// 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 "exprs/aggregate/aggregate_function_state_union.h"

namespace doris {

const static std::string AGG_MERGE_SUFFIX = "_merge";

class AggregateStateMerge : public AggregateStateUnion {

public:

    using AggregateStateUnion::create;

    AggregateStateMerge(AggregateFunctionPtr function, const DataTypes& argument_types_,

                        const DataTypePtr& return_type)

            : AggregateStateUnion(function, argument_types_, return_type) {}

    static AggregateFunctionPtr create(AggregateFunctionPtr function,

                                       const DataTypes& argument_types_,

                                       const DataTypePtr& return_type) {

        CHECK(argument_types_.size() == 1);

        if (function == nullptr) {

            return nullptr;

        }

        return std::make_shared<AggregateStateMerge>(function, argument_types_, return_type);

    }

    void set_version(const int version_) override {

        IAggregateFunctionHelper::set_version(version_);

        _function->set_version(version_);

    }

    String get_name() const override { return _function->get_name() + AGG_MERGE_SUFFIX; }

    DataTypePtr get_return_type() const override { return _function->get_return_type(); }

    void insert_result_into(ConstAggregateDataPtr __restrict place, IColumn& to) const override {

        _function->insert_result_into(place, to);

    }

};

} // namespace doris