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.beam.sdk.util.construction.resources;
  
  import static org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.base.Preconditions.checkArgument;
  
  import java.io.File;
  import java.io.IOException;
  import java.io.OutputStream;
  import java.util.List;
  import java.util.function.Predicate;
  import java.util.stream.Collectors;
  import org.apache.beam.sdk.options.FileStagingOptions;
  import org.apache.beam.sdk.options.PipelineOptions;
  import org.apache.beam.sdk.util.ZipFiles;
  import org.apache.beam.sdk.util.common.ReflectHelpers;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.base.MoreObjects;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.base.Preconditions;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.base.Strings;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.hash.Funnels;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.hash.Hasher;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.hash.Hashing;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /** Utilities for working with classpath resources for pipelines. */
  public class PipelineResources {
    private static final Logger LOG = LoggerFactory.getLogger(PipelineResources.class);
  
    /**
     * Uses algorithm provided via {@link PipelineResourcesOptions} to detect classpath resources.
     *
     * @param classLoader The URLClassLoader to use to detect resources to stage (optional).
     * @param options pipeline options
     * @return A list of absolute paths to the resources the class loader uses.
     */
    public static List<String> detectClassPathResourcesToStage(
        ClassLoader classLoader, PipelineOptions options) {
  
      PipelineResourcesOptions artifactsRelatedOptions = options.as(PipelineResourcesOptions.class);
      List<String> detectedResources =
          artifactsRelatedOptions.getPipelineResourcesDetector().detect(classLoader);
  
      return detectedResources.stream().filter(isStageable()).collect(Collectors.toList());
    }
  
    /**
     * Returns a predicate for filtering all resources that are impossible to stage (like gradle
     * wrapper jars).
     */
    private static Predicate<String> isStageable() {
      return resourcePath -> !resourcePath.contains("gradle/wrapper");
    }
  
    /**
     * Goes through the list of files that need to be staged on runner. Removes nonexistent
     * directories and packages existing ones. This is necessary for runners that require filesToStage
     * to be jars only.
     *
     * <p>This method mutates the filesToStage value of the given options.
     *
     * @param options options object with the files to stage and temp location for staging
     */
    public static void prepareFilesForStaging(FileStagingOptions options) {
      List<String> filesToStage = options.getFilesToStage();
      if (filesToStage == null || filesToStage.isEmpty()) {
        filesToStage = detectClassPathResourcesToStage(ReflectHelpers.findClassLoader(), options);
        LOG.info(
            "PipelineOptions.filesToStage was not specified. "
                + "Defaulting to files from the classpath: will stage {} files. "
                + "Enable logging at DEBUG level to see which files will be staged.",
            filesToStage.size());
        LOG.debug("Classpath elements: {}", filesToStage);
      }
      final String tmpJarLocation =
          MoreObjects.firstNonNull(options.getTempLocation(), System.getProperty("java.io.tmpdir"));
      final List<String> resourcesToStage = prepareFilesForStaging(filesToStage, tmpJarLocation);
      options.setFilesToStage(resourcesToStage);
    }
  
    /**
     * Goes through the list of files that need to be staged on runner. Fails if the directory does
     * not exist and packages the ones that exist. This is necessary for runners that require
     * filesToStage to be jars only.
     *
     * @param resourcesToStage list of resources that need to be staged
     * @param tmpJarLocation temporary directory to store the jars
     * @return A list of absolute paths to resources (jar files)
     * @throws IllegalStateException if the directory to be staged does not exist
     */
    public static List<String> prepareFilesForStaging(
        List<String> resourcesToStage, String tmpJarLocation) {
      return resourcesToStage.stream()
          .map(File::new)
          .map(
              file -> {
                Preconditions.checkState(
                    file.exists(), "To-be-staged file does not exist: '%s'", file);
                return file.isDirectory()
                    ? packageDirectoriesToStage(file, tmpJarLocation)
                    : file.getAbsolutePath();
              })
          .collect(Collectors.toList());
    }
  
    private static String packageDirectoriesToStage(File directoryToStage, String tmpJarLocation) {
      String hash = calculateDirectoryContentHash(directoryToStage);
      String pathForJar = getUniqueJarPath(hash, tmpJarLocation);
      try {
        ZipFiles.zipDirectoryOverwrite(directoryToStage, new File(pathForJar));
      } catch (IOException e) {
        throw new RuntimeException(e);
      }
      return pathForJar;
    }
  
    private static String calculateDirectoryContentHash(File directoryToStage) {
      Hasher hasher = Hashing.sha256().newHasher();
      try (OutputStream hashStream = Funnels.asOutputStream(hasher)) {
        ZipFiles.zipDirectory(directoryToStage, hashStream);
        return hasher.hash().toString();
      } catch (IOException e) {
        throw new RuntimeException(e);
      }
    }
  
    private static String getUniqueJarPath(String contentHash, String tmpJarLocation) {
      checkArgument(
          !Strings.isNullOrEmpty(tmpJarLocation),
          "Please provide temporary location for storing the jar files.");
  
      return String.format("%s%s%s.jar", tmpJarLocation, File.separator, contentHash);
    }
  }
  