/**
 *   Copyright 2016, Quickstep Research Group, Computer Sciences Department,
 *     University of Wisconsin—Madison.
 *
 *   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.
 **/

#ifndef QUICKSTEP_EXPRESSIONS_AGGREGATION_AGGREGATION_HANDLE_DISTINCT_HPP_
#define QUICKSTEP_EXPRESSIONS_AGGREGATION_AGGREGATION_HANDLE_DISTINCT_HPP_

#include <cstddef>
#include <memory>
#include <vector>

#include "catalog/CatalogTypedefs.hpp"
#include "expressions/aggregation/AggregationHandle.hpp"
#include "storage/HashTableBase.hpp"
#include "types/TypedValue.hpp"
#include "utility/Macros.hpp"

#include "glog/logging.h"

namespace quickstep {

class ColumnVector;
class StorageManager;
class Type;
class ValueAccessor;

/** \addtogroup Expressions
 *  @{
 */

class AggregationHandleDistinct : public AggregationHandle{
 public:
  /**
   * @brief Constructor.
   **/
  AggregationHandleDistinct() {
  }

  AggregationState* createInitialState() const override {
    LOG(FATAL) << "AggregationHandleDistinct does not support createInitialState().";
  }

  AggregationState* accumulateNullary(const std::size_t num_tuples) const override {
    LOG(FATAL) << "AggregationHandleDistinct does not support accumulateNullary().";
  }

  AggregationState* accumulateColumnVectors(
      const std::vector<std::unique_ptr<ColumnVector>> &column_vectors) const override {
    LOG(FATAL) << "AggregationHandleDistinct does not support accumulateColumnVectors().";
  }

#ifdef QUICKSTEP_ENABLE_VECTOR_COPY_ELISION_SELECTION
  AggregationState* accumulateValueAccessor(
      ValueAccessor *accessor,
      const std::vector<attribute_id> &accessor_ids) const override {
    LOG(FATAL) << "AggregationHandleDistinct does not support accumulateValueAccessor().";
  }
#endif

  void mergeStates(const AggregationState &source,
                   AggregationState *destination) const override {
    LOG(FATAL) << "AggregationHandleDistinct does not support mergeStates().";
  }

  TypedValue finalize(const AggregationState &state) const override {
    LOG(FATAL) << "AggregationHandleDistinct does not support finalize().";
  }

  AggregationStateHashTableBase* createGroupByHashTable(
      const HashTableImplType hash_table_impl,
      const std::vector<const Type*> &group_by_types,
      const std::size_t estimated_num_groups,
      StorageManager *storage_manager) const override;

  void aggregateValueAccessorIntoHashTable(
      ValueAccessor *accessor,
      const std::vector<attribute_id> &argument_ids,
      const std::vector<attribute_id> &group_by_key_ids,
      AggregationStateHashTableBase *hash_table) const override;

  ColumnVector* finalizeHashTable(
      const AggregationStateHashTableBase &hash_table,
      std::vector<std::vector<TypedValue>> *group_by_keys) const override;

 private:
  DISALLOW_COPY_AND_ASSIGN(AggregationHandleDistinct);
};

/** @} */

}  // namespace quickstep

#endif  // QUICKSTEP_EXPRESSIONS_AGGREGATION_AGGREGATION_HANDLE_DISTINCT_HPP_