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.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.io.FileUtils;
  import org.apache.commons.lang.StringUtils;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.io.ByteArrayOutputStream;
  import java.io.File;
  import java.io.IOException;
  import java.io.InputStream;
  import java.nio.file.Files;
  import java.nio.file.Path;
  import java.nio.file.Paths;
  import java.security.MessageDigest;
  import java.security.NoSuchAlgorithmException;
  import java.util.ArrayList;
  import java.util.List;
  import java.util.UUID;
  import java.util.zip.ZipEntry;
  import java.util.zip.ZipInputStream;
  
  import static org.apache.atlas.AtlasErrorCode.IMPORT_ATTEMPTING_EMPTY_ZIP;
  import static org.apache.atlas.AtlasErrorCode.IMPORT_INVALID_ZIP_ENTRY;
  
  public class ZipSourceWithBackingDirectory implements EntityImportStream {
      private static final Logger LOG = LoggerFactory.getLogger(ZipSourceWithBackingDirectory.class);
  
      private static final String TEMPORARY_DIRECTORY_PREFIX           = "atlas-import-temp-";
      private static final String EXT_JSON                             = ".json";
      private static final String RELATIVE_PARENT_PATH                 = "..";
      private static final String RELATIVE_PARENT_PATH_WITH_SEP_PREFIX = File.separator + RELATIVE_PARENT_PATH;
      private static final String RELATIVE_PARENT_PATH_WITH_SEP_SUFFIX = RELATIVE_PARENT_PATH + File.separator;
  
      private Path                    tempDirectory;
      private ImportTransforms        importTransform;
      private List<BaseEntityHandler> entityHandlers;
      private ArrayList<String>       creationOrder = new ArrayList<>();
      private int                     currentPosition;
      private int                     numberOfEntries;
      private String                  md5Hash;
  
      public ZipSourceWithBackingDirectory(InputStream inputStream) throws IOException, AtlasBaseException {
          this(inputStream, null);
      }
  
      public ZipSourceWithBackingDirectory(InputStream inputStream, String backingDirectory) throws IOException, AtlasBaseException {
          setupBackingStore(inputStream, backingDirectory);
  
          if (isZipFileEmpty()) {
              throw new AtlasBaseException(IMPORT_ATTEMPTING_EMPTY_ZIP, "Attempting to import empty ZIP.");
          }
      }
  
      @Override
      public boolean hasNext() {
          return (currentPosition < numberOfEntries);
      }
  
      @Override
      public AtlasEntity next() {
          AtlasEntity.AtlasEntityWithExtInfo entityWithExtInfo = getNextEntityWithExtInfo();
  
          return entityWithExtInfo != null ? entityWithExtInfo.getEntity() : null;
      }
  
      @Override
      public void reset() {
          currentPosition = 0;
      }
  
      @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 numberOfEntries;
      }
  
      @Override
      public int getPosition() {
          return currentPosition;
      }
  
      @Override
      public void setPosition(int index) {
          reset();
  
          for (int i = 0; i < numberOfEntries && i <= index; i++) {
              onImportComplete(moveNext());
          }
      }
  
      @Override
      public void setPositionUsingEntityGuid(String guid) {
          if (StringUtils.isEmpty(guid)) {
              return;
          }
  
          while (currentPosition < numberOfEntries) {
              String current = creationOrder.get(currentPosition);
  
              if (current.equals(guid)) {
                  return;
              }
  
              moveNext();
          }
      }
  
      @Override
      public AtlasEntity.AtlasEntityWithExtInfo getNextEntityWithExtInfo() {
          try {
              return getEntityWithExtInfo(moveNext());
          } catch (AtlasBaseException e) {
              LOG.error("getNextEntityWithExtInfo", e);
  
              return null;
          }
      }
  
      @Override
      public AtlasEntity.AtlasEntityWithExtInfo getEntityWithExtInfo(String guid) throws AtlasBaseException {
          final File file = getFileFromTemporaryDirectory(guid + EXT_JSON);
  
          if (!file.exists()) {
              return null;
          }
  
          String json = getJsonStringForFile(file);
  
          if (StringUtils.isEmpty(json)) {
              return null;
          }
  
          AtlasEntity.AtlasEntityWithExtInfo entityWithExtInfo = convertFromJson(AtlasEntity.AtlasEntityWithExtInfo.class, json);
  
          if (importTransform != null) {
              entityWithExtInfo = importTransform.apply(entityWithExtInfo);
          }
  
          if (entityHandlers != null) {
              applyTransformers(entityWithExtInfo);
          }
  
          return entityWithExtInfo;
      }
  
      @Override
      public void onImportComplete(String guid) {
          try {
              getFileFromTemporaryDirectory(guid + EXT_JSON).delete();
          } catch (AtlasBaseException excp) {
              LOG.error("onImportComplete(guid={}): failed", guid, excp);
          }
      }
  
      @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 {
          return getJsonFromEntry(ZipExportFileNames.ATLAS_TYPESDEF_NAME.toString(), AtlasTypesDef.class);
      }
  
      @Override
      public AtlasExportResult getExportResult() throws AtlasBaseException {
          return getJsonFromEntry(ZipExportFileNames.ATLAS_EXPORT_INFO_NAME.toString(), AtlasExportResult.class);
      }
  
      @Override
      public List<String> getCreationOrder() {
          return creationOrder;
      }
  
      @Override
      public void close() {
          creationOrder.clear();
  
          try {
              LOG.info("Import: Removing temporary directory: {}", tempDirectory.toString());
  
              FileUtils.deleteDirectory(tempDirectory.toFile());
          } catch (IOException e) {
              LOG.error("Import: Error deleting: {}", tempDirectory, e);
          }
      }
  
      private boolean isZipFileEmpty() {
          return (numberOfEntries == 0);
      }
  
      private <T> T getJsonFromEntry(String entryName, Class<T> clazz) throws AtlasBaseException {
          final File file = getFileFromTemporaryDirectory(entryName + EXT_JSON);
  
          if (!file.exists()) {
              throw new AtlasBaseException(entryName + " not found!");
          }
  
          return convertFromJson(clazz, getJsonStringForFile(file));
      }
  
      private void setupBackingStore(InputStream inputStream, String backingDirectory) throws AtlasBaseException, IOException {
          try {
              initTempDirectory(backingDirectory);
              unzipToTempDirectory(inputStream);
              setupIterator();
          } catch (Exception excp) {
              try {
                  LOG.info("ZipSourceWithBackingDirectory: setupBackingStore() failed. Cleaning up..");
  
                  this.close();
              } catch (Throwable t) {
                  LOG.warn("ZipSourceWithBackingDirectory cleanup failed", t);
              }
  
              throw excp;
          }
      }
  
      private void initTempDirectory(String backingDirectory) throws AtlasBaseException {
          try {
              tempDirectory = Files.createDirectory(Paths.get(backingDirectory, getChildDirectoryForSession()));
  
              if (!permissionChecks(tempDirectory.toFile())) {
                  throw new AtlasBaseException(String.format("Import: Temporary directory: %s does not have permissions for operation!", tempDirectory.toString()));
              }
          } catch (Exception ex) {
              throw new AtlasBaseException(String.format("Error fetching temporary directory: %s", tempDirectory.toString()), ex);
          }
      }
  
      private String getChildDirectoryForSession() {
          return String.format("%s%s", TEMPORARY_DIRECTORY_PREFIX, UUID.randomUUID());
      }
  
      private boolean permissionChecks(File f) {
          return f.exists() && f.isDirectory() && f.canWrite();
      }
  
      private void unzipToTempDirectory(InputStream inputStream) throws IOException {
          LOG.info("Import: Temporary directory: {}", tempDirectory);
  
          ZipInputStream zis = new ZipInputStream(inputStream);
  
          try {
              MessageDigest md5Digest = MessageDigest.getInstance("MD5");
              ZipEntry      zipEntry  = zis.getNextEntry();
  
              while (zipEntry != null) {
                  String entryName = zipEntry.getName();
  
                  writeJsonToFile(entryName, getJsonPayloadFromZipEntryStream(zis, md5Digest));
  
                  numberOfEntries++;
  
                  zipEntry = zis.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();
  
              numberOfEntries -= ZipExportFileNames.values().length;
          } catch (NoSuchAlgorithmException e) {
              throw new IOException(e);
          } finally {
              zis.close();
              inputStream.close();
          }
      }
  
      private void writeJsonToFile(String entryName, byte[] jsonPayload) throws IOException {
          try {
              File f = getFileFromTemporaryDirectory(entryName);
  
              Files.write(f.toPath(), jsonPayload);
          } catch (AtlasBaseException excp) {
              LOG.error("writeJsonToFile(entryName={}): failed", entryName, excp);
  
              throw new IOException(excp);
          }
      }
  
      private File getFileFromTemporaryDirectory(String entryName) throws AtlasBaseException {
          if (hasRelativeParentPath(entryName)) {
              LOG.error("failed to initialize import: found zipEntry having relative parent path '{}'", entryName);
  
              throw new AtlasBaseException(IMPORT_INVALID_ZIP_ENTRY, entryName, "has relative parent path");
          }
  
          return new File(tempDirectory.toFile(), entryName);
      }
  
      private boolean hasRelativeParentPath(String path) {
          final boolean ret;
  
          if (path == null || !path.contains(RELATIVE_PARENT_PATH)) {
              ret = false;
          } else {
              ret = path.equals(RELATIVE_PARENT_PATH) || path.contains(RELATIVE_PARENT_PATH_WITH_SEP_PREFIX) || path.contains(RELATIVE_PARENT_PATH_WITH_SEP_SUFFIX);
          }
  
          return ret;
      }
  
      private void setupIterator() {
          try {
              creationOrder = getJsonFromEntry(ZipExportFileNames.ATLAS_EXPORT_ORDER_NAME.toString(), ArrayList.class);
          } catch (AtlasBaseException e) {
              LOG.error("Error fetching: {}. Error generating order.", ZipExportFileNames.ATLAS_EXPORT_ORDER_NAME, e);
          }
  
          reset();
      }
  
      private byte[] getJsonPayloadFromZipEntryStream(ZipInputStream zipInputStream, MessageDigest md5Digest) {
          try {
              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);
              }
  
              return bos.toByteArray();
          } catch (IOException ex) {
              LOG.error("Error fetching string from entry.", ex);
          }
  
          return null;
      }
  
      private String getJsonStringForFile(File file) {
          try {
              byte[] bytes = Files.readAllBytes(file.toPath());
  
              return new String(bytes);
          } catch (IOException e) {
              LOG.warn("Error fetching: {}", file, e);
  
              return null;
          }
      }
  
      private void applyTransformers(AtlasEntity.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 {
          try {
              return AtlasType.fromJson(jsonData, clazz);
          } catch (Exception e) {
              throw new AtlasBaseException("Error converting file to JSON.", e);
          }
      }
  
      private AtlasEntity getEntity(String guid) throws AtlasBaseException {
          AtlasEntity.AtlasEntityWithExtInfo extInfo = getEntityWithExtInfo(guid);
  
          return (extInfo != null) ? extInfo.getEntity() : null;
      }
  
      private String moveNext() {
          if (currentPosition < numberOfEntries) {
              return creationOrder.get(currentPosition++);
          }
  
          return null;
      }
  
      @Override
      public String getMd5Hash() {
          return this.md5Hash;
      }
  }
  