// Copyright 2023 PingCAP, Inc.
//
// Licensed 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.

#include <Common/config.h>
#include <IO/Compression/CompressionSettings.h>
#include <Interpreters/Settings.h>
#include <lz4hc.h>

#include <magic_enum.hpp>


namespace DB
{
CompressionSetting::CompressionSetting(const Settings & settings)
{
    method = settings.network_compression_method;
    method_byte = method_byte_map[static_cast<size_t>(method)];
    switch (method)
    {
    case CompressionMethod::ZSTD:
        level = settings.network_zstd_compression_level;
        break;
    default:
        level = getDefaultLevel(method);
    }
}

int CompressionSetting::getDefaultLevel(CompressionMethod method)
{
    switch (method)
    {
    case CompressionMethod::LZ4:
        return 1;
    case CompressionMethod::LZ4HC:
        return LZ4HC_CLEVEL_DEFAULT;
    case CompressionMethod::ZSTD:
        return 1;
#if USE_QPL
    case CompressionMethod::QPL:
        return 1;
#endif
    case CompressionMethod::Lightweight:
        return 3;
    default:
        return -1;
    }
}

template <typename T>
CompressionSetting CompressionSetting::create(T method, int level, const IDataType & type)
{
    // Nullable type will be treated as Unknown
    CompressionSetting setting(method);
    if (type.isValueRepresentedByInteger())
    {
        auto data_type = magic_enum::enum_cast<CompressionDataType>(type.getSizeOfValueInMemory());
        setting.data_type = data_type ? *data_type : CompressionDataType::Unknown;
    }
    else if (type.isFloatingPoint() && type.getSizeOfValueInMemory() == 4)
        setting.data_type = CompressionDataType::Float32;
    else if (type.isFloatingPoint() && type.getSizeOfValueInMemory() == 8)
        setting.data_type = CompressionDataType::Float64;
    // TODO: support String
    // else if (type.isStringOrFixedString())
    //     setting.data_type = CompressionDataType::String;
    else
        setting.data_type = CompressionDataType::Unknown;
    setting.level = level;
    return setting;
}

template CompressionSetting CompressionSetting::create(CompressionMethod method, int level, const IDataType & type);
template CompressionSetting CompressionSetting::create(CompressionMethodByte method, int level, const IDataType & type);

} // namespace DB