-module(mist@encoder).
-compile(no_auto_import).

-export([to_bit_builder/1, response_builder/2, status_to_bit_string/1, encode_headers/1]).

-spec to_bit_builder(
    gleam@http@response:response(gleam@bit_builder:bit_builder())
) -> gleam@bit_builder:bit_builder().
to_bit_builder(Resp) ->
    Body_size = gleam@bit_builder:byte_size(erlang:element(4, Resp)),
    Headers = begin
        _pipe = gleam@map:from_list(
            [{<<"content-length"/utf8>>, gleam@int:to_string(Body_size)},
             {<<"connection"/utf8>>, <<"keep-alive"/utf8>>}]
        ),
        gleam@list:fold(
            erlang:element(3, Resp),
            _pipe,
            fun(Defaults, Tup) ->
                {Key, Value} = Tup,
                gleam@map:insert(Defaults, Key, Value)
            end
        )
    end,
    Body_builder = case Body_size of
        0 ->
            gleam@bit_builder:new();

        _@1 ->
            _pipe@1 = gleam@bit_builder:new(),
            _pipe@2 = gleam@bit_builder:append_builder(
                _pipe@1,
                erlang:element(4, Resp)
            ),
            gleam@bit_builder:append(_pipe@2, <<"\r\n"/utf8>>)
    end,
    _pipe@3 = erlang:element(2, Resp),
    _pipe@4 = response_builder(_pipe@3, gleam@map:to_list(Headers)),
    gleam@bit_builder:append_builder(_pipe@4, Body_builder).

-spec response_builder(integer(), list({binary(), binary()})) -> gleam@bit_builder:bit_builder().
response_builder(Status, Headers) ->
    Status_string = begin
        _pipe = Status,
        _pipe@1 = gleam@int:to_string(_pipe),
        _pipe@2 = gleam@bit_builder:from_string(_pipe@1),
        _pipe@3 = gleam@bit_builder:append(_pipe@2, <<" "/utf8>>),
        gleam@bit_builder:append(_pipe@3, status_to_bit_string(Status))
    end,
    _pipe@4 = gleam@bit_builder:new(),
    _pipe@5 = gleam@bit_builder:append(_pipe@4, <<"HTTP/1.1 "/utf8>>),
    _pipe@6 = gleam@bit_builder:append_builder(_pipe@5, Status_string),
    _pipe@7 = gleam@bit_builder:append(_pipe@6, <<"\r\n"/utf8>>),
    _pipe@8 = gleam@bit_builder:append_builder(_pipe@7, encode_headers(Headers)),
    gleam@bit_builder:append(_pipe@8, <<"\r\n"/utf8>>).

-spec status_to_bit_string(integer()) -> bitstring().
status_to_bit_string(Status) ->
    case Status of
        101 ->
            <<"Switching Protocols"/utf8>>;

        200 ->
            <<"Ok"/utf8>>;

        201 ->
            <<"Created"/utf8>>;

        202 ->
            <<"Accepted"/utf8>>;

        204 ->
            <<"No Content"/utf8>>;

        301 ->
            <<"Moved Permanently"/utf8>>;

        400 ->
            <<"Bad Request"/utf8>>;

        401 ->
            <<"Unauthorized"/utf8>>;

        403 ->
            <<"Forbidden"/utf8>>;

        404 ->
            <<"Not Found"/utf8>>;

        405 ->
            <<"Method Not Allowed"/utf8>>;

        500 ->
            <<"Internal Server Error"/utf8>>;

        502 ->
            <<"Bad Gateway"/utf8>>;

        503 ->
            <<"Service Unavailable"/utf8>>;

        504 ->
            <<"Gateway Timeout"/utf8>>
    end.

-spec encode_headers(list({binary(), binary()})) -> gleam@bit_builder:bit_builder().
encode_headers(Headers) ->
    gleam@list:fold(
        Headers,
        gleam@bit_builder:new(),
        fun(Builder, Tup) ->
            {Header, Value} = Tup,
            _pipe = Builder,
            _pipe@1 = gleam@bit_builder:append_string(_pipe, Header),
            _pipe@2 = gleam@bit_builder:append(_pipe@1, <<": "/utf8>>),
            _pipe@3 = gleam@bit_builder:append_string(_pipe@2, Value),
            gleam@bit_builder:append(_pipe@3, <<"\r\n"/utf8>>)
        end
    ).