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.repository.impexp;
  
  import org.apache.atlas.entitytransform.BaseEntityHandler;
  import org.apache.atlas.exception.AtlasBaseException;
  import org.apache.atlas.model.impexp.AtlasExportResult;
  import org.apache.atlas.model.instance.AtlasEntity;
  import org.apache.atlas.model.instance.AtlasEntity.AtlasEntityWithExtInfo;
  import org.apache.atlas.model.typedef.AtlasTypesDef;
  import org.apache.atlas.repository.store.graph.v2.EntityImportStream;
  import org.apache.atlas.type.AtlasType;
  import org.apache.commons.collections.MapUtils;
  import org.apache.commons.lang.StringUtils;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.io.ByteArrayOutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.security.MessageDigest;
  import java.security.NoSuchAlgorithmException;
  import java.util.Collections;
  import java.util.HashMap;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Map;
  import java.util.zip.ZipEntry;
  import java.util.zip.ZipInputStream;
  
  import static org.apache.atlas.AtlasErrorCode.IMPORT_ATTEMPTING_EMPTY_ZIP;
  
  public class ZipSource implements EntityImportStream {
      private static final Logger LOG = LoggerFactory.getLogger(ZipSource.class);
  
      private final InputStream             inputStream;
      private       List<String>            creationOrder;
      private       Iterator<String>        iterator;
      private final Map<String, String>     guidEntityJsonMap;
      private       ImportTransforms        importTransform;
      private       List<BaseEntityHandler> entityHandlers;
      private       int                     currentPosition;
      private       String                  md5Hash;
  
      public ZipSource(InputStream inputStream) throws IOException, AtlasBaseException {
          this(inputStream, null);
      }
  
      public ZipSource(InputStream inputStream, ImportTransforms importTransform) throws IOException, AtlasBaseException {
          this.inputStream       = inputStream;
          this.guidEntityJsonMap = new HashMap<>();
          this.importTransform   = importTransform;
  
          updateGuidZipEntryMap();
  
          if (isZipFileEmpty()) {
              throw new AtlasBaseException(IMPORT_ATTEMPTING_EMPTY_ZIP, "Attempting to import empty ZIP.");
          }
  
          setCreationOrder();
      }
  
      @Override
      public boolean hasNext() {
          return this.iterator.hasNext();
      }
  
      @Override
      public AtlasEntity next() {
          AtlasEntityWithExtInfo entityWithExtInfo = getNextEntityWithExtInfo();
  
          return entityWithExtInfo != null ? entityWithExtInfo.getEntity() : null;
      }
  
      @Override
      public void reset() {
          getCreationOrder();
  
          this.iterator = this.creationOrder != null ? this.creationOrder.iterator() : Collections.emptyIterator();
      }
  
      @Override
      public AtlasEntity getByGuid(String guid) {
          try {
              return getEntity(guid);
          } catch (AtlasBaseException e) {
              LOG.error("getByGuid: {} failed!", guid, e);
  
              return null;
          }
      }
  
      public int size() {
          return this.creationOrder.size();
      }
  
      @Override
      public int getPosition() {
          return currentPosition;
      }
  
      @Override
      public void setPosition(int index) {
          currentPosition = index;
  
          reset();
  
          for (int i = 0; i < creationOrder.size() && i <= index; i++) {
              onImportComplete(iterator.next());
          }
      }
  
      @Override
      public void setPositionUsingEntityGuid(String guid) {
          if (StringUtils.isBlank(guid)) {
              return;
          }
  
          int index = creationOrder.indexOf(guid);
  
          if (index == -1) {
              return;
          }
  
          setPosition(index);
      }
  
      @Override
      public AtlasEntityWithExtInfo getNextEntityWithExtInfo() {
          try {
              currentPosition++;
  
              return getEntityWithExtInfo(this.iterator.next());
          } catch (AtlasBaseException e) {
              LOG.warn("getNextEntityWithExtInfo", e);
              return null;
          }
      }
  
      public AtlasEntityWithExtInfo getEntityWithExtInfo(String guid) throws AtlasBaseException {
          String                 s                 = getFromCache(guid);
          AtlasEntityWithExtInfo entityWithExtInfo = convertFromJson(AtlasEntityWithExtInfo.class, s);
  
          if (importTransform != null) {
              entityWithExtInfo = importTransform.apply(entityWithExtInfo);
          }
  
          if (entityHandlers != null) {
              applyTransformers(entityWithExtInfo);
          }
  
          return entityWithExtInfo;
      }
  
      @Override
      public void onImportComplete(String guid) {
          guidEntityJsonMap.remove(guid);
      }
  
      @Override
      public ImportTransforms getImportTransform() {
          return this.importTransform;
      }
  
      @Override
      public void setImportTransform(ImportTransforms importTransform) {
          this.importTransform = importTransform;
      }
  
      @Override
      public List<BaseEntityHandler> getEntityHandlers() {
          return entityHandlers;
      }
  
      @Override
      public void setEntityHandlers(List<BaseEntityHandler> entityHandlers) {
          this.entityHandlers = entityHandlers;
      }
  
      @Override
      public AtlasTypesDef getTypesDef() throws AtlasBaseException {
          final String fileName = ZipExportFileNames.ATLAS_TYPESDEF_NAME.toString();
          String       s        = getFromCache(fileName);
  
          return convertFromJson(AtlasTypesDef.class, s);
      }
  
      @Override
      public AtlasExportResult getExportResult() throws AtlasBaseException {
          final String fileName = ZipExportFileNames.ATLAS_EXPORT_INFO_NAME.toString();
          String       s        = getFromCache(fileName);
  
          return convertFromJson(AtlasExportResult.class, s);
      }
  
      @Override
      public List<String> getCreationOrder() {
          return this.creationOrder;
      }
  
      @Override
      public void close() {
          try {
              inputStream.close();
              guidEntityJsonMap.clear();
          } catch (IOException ex) {
              LOG.warn("Error closing streams.", ex);
          }
      }
  
      private boolean isZipFileEmpty() {
          if (MapUtils.isEmpty(guidEntityJsonMap)) {
              return true;
          }
  
          String key = ZipExportFileNames.ATLAS_EXPORT_ORDER_NAME.toString();
  
          return (guidEntityJsonMap.containsKey(key) && StringUtils.isNotEmpty(guidEntityJsonMap.get(key)) && guidEntityJsonMap.get(key).equals("[]"));
      }
  
      private void setCreationOrder() {
          String fileName = ZipExportFileNames.ATLAS_EXPORT_ORDER_NAME.toString();
  
          try {
              String s = getFromCache(fileName);
  
              this.creationOrder = convertFromJson(List.class, s);
  
              this.iterator = this.creationOrder != null ? this.creationOrder.iterator() : Collections.emptyIterator();
          } catch (AtlasBaseException e) {
              LOG.error("Error retrieving '{}' from zip.", fileName, e);
          }
      }
  
      private void updateGuidZipEntryMap() throws IOException {
          try (ZipInputStream zipInputStream = new ZipInputStream(inputStream)) {
              MessageDigest md5Digest = MessageDigest.getInstance("MD5");
              ZipEntry      zipEntry  = zipInputStream.getNextEntry();
  
              while (zipEntry != null) {
                  String entryName = zipEntry.getName().replace(".json", "");
  
                  if (guidEntityJsonMap.containsKey(entryName)) {
                      continue;
                  }
  
                  byte[]                buf = new byte[1024];
                  ByteArrayOutputStream bos = new ByteArrayOutputStream();
                  int                   n;
  
                  while ((n = zipInputStream.read(buf, 0, 1024)) > -1) {
                      md5Digest.update(buf, 0, n);
                      bos.write(buf, 0, n);
                  }
  
                  guidEntityJsonMap.put(entryName, bos.toString());
  
                  zipEntry = zipInputStream.getNextEntry();
              }
  
              // Compute the final MD5 hash after processing the entire ZIP file
              byte[]        hashBytes = md5Digest.digest();
              StringBuilder md5Hash   = new StringBuilder();
  
              for (byte b : hashBytes) {
                  md5Hash.append(String.format("%02x", b));
              }
  
              this.md5Hash = md5Hash.toString();
          } catch (NoSuchAlgorithmException e) {
              throw new IOException(e);
          }
      }
  
      private void applyTransformers(AtlasEntityWithExtInfo entityWithExtInfo) {
          if (entityWithExtInfo == null) {
              return;
          }
  
          transform(entityWithExtInfo.getEntity());
  
          if (MapUtils.isNotEmpty(entityWithExtInfo.getReferredEntities())) {
              for (AtlasEntity e : entityWithExtInfo.getReferredEntities().values()) {
                  transform(e);
              }
          }
      }
  
      private void transform(AtlasEntity e) {
          for (BaseEntityHandler handler : entityHandlers) {
              handler.transform(e);
          }
      }
  
      private <T> T convertFromJson(Class<T> clazz, String jsonData) throws AtlasBaseException {
          T t;
  
          try {
              t = AtlasType.fromJson(jsonData, clazz);
  
              if (t == null) {
                  LOG.error("Error converting file to JSON.");
  
                  return null;
              }
          } catch (Exception e) {
              throw new AtlasBaseException("Error converting file to JSON.", e);
          }
  
          return t;
      }
  
      private String getFromCache(String entryName) {
          String s = guidEntityJsonMap.get(entryName);
  
          if (StringUtils.isEmpty(s)) {
              LOG.warn("Could not fetch requested contents of file: {}", entryName);
          }
  
          return s;
      }
  
      private AtlasEntity getEntity(String guid) throws AtlasBaseException {
          if (guidEntityJsonMap.containsKey(guid)) {
              AtlasEntityWithExtInfo extInfo = getEntityWithExtInfo(guid);
  
              return (extInfo != null) ? extInfo.getEntity() : null;
          }
  
          return null;
      }
  
      @Override
      public String getMd5Hash() {
          return this.md5Hash;
      }
  }
  