// 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 <memory>
#include <vector>

#include "arrow/compute/api_aggregate.h"
#include "arrow/compute/exec.h"
#include "arrow/compute/exec/exec_plan.h"
#include "arrow/compute/kernel.h"
#include "arrow/datum.h"
#include "arrow/result.h"
#include "arrow/util/visibility.h"

namespace arrow {
namespace compute {
namespace internal {

/// Internal use only: helper function for testing HashAggregateKernels.
/// For public use see arrow::compute::Grouper or create an execution plan
/// and use an aggregate node.
ARROW_EXPORT
Result<Datum> GroupBy(const std::vector<Datum>& arguments, const std::vector<Datum>& keys,
                      const std::vector<Aggregate>& aggregates, bool use_threads = false,
                      ExecContext* ctx = default_exec_context());

Result<std::vector<const HashAggregateKernel*>> GetKernels(
    ExecContext* ctx, const std::vector<Aggregate>& aggregates,
    const std::vector<TypeHolder>& in_types);

Result<std::vector<std::unique_ptr<KernelState>>> InitKernels(
    const std::vector<const HashAggregateKernel*>& kernels, ExecContext* ctx,
    const std::vector<Aggregate>& aggregates, const std::vector<TypeHolder>& in_types);

Result<FieldVector> ResolveKernels(
    const std::vector<Aggregate>& aggregates,
    const std::vector<const HashAggregateKernel*>& kernels,
    const std::vector<std::unique_ptr<KernelState>>& states, ExecContext* ctx,
    const std::vector<TypeHolder>& in_types);

}  // namespace internal
}  // namespace compute
}  // namespace arrow