/**
 * 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_SQL_EXPR_CONCAT_H_
#define _OB_SQL_EXPR_CONCAT_H_

#include "sql/engine/expr/ob_expr_operator.h"

namespace oceanbase
{
namespace sql
{
class ObExprConcat : public ObStringExprOperator
{
public:
  explicit  ObExprConcat(common::ObIAllocator &alloc);
  virtual ~ObExprConcat();

  virtual int calc_result_typeN(ObExprResType &type,
                                ObExprResType *types,
                                int64_t param_num,
                                common::ObExprTypeCtx &type_ctx) const;
  static int calc(common::ObObj &result,
                  const common::ObObj &obj1,
                  const common::ObObj &obj2,
                  common::ObIAllocator *allocator,
                  const common::ObObjType result_type,
                  bool is_oracle_mode,
                  const int64_t max_result_len);
  // Check result length with %max_result_len (if %max_result_len greater than zero)
  // or max length of varchar.
  // %result type is set to varchar.
  static int calc(common::ObObj &result,
                  const common::ObString obj1,
                  const common::ObString obj2,
                  common::ObIAllocator *allocator,
                  bool is_oracle_mode,
                  const int64_t max_result_len);
  // Check result length with OB_MAX_PACKET_LENGTH.
  // %result type is set to ObLongTextType
  static int calc(common::ObObj &result,
                         const char *obj1_ptr,
                         const int32_t this_len,
                         const char *obj2_ptr,
                         const int32_t other_len,
                         common::ObIAllocator *allocator);
  static int calc_text(common::ObObj &result,
                                     const common::ObObj obj1,
                                     const common::ObObj obj2,
                                     ObIAllocator *allocator);

  virtual int cg_expr(ObExprCGCtx &op_cg_ctx,
                      const ObRawExpr &raw_expr,
                      ObExpr &rt_expr) const override;

  static int eval_concat(const ObExpr &expr, ObEvalCtx &ctx, ObDatum &expr_datum);

private:
  // disallow copy
  DISALLOW_COPY_AND_ASSIGN(ObExprConcat);
};

}
}
#endif /* _OB_SQL_EXPR_CONCAT_H_ */