-module(gleeth@encoding@rlp).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch, inline]).
-define(FILEPATH, "src/gleeth/encoding/rlp.gleam").
-export([encode_string/1, encode_int/1, encode_hex_field/1, decode/1, encode/1]).
-export_type([rlp_item/0, rlp_error/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 rlp_item() :: {rlp_bytes, bitstring()} | {rlp_list, list(rlp_item())}.

-type rlp_error() :: {invalid_prefix, integer()} |
    unexpected_end |
    extra_data |
    invalid_length.

-file("src/gleeth/encoding/rlp.gleam", 186).
?DOC(" Convert a UTF-8 string to an RLP item\n").
-spec encode_string(binary()) -> rlp_item().
encode_string(Value) ->
    {rlp_bytes, gleam_stdlib:identity(Value)}.

-file("src/gleeth/encoding/rlp.gleam", 221).
-spec do_to_binary_be(integer(), bitstring()) -> bitstring().
do_to_binary_be(Value, Acc) ->
    case Value of
        0 ->
            Acc;

        _ ->
            Byte = erlang:'band'(Value, 16#ff),
            Rest = erlang:'bsr'(Value, 8),
            do_to_binary_be(Rest, <<Byte:8, Acc/bitstring>>)
    end.

-file("src/gleeth/encoding/rlp.gleam", 214).
?DOC(" Convert a non-negative integer to minimal big-endian bytes\n").
-spec to_binary_be(integer()) -> bitstring().
to_binary_be(Value) ->
    case Value of
        0 ->
            <<>>;

        _ ->
            do_to_binary_be(Value, <<>>)
    end.

-file("src/gleeth/encoding/rlp.gleam", 67).
-spec encode_length(integer(), integer()) -> bitstring().
encode_length(Len, Offset) ->
    case Len =< 55 of
        true ->
            Prefix_byte = Offset + Len,
            <<Prefix_byte:8>>;

        false ->
            Len_bytes = to_binary_be(Len),
            Len_of_len = erlang:byte_size(Len_bytes),
            Prefix_byte@1 = (Offset + 55) + Len_of_len,
            <<Prefix_byte@1:8, Len_bytes/bitstring>>
    end.

-file("src/gleeth/encoding/rlp.gleam", 35).
-spec encode_bytes(bitstring()) -> bitstring().
encode_bytes(Data) ->
    case Data of
        <<Byte:8>> ->
            case Byte < 16#80 of
                true ->
                    Data;

                false ->
                    Prefix = encode_length(1, 16#80),
                    <<Prefix/bitstring, Data/bitstring>>
            end;

        _ ->
            Len = erlang:byte_size(Data),
            Prefix@1 = encode_length(Len, 16#80),
            <<Prefix@1/bitstring, Data/bitstring>>
    end.

-file("src/gleeth/encoding/rlp.gleam", 178).
?DOC(
    " Convert an integer to an RLP item.\n"
    " Uses big-endian minimal encoding: 0 becomes empty bytes.\n"
).
-spec encode_int(integer()) -> rlp_item().
encode_int(Value) ->
    case Value of
        0 ->
            {rlp_bytes, <<>>};

        _ ->
            {rlp_bytes, to_binary_be(Value)}
    end.

-file("src/gleeth/encoding/rlp.gleam", 237).
-spec do_bytes_to_int(bitstring(), integer()) -> integer().
do_bytes_to_int(Data, Acc) ->
    case Data of
        <<Byte:8, Rest/bitstring>> ->
            do_bytes_to_int(Rest, (Acc * 256) + Byte);

        _ ->
            Acc
    end.

-file("src/gleeth/encoding/rlp.gleam", 233).
?DOC(" Convert big-endian bytes to an integer\n").
-spec bytes_to_int(bitstring()) -> integer().
bytes_to_int(Data) ->
    do_bytes_to_int(Data, 0).

-file("src/gleeth/encoding/rlp.gleam", 245).
?DOC(" Take n bytes from the front of a BitArray\n").
-spec take_bytes(bitstring(), integer()) -> {ok, {bitstring(), bitstring()}} |
    {error, rlp_error()}.
take_bytes(Data, N) ->
    case N =:= 0 of
        true ->
            {ok, {<<>>, Data}};

        false ->
            Available = erlang:byte_size(Data),
            case Available >= N of
                true ->
                    Taken@1 = case gleam_stdlib:bit_array_slice(Data, 0, N) of
                        {ok, Taken} -> Taken;
                        _assert_fail ->
                            erlang:error(#{gleam_error => let_assert,
                                        message => <<"Pattern match failed, no pattern matched the value."/utf8>>,
                                        file => <<?FILEPATH/utf8>>,
                                        module => <<"gleeth/encoding/rlp"/utf8>>,
                                        function => <<"take_bytes"/utf8>>,
                                        line => 252,
                                        value => _assert_fail,
                                        start => 7217,
                                        'end' => 7267,
                                        pattern_start => 7228,
                                        pattern_end => 7237})
                    end,
                    Rest@1 = case gleam_stdlib:bit_array_slice(
                        Data,
                        N,
                        Available - N
                    ) of
                        {ok, Rest} -> Rest;
                        _assert_fail@1 ->
                            erlang:error(#{gleam_error => let_assert,
                                        message => <<"Pattern match failed, no pattern matched the value."/utf8>>,
                                        file => <<?FILEPATH/utf8>>,
                                        module => <<"gleeth/encoding/rlp"/utf8>>,
                                        function => <<"take_bytes"/utf8>>,
                                        line => 253,
                                        value => _assert_fail@1,
                                        start => 7278,
                                        'end' => 7339,
                                        pattern_start => 7289,
                                        pattern_end => 7297})
                    end,
                    {ok, {Taken@1, Rest@1}};

                false ->
                    {error, unexpected_end}
            end
    end.

-file("src/gleeth/encoding/rlp.gleam", 263).
?DOC(" Strip leading zero bytes from a BitArray\n").
-spec strip_leading_zeros(bitstring()) -> bitstring().
strip_leading_zeros(Data) ->
    case Data of
        <<0:8, Rest/bitstring>> ->
            strip_leading_zeros(Rest);

        _ ->
            Data
    end.

-file("src/gleeth/encoding/rlp.gleam", 192).
?DOC(
    " Convert a \"0x...\" hex string to an RLP item with minimal encoding.\n"
    " Strips the 0x prefix, decodes hex to bytes, and removes leading zero bytes.\n"
).
-spec encode_hex_field(binary()) -> rlp_item().
encode_hex_field(Hex_string) ->
    Stripped = gleeth@utils@hex:strip_prefix(Hex_string),
    case Stripped of
        <<""/utf8>> ->
            {rlp_bytes, <<>>};

        _ ->
            Padded = case string:length(Stripped) rem 2 of
                0 ->
                    Stripped;

                _ ->
                    <<"0"/utf8, Stripped/binary>>
            end,
            case gleeth@utils@hex:decode(Padded) of
                {ok, Bytes} ->
                    {rlp_bytes, strip_leading_zeros(Bytes)};

                {error, _} ->
                    {rlp_bytes, <<>>}
            end
    end.

-file("src/gleeth/encoding/rlp.gleam", 161).
-spec decode_list_payload(bitstring()) -> {ok, list(rlp_item())} |
    {error, rlp_error()}.
decode_list_payload(Data) ->
    case erlang:byte_size(Data) of
        0 ->
            {ok, []};

        _ ->
            gleam@result:'try'(
                decode_item(Data),
                fun(_use0) ->
                    {Item, Rest} = _use0,
                    gleam@result:'try'(
                        decode_list_payload(Rest),
                        fun(Items) -> {ok, [Item | Items]} end
                    )
                end
            )
    end.

-file("src/gleeth/encoding/rlp.gleam", 95).
-spec decode_item(bitstring()) -> {ok, {rlp_item(), bitstring()}} |
    {error, rlp_error()}.
decode_item(Data) ->
    case Data of
        <<>> ->
            {error, unexpected_end};

        <<Prefix:8, Rest/bitstring>> ->
            decode_with_prefix(Prefix, Rest);

        _ ->
            {error, unexpected_end}
    end.

-file("src/gleeth/encoding/rlp.gleam", 103).
-spec decode_with_prefix(integer(), bitstring()) -> {ok,
        {rlp_item(), bitstring()}} |
    {error, rlp_error()}.
decode_with_prefix(Prefix, Rest) ->
    case Prefix < 16#80 of
        true ->
            {ok, {{rlp_bytes, <<Prefix:8>>}, Rest}};

        false ->
            case Prefix < 16#b8 of
                true ->
                    Len = Prefix - 16#80,
                    gleam@result:'try'(
                        take_bytes(Rest, Len),
                        fun(_use0) ->
                            {Bytes, Remaining} = _use0,
                            {ok, {{rlp_bytes, Bytes}, Remaining}}
                        end
                    );

                false ->
                    case Prefix < 16#c0 of
                        true ->
                            Len_of_len = Prefix - 16#b7,
                            gleam@result:'try'(
                                take_bytes(Rest, Len_of_len),
                                fun(_use0@1) ->
                                    {Len_bytes, After_len} = _use0@1,
                                    Len@1 = bytes_to_int(Len_bytes),
                                    gleam@result:'try'(
                                        take_bytes(After_len, Len@1),
                                        fun(_use0@2) ->
                                            {Bytes@1, Remaining@1} = _use0@2,
                                            {ok,
                                                {{rlp_bytes, Bytes@1},
                                                    Remaining@1}}
                                        end
                                    )
                                end
                            );

                        false ->
                            case Prefix < 16#f8 of
                                true ->
                                    Len@2 = Prefix - 16#c0,
                                    gleam@result:'try'(
                                        take_bytes(Rest, Len@2),
                                        fun(_use0@3) ->
                                            {Payload, Remaining@2} = _use0@3,
                                            gleam@result:'try'(
                                                decode_list_payload(Payload),
                                                fun(Items) ->
                                                    {ok,
                                                        {{rlp_list, Items},
                                                            Remaining@2}}
                                                end
                                            )
                                        end
                                    );

                                false ->
                                    Len_of_len@1 = Prefix - 16#f7,
                                    gleam@result:'try'(
                                        take_bytes(Rest, Len_of_len@1),
                                        fun(_use0@4) ->
                                            {Len_bytes@1, After_len@1} = _use0@4,
                                            Len@3 = bytes_to_int(Len_bytes@1),
                                            gleam@result:'try'(
                                                take_bytes(After_len@1, Len@3),
                                                fun(_use0@5) ->
                                                    {Payload@1, Remaining@3} = _use0@5,
                                                    gleam@result:'try'(
                                                        decode_list_payload(
                                                            Payload@1
                                                        ),
                                                        fun(Items@1) ->
                                                            {ok,
                                                                {{rlp_list,
                                                                        Items@1},
                                                                    Remaining@3}}
                                                        end
                                                    )
                                                end
                                            )
                                        end
                                    )
                            end
                    end
            end
    end.

-file("src/gleeth/encoding/rlp.gleam", 87).
?DOC(" Decode bytes into an RLP item\n").
-spec decode(bitstring()) -> {ok, rlp_item()} | {error, rlp_error()}.
decode(Data) ->
    gleam@result:'try'(
        decode_item(Data),
        fun(_use0) ->
            {Item, Rest} = _use0,
            case erlang:byte_size(Rest) of
                0 ->
                    {ok, Item};

                _ ->
                    {error, extra_data}
            end
        end
    ).

-file("src/gleeth/encoding/rlp.gleam", 56).
-spec encode_list(list(rlp_item())) -> bitstring().
encode_list(Items) ->
    Payload = gleam@list:fold(
        Items,
        <<>>,
        fun(Acc, Item) ->
            Encoded = encode(Item),
            <<Acc/bitstring, Encoded/bitstring>>
        end
    ),
    Len = erlang:byte_size(Payload),
    Prefix = encode_length(Len, 16#c0),
    <<Prefix/bitstring, Payload/bitstring>>.

-file("src/gleeth/encoding/rlp.gleam", 28).
?DOC(" Encode an RLP item to bytes\n").
-spec encode(rlp_item()) -> bitstring().
encode(Item) ->
    case Item of
        {rlp_bytes, Data} ->
            encode_bytes(Data);

        {rlp_list, Items} ->
            encode_list(Items)
    end.