multipartkit

-module(multipartkit@content_disposition).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch, inline]).
-define(FILEPATH, "src/multipartkit/content_disposition.gleam").
-export([parse/1]).
-export_type([content_disposition/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 content_disposition() :: {content_disposition,
        binary(),
        gleam@option:option(binary()),
        gleam@option:option(binary()),
        list({binary(), binary()})}.

-file("src/multipartkit/content_disposition.gleam", 122).
-spec find_param_ci(list({binary(), binary()}), binary()) -> gleam@option:option(binary()).
find_param_ci(Params, Key) ->
    case Params of
        [] ->
            none;

        [{K, V} | Rest] ->
            case multipartkit@internal@text:equals_ci(K, Key) of
                true ->
                    {some, V};

                false ->
                    find_param_ci(Rest, Key)
            end
    end.

-file("src/multipartkit/content_disposition.gleam", 177).
-spec ascii_byte_to_string(integer()) -> binary().
ascii_byte_to_string(Byte) ->
    gleam@result:unwrap(gleam@bit_array:to_string(<<Byte>>), <<""/utf8>>).

-file("src/multipartkit/content_disposition.gleam", 166).
-spec code_point_to_string(integer()) -> binary().
code_point_to_string(Byte) ->
    case Byte < 16#80 of
        true ->
            ascii_byte_to_string(Byte);

        false ->
            High = 16#C0 + (Byte div 64),
            Low = 16#80 + (Byte rem 64),
            gleam@result:unwrap(
                gleam@bit_array:to_string(<<High, Low>>),
                <<""/utf8>>
            )
    end.

-file("src/multipartkit/content_disposition.gleam", 158).
-spec latin1_to_utf8(bitstring(), binary()) -> binary().
latin1_to_utf8(Bytes, Acc) ->
    case Bytes of
        <<>> ->
            Acc;

        <<B, Rest/binary>> ->
            latin1_to_utf8(
                Rest,
                <<Acc/binary, (code_point_to_string(B))/binary>>
            );

        _ ->
            Acc
    end.

-file("src/multipartkit/content_disposition.gleam", 149).
-spec decode_with_charset(binary(), bitstring()) -> {ok, binary()} |
    {error, nil}.
decode_with_charset(Charset, Bytes) ->
    Lower = multipartkit@internal@text:ascii_lowercase(Charset),
    case Lower of
        <<"utf-8"/utf8>> ->
            gleam@bit_array:to_string(Bytes);

        <<"iso-8859-1"/utf8>> ->
            {ok, latin1_to_utf8(Bytes, <<""/utf8>>)};

        _ ->
            {error, nil}
    end.

-file("src/multipartkit/content_disposition.gleam", 210).
-spec hex_digit(binary()) -> {ok, integer()} | {error, nil}.
hex_digit(Grapheme) ->
    case Grapheme of
        <<"0"/utf8>> ->
            {ok, 0};

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

        <<"2"/utf8>> ->
            {ok, 2};

        <<"3"/utf8>> ->
            {ok, 3};

        <<"4"/utf8>> ->
            {ok, 4};

        <<"5"/utf8>> ->
            {ok, 5};

        <<"6"/utf8>> ->
            {ok, 6};

        <<"7"/utf8>> ->
            {ok, 7};

        <<"8"/utf8>> ->
            {ok, 8};

        <<"9"/utf8>> ->
            {ok, 9};

        <<"a"/utf8>> ->
            {ok, 10};

        <<"A"/utf8>> ->
            {ok, 10};

        <<"b"/utf8>> ->
            {ok, 11};

        <<"B"/utf8>> ->
            {ok, 11};

        <<"c"/utf8>> ->
            {ok, 12};

        <<"C"/utf8>> ->
            {ok, 12};

        <<"d"/utf8>> ->
            {ok, 13};

        <<"D"/utf8>> ->
            {ok, 13};

        <<"e"/utf8>> ->
            {ok, 14};

        <<"E"/utf8>> ->
            {ok, 14};

        <<"f"/utf8>> ->
            {ok, 15};

        <<"F"/utf8>> ->
            {ok, 15};

        _ ->
            {error, nil}
    end.

-file("src/multipartkit/content_disposition.gleam", 204).
-spec hex_pair(binary(), binary()) -> {ok, integer()} | {error, nil}.
hex_pair(High, Low) ->
    gleam@result:'try'(
        hex_digit(High),
        fun(H) ->
            gleam@result:'try'(hex_digit(Low), fun(L) -> {ok, (H * 16) + L} end)
        end
    ).

-file("src/multipartkit/content_disposition.gleam", 185).
-spec percent_decode_loop(list(binary()), bitstring()) -> {ok, bitstring()} |
    {error, nil}.
percent_decode_loop(Remaining, Acc) ->
    case Remaining of
        [] ->
            {ok, Acc};

        [<<"%"/utf8>>, High, Low | Rest] ->
            case hex_pair(High, Low) of
                {error, _} ->
                    {error, nil};

                {ok, Byte} ->
                    percent_decode_loop(Rest, <<Acc/bitstring, Byte>>)
            end;

        [<<"%"/utf8>> | _] ->
            {error, nil};

        [Other | Rest@1] ->
            Chunk = gleam_stdlib:identity(Other),
            percent_decode_loop(Rest@1, <<Acc/bitstring, Chunk/bitstring>>)
    end.

-file("src/multipartkit/content_disposition.gleam", 181).
-spec percent_decode(binary()) -> {ok, bitstring()} | {error, nil}.
percent_decode(Input) ->
    percent_decode_loop(gleam@string:to_graphemes(Input), <<>>).

-file("src/multipartkit/content_disposition.gleam", 135).
?DOC(
    " Decode a RFC 5987 / 8187 `charset 'lang' value` parameter into a Gleam\n"
    " `String`. Supports UTF-8 and ISO-8859-1.\n"
).
-spec decode_rfc5987(binary()) -> {ok, binary()} | {error, nil}.
decode_rfc5987(Input) ->
    case gleam@string:split_once(Input, <<"'"/utf8>>) of
        {error, _} ->
            {error, nil};

        {ok, {Charset, After_first}} ->
            case gleam@string:split_once(After_first, <<"'"/utf8>>) of
                {error, _} ->
                    {error, nil};

                {ok, {_, Encoded_value}} ->
                    gleam@result:'try'(
                        percent_decode(Encoded_value),
                        fun(Bytes) -> decode_with_charset(Charset, Bytes) end
                    )
            end
    end.

-file("src/multipartkit/content_disposition.gleam", 102).
-spec pick_convenience(list({binary(), binary()}), binary(), binary()) -> {ok,
        gleam@option:option(binary())} |
    {error, multipartkit@error:multipart_error()}.
pick_convenience(Params, Base_name, Original) ->
    Star = <<Base_name/binary, "*"/utf8>>,
    case find_param_ci(Params, Star) of
        {some, Raw} ->
            case decode_rfc5987(Raw) of
                {ok, Value} ->
                    {ok, {some, Value}};

                {error, _} ->
                    {error, {invalid_content_disposition, Original}}
            end;

        none ->
            case find_param_ci(Params, Base_name) of
                {some, Raw@1} ->
                    {ok, {some, Raw@1}};

                none ->
                    {ok, none}
            end
    end.

-file("src/multipartkit/content_disposition.gleam", 80).
-spec parse_one_param(binary(), list({binary(), binary()}), binary()) -> {ok,
        list({binary(), binary()})} |
    {error, multipartkit@error:multipart_error()}.
parse_one_param(Rest, Acc, Original) ->
    Inner_rest = multipartkit@internal@text:skip_ows(Rest),
    {Key, After_key} = multipartkit@internal@text:read_token(Inner_rest),
    case Key of
        <<""/utf8>> ->
            {error, {invalid_content_disposition, Original}};

        _ ->
            case gleam_stdlib:string_pop_grapheme(After_key) of
                {ok, {<<"="/utf8>>, Value_rest}} ->
                    case multipartkit@internal@text:read_token_or_quoted(
                        Value_rest
                    ) of
                        {error, nil} ->
                            {error, {invalid_content_disposition, Original}};

                        {ok, {Raw_value, Tail}} ->
                            parse_params(
                                Tail,
                                [{Key, Raw_value} | Acc],
                                Original
                            )
                    end;

                _ ->
                    {error, {invalid_content_disposition, Original}}
            end
    end.

-file("src/multipartkit/content_disposition.gleam", 64).
-spec parse_params(binary(), list({binary(), binary()}), binary()) -> {ok,
        list({binary(), binary()})} |
    {error, multipartkit@error:multipart_error()}.
parse_params(Input, Acc, Original) ->
    After_ows = multipartkit@internal@text:skip_ows(Input),
    case After_ows of
        <<""/utf8>> ->
            {ok, lists:reverse(Acc)};

        _ ->
            case gleam_stdlib:string_pop_grapheme(After_ows) of
                {ok, {<<";"/utf8>>, Rest}} ->
                    parse_one_param(Rest, Acc, Original);

                _ ->
                    {error, {invalid_content_disposition, Original}}
            end
    end.

-file("src/multipartkit/content_disposition.gleam", 35).
?DOC(
    " Parse a Content-Disposition header value.\n"
    "\n"
    " Returns `Error(InvalidContentDisposition(value))` for unparseable input.\n"
).
-spec parse(binary()) -> {ok, content_disposition()} |
    {error, multipartkit@error:multipart_error()}.
parse(Value) ->
    Original = Value,
    Rest = multipartkit@internal@text:skip_ows(Value),
    {Token, Rest_after_token} = multipartkit@internal@text:read_token(Rest),
    case Token of
        <<""/utf8>> ->
            {error, {invalid_content_disposition, Original}};

        _ ->
            case parse_params(Rest_after_token, [], Original) of
                {error, Err} ->
                    {error, Err};

                {ok, Params} ->
                    Disposition = multipartkit@internal@text:ascii_lowercase(
                        Token
                    ),
                    Name_value = pick_convenience(
                        Params,
                        <<"name"/utf8>>,
                        Original
                    ),
                    Filename_value = pick_convenience(
                        Params,
                        <<"filename"/utf8>>,
                        Original
                    ),
                    case {Name_value, Filename_value} of
                        {{error, Err@1}, _} ->
                            {error, Err@1};

                        {_, {error, Err@2}} ->
                            {error, Err@2};

                        {{ok, Name}, {ok, Filename}} ->
                            {ok,
                                {content_disposition,
                                    Disposition,
                                    Name,
                                    Filename,
                                    Params}}
                    end
            end
    end.