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.calcite.adapter.geode.util;
  
  import org.apache.calcite.adapter.java.JavaTypeFactory;
  import org.apache.calcite.jdbc.JavaRecordType;
  import org.apache.calcite.jdbc.JavaTypeFactoryImpl;
  import org.apache.calcite.rel.type.RelDataType;
  import org.apache.calcite.rel.type.RelDataTypeField;
  import org.apache.calcite.rel.type.RelDataTypeFieldImpl;
  import org.apache.calcite.rel.type.RelRecordType;
  
  import org.apache.geode.pdx.PdxInstance;
  
  import java.lang.reflect.Field;
  import java.lang.reflect.Type;
  import java.util.ArrayList;
  import java.util.List;
  import java.util.Map;
  
  import static org.apache.calcite.util.ReflectUtil.isStatic;
  
  /**
   * Implementation of {@link JavaTypeFactory}.
   *
   * <p><strong>NOTE: This class is experimental and subject to
   * change/removal without notice</strong>.
   */
  public class JavaTypeFactoryExtImpl
      extends JavaTypeFactoryImpl {
  
    /**
     * See <a href="http://stackoverflow.com/questions/16966629/what-is-the-difference-between-getfields-and-getdeclaredfields-in-java-reflectio">
     *   the difference between fields and declared fields</a>.
     */
    @Override public RelDataType createStructType(Class type) {
  
      final List<RelDataTypeField> list = new ArrayList<>();
      for (Field field : type.getDeclaredFields()) {
        if (!isStatic(field)) {
          // FIXME: watch out for recursion
          final Type fieldType = field.getType();
          list.add(
              new RelDataTypeFieldImpl(
                  field.getName(),
                  list.size(),
                  createType(fieldType)));
        }
      }
      return canonize(new JavaRecordType(list, type));
    }
  
    public RelDataType createPdxType(PdxInstance pdxInstance) {
      final List<RelDataTypeField> list = new ArrayList<>();
      for (String fieldName : pdxInstance.getFieldNames()) {
        Object field = pdxInstance.getField(fieldName);
  
        Type fieldType;
  
        if (field == null) {
          fieldType = String.class;
        } else if (field instanceof PdxInstance) {
          // Map Nested PDX structures as String. This relates with
          // GeodeUtils.convert case when clazz is Null.
          fieldType = Map.class;
          // RelDataType boza = createPdxType((PdxInstance) field);
        } else {
          fieldType = field.getClass();
        }
  
        list.add(
            new RelDataTypeFieldImpl(
                fieldName,
                list.size(),
                createType(fieldType)));
      }
  
      return canonize(new RelRecordType(list));
    }
  
    // Experimental flattering the nested structures.
    public RelDataType createPdxType2(PdxInstance pdxInstance) {
      final List<RelDataTypeField> list = new ArrayList<>();
      recursiveCreatePdxType(pdxInstance, list, "");
      return canonize(new RelRecordType(list));
    }
  
    private void recursiveCreatePdxType(PdxInstance pdxInstance,
        List<RelDataTypeField> list, String fieldNamePrefix) {
  
      for (String fieldName : pdxInstance.getFieldNames()) {
        Object field = pdxInstance.getField(fieldName);
        final Type fieldType = field.getClass();
        if (fieldType instanceof PdxInstance) {
          recursiveCreatePdxType(
              (PdxInstance) field, list, fieldNamePrefix + fieldName + ".");
        } else {
          list.add(
              new RelDataTypeFieldImpl(
                  fieldNamePrefix + fieldName,
                  list.size(),
                  createType(fieldType)));
        }
      }
    }
  
  }
  