-module(regular_ffi).
-export([
    compress/1,
    decompress/1,
    new_compression_context/0,
    compress_chunk/2,
    finish_compress_frame/2,
    new_decompression_context/0,
    decompress_chunk/2,
    finish_decompress_frame/2
]).

-spec compress(Data :: bitstring()) -> {ok, binary()} | {error, nil}.
compress(Data) ->
    try zstd:compress(Data) of
        Compressed -> {ok, iolist_to_binary(Compressed)}
    catch
        _:_ -> {error, nil}
    end.

-spec decompress(Data :: bitstring()) -> {ok, binary()} | {error, nil}.
decompress(Data) ->
    try zstd:decompress(Data) of
        Decompressed -> {ok, iolist_to_binary(Decompressed)}
    catch
        _:_ -> {error, nil}
    end.

-spec new_compression_context() -> zstd:context().
new_compression_context() ->
    {ok, Context} = zstd:context(compress),
    Context.

-spec compress_chunk(Context :: zstd:context(), Chunk :: bitstring()) ->
    {ok, {compression_finished, binary()}} |
    {ok, {compression_unfinished, binary(), binary()}} |
    {error, nil}.
compress_chunk(Context, Chunk) ->
    try zstd:stream(Context, Chunk) of
        {continue, Remainder, Output} ->
            {ok, {compression_unfinished, Output, iolist_to_binary(Remainder)}};
        {continue, Output} -> {ok, {compression_finished, Output}}
    catch
        _:_ -> {error, nil}
    end.
        

-spec finish_compress_frame(Context :: zstd:context(), Chunk :: bitstring()) ->
    {ok, binary()} |
    {error, nil}.
finish_compress_frame(Context, Chunk) ->
    try zstd:finish(Context, Chunk) of
        {done, Output} -> {ok, iolist_to_binary(Output)}
    catch
        _:_ -> {error, nil}
    end.

-spec new_decompression_context() -> zstd:context().
new_decompression_context() ->
    {ok, Context} = zstd:context(decompress),
    Context.


-spec decompress_chunk(Context :: zstd:context(), Chunk :: bitstring()) ->
    {ok, {decompression_finished, binary()}} |
    {ok, {decompression_unfinished, binary(), binary()}} |
    {error, nil}.
decompress_chunk(Context, Chunk) ->
    try zstd:stream(Context, Chunk) of
        {continue, Remainder, Output} ->
            {ok, {decompression_unfinished, Output, iolist_to_binary(Remainder)}};
        {continue, Output} -> {ok, {decompression_finished, Output}}
    catch
        _:_ -> {error, nil}
    end.

-spec finish_decompress_frame(Context :: zstd:context(), Chunk :: bitstring()) ->
    {ok, binary()} |
    {error, nil}.
finish_decompress_frame(Context, Chunk) ->
    try zstd:finish(Context, Chunk) of
        {done, Output} -> {ok, iolist_to_binary(Output)}
    catch
        _:_ -> {error, nil}
    end.