/**
 * Copyright (c) 2021 OceanBase
 * OceanBase CE is licensed under Mulan PubL v2.
 * You can use this software according to the terms and conditions of the Mulan PubL v2.
 * You may obtain a copy of Mulan PubL v2 at:
 *          http://license.coscl.org.cn/MulanPubL-2.0
 * THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
 * EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
 * MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
 * See the Mulan PubL v2 for more details.
 */

#ifndef _OB_RAW_EXPR_CANONICALIZER_IMPL_H
#define _OB_RAW_EXPR_CANONICALIZER_IMPL_H
#include "sql/resolver/expr/ob_raw_expr_canonicalizer.h"
namespace oceanbase {
namespace sql {
class ObRawExprCanonicalizerImpl : public ObRawExprCanonicalizer {
public:
  explicit ObRawExprCanonicalizerImpl(ObExprResolveContext& ctx);
  virtual ~ObRawExprCanonicalizerImpl()
  {}

  virtual int canonicalize(ObRawExpr*& expr);

private:
  // types and constants
private:
  // disallow copy
  DISALLOW_COPY_AND_ASSIGN(ObRawExprCanonicalizerImpl);
  // function members
  typedef int (ObRawExprCanonicalizerImpl::*process_action)(ObRawExpr*& expr);
  int process_children(ObRawExpr*& expr, process_action trave_action);
  int push_not(ObRawExpr*& expr);
  int do_push_not(ObRawExpr*& expr);
  int pull_parallel_expr(ObRawExpr*& expr);
  int pull_and_factor(ObRawExpr*& expr);
  int pull_similar_expr(ObRawExpr*& expr);
  int cluster_and_or(ObRawExpr*& expr);

private:
  struct ObOppositeOpPair {
    ObItemType original_;
    ObItemType opposite_;
  };
  static ObItemType get_opposite_op(ObItemType type);
  static ObOppositeOpPair OPPOSITE_PAIRS[];

private:
  // data members
  ObExprResolveContext& ctx_;
  //  ObIAllocator &allocator_;
};

}  // end namespace sql
}  // end namespace oceanbase

#endif /* _OB_RAW_EXPR_CANONICALIZER_IMPL_H */
