content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you under the Apache License, Version 2.0 (the
   * "License"); you may not use this file except in compliance
   * with the License.  You may obtain a copy of the License at
   *
   *   http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing,
   * software distributed under the License is distributed on an
   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
   * KIND, either express or implied.  See the License for the
   * specific language governing permissions and limitations
   * under the License.
   */
  package org.apache.asterix.om.utils;
  
  import org.apache.asterix.om.base.ABoolean;
  import org.apache.asterix.om.base.ADouble;
  import org.apache.asterix.om.base.AInt32;
  import org.apache.asterix.om.base.AInt64;
  import org.apache.asterix.om.base.AOrderedList;
  import org.apache.asterix.om.base.AString;
  import org.apache.asterix.om.base.AUnorderedList;
  import org.apache.asterix.om.base.IAObject;
  import org.apache.asterix.om.constants.AsterixConstantValue;
  import org.apache.asterix.om.types.ATypeTag;
  import org.apache.hyracks.algebricks.core.algebra.base.ILogicalExpression;
  import org.apache.hyracks.algebricks.core.algebra.base.LogicalExpressionTag;
  import org.apache.hyracks.algebricks.core.algebra.expressions.AbstractFunctionCallExpression;
  import org.apache.hyracks.algebricks.core.algebra.expressions.ConstantExpression;
  import org.apache.hyracks.algebricks.core.algebra.expressions.IAlgebricksConstantValue;
  import org.apache.hyracks.api.exceptions.SourceLocation;
  
  public class ConstantExpressionUtil {
  
      private ConstantExpressionUtil() {
      }
  
      public static IAObject getConstantIaObject(ILogicalExpression expr, ATypeTag typeTag) {
          if (expr.getExpressionTag() != LogicalExpressionTag.CONSTANT) {
              return null;
          }
          final IAlgebricksConstantValue acv = ((ConstantExpression) expr).getValue();
          if (!(acv instanceof AsterixConstantValue)) {
              return null;
          }
          final IAObject iaObject = ((AsterixConstantValue) acv).getObject();
          if (typeTag != null) {
              return iaObject.getType().getTypeTag() == typeTag ? iaObject : null;
          } else {
              return iaObject;
          }
      }
  
      public static ATypeTag getConstantIaObjectType(ILogicalExpression expr) {
          IAObject iaObject = getConstantIaObject(expr, null);
          return iaObject.getType().getTypeTag();
      }
  
      public static Long getLongConstant(ILogicalExpression expr) {
          final IAObject iaObject = getConstantIaObject(expr, ATypeTag.BIGINT);
          return iaObject != null ? ((AInt64) iaObject).getLongValue() : null;
      }
  
      public static Integer getIntConstant(ILogicalExpression expr) {
          final IAObject iaObject = getConstantIaObject(expr, ATypeTag.INTEGER);
          return iaObject != null ? ((AInt32) iaObject).getIntegerValue() : null;
      }
  
      public static String getStringConstant(ILogicalExpression expr) {
          final IAObject iaObject = getConstantIaObject(expr, ATypeTag.STRING);
          return iaObject != null ? ((AString) iaObject).getStringValue() : null;
      }
  
      public static String getStringConstant(IAObject iaObject) {
          // Make sure to call this method after checking the type of the given object.
          return iaObject != null ? ((AString) iaObject).getStringValue() : null;
      }
  
      public static AOrderedList getOrderedListConstant(IAObject iaObject) {
          // Make sure to call this method after checking the type of the given object.
          return iaObject != null ? (AOrderedList) iaObject : null;
      }
  
      public static AUnorderedList getUnorderedListConstant(IAObject iaObject) {
          // Make sure to call this method after checking the type of the given object.
          return iaObject != null ? (AUnorderedList) iaObject : null;
      }
  
      public static Boolean getBooleanConstant(ILogicalExpression expr) {
          final IAObject iaObject = getConstantIaObject(expr, ATypeTag.BOOLEAN);
          return iaObject != null ? ((ABoolean) iaObject).getBoolean() : null;
      }
  
      public static Integer getIntArgument(AbstractFunctionCallExpression f, int index) {
          return getIntConstant(f.getArguments().get(index).getValue());
      }
  
      public static Long getLongArgument(AbstractFunctionCallExpression f, int index) {
          return getLongConstant(f.getArguments().get(index).getValue());
      }
  
      public static String getStringArgument(AbstractFunctionCallExpression f, int index) {
          return getStringConstant(f.getArguments().get(index).getValue());
      }
  
      public static Integer getIntArgument(ILogicalExpression expr, int index) {
          return expr.getExpressionTag() == LogicalExpressionTag.FUNCTION_CALL
                  ? getIntArgument((AbstractFunctionCallExpression) expr, index) : null;
      }
  
      public static String getStringArgument(ILogicalExpression expr, int index) {
          return expr.getExpressionTag() == LogicalExpressionTag.FUNCTION_CALL
                  ? getStringArgument((AbstractFunctionCallExpression) expr, index) : null;
      }
  
      public static ConstantExpression create(String value, SourceLocation sourceLocation) {
          return createExpression(new AString(value), sourceLocation);
      }
  
      public static ConstantExpression create(long value, SourceLocation sourceLocation) {
          return createExpression(new AInt64(value), sourceLocation);
      }
  
      public static ConstantExpression create(double value, SourceLocation sourceLocation) {
          return createExpression(new ADouble(value), sourceLocation);
      }
  
      private static ConstantExpression createExpression(IAObject value, SourceLocation sourceLocation) {
          ConstantExpression constExpr = new ConstantExpression(new AsterixConstantValue(value));
          constExpr.setSourceLocation(sourceLocation);
          return constExpr;
      }
  }
  