package com.chenyang.druid.sql.visitor.functions;

import com.chenyang.druid.sql.ast.SQLExpr;
import com.chenyang.druid.sql.ast.expr.SQLMethodInvokeExpr;
import com.chenyang.druid.sql.visitor.SQLEvalVisitor;

public class BitLength implements Function {
   public static final BitLength instance = new BitLength();

   public Object eval(SQLEvalVisitor visitor, SQLMethodInvokeExpr x) {
      if (x.getArguments().size() != 1) {
         return SQLEvalVisitor.EVAL_ERROR;
      } else {
         SQLExpr param0 = (SQLExpr)x.getArguments().get(0);
         param0.accept(visitor);
         Object param0Value = param0.getAttributes().get("eval.value");
         if (param0Value == null) {
            return SQLEvalVisitor.EVAL_ERROR;
         } else {
            return param0Value instanceof String ? ((String)param0Value).getBytes().length * 8 : SQLEvalVisitor.EVAL_ERROR;
         }
      }
   }
}
