/*
    * This file is part of dependency-check-core.
    *
    * Licensed 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.
   *
   * Copyright (c) 2012 Jeremy Long. All Rights Reserved.
   */
  package org.owasp.dependencycheck;
  
  import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
  import org.apache.commons.jcs3.JCS;
  import org.jetbrains.annotations.NotNull;
  import org.jetbrains.annotations.Nullable;
  import org.owasp.dependencycheck.analyzer.AnalysisPhase;
  import org.owasp.dependencycheck.analyzer.Analyzer;
  import org.owasp.dependencycheck.analyzer.AnalyzerService;
  import org.owasp.dependencycheck.analyzer.FileTypeAnalyzer;
  import org.owasp.dependencycheck.data.nvdcve.DatabaseManager;
  import org.owasp.dependencycheck.data.nvdcve.CveDB;
  import org.owasp.dependencycheck.data.nvdcve.DatabaseException;
  import org.owasp.dependencycheck.data.nvdcve.DatabaseProperties;
  import org.owasp.dependencycheck.data.update.CachedWebDataSource;
  import org.owasp.dependencycheck.data.update.UpdateService;
  import org.owasp.dependencycheck.data.update.exception.UpdateException;
  import org.owasp.dependencycheck.dependency.Dependency;
  import org.owasp.dependencycheck.exception.ExceptionCollection;
  import org.owasp.dependencycheck.exception.InitializationException;
  import org.owasp.dependencycheck.exception.NoDataException;
  import org.owasp.dependencycheck.exception.ReportException;
  import org.owasp.dependencycheck.exception.WriteLockException;
  import org.owasp.dependencycheck.reporting.ReportGenerator;
  import org.owasp.dependencycheck.utils.FileUtils;
  import org.owasp.dependencycheck.utils.Settings;
  import org.owasp.dependencycheck.utils.WriteLock;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import javax.annotation.concurrent.NotThreadSafe;
  import java.io.File;
  import java.io.FileFilter;
  import java.io.IOException;
  import java.nio.file.Files;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.EnumMap;
  import java.util.HashMap;
  import java.util.HashSet;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Map;
  import java.util.Objects;
  import java.util.Set;
  import java.util.concurrent.CancellationException;
  import java.util.concurrent.ExecutionException;
  import java.util.concurrent.ExecutorService;
  import java.util.concurrent.Executors;
  import java.util.concurrent.Future;
  import java.util.concurrent.TimeUnit;
  
  import static org.owasp.dependencycheck.analyzer.AnalysisPhase.FINAL;
  import static org.owasp.dependencycheck.analyzer.AnalysisPhase.FINDING_ANALYSIS;
  import static org.owasp.dependencycheck.analyzer.AnalysisPhase.FINDING_ANALYSIS_PHASE2;
  import static org.owasp.dependencycheck.analyzer.AnalysisPhase.IDENTIFIER_ANALYSIS;
  import static org.owasp.dependencycheck.analyzer.AnalysisPhase.INFORMATION_COLLECTION;
  import static org.owasp.dependencycheck.analyzer.AnalysisPhase.INFORMATION_COLLECTION2;
  import static org.owasp.dependencycheck.analyzer.AnalysisPhase.INITIAL;
  import static org.owasp.dependencycheck.analyzer.AnalysisPhase.POST_FINDING_ANALYSIS;
  import static org.owasp.dependencycheck.analyzer.AnalysisPhase.POST_IDENTIFIER_ANALYSIS;
  import static org.owasp.dependencycheck.analyzer.AnalysisPhase.POST_INFORMATION_COLLECTION1;
  import static org.owasp.dependencycheck.analyzer.AnalysisPhase.POST_INFORMATION_COLLECTION2;
  import static org.owasp.dependencycheck.analyzer.AnalysisPhase.POST_INFORMATION_COLLECTION3;
  import static org.owasp.dependencycheck.analyzer.AnalysisPhase.PRE_FINDING_ANALYSIS;
  import static org.owasp.dependencycheck.analyzer.AnalysisPhase.PRE_IDENTIFIER_ANALYSIS;
  import static org.owasp.dependencycheck.analyzer.AnalysisPhase.PRE_INFORMATION_COLLECTION;
  import org.owasp.dependencycheck.analyzer.DependencyBundlingAnalyzer;
  import org.owasp.dependencycheck.dependency.naming.Identifier;
  import org.owasp.dependencycheck.utils.Utils;
  
  /**
   * Scans files, directories, etc. for Dependencies. Analyzers are loaded and
   * used to process the files found by the scan, if a file is encountered and an
   * Analyzer is associated with the file type then the file is turned into a
   * dependency.
   *
   * @author Jeremy Long
   */
  @NotThreadSafe
 public class Engine implements FileFilter, AutoCloseable {
 
     /**
      * The Logger for use throughout the class.
      */
     private static final Logger LOGGER = LoggerFactory.getLogger(Engine.class);
     /**
      * The list of dependencies.
      */
     private final List<Dependency> dependencies = Collections.synchronizedList(new ArrayList<>());
     /**
      * A Map of analyzers grouped by Analysis phase.
      */
     private final Map<AnalysisPhase, List<Analyzer>> analyzers = new EnumMap<>(AnalysisPhase.class);
     /**
      * A Map of analyzers grouped by Analysis phase.
      */
     private final Set<FileTypeAnalyzer> fileTypeAnalyzers = new HashSet<>();
     /**
      * The engine execution mode indicating it will either collect evidence or
      * process evidence or both.
      */
     private final Mode mode;
     /**
      * The ClassLoader to use when dynamically loading Analyzer and Update
      * services.
      */
     private final ClassLoader serviceClassLoader;
     /**
      * The configured settings.
      */
     private final Settings settings;
     /**
      * A storage location to persist objects throughout the execution of ODC.
      */
     private final Map<String, Object> objects = new HashMap<>();
     /**
      * The external view of the dependency list.
      */
     private Dependency[] dependenciesExternalView = null;
     /**
      * A reference to the database.
      */
     private CveDB database = null;
     /**
      * Used to store the value of
      * System.getProperty("javax.xml.accessExternalSchema") - ODC may change the
      * value of this system property at runtime. We store the value to reset the
      * property to its original value.
      */
     private final String accessExternalSchema;
 
     /**
      * Creates a new {@link Mode#STANDALONE} Engine.
      *
      * @param settings reference to the configured settings
      */
     public Engine(@NotNull final Settings settings) {
         this(Mode.STANDALONE, settings);
     }
 
     /**
      * Creates a new Engine.
      *
      * @param mode the mode of operation
      * @param settings reference to the configured settings
      */
     public Engine(@NotNull final Mode mode, @NotNull final Settings settings) {
         this(Thread.currentThread().getContextClassLoader(), mode, settings);
     }
 
     /**
      * Creates a new {@link Mode#STANDALONE} Engine.
      *
      * @param serviceClassLoader a reference the class loader being used
      * @param settings reference to the configured settings
      */
     public Engine(@NotNull final ClassLoader serviceClassLoader, @NotNull final Settings settings) {
         this(serviceClassLoader, Mode.STANDALONE, settings);
     }
 
     /**
      * Creates a new Engine.
      *
      * @param serviceClassLoader a reference the class loader being used
      * @param mode the mode of the engine
      * @param settings reference to the configured settings
      */
     public Engine(@NotNull final ClassLoader serviceClassLoader, @NotNull final Mode mode, @NotNull final Settings settings) {
         this.settings = settings;
         this.serviceClassLoader = serviceClassLoader;
         this.mode = mode;
         this.accessExternalSchema = System.getProperty("javax.xml.accessExternalSchema");
 
         checkRuntimeVersion();
 
         initializeEngine();
     }
 
     /**
      * Creates a new Engine using the specified classloader to dynamically load
      * Analyzer and Update services.
      *
      * @throws DatabaseException thrown if there is an error connecting to the
      * database
      */
     protected final void initializeEngine() {
         loadAnalyzers();
     }
 
     /**
      * Properly cleans up resources allocated during analysis.
      */
     @Override
     public void close() {
         if (mode.isDatabaseRequired()) {
             if (database != null) {
                 database.close();
                 database = null;
             }
         }
         if (accessExternalSchema != null) {
             System.setProperty("javax.xml.accessExternalSchema", accessExternalSchema);
         } else {
             System.clearProperty("javax.xml.accessExternalSchema");
         }
         JCS.shutdown();
     }
 
     /**
      * Loads the analyzers specified in the configuration file (or system
      * properties).
      */
     private void loadAnalyzers() {
         if (!analyzers.isEmpty()) {
             return;
         }
         mode.getPhases().forEach((phase) -> analyzers.put(phase, new ArrayList<>()));
         final AnalyzerService service = new AnalyzerService(serviceClassLoader, settings);
         final List<Analyzer> iterator = service.getAnalyzers(mode.getPhases());
         iterator.forEach((a) -> {
             a.initialize(this.settings);
             analyzers.get(a.getAnalysisPhase()).add(a);
             if (a instanceof FileTypeAnalyzer) {
                 this.fileTypeAnalyzers.add((FileTypeAnalyzer) a);
             }
         });
     }
 
     /**
      * Get the List of the analyzers for a specific phase of analysis.
      *
      * @param phase the phase to get the configured analyzers.
      * @return the analyzers loaded
      */
     public List<Analyzer> getAnalyzers(AnalysisPhase phase) {
         return analyzers.get(phase);
     }
 
     /**
      * Adds a dependency. In some cases, when adding a virtual dependency, the
      * method will identify if the virtual dependency was previously added and
      * update the existing dependency rather then adding a duplicate.
      *
      * @param dependency the dependency to add
      */
     public synchronized void addDependency(Dependency dependency) {
         if (dependency.isVirtual()) {
             for (Dependency existing : dependencies) {
                 if (existing.isVirtual()
                         && existing.getSha256sum() != null
                         && existing.getSha256sum().equals(dependency.getSha256sum())
                         && existing.getDisplayFileName() != null
                         && existing.getDisplayFileName().equals(dependency.getDisplayFileName())
                         && identifiersMatch(existing.getSoftwareIdentifiers(), dependency.getSoftwareIdentifiers())) {
                     DependencyBundlingAnalyzer.mergeDependencies(existing, dependency, null);
                     return;
                 }
             }
         }
         dependencies.add(dependency);
         dependenciesExternalView = null;
     }
 
     /**
      * Sorts the dependency list.
      */
     public synchronized void sortDependencies() {
         //TODO - is this actually necassary????
 //        Collections.sort(dependencies);
 //        dependenciesExternalView = null;
     }
 
     /**
      * Removes the dependency.
      *
      * @param dependency the dependency to remove.
      */
     public synchronized void removeDependency(@NotNull final Dependency dependency) {
         dependencies.remove(dependency);
         dependenciesExternalView = null;
     }
 
     /**
      * Returns a copy of the dependencies as an array.
      *
      * @return the dependencies identified
      */
     @SuppressFBWarnings(justification = "This is the intended external view of the dependencies", value = {"EI_EXPOSE_REP"})
     public synchronized Dependency[] getDependencies() {
         if (dependenciesExternalView == null) {
             dependenciesExternalView = dependencies.toArray(new Dependency[0]);
         }
         return dependenciesExternalView;
     }
 
     /**
      * Sets the dependencies.
      *
      * @param dependencies the dependencies
      */
     public synchronized void setDependencies(@NotNull final List<Dependency> dependencies) {
         this.dependencies.clear();
         this.dependencies.addAll(dependencies);
         dependenciesExternalView = null;
     }
 
     /**
      * Scans an array of files or directories. If a directory is specified, it
      * will be scanned recursively. Any dependencies identified are added to the
      * dependency collection.
      *
      * @param paths an array of paths to files or directories to be analyzed
      * @return the list of dependencies scanned
      * @since v0.3.2.5
      */
     public List<Dependency> scan(@NotNull final String[] paths) {
         return scan(paths, null);
     }
 
     /**
      * Scans an array of files or directories. If a directory is specified, it
      * will be scanned recursively. Any dependencies identified are added to the
      * dependency collection.
      *
      * @param paths an array of paths to files or directories to be analyzed
      * @param projectReference the name of the project or scope in which the
      * dependency was identified
      * @return the list of dependencies scanned
      * @since v1.4.4
      */
     public List<Dependency> scan(@NotNull final String[] paths, @Nullable final String projectReference) {
         final List<Dependency> deps = new ArrayList<>();
         for (String path : paths) {
             final List<Dependency> d = scan(path, projectReference);
             if (d != null) {
                 deps.addAll(d);
             }
         }
         return deps;
     }
 
     /**
      * Scans a given file or directory. If a directory is specified, it will be
      * scanned recursively. Any dependencies identified are added to the
      * dependency collection.
      *
      * @param path the path to a file or directory to be analyzed
      * @return the list of dependencies scanned
      */
     public List<Dependency> scan(@NotNull final String path) {
         return scan(path, null);
     }
 
     /**
      * Scans a given file or directory. If a directory is specified, it will be
      * scanned recursively. Any dependencies identified are added to the
      * dependency collection.
      *
      * @param path the path to a file or directory to be analyzed
      * @param projectReference the name of the project or scope in which the
      * dependency was identified
      * @return the list of dependencies scanned
      * @since v1.4.4
      */
     public List<Dependency> scan(@NotNull final String path, String projectReference) {
         final File file = new File(path);
         return scan(file, projectReference);
     }
 
     /**
      * Scans an array of files or directories. If a directory is specified, it
      * will be scanned recursively. Any dependencies identified are added to the
      * dependency collection.
      *
      * @param files an array of paths to files or directories to be analyzed.
      * @return the list of dependencies
      * @since v0.3.2.5
      */
     public List<Dependency> scan(File[] files) {
         return scan(files, null);
     }
 
     /**
      * Scans an array of files or directories. If a directory is specified, it
      * will be scanned recursively. Any dependencies identified are added to the
      * dependency collection.
      *
      * @param files an array of paths to files or directories to be analyzed.
      * @param projectReference the name of the project or scope in which the
      * dependency was identified
      * @return the list of dependencies
      * @since v1.4.4
      */
     public List<Dependency> scan(File[] files, String projectReference) {
         final List<Dependency> deps = new ArrayList<>();
         for (File file : files) {
             final List<Dependency> d = scan(file, projectReference);
             if (d != null) {
                 deps.addAll(d);
             }
         }
         return deps;
     }
 
     /**
      * Scans a collection of files or directories. If a directory is specified,
      * it will be scanned recursively. Any dependencies identified are added to
      * the dependency collection.
      *
      * @param files a set of paths to files or directories to be analyzed
      * @return the list of dependencies scanned
      * @since v0.3.2.5
      */
     public List<Dependency> scan(Collection<File> files) {
         return scan(files, null);
     }
 
     /**
      * Scans a collection of files or directories. If a directory is specified,
      * it will be scanned recursively. Any dependencies identified are added to
      * the dependency collection.
      *
      * @param files a set of paths to files or directories to be analyzed
      * @param projectReference the name of the project or scope in which the
      * dependency was identified
      * @return the list of dependencies scanned
      * @since v1.4.4
      */
     public List<Dependency> scan(Collection<File> files, String projectReference) {
         final List<Dependency> deps = new ArrayList<>();
         files.stream().map((file) -> scan(file, projectReference))
                 .filter(Objects::nonNull)
                 .forEach(deps::addAll);
         return deps;
     }
 
     /**
      * Scans a given file or directory. If a directory is specified, it will be
      * scanned recursively. Any dependencies identified are added to the
      * dependency collection.
      *
      * @param file the path to a file or directory to be analyzed
      * @return the list of dependencies scanned
      * @since v0.3.2.4
      */
     public List<Dependency> scan(File file) {
         return scan(file, null);
     }
 
     /**
      * Scans a given file or directory. If a directory is specified, it will be
      * scanned recursively. Any dependencies identified are added to the
      * dependency collection.
      *
      * @param file the path to a file or directory to be analyzed
      * @param projectReference the name of the project or scope in which the
      * dependency was identified
      * @return the list of dependencies scanned
      * @since v1.4.4
      */
     @Nullable
     public List<Dependency> scan(@NotNull final File file, String projectReference) {
         if (file.exists()) {
             if (file.isDirectory()) {
                 return scanDirectory(file, projectReference);
             } else {
                 final Dependency d = scanFile(file, projectReference);
                 if (d != null) {
                     final List<Dependency> deps = new ArrayList<>();
                     deps.add(d);
                     return deps;
                 }
             }
         }
         return null;
     }
 
     /**
      * Recursively scans files and directories. Any dependencies identified are
      * added to the dependency collection.
      *
      * @param dir the directory to scan
      * @return the list of Dependency objects scanned
      */
     protected List<Dependency> scanDirectory(File dir) {
         return scanDirectory(dir, null);
     }
 
     /**
      * Recursively scans files and directories. Any dependencies identified are
      * added to the dependency collection.
      *
      * @param dir the directory to scan
      * @param projectReference the name of the project or scope in which the
      * dependency was identified
      * @return the list of Dependency objects scanned
      * @since v1.4.4
      */
     protected List<Dependency> scanDirectory(@NotNull final File dir, @Nullable final String projectReference) {
         final File[] files = dir.listFiles();
         final List<Dependency> deps = new ArrayList<>();
         if (files != null) {
             for (File f : files) {
                 if (f.isDirectory()) {
                     final List<Dependency> d = scanDirectory(f, projectReference);
                     if (d != null) {
                         deps.addAll(d);
                     }
                 } else {
                     final Dependency d = scanFile(f, projectReference);
                     if (d != null) {
                         deps.add(d);
                     }
                 }
             }
         }
         return deps;
     }
 
     /**
      * Scans a specified file. If a dependency is identified it is added to the
      * dependency collection.
      *
      * @param file The file to scan
      * @return the scanned dependency
      */
     protected Dependency scanFile(@NotNull final File file) {
         return scanFile(file, null);
     }
 
     //CSOFF: NestedIfDepth
     /**
      * Scans a specified file. If a dependency is identified it is added to the
      * dependency collection.
      *
      * @param file The file to scan
      * @param projectReference the name of the project or scope in which the
      * dependency was identified
      * @return the scanned dependency
      * @since v1.4.4
      */
     protected synchronized Dependency scanFile(@NotNull final File file, @Nullable final String projectReference) {
         Dependency dependency = null;
         if (file.isFile()) {
             if (accept(file)) {
                 dependency = new Dependency(file);
                 if (projectReference != null) {
                     dependency.addProjectReference(projectReference);
                 }
                 final String sha1 = dependency.getSha1sum();
                 boolean found = false;
 
                 if (sha1 != null) {
                     for (Dependency existing : dependencies) {
                         if (sha1.equals(existing.getSha1sum())) {
                             if (existing.getDisplayFileName().contains(": ")
                                     || dependency.getDisplayFileName().contains(": ")
                                     || dependency.getActualFilePath().contains("dctemp")) {
                                 continue;
                             }
                             found = true;
                             if (projectReference != null) {
                                 existing.addProjectReference(projectReference);
                             }
                             if (existing.getActualFilePath() != null && dependency.getActualFilePath() != null
                                     && !existing.getActualFilePath().equals(dependency.getActualFilePath())) {
 
                                 if (DependencyBundlingAnalyzer.firstPathIsShortest(existing.getFilePath(), dependency.getFilePath())) {
                                     DependencyBundlingAnalyzer.mergeDependencies(existing, dependency, null);
 
                                     //return null;
                                     return existing;
                                 } else {
                                     //Merging dependency<-existing could be complicated. Instead analyze them seperately
                                     //and possibly merge them at the end.
                                     found = false;
                                 }
 
                             } else { //somehow we scanned the same file twice?
                                 //return null;
                                 return existing;
                             }
                             break;
                         }
                     }
                 }
                 if (!found) {
                     dependencies.add(dependency);
                     dependenciesExternalView = null;
                 }
             }
         } else {
             LOGGER.debug("Path passed to scanFile(File) is not a file that can be scanned by dependency-check: {}. Skipping the file.", file);
         }
         return dependency;
     }
     //CSON: NestedIfDepth
 
     /**
      * Runs the analyzers against all of the dependencies. Since the mutable
      * dependencies list is exposed via {@link #getDependencies()}, this method
      * iterates over a copy of the dependencies list. Thus, the potential for
      * {@link java.util.ConcurrentModificationException}s is avoided, and
      * analyzers may safely add or remove entries from the dependencies list.
      * <p>
      * Every effort is made to complete analysis on the dependencies. In some
      * cases an exception will occur with part of the analysis being performed
      * which may not affect the entire analysis. If an exception occurs it will
      * be included in the thrown exception collection.
      *
      * @throws ExceptionCollection a collections of any exceptions that occurred
      * during analysis
      */
     public void analyzeDependencies() throws ExceptionCollection {
         final List<Throwable> exceptions = Collections.synchronizedList(new ArrayList<>());
 
         initializeAndUpdateDatabase(exceptions);
 
         //need to ensure that data exists
         try {
             ensureDataExists();
         } catch (NoDataException ex) {
             throwFatalExceptionCollection("Unable to continue dependency-check analysis.", ex, exceptions);
         }
         LOGGER.info("\n\nDependency-Check is an open source tool performing a best effort analysis of 3rd party dependencies; false positives and "
                 + "false negatives may exist in the analysis performed by the tool. Use of the tool and the reporting provided constitutes "
                 + "acceptance for use in an AS IS condition, and there are NO warranties, implied or otherwise, with regard to the analysis "
                 + "or its use. Any use of the tool and the reporting provided is at the user's risk. In no event shall the copyright holder "
                 + "or OWASP be held liable for any damages whatsoever arising out of or in connection with the use of this tool, the analysis "
                 + "performed, or the resulting report.\n\n\n"
                 + "   About ODC: https://jeremylong.github.io/DependencyCheck/general/internals.html\n"
                 + "   False Positives: https://jeremylong.github.io/DependencyCheck/general/suppression.html\n"
                 + "\n"
                 + "💖 Sponsor: https://github.com/sponsors/jeremylong\n\n");
         LOGGER.debug("\n----------------------------------------------------\nBEGIN ANALYSIS\n----------------------------------------------------");
         LOGGER.info("Analysis Started");
         final long analysisStart = System.currentTimeMillis();
 
         // analysis phases
         for (AnalysisPhase phase : mode.getPhases()) {
             final List<Analyzer> analyzerList = analyzers.get(phase);
 
             for (final Analyzer analyzer : analyzerList) {
                 final long analyzerStart = System.currentTimeMillis();
                 try {
                     initializeAnalyzer(analyzer);
                 } catch (InitializationException ex) {
                     exceptions.add(ex);
                     if (ex.isFatal()) {
                         continue;
                     }
                 }
 
                 if (analyzer.isEnabled()) {
                     executeAnalysisTasks(analyzer, exceptions);
 
                     final long analyzerDurationMillis = System.currentTimeMillis() - analyzerStart;
                     final long analyzerDurationSeconds = TimeUnit.MILLISECONDS.toSeconds(analyzerDurationMillis);
                     LOGGER.info("Finished {} ({} seconds)", analyzer.getName(), analyzerDurationSeconds);
                 } else {
                     LOGGER.debug("Skipping {} (not enabled)", analyzer.getName());
                 }
             }
         }
         mode.getPhases().stream()
                 .map(analyzers::get)
                 .forEach((analyzerList) -> analyzerList.forEach(this::closeAnalyzer));
 
         LOGGER.debug("\n----------------------------------------------------\nEND ANALYSIS\n----------------------------------------------------");
         final long analysisDurationSeconds = TimeUnit.MILLISECONDS.toSeconds(System.currentTimeMillis() - analysisStart);
         LOGGER.info("Analysis Complete ({} seconds)", analysisDurationSeconds);
         if (exceptions.size() > 0) {
             throw new ExceptionCollection(exceptions);
         }
     }
 
     /**
      * Performs any necessary updates and initializes the database.
      *
      * @param exceptions a collection to store non-fatal exceptions
      * @throws ExceptionCollection thrown if fatal exceptions occur
      */
     private void initializeAndUpdateDatabase(@NotNull final List<Throwable> exceptions) throws ExceptionCollection {
         if (!mode.isDatabaseRequired()) {
             return;
         }
         final boolean autoUpdate;
         autoUpdate = settings.getBoolean(Settings.KEYS.AUTO_UPDATE, true);
         if (autoUpdate) {
             try {
                 doUpdates(true);
             } catch (UpdateException ex) {
                 exceptions.add(ex);
                 LOGGER.warn("Unable to update 1 or more Cached Web DataSource, using local "
                         + "data instead. Results may not include recent vulnerabilities.");
                 LOGGER.debug("Update Error", ex);
             } catch (DatabaseException ex) {
                 throwFatalDatabaseException(ex, exceptions);
             }
         } else {
             try {
                 if (DatabaseManager.isH2Connection(settings) && !DatabaseManager.h2DataFileExists(settings)) {
                     throw new ExceptionCollection(new NoDataException("Autoupdate is disabled and the database does not exist"), true);
                 } else {
                     openDatabase(true, true);
                 }
             } catch (IOException ex) {
                 throw new ExceptionCollection(new DatabaseException("Autoupdate is disabled and unable to connect to the database"), true);
             } catch (DatabaseException ex) {
                 throwFatalDatabaseException(ex, exceptions);
             }
         }
     }
 
     /**
      * Utility method to throw a fatal database exception.
      *
      * @param ex the exception that was caught
      * @param exceptions the exception collection
      * @throws ExceptionCollection the collection of exceptions is always thrown
      * as a fatal exception
      */
     private void throwFatalDatabaseException(DatabaseException ex, final List<Throwable> exceptions) throws ExceptionCollection {
         final String msg;
         if (ex.getMessage().contains("Unable to connect") && DatabaseManager.isH2Connection(settings)) {
             msg = "Unable to connect to the database - if this error persists it may be "
                     + "due to a corrupt database. Consider running `purge` to delete the existing database";
         } else {
             msg = "Unable to connect to the dependency-check database";
         }
         exceptions.add(new DatabaseException(msg, ex));
         throw new ExceptionCollection(exceptions, true);
     }
 
     /**
      * Executes executes the analyzer using multiple threads.
      *
      * @param exceptions a collection of exceptions that occurred during
      * analysis
      * @param analyzer the analyzer to execute
      * @throws ExceptionCollection thrown if exceptions occurred during analysis
      */
     protected void executeAnalysisTasks(@NotNull final Analyzer analyzer, List<Throwable> exceptions) throws ExceptionCollection {
         LOGGER.debug("Starting {}", analyzer.getName());
         final List<AnalysisTask> analysisTasks = getAnalysisTasks(analyzer, exceptions);
         final ExecutorService executorService = getExecutorService(analyzer);
 
         try {
             final int timeout = settings.getInt(Settings.KEYS.ANALYSIS_TIMEOUT, 180);
             final List<Future<Void>> results = executorService.invokeAll(analysisTasks, timeout, TimeUnit.MINUTES);
 
             // ensure there was no exception during execution
             for (Future<Void> result : results) {
                 try {
                     result.get();
                 } catch (ExecutionException e) {
                     throwFatalExceptionCollection("Analysis task failed with a fatal exception.", e, exceptions);
                 } catch (CancellationException e) {
                     throwFatalExceptionCollection("Analysis task was cancelled.", e, exceptions);
                 }
             }
         } catch (InterruptedException e) {
             Thread.currentThread().interrupt();
             throwFatalExceptionCollection("Analysis has been interrupted.", e, exceptions);
         } finally {
             executorService.shutdown();
         }
     }
 
     /**
      * Returns the analysis tasks for the dependencies.
      *
      * @param analyzer the analyzer to create tasks for
      * @param exceptions the collection of exceptions to collect
      * @return a collection of analysis tasks
      */
     protected synchronized List<AnalysisTask> getAnalysisTasks(Analyzer analyzer, List<Throwable> exceptions) {
         final List<AnalysisTask> result = new ArrayList<>();
         dependencies.stream().map((dependency) -> new AnalysisTask(analyzer, dependency, this, exceptions)).forEach(result::add);
         return result;
     }
 
     /**
      * Returns the executor service for a given analyzer.
      *
      * @param analyzer the analyzer to obtain an executor
      * @return the executor service
      */
     protected ExecutorService getExecutorService(Analyzer analyzer) {
         if (analyzer.supportsParallelProcessing()) {
             final int maximumNumberOfThreads = Runtime.getRuntime().availableProcessors();
             LOGGER.debug("Parallel processing with up to {} threads: {}.", maximumNumberOfThreads, analyzer.getName());
             return Executors.newFixedThreadPool(maximumNumberOfThreads);
         } else {
             LOGGER.debug("Parallel processing is not supported: {}.", analyzer.getName());
             return Executors.newSingleThreadExecutor();
         }
     }
 
     /**
      * Initializes the given analyzer.
      *
      * @param analyzer the analyzer to prepare
      * @throws InitializationException thrown when there is a problem
      * initializing the analyzer
      */
     protected void initializeAnalyzer(@NotNull final Analyzer analyzer) throws InitializationException {
         try {
             LOGGER.debug("Initializing {}", analyzer.getName());
             analyzer.prepare(this);
         } catch (InitializationException ex) {
             LOGGER.error("Exception occurred initializing {}.", analyzer.getName());
             LOGGER.debug("", ex);
             if (ex.isFatal()) {
                 try {
                     analyzer.close();
                 } catch (Throwable ex1) {
                     LOGGER.trace("", ex1);
                 }
             }
             throw ex;
         } catch (Throwable ex) {
             LOGGER.error("Unexpected exception occurred initializing {}.", analyzer.getName());
             LOGGER.debug("", ex);
             try {
                 analyzer.close();
             } catch (Throwable ex1) {
                 LOGGER.trace("", ex1);
             }
             throw new InitializationException("Unexpected Exception", ex);
         }
     }
 
     /**
      * Closes the given analyzer.
      *
      * @param analyzer the analyzer to close
      */
     protected void closeAnalyzer(@NotNull final Analyzer analyzer) {
         LOGGER.debug("Closing Analyzer '{}'", analyzer.getName());
         try {
             analyzer.close();
         } catch (Throwable ex) {
             LOGGER.trace("", ex);
         }
     }
 
     /**
      * Cycles through the cached web data sources and calls update on all of
      * them.
      *
      * @throws UpdateException thrown if the operation fails
      * @throws DatabaseException if the operation fails due to a local database
      * failure
      * @return Whether any updates actually happened
      */
     public boolean doUpdates() throws UpdateException, DatabaseException {
         return doUpdates(false);
     }
 
     /**
      * Cycles through the cached web data sources and calls update on all of
      * them.
      *
      * @param remainOpen whether or not the database connection should remain
      * open
      * @throws UpdateException thrown if the operation fails
      * @throws DatabaseException if the operation fails due to a local database
      * failure
      * @return Whether any updates actually happened
      */
     public boolean doUpdates(boolean remainOpen) throws UpdateException, DatabaseException {
         if (mode.isDatabaseRequired()) {
             try (WriteLock dblock = new WriteLock(getSettings(), DatabaseManager.isH2Connection(getSettings()))) {
                 //lock is not needed as we already have the lock held
                 openDatabase(false, false);
                 LOGGER.info("Checking for updates");
                 final long updateStart = System.currentTimeMillis();
                 final UpdateService service = new UpdateService(serviceClassLoader);
                 final Iterator<CachedWebDataSource> iterator = service.getDataSources();
                 boolean dbUpdatesMade = false;
                 UpdateException updateException = null;
                 while (iterator.hasNext()) {
                     try {
                         final CachedWebDataSource source = iterator.next();
                         dbUpdatesMade |= source.update(this);
                     } catch (UpdateException ex) {
                         updateException = ex;
                         LOGGER.error(ex.getMessage(), ex);
                     }
                 }
                 if (dbUpdatesMade) {
                     database.defrag();
                 }
                 database.close();
                 database = null;
                 if (updateException != null) {
                     throw updateException;
                 }
                 LOGGER.info("Check for updates complete ({} ms)", System.currentTimeMillis() - updateStart);
                 if (remainOpen) {
                     //lock is not needed as we already have the lock held
                     openDatabase(true, false);
                 }
 
                 return dbUpdatesMade;
             } catch (WriteLockException ex) {
                 throw new UpdateException("Unable to obtain an exclusive lock on the H2 database to perform updates", ex);
             }
         } else {
             LOGGER.info("Skipping update check in evidence collection mode.");
             return false;
         }
     }
 
     /**
      * Purges the cached web data sources.
      *
      * @return <code>true</code> if the purge was successful; otherwise
      * <code>false</code>
      */
     public boolean purge() {
         boolean result = true;
         final UpdateService service = new UpdateService(serviceClassLoader);
         final Iterator<CachedWebDataSource> iterator = service.getDataSources();
         while (iterator.hasNext()) {
             result &= iterator.next().purge(this);
         }
         try {
             final File cache = new File(settings.getDataDirectory(), "cache");
             if (cache.exists()) {
                 if (FileUtils.delete(cache)) {
                     LOGGER.info("Cache directory purged");
                 }
             }
         } catch (IOException ex) {
             throw new RuntimeException(ex);
         }
         try {
             final File cache = new File(settings.getDataDirectory(), "oss_cache");
             if (cache.exists()) {
                 if (FileUtils.delete(cache)) {
                     LOGGER.info("OSS Cache directory purged");
                 }
             }
         } catch (IOException ex) {
             throw new RuntimeException(ex);
         }
 
         return result;
     }
 
     /**
      * <p>
      * This method is only public for unit/integration testing. This method
      * should not be called by any integration that uses
      * dependency-check-core.</p>
      * <p>
      * Opens the database connection.</p>
      *
      * @throws DatabaseException if the database connection could not be created
      */
     public void openDatabase() throws DatabaseException {
         openDatabase(false, true);
     }
 
     /**
      * <p>
      * This method is only public for unit/integration testing. This method
      * should not be called by any integration that uses
      * dependency-check-core.</p>
      * <p>
      * Opens the database connection; if readOnly is true a copy of the database
      * will be made.</p>
      *
      * @param readOnly whether or not the database connection should be readonly
      * @param lockRequired whether or not a lock needs to be acquired when
      * opening the database
      * @throws DatabaseException if the database connection could not be created
      */
     @SuppressWarnings("try")
     public void openDatabase(boolean readOnly, boolean lockRequired) throws DatabaseException {
         if (mode.isDatabaseRequired() && database == null) {
             try (WriteLock dblock = new WriteLock(getSettings(), lockRequired && DatabaseManager.isH2Connection(settings))) {
                 if (readOnly
                         && DatabaseManager.isH2Connection(settings)
                         && settings.getString(Settings.KEYS.DB_CONNECTION_STRING).contains("file:%s")) {
                     final File db = DatabaseManager.getH2DataFile(settings);
                     if (db.isFile()) {
                         final File temp = settings.getTempDirectory();
                         final File tempDB = new File(temp, db.getName());
                         LOGGER.debug("copying database {} to {}", db.toPath(), temp.toPath());
                         Files.copy(db.toPath(), tempDB.toPath());
                         settings.setString(Settings.KEYS.H2_DATA_DIRECTORY, temp.getPath());
                         final String connStr = settings.getString(Settings.KEYS.DB_CONNECTION_STRING);
                         if (!connStr.contains("ACCESS_MODE_DATA")) {
                             settings.setString(Settings.KEYS.DB_CONNECTION_STRING, connStr + "ACCESS_MODE_DATA=r");
                         }
                         settings.setBoolean(Settings.KEYS.AUTO_UPDATE, false);
                         database = new CveDB(settings);
                     } else {
                         throw new DatabaseException("Unable to open database - configured database file does not exist: " + db);
                     }
                 } else {
                     database = new CveDB(settings);
                 }
             } catch (IOException ex) {
                 throw new DatabaseException("Unable to open database in read only mode", ex);
             } catch (WriteLockException ex) {
                 throw new DatabaseException("Failed to obtain lock - unable to open database", ex);
             }
             database.open();
         }
     }
 
     /**
      * Returns a reference to the database.
      *
      * @return a reference to the database
      */
     public CveDB getDatabase() {
         return this.database;
     }
 
     /**
      * Returns a full list of all of the analyzers. This is useful for reporting
      * which analyzers where used.
      *
      * @return a list of Analyzers
      */
     @NotNull
     public List<Analyzer> getAnalyzers() {
         final List<Analyzer> analyzerList = new ArrayList<>();
         //insteae of forEach - we can just do a collect
         mode.getPhases().stream()
                 .map(analyzers::get)
                 .forEachOrdered(analyzerList::addAll);
         return analyzerList;
     }
 
     /**
      * Checks all analyzers to see if an extension is supported.
      *
      * @param file a file extension
      * @return true or false depending on whether or not the file extension is
      * supported
      */
     @Override
     public boolean accept(@Nullable final File file) {
         if (file == null) {
             return false;
         }
         /* note, we can't break early on this loop as the analyzers need to know if
         they have files to work on prior to initialization */
         return this.fileTypeAnalyzers.stream().map((a) -> a.accept(file)).reduce(false, (accumulator, result) -> accumulator || result);
     }
 
     /**
      * Returns the set of file type analyzers.
      *
      * @return the set of file type analyzers
      */
     public Set<FileTypeAnalyzer> getFileTypeAnalyzers() {
         return this.fileTypeAnalyzers;
     }
 
     /**
      * Returns the configured settings.
      *
      * @return the configured settings
      */
     public Settings getSettings() {
         return settings;
     }
 
     /**
      * Retrieve an object from the objects collection.
      *
      * @param key the key to retrieve the object
      * @return the object
      */
     public Object getObject(String key) {
         return objects.get(key);
     }
 
     /**
      * Put an object in the object collection.
      *
      * @param key the key to store the object
      * @param object the object to store
      */
     public void putObject(String key, Object object) {
         objects.put(key, object);
     }
 
     /**
      * Verifies if the object exists in the object store.
      *
      * @param key the key to retrieve the object
      * @return <code>true</code> if the object exists; otherwise
      * <code>false</code>
      */
     public boolean hasObject(String key) {
         return objects.containsKey(key);
     }
 
     /**
      * Removes an object from the object store.
      *
      * @param key the key to the object
      */
     public void removeObject(String key) {
         objects.remove(key);
     }
 
     /**
      * Returns the mode of the engine.
      *
      * @return the mode of the engine
      */
     public Mode getMode() {
         return mode;
     }
 
     /**
      * Adds a file type analyzer. This has been added solely to assist in unit
      * testing the Engine.
      *
      * @param fta the file type analyzer to add
      */
     protected void addFileTypeAnalyzer(@NotNull final FileTypeAnalyzer fta) {
         this.fileTypeAnalyzers.add(fta);
     }
 
     /**
      * Checks the CPE Index to ensure documents exists. If none exist a
      * NoDataException is thrown.
      *
      * @throws NoDataException thrown if no data exists in the CPE Index
      */
     private void ensureDataExists() throws NoDataException {
         if (mode.isDatabaseRequired() && (database == null || !database.dataExists())) {
             throw new NoDataException("No documents exist");
         }
     }
 
     /**
      * Constructs and throws a fatal exception collection.
      *
      * @param message the exception message
      * @param throwable the cause
      * @param exceptions a collection of exception to include
      * @throws ExceptionCollection a collection of exceptions that occurred
      * during analysis
      */
     private void throwFatalExceptionCollection(String message, @NotNull final Throwable throwable,
             @NotNull final List<Throwable> exceptions) throws ExceptionCollection {
         LOGGER.error(message);
         LOGGER.debug("", throwable);
         exceptions.add(throwable);
         throw new ExceptionCollection(exceptions, true);
     }
 
     /**
      * Writes the report to the given output directory.
      *
      * @param applicationName the name of the application/project
      * @param outputDir the path to the output directory (can include the full
      * file name if the format is not ALL)
      * @param format the report format (see {@link ReportGenerator.Format})
      * @throws ReportException thrown if there is an error generating the report
      * @deprecated use
      * {@link #writeReports(java.lang.String, java.io.File, java.lang.String, org.owasp.dependencycheck.exception.ExceptionCollection)}
      */
     @Deprecated
     public void writeReports(String applicationName, File outputDir, String format) throws ReportException {
         writeReports(applicationName, null, null, null, outputDir, format, null);
     }
 
     //CSOFF: LineLength
     /**
      * Writes the report to the given output directory.
      *
      * @param applicationName the name of the application/project
      * @param outputDir the path to the output directory (can include the full
      * file name if the format is not ALL)
      * @param format the report format (see {@link ReportGenerator.Format})
      * @param exceptions a collection of exceptions that may have occurred
      * during the analysis
      * @throws ReportException thrown if there is an error generating the report
      */
     public void writeReports(String applicationName, File outputDir, String format, ExceptionCollection exceptions) throws ReportException {
         writeReports(applicationName, null, null, null, outputDir, format, exceptions);
     }
     //CSON: LineLength
 
     /**
      * Writes the report to the given output directory.
      *
      * @param applicationName the name of the application/project
      * @param groupId the Maven groupId
      * @param artifactId the Maven artifactId
      * @param version the Maven version
      * @param outputDir the path to the output directory (can include the full
      * file name if the format is not ALL)
      * @param format the report format (see {@link ReportGenerator.Format})
      * @throws ReportException thrown if there is an error generating the report
      * @deprecated use
      * {@link #writeReports(String, String, String, String, File, String, ExceptionCollection)}
      */
     @Deprecated
     public synchronized void writeReports(String applicationName, @Nullable final String groupId,
             @Nullable final String artifactId, @Nullable final String version,
             @NotNull final File outputDir, String format) throws ReportException {
         writeReports(applicationName, groupId, artifactId, version, outputDir, format, null);
     }
 
     //CSOFF: LineLength
     /**
      * Writes the report to the given output directory.
      *
      * @param applicationName the name of the application/project
      * @param groupId the Maven groupId
      * @param artifactId the Maven artifactId
      * @param version the Maven version
      * @param outputDir the path to the output directory (can include the full
      * file name if the format is not ALL)
      * @param format the report format  (see {@link ReportGenerator.Format})
      * @param exceptions a collection of exceptions that may have occurred
      * during the analysis
      * @throws ReportException thrown if there is an error generating the report
      */
     public synchronized void writeReports(String applicationName, @Nullable final String groupId,
             @Nullable final String artifactId, @Nullable final String version,
             @NotNull final File outputDir, String format, ExceptionCollection exceptions) throws ReportException {
         if (mode == Mode.EVIDENCE_COLLECTION) {
             throw new UnsupportedOperationException("Cannot generate report in evidence collection mode.");
         }
         final DatabaseProperties prop = database.getDatabaseProperties();
 
         final ReportGenerator r = new ReportGenerator(applicationName, groupId, artifactId, version,
                 dependencies, getAnalyzers(), prop, settings, exceptions);
         try {
             r.write(outputDir.getAbsolutePath(), format);
         } catch (ReportException ex) {
             final String msg = String.format("Error generating the report for %s", applicationName);
             LOGGER.debug(msg, ex);
             throw new ReportException(msg, ex);
         }
     }
     //CSON: LineLength
 
     private boolean identifiersMatch(Set<Identifier> left, Set<Identifier> right) {
         if (left != null && right != null && left.size() > 0 && left.size() == right.size()) {
             int count = 0;
             for (Identifier l : left) {
                 for (Identifier r : right) {
                     if (l.getValue().equals(r.getValue())) {
                         count += 1;
                         break;
                     }
                 }
             }
             return count == left.size();
         }
         return false;
     }
 
     /**
      * Checks that if Java 8 is being used, it is at least update 251. This is
      * required as a new method was introduced that is used by Apache HTTP
      * Client. See
      * https://stackoverflow.com/questions/76226322/exception-in-thread-httpclient-dispatch-1-java-lang-nosuchmethoderror-javax-n#comment134427003_76226322
      */
     private void checkRuntimeVersion() {
         if (Utils.getJavaVersion() == 8 && Utils.getJavaUpdateVersion() < 251) {
             LOGGER.error("Non-supported Java Runtime: dependency-check requires at least Java 8 update 251 or higher.");
             throw new RuntimeException("dependency-check requires Java 8 update 251 or higher");
         }
     }
 
     /**
      * {@link Engine} execution modes.
      */
     public enum Mode {
         /**
          * In evidence collection mode the {@link Engine} only collects evidence
          * from the scan targets, and doesn't require a database.
          */
         EVIDENCE_COLLECTION(
                 false,
                 INITIAL,
                 PRE_INFORMATION_COLLECTION,
                 INFORMATION_COLLECTION,
                 INFORMATION_COLLECTION2,
                 POST_INFORMATION_COLLECTION1,
                 POST_INFORMATION_COLLECTION2,
                 POST_INFORMATION_COLLECTION3
         ),
         /**
          * In evidence processing mode the {@link Engine} processes the evidence
          * collected using the {@link #EVIDENCE_COLLECTION} mode. Dependencies
          * should be injected into the {@link Engine} using
          * {@link Engine#setDependencies(List)}.
          */
         EVIDENCE_PROCESSING(
                 true,
                 PRE_IDENTIFIER_ANALYSIS,
                 IDENTIFIER_ANALYSIS,
                 POST_IDENTIFIER_ANALYSIS,
                 PRE_FINDING_ANALYSIS,
                 FINDING_ANALYSIS,
                 POST_FINDING_ANALYSIS,
                 FINDING_ANALYSIS_PHASE2,
                 FINAL
         ),
         /**
          * In standalone mode the {@link Engine} will collect and process
          * evidence in a single execution.
          */
         STANDALONE(true, AnalysisPhase.values());
 
         /**
          * Whether the database is required in this mode.
          */
         private final boolean databaseRequired;
         /**
          * The analysis phases included in the mode.
          */
         private final List<AnalysisPhase> phases;
 
         /**
          * Constructs a new mode.
          *
          * @param databaseRequired if the database is required for the mode
          * @param phases the analysis phases to include in the mode
          */
         Mode(boolean databaseRequired, AnalysisPhase... phases) {
             this.databaseRequired = databaseRequired;
             this.phases = Collections.unmodifiableList(Arrays.asList(phases));
         }
 
         /**
          * Returns true if the database is required; otherwise false.
          *
          * @return whether or not the database is required
          */
         private boolean isDatabaseRequired() {
             return databaseRequired;
         }
 
         /**
          * Returns the phases for this mode.
          *
          * @return the phases for this mode
          */
         public List<AnalysisPhase> getPhases() {
             return phases;
         }
     }
 }