/**
 *   Copyright 2011-2015 Quickstep Technologies LLC.
 *   Copyright 2015 Pivotal Software, Inc.
 *
 *   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_QUERY_OPTIMIZER_LOGICAL_LOGICAL_HPP_
#define QUICKSTEP_QUERY_OPTIMIZER_LOGICAL_LOGICAL_HPP_

#include <memory>
#include <vector>

#include "query_optimizer/OptimizerTree.hpp"
#include "query_optimizer/expressions/AttributeReference.hpp"
#include "query_optimizer/logical/LogicalType.hpp"
#include "utility/Macros.hpp"

namespace quickstep {
namespace optimizer {
namespace logical {

/** \addtogroup OptimizerLogical
 *  @{
 */

class Logical;
typedef std::shared_ptr<const Logical> LogicalPtr;

/**
 * @brief Base class for all logical operator/node.
 */
class Logical : public OptimizerTree<Logical> {
 public:
  /**
   * @brief Destructor.
   */
  ~Logical() {}

  /**
   * @return The type of this logical operator.
   */
  virtual LogicalType getLogicalType() const = 0;

  /**
   * @return The references to the output attributes produced by this logical
   * operator.
   */
  virtual std::vector<expressions::AttributeReferencePtr> getOutputAttributes() const = 0;

  /**
   * @return The references to the input attributes used in this logical
   * operator.
   */
  virtual std::vector<expressions::AttributeReferencePtr> getReferencedAttributes() const = 0;

 protected:
  /**
   * @brief Constructor.
   */
  Logical() {}

 private:
  DISALLOW_COPY_AND_ASSIGN(Logical);
};

/** @} */

}  // namespace logical
}  // namespace optimizer
}  // namespace quickstep

#endif /* QUICKSTEP_QUERY_OPTIMIZER_LOGICAL_LOGICAL_HPP_ */