////////////////////////////////////////////////////////////////////////////////
/// DISCLAIMER
///
/// Copyright 2014-2016 ArangoDB GmbH, Cologne, Germany
/// Copyright 2004-2014 triAGENS 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 Michael Hackstein
////////////////////////////////////////////////////////////////////////////////

#ifndef ARANGOD_AQL_CONDITION_FINDER_H
#define ARANGOD_AQL_CONDITION_FINDER_H 1

#include "Aql/ExecutionNode.h"
#include "Aql/WalkerWorker.h"

#include <cstdint>
#include <unordered_map>

namespace arangodb {
namespace aql {
class Condition;
class ExecutionPlan;
class SortCondition;
struct Variable;

/// @brief condition finder
class ConditionFinder : public WalkerWorker<ExecutionNode> {
 public:
  ConditionFinder(ExecutionPlan* plan, std::unordered_map<size_t, ExecutionNode*>* changes,
                  bool* hasEmptyResult, bool viewMode);

  ~ConditionFinder() override = default;

  bool before(ExecutionNode*) final;

  bool enterSubquery(ExecutionNode*, ExecutionNode*) final;

 protected:
  bool handleFilterCondition(ExecutionNode* en, std::unique_ptr<Condition> const& condition);
  void handleSortCondition(ExecutionNode* en, Variable const* outVar,
                           std::unique_ptr<Condition> const& condition,
                           std::unique_ptr<SortCondition>& sortCondition);

 private:
  ExecutionPlan* _plan;
  std::unordered_map<VariableId, AstNode const*> _variableDefinitions;
  ::arangodb::containers::HashSet<VariableId> _filters;
  std::vector<std::pair<Variable const*, bool>> _sorts;
  // note: this class will never free the contents of this map
  std::unordered_map<size_t, ExecutionNode*>* _changes;
  bool* _hasEmptyResult;
};
}  // namespace aql
}  // namespace arangodb

#endif