// Licensed to the Apache Software Foundation (ASF) under one

// or more contributor license agreements.  See the NOTICE file

// distributed with this work for additional information

// regarding copyright ownership.  The ASF licenses this file

// to you under the Apache License, Version 2.0 (the

// "License"); you may not use this file except in compliance

// with the License.  You may obtain a copy of the License at

//

//   http://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing,

// software distributed under the License is distributed on an

// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY

// KIND, either express or implied.  See the License for the

// specific language governing permissions and limitations

// under the License.

#pragma once

#include <gen_cpp/parquet_types.h>

#include <stddef.h>

#include <cstdint>

#include "common/status.h"

#include "format/parquet/parquet_common.h"

#include "util/bit_stream_utils.h"

#include "util/rle_encoding.h"

#include "util/slice.h"

namespace doris {

class LevelDecoder {

public:

    LevelDecoder() = default;

    ~LevelDecoder() = default;

    Status init(Slice* slice, tparquet::Encoding::type encoding, level_t max_level,

                uint32_t num_levels);

    Status init_v2(const Slice& levels, level_t max_level, uint32_t num_levels);

    inline bool has_levels() const { return _num_levels > 0; }

    size_t get_levels(level_t* levels, size_t n);

    inline size_t get_next_run(level_t* val, size_t max_run) {

        return _rle_decoder.GetNextRun(val, max_run);

    }

    inline level_t get_next() {

        level_t next = -1;

        _rle_decoder.Get(&next);

        return next;

    }

    inline void rewind_one() { _rle_decoder.RewindOne(); }

    const RleDecoder<level_t>& rle_decoder() const { return _rle_decoder; }

private:

    tparquet::Encoding::type _encoding;

    level_t _bit_width = 0;

    level_t _max_level = 0;

    uint32_t _num_levels = 0;

    RleDecoder<level_t> _rle_decoder;

    BitReader _bit_packed_decoder;

};

} // namespace doris