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
   * <p>
   * http://www.apache.org/licenses/LICENSE-2.0
   * <p>
   * 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.atlas.entitytransform;
  
  import org.apache.atlas.model.impexp.AttributeTransform;
  import org.apache.atlas.model.instance.AtlasEntity;
  import org.apache.atlas.type.AtlasType;
  import org.apache.commons.collections.CollectionUtils;
  import org.apache.commons.lang.StringUtils;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.util.ArrayList;
  import java.util.List;
  
  public class BaseEntityHandler {
      private static final Logger LOG = LoggerFactory.getLogger(BaseEntityHandler.class);
  
      protected final List<AtlasEntityTransformer> transformers;
  
      public BaseEntityHandler(List<AtlasEntityTransformer> transformers) {
          this.transformers = transformers;
      }
  
      public static List<BaseEntityHandler> createEntityHandlers(List<AttributeTransform> transforms, TransformerContext context) {
          LOG.debug("==> BaseEntityHandler.createEntityHandlers(transforms={})", transforms);
  
          List<BaseEntityHandler> ret = new ArrayList<>();
  
          if (CollectionUtils.isNotEmpty(transforms)) {
              List<AtlasEntityTransformer> transformers = new ArrayList<>();
  
              for (AttributeTransform transform : transforms) {
                  transformers.add(new AtlasEntityTransformer(transform, context));
              }
  
              if (hasTransformerForAnyAttribute(transformers, HdfsPathEntityHandler.CUSTOM_TRANSFORM_ATTRIBUTES)) {
                  ret.add(new HdfsPathEntityHandler(transformers));
              }
  
              if (hasTransformerForAnyAttribute(transformers, HiveDatabaseEntityHandler.CUSTOM_TRANSFORM_ATTRIBUTES)) {
                  ret.add(new HiveDatabaseEntityHandler(transformers));
              }
  
              if (hasTransformerForAnyAttribute(transformers, HiveTableEntityHandler.CUSTOM_TRANSFORM_ATTRIBUTES)) {
                  ret.add(new HiveTableEntityHandler(transformers));
              }
  
              if (hasTransformerForAnyAttribute(transformers, HiveColumnEntityHandler.CUSTOM_TRANSFORM_ATTRIBUTES)) {
                  ret.add(new HiveColumnEntityHandler(transformers));
              }
  
              if (hasTransformerForAnyAttribute(transformers, HiveStorageDescriptorEntityHandler.CUSTOM_TRANSFORM_ATTRIBUTES)) {
                  ret.add(new HiveStorageDescriptorEntityHandler(transformers));
              }
  
              if (CollectionUtils.isEmpty(ret)) {
                  ret.add(new BaseEntityHandler(transformers));
              }
          }
  
          LOG.debug("<== BaseEntityHandler.createEntityHandlers(transforms={}): ret.size={}", transforms, ret.size());
  
          return ret;
      }
  
      public static List<BaseEntityHandler> fromJson(String transformersString, TransformerContext context) {
          if (StringUtils.isEmpty(transformersString)) {
              return null;
          }
  
          Object  transformersObj = AtlasType.fromJson(transformersString, Object.class);
          List<?> transformers    = (transformersObj instanceof List) ? (List<?>) transformersObj : null;
  
          List<AttributeTransform> attributeTransforms = new ArrayList<>();
  
          if (CollectionUtils.isEmpty(transformers)) {
              return null;
          }
  
          for (Object transformer : transformers) {
              String             transformerStr     = AtlasType.toJson(transformer);
              AttributeTransform attributeTransform = AtlasType.fromJson(transformerStr, AttributeTransform.class);
  
              if (attributeTransform == null) {
                  continue;
              }
  
              attributeTransforms.add(attributeTransform);
          }
  
          if (CollectionUtils.isEmpty(attributeTransforms)) {
              return null;
          }
  
          List<BaseEntityHandler> entityHandlers = createEntityHandlers(attributeTransforms, context);
  
          if (CollectionUtils.isEmpty(entityHandlers)) {
              return null;
          }
  
          return entityHandlers;
      }
  
      public AtlasEntity transform(AtlasEntity entity) {
          if (CollectionUtils.isEmpty(transformers)) {
              return entity;
          }
  
          AtlasTransformableEntity transformableEntity = getTransformableEntity(entity);
  
          if (transformableEntity == null) {
              return entity;
          }
  
          for (AtlasEntityTransformer transformer : transformers) {
              transformer.transform(transformableEntity);
          }
  
          transformableEntity.transformComplete();
  
          return entity;
      }
  
      public AtlasTransformableEntity getTransformableEntity(AtlasEntity entity) {
          return new AtlasTransformableEntity(entity);
      }
  
      private static boolean hasTransformerForAnyAttribute(List<AtlasEntityTransformer> transformers, List<String> attributes) {
          if (CollectionUtils.isNotEmpty(transformers) && CollectionUtils.isNotEmpty(attributes)) {
              for (AtlasEntityTransformer transformer : transformers) {
                  for (Action action : transformer.getActions()) {
                      if (attributes.contains(action.getAttribute().getAttributeKey())) {
                          return true;
                      }
                  }
              }
          }
  
          return false;
      }
  
      public static class AtlasTransformableEntity {
          protected final AtlasEntity entity;
  
          protected AtlasTransformableEntity(AtlasEntity entity) {
              this.entity = entity;
          }
  
          public AtlasEntity getEntity() {
              return entity;
          }
  
          public Object getAttribute(EntityAttribute attribute) {
              final Object ret;
  
              if (attribute.appliesToEntityType(entity.getTypeName())) {
                  ret = entity.getAttribute(attribute.getAttributeName());
              } else {
                  ret = null;
              }
  
              return ret;
          }
  
          public void setAttribute(EntityAttribute attribute, String attributeValue) {
              if (attribute.appliesToEntityType(entity.getTypeName())) {
                  entity.setAttribute(attribute.getAttributeName(), attributeValue);
              }
          }
  
          public boolean hasAttribute(EntityAttribute attribute) {
              return getAttribute(attribute) != null;
          }
  
          public void transformComplete() {
              // implementations can override to set value of computed-attributes
          }
      }
  }
  