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.typecomputer.impl;
  
  import java.util.ArrayList;
  import java.util.List;
  
  import org.apache.asterix.om.base.AOrderedList;
  import org.apache.asterix.om.base.AString;
  import org.apache.asterix.om.base.IAObject;
  import org.apache.asterix.om.constants.AsterixConstantValue;
  import org.apache.asterix.om.typecomputer.base.AbstractResultTypeComputer;
  import org.apache.asterix.om.types.AOrderedListType;
  import org.apache.asterix.om.types.ARecordType;
  import org.apache.asterix.om.types.ATypeTag;
  import org.apache.asterix.om.types.BuiltinType;
  import org.apache.asterix.om.types.IAType;
  import org.apache.hyracks.algebricks.common.exceptions.AlgebricksException;
  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;
  
  public class FieldAccessNestedResultType extends AbstractResultTypeComputer {
      public static final FieldAccessNestedResultType INSTANCE = new FieldAccessNestedResultType();
  
      private FieldAccessNestedResultType() {
      }
  
      @Override
      protected IAType getResultType(ILogicalExpression expr, IAType... strippedInputTypes) throws AlgebricksException {
          IAType firstArgType = strippedInputTypes[0];
          if (firstArgType.getTypeTag() != ATypeTag.OBJECT) {
              return BuiltinType.ANY;
          }
          AbstractFunctionCallExpression funcExpr = (AbstractFunctionCallExpression) expr;
          ILogicalExpression arg1 = funcExpr.getArguments().get(1).getValue();
          if (arg1.getExpressionTag() != LogicalExpressionTag.CONSTANT) {
              return BuiltinType.ANY;
          }
          ConstantExpression ce = (ConstantExpression) arg1;
          IAObject v = ((AsterixConstantValue) ce.getValue()).getObject();
          List<String> fieldPath = new ArrayList<>();
          ATypeTag tag = v.getType().getTypeTag();
          if (tag == ATypeTag.ARRAY && ((AOrderedListType) v.getType()).getItemType().getTypeTag() == ATypeTag.STRING) {
              for (int i = 0; i < ((AOrderedList) v).size(); i++) {
                  fieldPath.add(((AString) ((AOrderedList) v).getItem(i)).getStringValue());
              }
          } else if (tag == ATypeTag.STRING) {
              fieldPath.add(((AString) v).getStringValue());
          } else {
              return BuiltinType.ANY;
          }
          ARecordType recType = (ARecordType) firstArgType;
          IAType fieldType = recType.getSubFieldType(fieldPath);
          return fieldType == null ? BuiltinType.ANY : fieldType;
      }
  }
  