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.camel.component.google.storage;
  
  import java.io.ByteArrayInputStream;
  import java.io.ByteArrayOutputStream;
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.net.URL;
  import java.util.*;
  import java.util.concurrent.TimeUnit;
  
  import com.google.cloud.storage.Blob;
  import com.google.cloud.storage.BlobId;
  import com.google.cloud.storage.BlobInfo;
  import com.google.cloud.storage.Bucket;
  import com.google.cloud.storage.CopyWriter;
  import com.google.cloud.storage.Storage;
  import com.google.cloud.storage.Storage.CopyRequest;
  import org.apache.camel.Exchange;
  import org.apache.camel.InvalidPayloadException;
  import org.apache.camel.Message;
  import org.apache.camel.WrappedFile;
  import org.apache.camel.support.DefaultProducer;
  import org.apache.camel.util.IOHelper;
  import org.apache.camel.util.ObjectHelper;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  public class GoogleCloudStorageProducer extends DefaultProducer {
  
      private static final Logger LOG = LoggerFactory.getLogger(GoogleCloudStorageProducer.class);
  
      private GoogleCloudStorageEndpoint endpoint;
  
      public GoogleCloudStorageProducer(GoogleCloudStorageEndpoint endpoint) {
          super(endpoint);
          this.endpoint = endpoint;
      }
  
      public void process(Exchange exchange) throws Exception {
  
          GoogleCloudStorageOperations operation = determineOperation(exchange);
          if (ObjectHelper.isEmpty(operation)) {
              processFile(getEndpoint().getStorageClient(), exchange);
          } else {
              switch (operation) {
                  case copyObject:
                      copyObject(getEndpoint().getStorageClient(), exchange);
                      break;
                  case deleteObject:
                      deleteObject(getEndpoint().getStorageClient(), exchange);
                      break;
                  case listBuckets:
                      listBuckets(getEndpoint().getStorageClient(), exchange);
                      break;
                  case deleteBucket:
                      deleteBucket(getEndpoint().getStorageClient(), exchange);
                      break;
                  case listObjects:
                      listObjects(getEndpoint().getStorageClient(), exchange);
                      break;
                  case getObject:
                      getObject(getEndpoint().getStorageClient(), exchange);
                      break;
                  case createDownloadLink:
                      createDownloadLink(getEndpoint().getStorageClient(), exchange);
                      break;
  
                  default:
                      throw new IllegalArgumentException("Unsupported operation");
              }
          }
  
      }
  
      private void processFile(Storage storage, Exchange exchange) throws IOException, InvalidPayloadException {
          final String bucketName = determineBucketName(exchange);
          final String objectName = determineObjectName(exchange);
  
          Map<String, String> objectMetadata = determineMetadata(exchange);
  
          InputStream is;
          Object obj = exchange.getIn().getMandatoryBody();
  
          // Need to check if the message body is WrappedFile
          if (obj instanceof WrappedFile) {
              obj = ((WrappedFile<?>) obj).getFile();
          }
          if (obj instanceof File) {
              File filePayload = (File) obj;
              is = new FileInputStream(filePayload);
          } else {
              is = exchange.getIn().getMandatoryBody(InputStream.class);
          }
          // Handle Content-Length if not already set
          is = setContentLength(objectMetadata, is);
  
          Blob createdBlob;
          BlobId blobId = BlobId.of(bucketName, objectName);
  
          BlobInfo.Builder builder = BlobInfo.newBuilder(blobId);
          String ct = objectMetadata.remove("Content-Type");
          if (ct != null) {
              builder.setContentType(ct);
          }
          String cd = objectMetadata.remove("Content-Disposition");
          if (cd != null) {
              builder.setContentDisposition(cd);
          }
          String ce = objectMetadata.remove("Content-Encoding");
          if (ce != null) {
              builder.setContentEncoding(ct);
          }
          String md5 = objectMetadata.remove("Content-Md5");
          if (md5 != null) {
              builder.setMd5(md5);
          }
          String cc = objectMetadata.remove("Cache-Control");
          if (cc != null) {
              builder.setCacheControl(ct);
          }
          BlobInfo blobInfo = builder.setMetadata(objectMetadata).build();
          // According to documentation, this internally uses a WriteChannel
          createdBlob = storage.createFrom(blobInfo, is);
          LOG.trace("created createdBlob [{}]", createdBlob);
          Message message = getMessageForResponse(exchange);
          message.setBody(createdBlob);
  
          IOHelper.close(is);
      }
  
      /**
       * If no content-length header was found, calculate length by reading the content.
       *
       * @param  objectMetadata Metadata set from Exchange headers
       * @param  is             InputStream to read the Exchange body content
       * @return                the original InputStream if Content-Length is set or a ByteArrayInputStream if the
       *                        original stream was read to determine the length.
       * @throws IOException    if the InputStream cannot be read.
       */
      private InputStream setContentLength(Map<String, String> objectMetadata, InputStream is) throws IOException {
          if (!objectMetadata.containsKey(Exchange.CONTENT_LENGTH) ||
                  objectMetadata.get(Exchange.CONTENT_LENGTH).equals("0")) {
              LOG.debug(
                      "The content length is not defined. It needs to be determined by reading the data into memory");
              ByteArrayOutputStream baos = determineLengthInputStream(is);
              objectMetadata.put("Content-Length", String.valueOf(baos.size()));
              return new ByteArrayInputStream(baos.toByteArray());
          } else {
              return is;
          }
      }
  
      private ByteArrayOutputStream determineLengthInputStream(InputStream is) throws IOException {
          ByteArrayOutputStream out = new ByteArrayOutputStream();
          byte[] bytes = new byte[1024];
          int count;
          while ((count = is.read(bytes)) > 0) {
              out.write(bytes, 0, count);
          }
          return out;
      }
  
      private Map<String, String> determineMetadata(final Exchange exchange) {
          Map<String, String> objectMetadata = new HashMap<>();
  
          Long contentLength = exchange.getIn().getHeader(GoogleCloudStorageConstants.CONTENT_LENGTH, Long.class);
          if (contentLength != null) {
              objectMetadata.put("Content-Length", String.valueOf(contentLength));
          } else if (ObjectHelper.isNotEmpty(exchange.getProperty(Exchange.CONTENT_LENGTH))) {
              objectMetadata.put("Content-Length",
                      exchange.getProperty(Exchange.CONTENT_LENGTH, String.class));
          }
  
          String contentType = exchange.getIn().getHeader(GoogleCloudStorageConstants.CONTENT_TYPE, String.class);
          if (contentType != null) {
              objectMetadata.put("Content-Type", contentType);
          }
  
          String cacheControl = exchange.getIn().getHeader(GoogleCloudStorageConstants.CACHE_CONTROL, String.class);
          if (cacheControl != null) {
              objectMetadata.put("Cache-Control", cacheControl);
          }
  
          String contentDisposition = exchange.getIn().getHeader(GoogleCloudStorageConstants.CONTENT_DISPOSITION,
                  String.class);
          if (contentDisposition != null) {
              objectMetadata.put("Content-Disposition", contentDisposition);
          }
  
          String contentEncoding = exchange.getIn().getHeader(GoogleCloudStorageConstants.CONTENT_ENCODING, String.class);
          if (contentEncoding != null) {
              objectMetadata.put("Content-Encoding", contentEncoding);
          }
  
          String contentMD5 = exchange.getIn().getHeader(GoogleCloudStorageConstants.CONTENT_MD5, String.class);
          if (contentMD5 != null) {
              objectMetadata.put("Content-Md5", contentMD5);
          }
  
          return objectMetadata;
      }
  
      private void createDownloadLink(Storage storage, Exchange exchange) {
          final String bucketName = determineBucketName(exchange);
          final String objectName = determineObjectName(exchange);
          Long expirationMillis
                  = exchange.getIn().getHeader(GoogleCloudStorageConstants.DOWNLOAD_LINK_EXPIRATION_TIME, 300000L, Long.class);
          long milliSeconds = 0;
          if (expirationMillis != null) {
              milliSeconds += expirationMillis;
          } else {
              milliSeconds += 1000 * 60 * 60;
          }
  
          BlobId blobId = BlobId.of(bucketName, objectName);
          BlobInfo blobInfo = BlobInfo.newBuilder(blobId).build();
          URL url = storage.signUrl(blobInfo, milliSeconds, TimeUnit.MILLISECONDS);
  
          Message message = getMessageForResponse(exchange);
          message.setBody(url.toString());
  
      }
  
      private void copyObject(Storage storage, Exchange exchange) {
          final String bucketName = determineBucketName(exchange);
          final String objectName = determineObjectName(exchange);
          final String destinationObjectName = exchange.getIn()
                  .getHeader(GoogleCloudStorageConstants.DESTINATION_OBJECT_NAME, String.class);
          final String bucketNameDestination = exchange.getIn()
                  .getHeader(GoogleCloudStorageConstants.DESTINATION_BUCKET_NAME, String.class);
  
          if (ObjectHelper.isEmpty(bucketNameDestination)) {
              throw new IllegalArgumentException("Bucket Name Destination must be specified for copyObject Operation");
          }
          if (ObjectHelper.isEmpty(destinationObjectName)) {
              throw new IllegalArgumentException("Destination Key must be specified for copyObject Operation");
          }
  
          //if bucket does not exsist, create it
          Bucket destinationBucketCheck = storage.get(bucketNameDestination);
          if (destinationBucketCheck != null) {
              LOG.trace("destinationBucketCheck [{}] already exists", destinationBucketCheck.getName());
          } else {
              LOG.trace("Destination Bucket [{}] doesn't exist yet", bucketNameDestination);
              if (getConfiguration().isAutoCreateBucket()) {
                  // creates the new bucket because it doesn't exist yet
                  destinationBucketCheck
                          = GoogleCloudStorageEndpoint.createNewBucket(bucketNameDestination, getConfiguration(), storage);
              }
          }
  
          BlobId sourceBlobId = BlobId.of(bucketName, objectName);
          BlobId targetBlobId = BlobId.of(bucketNameDestination, destinationObjectName);
          CopyRequest request = CopyRequest.of(sourceBlobId, targetBlobId);
          CopyWriter copyWriter = storage.copy(request);
  
          Message message = getMessageForResponse(exchange);
          message.setBody(copyWriter);
  
      }
  
      private void deleteObject(Storage storage, Exchange exchange) {
          final String bucketName = determineBucketName(exchange);
          final String objectName = determineObjectName(exchange);
  
          BlobId blobId = BlobId.of(bucketName, objectName);
          boolean result = storage.delete(blobId);
          Message message = getMessageForResponse(exchange);
          message.setBody(result);
  
      }
  
      private void deleteBucket(Storage storage, Exchange exchange) {
          final String bucketName = determineBucketName(exchange);
  
          for (Blob blob : storage.list(bucketName).iterateAll()) {
              storage.delete(blob.getBlobId());
          }
  
          boolean result = storage.delete(bucketName);
          Message message = getMessageForResponse(exchange);
          message.setBody(result);
  
      }
  
      private void listBuckets(Storage storage, Exchange exchange) {
          List<Bucket> bucketsList = new LinkedList<>();
          for (Bucket bucket : storage.list().iterateAll()) {
              bucketsList.add(bucket);
          }
  
          Message message = getMessageForResponse(exchange);
          message.setBody(bucketsList);
      }
  
      private void getObject(Storage storage, Exchange exchange) {
          final String bucketName = determineBucketName(exchange);
          final String objectName = determineObjectName(exchange);
  
          Blob blob = storage.get(BlobId.of(bucketName, objectName));
          Message message = getMessageForResponse(exchange);
          message.setBody(blob.getContent(Blob.BlobSourceOption.generationMatch()));
          message.setHeader(GoogleCloudStorageConstants.OBJECT_NAME, blob.getName());
          message.setHeader(GoogleCloudStorageConstants.CACHE_CONTROL, blob.getCacheControl());
          message.setHeader(GoogleCloudStorageConstants.METADATA_COMPONENT_COUNT, blob.getComponentCount());
          message.setHeader(GoogleCloudStorageConstants.CONTENT_DISPOSITION, blob.getContentDisposition());
          message.setHeader(GoogleCloudStorageConstants.CONTENT_ENCODING, blob.getContentEncoding());
          message.setHeader(GoogleCloudStorageConstants.METADATA_CONTENT_LANGUAGE, blob.getContentLanguage());
          message.setHeader(GoogleCloudStorageConstants.CONTENT_TYPE, blob.getContentType());
          message.setHeader(GoogleCloudStorageConstants.METADATA_CUSTOM_TIME, blob.getCustomTime());
          message.setHeader(GoogleCloudStorageConstants.METADATA_CRC32C_HEX, blob.getCrc32cToHexString());
          message.setHeader(GoogleCloudStorageConstants.METADATA_ETAG, blob.getEtag());
          message.setHeader(GoogleCloudStorageConstants.METADATA_GENERATION, blob.getGeneration());
          message.setHeader(GoogleCloudStorageConstants.METADATA_BLOB_ID, blob.getBlobId());
          message.setHeader(GoogleCloudStorageConstants.METADATA_KMS_KEY_NAME, blob.getKmsKeyName());
          message.setHeader(GoogleCloudStorageConstants.CONTENT_MD5, blob.getMd5ToHexString());
          message.setHeader(GoogleCloudStorageConstants.METADATA_MEDIA_LINK, blob.getMediaLink());
          message.setHeader(GoogleCloudStorageConstants.METADATA_METAGENERATION, blob.getMetageneration());
          message.setHeader(GoogleCloudStorageConstants.CONTENT_LENGTH, blob.getSize());
          message.setHeader(GoogleCloudStorageConstants.METADATA_STORAGE_CLASS, blob.getStorageClass());
          message.setHeader(GoogleCloudStorageConstants.METADATA_CREATE_TIME, blob.getCreateTime());
          message.setHeader(GoogleCloudStorageConstants.METADATA_LAST_UPDATE, new Date(blob.getUpdateTime()));
      }
  
      private void listObjects(Storage storage, Exchange exchange) {
          final String bucketName = determineBucketName(exchange);
          String prefix = exchange.getMessage().getHeader(GoogleCloudStorageConstants.PREFIX_NAME, String.class);
          List<Blob> bloblist;
          if (ObjectHelper.isEmpty(prefix)) {
              bloblist = new LinkedList<>();
              for (Blob blob : storage.list(bucketName).iterateAll()) {
                  bloblist.add(blob);
              }
          } else {
              bloblist = new LinkedList<>();
              for (Blob blob : storage.list(bucketName, Storage.BlobListOption.prefix(prefix)).iterateAll()) {
                  bloblist.add(blob);
              }
          }
  
          Message message = getMessageForResponse(exchange);
          message.setBody(bloblist);
  
      }
  
      private String determineObjectName(Exchange exchange) {
          String key = getConfiguration().getObjectName();
          if (ObjectHelper.isEmpty(key)) {
              key = exchange.getIn().getHeader(GoogleCloudStorageConstants.OBJECT_NAME, String.class);
          }
          if (key == null) {
              throw new IllegalArgumentException("Google Cloud Storage object name header missing.");
          }
          return key;
      }
  
      private String determineBucketName(Exchange exchange) {
          String bucketName = exchange.getMessage().getHeader(GoogleCloudStorageConstants.OVERRIDE_BUCKET_NAME, String.class);
          if (ObjectHelper.isEmpty(bucketName)) {
              bucketName = getConfiguration().getBucketName();
          }
          if (bucketName == null) {
              throw new IllegalArgumentException("Bucket name is missing or not configured.");
          }
          return bucketName;
      }
  
      public static Message getMessageForResponse(final Exchange exchange) {
          return exchange.getMessage();
      }
  
      private GoogleCloudStorageOperations determineOperation(Exchange exchange) {
          GoogleCloudStorageOperations operation = exchange.getIn().getHeader(
                  GoogleCloudStorageConstants.OPERATION,
                  GoogleCloudStorageOperations.class);
          if (operation == null) {
              operation = getConfiguration().getOperation();
          }
          return operation;
      }
  
      @Override
      public GoogleCloudStorageEndpoint getEndpoint() {
          return (GoogleCloudStorageEndpoint) super.getEndpoint();
      }
  
      private GoogleCloudStorageConfiguration getConfiguration() {
          return this.endpoint.getConfiguration();
      }
  
  }
  