/**
 * 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.
 */

#define USING_LOG_PREFIX SQL_ENG
#include <string.h>
#include "objit/common/ob_item_type.h"
#include "sql/engine/expr/ob_expr_hextoraw.h"
#include "sql/engine/expr/ob_expr_unhex.h"
#include "sql/engine/expr/ob_datum_cast.h"
#include "sql/engine/expr/ob_expr_operator.h"
#include "share/object/ob_obj_cast.h"
#include "lib/oblog/ob_log.h"
#include "sql/session/ob_sql_session_info.h"
using namespace oceanbase::common;

namespace oceanbase
{
namespace sql
{

ObExprHextoraw::ObExprHextoraw(ObIAllocator &alloc)
    : ObStringExprOperator(alloc, T_FUN_SYS_HEXTORAW, N_HEXTORAW, 1)
{
  disable_operand_auto_cast();
}

ObExprHextoraw::~ObExprHextoraw()
{
}

int ObExprHextoraw::calc_result_type1(ObExprResType &type, ObExprResType &text,
                                      ObExprTypeCtx &type_ctx) const
{
  UNUSED(type_ctx);
  int ret = OB_SUCCESS;

  common::ObObjType param_type = text.get_type();
  if (ob_is_text_tc(param_type)) {
    ret = OB_ERR_INVALID_TYPE_FOR_OP;
    LOG_WARN("lob as param not support in hextoraw", K(ret), K(param_type));
  } else if (!ob_is_null(param_type)
             && !ob_is_raw(param_type)
             && !ob_is_string_tc(param_type)
             && !ob_is_numeric_type(param_type)) {
    // TODO:@xiaofeng.lby, to support other param types of hextoraw
    ret = OB_ERR_INVALID_HEX_NUMBER;
    LOG_WARN("invalid hex number", K(ret), K(param_type), K(text));
  } else {
    common::ObLength length = -1;
    const int64_t oracle_max_avail_len = 40;
    type.set_collation_level(common::CS_LEVEL_NUMERIC);
    type.set_collation_type(common::CS_TYPE_BINARY);
    type.set_raw();
    if (ob_is_numeric_type(param_type)) {
      length = oracle_max_avail_len;//enough !
    } else if (ob_is_string_tc(param_type)) {
      length = text.get_length() / 2 + (text.get_length() % 2);
    }
    if (length <= 0 || length > common::OB_MAX_VARCHAR_LENGTH) {
      length = common::OB_MAX_VARCHAR_LENGTH;
    }
    type.set_length(length);
  }
  return ret;
}

int ObExprHextoraw::calc_hextoraw_expr(const ObExpr &expr, ObEvalCtx &ctx, ObDatum &res_datum)
{
  int ret = OB_SUCCESS;
  ObDatum *arg = NULL;
  if (OB_UNLIKELY(1 != expr.arg_cnt_)) {
    ret = OB_ERR_UNEXPECTED;
    LOG_WARN("invalid arg cnt", K(ret), K(expr.arg_cnt_));
  } else if (OB_FAIL(expr.args_[0]->eval(ctx, arg))) {
    LOG_WARN("eval arg failed", K(ret));
  } else if (arg->is_null()) {
    res_datum.set_null();
  } else if (OB_FAIL(ObDatumHexUtils::hextoraw(expr, *arg, expr.args_[0]->datum_meta_.type_,
                                       expr.args_[0]->datum_meta_.cs_type_, ctx, res_datum))) {
    LOG_WARN("hextoraw failed", K(ret));
  }
  return ret;
}

int ObExprHextoraw::cg_expr(ObExprCGCtx &expr_cg_ctx, const ObRawExpr &raw_expr,
                            ObExpr &rt_expr) const
{
  int ret = OB_SUCCESS;
  UNUSED(expr_cg_ctx);
  UNUSED(raw_expr);
  rt_expr.eval_func_ = calc_hextoraw_expr;
  return ret;
}

}
}