////////////////////////////////////////////////////////////////////////////////
/// DISCLAIMER
///
/// Copyright 2018 ArangoDB GmbH, Cologne, Germany
///
/// 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.
///
/// Copyright holder is ArangoDB GmbH, Cologne, Germany
///
/// @author Jan Christoph Uhde
////////////////////////////////////////////////////////////////////////////////

#ifndef ARANGOD_AQL_SINGLE_REMOTE_MODIFICATION_EXECUTOR_H
#define ARANGOD_AQL_SINGLE_REMOTE_MODIFICATION_EXECUTOR_H 1

#include "Aql/ModificationExecutor.h"

namespace arangodb {
namespace aql {

struct SingleRemoteModificationInfos : ModificationExecutorInfos {
  SingleRemoteModificationInfos(
      RegisterId inputRegister, RegisterId outputNewRegisterId,
      RegisterId outputOldRegisterId, RegisterId outputRegisterId,
      RegisterId nrInputRegisters, RegisterId nrOutputRegisters,
      std::unordered_set<RegisterId> const& registersToClear,
      std::unordered_set<RegisterId>&& registersToKeep, transaction::Methods* trx,
      OperationOptions options, aql::Collection const* aqlCollection,
      ConsultAqlWriteFilter consultAqlWriteFilter, IgnoreErrors ignoreErrors,
      IgnoreDocumentNotFound ignoreDocumentNotFound,  // end of base class params
      std::string key, bool hasParent, bool replaceIndex)
      : ModificationExecutorInfos(inputRegister, ExecutionNode::MaxRegisterId,
                                  ExecutionNode::MaxRegisterId, outputNewRegisterId,
                                  outputOldRegisterId, outputRegisterId,
                                  nrInputRegisters, nrOutputRegisters,
                                  registersToClear, std::move(registersToKeep),
                                  trx, std::move(options), aqlCollection,
                                  ProducesResults(false), consultAqlWriteFilter,
                                  ignoreErrors, DoCount(true), IsReplace(false),
                                  ignoreDocumentNotFound),
        _key(std::move(key)),
        _hasParent(hasParent),
        _replaceIndex(replaceIndex) {}

  std::string _key;

  bool _hasParent;  // node->hasParent();

  bool _replaceIndex;

  constexpr static double const defaultTimeOut = 3600.0;
};

struct IndexTag {};

template <typename Modifier>
struct SingleRemoteModificationExecutor {
  struct Properties {
    static const bool preservesOrder = true;
    static const bool allowsBlockPassthrough = false;
    static const bool inputSizeRestrictsOutputSize = false;
  };
  using Infos = SingleRemoteModificationInfos;
  using Fetcher = SingleRowFetcher<Properties::allowsBlockPassthrough>;
  using Stats = SingleRemoteModificationStats;
  using Modification = Modifier;

  SingleRemoteModificationExecutor(Fetcher&, Infos&);
  ~SingleRemoteModificationExecutor() = default;

  /**
   * @brief produce the next Row of Aql Values.
   *
   * @return ExecutionState,
   *         if something was written output.hasValue() == true
   */
  std::pair<ExecutionState, Stats> produceRows(OutputAqlItemRow& output);

 protected:
  bool doSingleRemoteModificationOperation(InputAqlItemRow&, OutputAqlItemRow&, Stats&);

  Infos& _info;
  Fetcher& _fetcher;
  ExecutionState _upstreamState;
};

}  // namespace aql
}  // namespace arangodb

#endif