content: /*
   * Copyright (C) 2016-2023 ActionTech.
   * License: http://www.gnu.org/licenses/gpl.html GPL version 2 or higher.
   */
  
  package com.actiontech.dble.plan.common.item.function.mathsfunc.operator;
  
  import com.actiontech.dble.plan.common.field.Field;
  import com.actiontech.dble.plan.common.item.Item;
  import com.actiontech.dble.plan.common.item.function.primary.ItemNumOp;
  import com.alibaba.druid.sql.ast.SQLExpr;
  import com.alibaba.druid.sql.ast.expr.SQLBinaryOpExpr;
  import com.alibaba.druid.sql.ast.expr.SQLBinaryOperator;
  
  import java.math.BigDecimal;
  import java.math.BigInteger;
  import java.math.RoundingMode;
  import java.util.List;
  
  
  public class ItemFuncDiv extends ItemNumOp {
  
      /**
       * default size of bigdecimal, the correct way is get the conf of mysql
       */
      private int precIncrement = 4;
  
      public ItemFuncDiv(Item a, Item b, int charsetIndex) {
          super(a, b, charsetIndex);
      }
  
      @Override
      public final String funcName() {
          return "/";
      }
  
      @Override
      public void fixLengthAndDec() {
          super.fixLengthAndDec();
          if (hybridType == ItemResult.REAL_RESULT) {
              decimals = Math.max(args.get(0).getDecimals(), args.get(1).getDecimals()) + precIncrement;
              decimals = Math.min(decimals, NOT_FIXED_DEC);
              int tmp = floatLength(decimals);
              if (decimals == NOT_FIXED_DEC)
                  maxLength = tmp;
              else {
                  maxLength = args.get(0).getMaxLength() - args.get(1).getDecimals() + decimals;
                  maxLength = Math.min(maxLength, tmp);
              }
          } else if (hybridType == ItemResult.INT_RESULT) {
              hybridType = ItemResult.DECIMAL_RESULT;
              resultPrecision();
  
          } else if (hybridType == ItemResult.DECIMAL_RESULT) {
              resultPrecision();
  
  
          }
      }
  
      @Override
      public BigDecimal realOp() {
          BigDecimal val0 = args.get(0).valReal();
          BigDecimal val1 = args.get(1).valReal();
          if (this.nullValue = (args.get(0).isNull() || args.get(1).isNull()))
              return BigDecimal.ZERO;
          if (val1.compareTo(BigDecimal.ZERO) == 0) {
              signalDivideByNull();
              return BigDecimal.ZERO;
          }
          return val0.divide(val1, decimals, RoundingMode.HALF_UP);
      }
  
      @Override
      public BigInteger intOp() {
          assert (false);
          return BigInteger.ZERO;
      }
  
      @Override
      public BigDecimal decimalOp() {
          if ((this.nullValue = args.get(0).isNull()))
              return new BigDecimal(0);
          if ((this.nullValue = args.get(1).isNull()))
              return new BigDecimal(0);
  
          final BigDecimal val2 = args.get(1).valDecimal();
          if (val2.compareTo(BigDecimal.ZERO) == 0) {
              signalDivideByNull();
              return BigDecimal.ZERO;
          }
          final BigDecimal val1 = args.get(0).valDecimal();
          BigDecimal bd = val1.divide(val2, decimals, RoundingMode.HALF_UP);
          return bd;
      }
  
      @Override
      public void resultPrecision() {
          decimals = Math.min(args.get(0).getDecimals() + precIncrement, DECIMAL_MAX_SCALE);
      }
  
      @Override
      public SQLExpr toExpression() {
          return new SQLBinaryOpExpr(args.get(0).toExpression(), SQLBinaryOperator.Divide, args.get(1).toExpression());
      }
  
      @Override
      protected Item cloneStruct(boolean forCalculate, List<Item> calArgs, boolean isPushDown, List<Field> fields) {
          List<Item> newArgs = null;
          if (!forCalculate)
              newArgs = cloneStructList(args);
          else
              newArgs = calArgs;
          return new ItemFuncDiv(newArgs.get(0), newArgs.get(1), charsetIndex);
      }
  
  }
  