/**
 * 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.
 **/

#ifndef QUICKSTEP_RELATIONAL_OPERATORS_WINDOW_AGGREGATION_OPERATOR_HPP_
#define QUICKSTEP_RELATIONAL_OPERATORS_WINDOW_AGGREGATION_OPERATOR_HPP_

#include <string>
#include <utility>
#include <vector>

#include "catalog/CatalogRelation.hpp"
#include "query_execution/QueryContext.hpp"
#include "relational_operators/RelationalOperator.hpp"
#include "relational_operators/WorkOrder.hpp"
#include "storage/StorageBlockInfo.hpp"
#include "utility/Macros.hpp"

#include "glog/logging.h"

#include "tmb/id_typedefs.h"

namespace tmb { class MessageBus; }

namespace quickstep {

class StorageManager;
class WindowAggregationOperationState;
class WorkOrderProtosContainer;
class WorkOrdersContainer;

namespace serialization { class WorkOrder; }

/** \addtogroup RelationalOperators
 *  @{
 */

/**
 * @brief An operator which performs window aggregation over a relation.
 **/
class WindowAggregationOperator : public RelationalOperator {
 public:
  /**
   * @brief Constructor.
   *
   * @param query_id The ID of this query.
   * @param input_relation The relation to perform aggregation over.
   * @param output_relation The relation for output.
   * @param window_aggregation_state_index The index of WindowAggregationState
   *                                       in QueryContext.
   * @param output_destination_index The index of InsertDestination in
   *                                 QueryContext for the output.
   **/
  WindowAggregationOperator(const std::size_t query_id,
                            const CatalogRelation &input_relation,
                            const CatalogRelation &output_relation,
                            const QueryContext::window_aggregation_state_id window_aggregation_state_index,
                            const QueryContext::insert_destination_id output_destination_index)
      : RelationalOperator(query_id, input_relation.getNumPartitions(),
                           input_relation.getNumPartitions() !=
                               output_relation.getNumPartitions() /* has_repartition */,
                           output_relation.getNumPartitions()),
        input_relation_(input_relation),
        output_relation_(output_relation),
        window_aggregation_state_index_(window_aggregation_state_index),
        output_destination_index_(output_destination_index),
        generated_(false) {}

  ~WindowAggregationOperator() override {}

  OperatorType getOperatorType() const override {
    return kWindowAggregation;
  }

  std::string getName() const override {
    return "WindowAggregationOperator";
  }

  bool getAllWorkOrders(WorkOrdersContainer *container,
                        QueryContext *query_context,
                        StorageManager *storage_manager,
                        const tmb::client_id scheduler_client_id,
                        tmb::MessageBus *bus) override;

  bool getAllWorkOrderProtos(WorkOrderProtosContainer *container) override;

  const relation_id getOutputRelationID() const override {
    return output_relation_.getID();
  }

  QueryContext::insert_destination_id getInsertDestinationID() const override {
    return output_destination_index_;
  }

 private:
  /**
   * @brief Create Work Order proto.
   *
   * @return A window aggregation work order.
   **/
  serialization::WorkOrder* createWorkOrderProto();

  const CatalogRelation &input_relation_;
  const CatalogRelation &output_relation_;
  const QueryContext::window_aggregation_state_id window_aggregation_state_index_;
  const QueryContext::insert_destination_id output_destination_index_;
  bool generated_;

  DISALLOW_COPY_AND_ASSIGN(WindowAggregationOperator);
};

/**
 * @brief A WorkOrder produced by WindowAggregationOperator.
 **/
class WindowAggregationWorkOrder : public WorkOrder {
 public:
  /**
   * @brief Constructor
   *
   * @param query_id The ID of this query.
   * @param state The WindowAggregationOperatorState to use.
   * @param block_ids The blocks' id of the input relation.
   * @param output_destination The InsertDestination for output.
   **/
  WindowAggregationWorkOrder(const std::size_t query_id,
                             WindowAggregationOperationState *state,
                             std::vector<block_id> &&block_ids,
                             InsertDestination *output_destination)
      : WorkOrder(query_id),
        state_(state),
        block_ids_(std::move(block_ids)),
        output_destination_(output_destination)  {}

  ~WindowAggregationWorkOrder() override {}

  void execute() override;

 private:
  WindowAggregationOperationState *state_;
  const std::vector<block_id> block_ids_;
  InsertDestination *output_destination_;

  DISALLOW_COPY_AND_ASSIGN(WindowAggregationWorkOrder);
};

/** @} */

}  // namespace quickstep

#endif  // QUICKSTEP_RELATIONAL_OPERATORS_WINDOW_AGGREGATION_OPERATOR_HPP_