// 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 <stddef.h>

#include <stdint.h>

#include <algorithm>

#include <memory>

#include <vector>

#include "slice.h"

namespace doris {

class TDigest;

const static int QUANTILE_STATE_EXPLICIT_NUM = 2048;

const static int QUANTILE_STATE_COMPRESSION_MIN = 2048;

const static int QUANTILE_STATE_COMPRESSION_MAX = 10000;

enum QuantileStateType {

    EMPTY = 0,

    SINGLE = 1,   // single element

    EXPLICIT = 2, // more than one elements,stored in vector

    TDIGEST = 3   // TDIGEST object

};

class QuantileState {

public:

    QuantileState();

    explicit QuantileState(float compression);

    explicit QuantileState(const Slice& slice);

    QuantileState& operator=(const QuantileState& other) noexcept = default;

    QuantileState(const QuantileState& other) noexcept = default;

    QuantileState& operator=(QuantileState&& other) noexcept = default;

    QuantileState(QuantileState&& other) noexcept = default;

    void set_compression(float compression);

    bool deserialize(const Slice& slice);

    size_t serialize(uint8_t* dst) const;

    void merge(const QuantileState& other);

    void add_value(const double& value);

    void clear();

    bool is_valid(const Slice& slice);

    size_t get_serialized_size();

    double get_value_by_percentile(float percentile) const;

    double get_explicit_value_by_percentile(float percentile) const;

    ~QuantileState() = default;

private:

    QuantileStateType _type = EMPTY;

    std::shared_ptr<TDigest> _tdigest_ptr;

    double _single_data;

    std::vector<double> _explicit_data;

    float _compression;

};

} // namespace doris