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 java.util.ArrayList;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.stream.Stream;
  
  import org.apache.asterix.om.types.AOrderedListType;
  import org.apache.asterix.om.types.ARecordType;
  import org.apache.asterix.om.types.AUnionType;
  import org.apache.asterix.om.types.AUnorderedListType;
  import org.apache.asterix.om.types.BuiltinType;
  import org.apache.asterix.om.types.IAType;
  
  import com.fasterxml.jackson.databind.JsonNode;
  import com.google.common.collect.Lists;
  
  public class JSONDeserializerForTypes {
      private static final Map<String, IAType> primitiveTypeMap;
      static {
          primitiveTypeMap = new HashMap<>();
          Class<?> buildInTypeClass = BuiltinType.class;
          Stream.of(buildInTypeClass.getDeclaredFields()).filter(f -> f.getType().isAssignableFrom(BuiltinType.class))
                  .forEach(f -> {
                      try {
                          primitiveTypeMap.put(f.getName().toUpperCase(), (IAType) f.get(null));
                      } catch (IllegalAccessException e) {
                          throw new IllegalStateException(e);
                      }
                  });
          // for backward-compatibility
          primitiveTypeMap.put("ASTERIX_TYPE", BuiltinType.ALL_TYPE);
      }
  
      private JSONDeserializerForTypes() {
      }
  
      /**
       * Deserialize an arbitrary JSON representation of a type.
       *
       * @param typeInJSON
       *            the JSON representation of the type.
       * @return an valid AsterixDB type.
       * @throws Exception
       */
      public static IAType convertFromJSON(JsonNode typeInJSON) throws Exception {
          String typeName = typeInJSON.get("type").asText();
          // Deals with ordered list.
          if (typeName.equals(AOrderedListType.class.getName())) {
              IAType itemType = convertFromJSON(typeInJSON.get("item-type"));
              return new AOrderedListType(itemType, "ordered-list");
          }
  
          // Deals with unordered list.
          if (typeName.equals(AUnorderedListType.class.getName())) {
              IAType itemType = convertFromJSON(typeInJSON.get("item-type"));
              return new AUnorderedListType(itemType, "unordered-list");
          }
  
          // Deals with Union Type.
          if (typeName.equals(AUnionType.class.getName())) {
              List<IAType> unionTypes = new ArrayList<>();
              JsonNode fields = typeInJSON.get("fields");
              for (int i = 0; i < fields.size(); i++) {
                  JsonNode fieldType = fields.get(i);
                  unionTypes.add(convertFromJSON(fieldType));
              }
              return new AUnionType(unionTypes, "union");
          }
  
          // Deals with record types.
          if (typeName.equals(ARecordType.class.getName())) {
              String name = typeInJSON.get("name").asText();
              boolean openType = typeInJSON.get("open").asBoolean();
              JsonNode fields = typeInJSON.get("fields");
              String[] fieldNames = new String[fields.size()];
              IAType[] fieldTypes = new IAType[fields.size()];
              for (int i = 0; i < fields.size(); ++i) {
                  JsonNode field = fields.get(i);
                  List<String> names = Lists.newArrayList(field.fieldNames());
                  String fieldName = names.get(0);
                  fieldNames[i] = fieldName;
                  fieldTypes[i] = convertFromJSON(field.get(fieldName));
              }
              return new ARecordType(name, fieldNames, fieldTypes, openType);
          }
  
          // Deals with primitive types.
          return primitiveTypeMap.get(typeName.toUpperCase());
      }
  }
  