {error, invalid_status_line};

        _ ->
            {error, wrong_packet_type}
    end.