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.strfunc;
  
  import com.actiontech.dble.plan.common.item.Item;
  import com.actiontech.dble.plan.common.item.function.ItemFunc;
  import com.actiontech.dble.plan.common.item.function.primary.ItemIntFunc;
  
  import java.math.BigInteger;
  import java.util.List;
  
  
  public class ItemFuncLocate extends ItemIntFunc {
  
      public ItemFuncLocate(List<Item> args, int charsetIndex) {
          super(args, charsetIndex);
      }
  
      @Override
      public String funcName() {
          return "locate";
      }
  
      @Override
      public BigInteger valInt() {
          String sub = args.get(0).valStr();
          String str = args.get(1).valStr();
          int pos = -1;
          if (args.size() == 3) {
              pos = args.get(2).valInt().intValue();
          }
          if (args.get(0).isNull() || args.get(1).isNull()) {
              this.nullValue = true;
              return BigInteger.ZERO;
          }
          if (pos <= 1) {
              return BigInteger.valueOf(str.indexOf(sub) + 1);
          } else {
              String posStr = str.substring(pos - 1);
              int find = posStr.indexOf(sub);
              if (find < 0)
                  return BigInteger.ZERO;
              else
                  return BigInteger.valueOf(pos + find);
          }
      }
  
      @Override
      public ItemFunc nativeConstruct(List<Item> realArgs) {
          return new ItemFuncLocate(realArgs, charsetIndex);
      }
  
  }
  