////////////////////////////////////////////////////////////////////////////////
   // checkstyle: Checks Java source code for adherence to a set of rules.
   // Copyright (C) 2001-2019 the original author or authors.
   //
   // This library is free software; you can redistribute it and/or
   // modify it under the terms of the GNU Lesser General Public
   // License as published by the Free Software Foundation; either
   // version 2.1 of the License, or (at your option) any later version.
   //
  // This library is distributed in the hope that it will be useful,
  // but WITHOUT ANY WARRANTY; without even the implied warranty of
  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  // Lesser General Public License for more details.
  //
  // You should have received a copy of the GNU Lesser General Public
  // License along with this library; if not, write to the Free Software
  // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  ////////////////////////////////////////////////////////////////////////////////
  
  package com.puppycrawl.tools.checkstyle.ant;
  
  import java.io.File;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.nio.file.Files;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.List;
  import java.util.Locale;
  import java.util.Map;
  import java.util.Objects;
  import java.util.Properties;
  import java.util.stream.Collectors;
  
  import org.apache.tools.ant.AntClassLoader;
  import org.apache.tools.ant.BuildException;
  import org.apache.tools.ant.DirectoryScanner;
  import org.apache.tools.ant.Project;
  import org.apache.tools.ant.Task;
  import org.apache.tools.ant.taskdefs.LogOutputStream;
  import org.apache.tools.ant.types.EnumeratedAttribute;
  import org.apache.tools.ant.types.FileSet;
  import org.apache.tools.ant.types.Path;
  import org.apache.tools.ant.types.Reference;
  
  import com.puppycrawl.tools.checkstyle.Checker;
  import com.puppycrawl.tools.checkstyle.ConfigurationLoader;
  import com.puppycrawl.tools.checkstyle.DefaultLogger;
  import com.puppycrawl.tools.checkstyle.ModuleFactory;
  import com.puppycrawl.tools.checkstyle.PackageObjectFactory;
  import com.puppycrawl.tools.checkstyle.PropertiesExpander;
  import com.puppycrawl.tools.checkstyle.ThreadModeSettings;
  import com.puppycrawl.tools.checkstyle.XMLLogger;
  import com.puppycrawl.tools.checkstyle.api.AuditListener;
  import com.puppycrawl.tools.checkstyle.api.AutomaticBean;
  import com.puppycrawl.tools.checkstyle.api.CheckstyleException;
  import com.puppycrawl.tools.checkstyle.api.Configuration;
  import com.puppycrawl.tools.checkstyle.api.RootModule;
  import com.puppycrawl.tools.checkstyle.api.SeverityLevel;
  import com.puppycrawl.tools.checkstyle.api.SeverityLevelCounter;
  
  /**
   * An implementation of a ANT task for calling checkstyle. See the documentation
   * of the task for usage.
   * @noinspection ClassLoaderInstantiation
   */
  public class CheckstyleAntTask extends Task {
  
      /** Poor man's enum for an xml formatter. */
      private static final String E_XML = "xml";
      /** Poor man's enum for an plain formatter. */
      private static final String E_PLAIN = "plain";
  
      /** Suffix for time string. */
      private static final String TIME_SUFFIX = " ms.";
  
      /** Contains the paths to process. */
      private final List<Path> paths = new ArrayList<>();
  
      /** Contains the filesets to process. */
      private final List<FileSet> fileSets = new ArrayList<>();
  
      /** Contains the formatters to log to. */
      private final List<Formatter> formatters = new ArrayList<>();
  
      /** Contains the Properties to override. */
      private final List<Property> overrideProps = new ArrayList<>();
  
      /** Class path to locate class files. */
      private Path classpath;
  
      /** Name of file to check. */
      private String fileName;
  
      /** Config file containing configuration. */
      private String config;
  
      /** Whether to fail build on violations. */
     private boolean failOnViolation = true;
 
     /** Property to set on violations. */
     private String failureProperty;
 
     /** The name of the properties file. */
     private File properties;
 
     /** The maximum number of errors that are tolerated. */
     private int maxErrors;
 
     /** The maximum number of warnings that are tolerated. */
     private int maxWarnings = Integer.MAX_VALUE;
 
     /**
      * Whether to execute ignored modules - some modules may log above
      * their severity depending on their configuration (e.g. WriteTag) so
      * need to be included
      */
     private boolean executeIgnoredModules;
 
     ////////////////////////////////////////////////////////////////////////////
     // Setters for ANT specific attributes
     ////////////////////////////////////////////////////////////////////////////
 
     /**
      * Tells this task to write failure message to the named property when there
      * is a violation.
      * @param propertyName the name of the property to set
      *                      in the event of an failure.
      */
     public void setFailureProperty(String propertyName) {
         failureProperty = propertyName;
     }
 
     /**
      * Sets flag - whether to fail if a violation is found.
      * @param fail whether to fail if a violation is found
      */
     public void setFailOnViolation(boolean fail) {
         failOnViolation = fail;
     }
 
     /**
      * Sets the maximum number of errors allowed. Default is 0.
      * @param maxErrors the maximum number of errors allowed.
      */
     public void setMaxErrors(int maxErrors) {
         this.maxErrors = maxErrors;
     }
 
     /**
      * Sets the maximum number of warnings allowed. Default is
      * {@link Integer#MAX_VALUE}.
      * @param maxWarnings the maximum number of warnings allowed.
      */
     public void setMaxWarnings(int maxWarnings) {
         this.maxWarnings = maxWarnings;
     }
 
     /**
      * Adds a path.
      * @param path the path to add.
      */
     public void addPath(Path path) {
         paths.add(path);
     }
 
     /**
      * Adds set of files (nested fileset attribute).
      * @param fileSet the file set to add
      */
     public void addFileset(FileSet fileSet) {
         fileSets.add(fileSet);
     }
 
     /**
      * Add a formatter.
      * @param formatter the formatter to add for logging.
      */
     public void addFormatter(Formatter formatter) {
         formatters.add(formatter);
     }
 
     /**
      * Add an override property.
      * @param property the property to add
      */
     public void addProperty(Property property) {
         overrideProps.add(property);
     }
 
     /**
      * Set the class path.
      * @param classpath the path to locate classes
      */
     public void setClasspath(Path classpath) {
         if (this.classpath == null) {
             this.classpath = classpath;
         }
         else {
             this.classpath.append(classpath);
         }
     }
 
     /**
      * Set the class path from a reference defined elsewhere.
      * @param classpathRef the reference to an instance defining the classpath
      */
     public void setClasspathRef(Reference classpathRef) {
         createClasspath().setRefid(classpathRef);
     }
 
     /**
      * Creates classpath.
      * @return a created path for locating classes
      */
     public Path createClasspath() {
         if (classpath == null) {
             classpath = new Path(getProject());
         }
         return classpath.createPath();
     }
 
     /**
      * Sets file to be checked.
      * @param file the file to be checked
      */
     public void setFile(File file) {
         fileName = file.getAbsolutePath();
     }
 
     /**
      * Sets configuration file.
      * @param configuration the configuration file, URL, or resource to use
      */
     public void setConfig(String configuration) {
         if (config != null) {
             throw new BuildException("Attribute 'config' has already been set");
         }
         config = configuration;
     }
 
     /**
      * Sets flag - whether to execute ignored modules.
      * @param omit whether to execute ignored modules
      */
     public void setExecuteIgnoredModules(boolean omit) {
         executeIgnoredModules = omit;
     }
 
     ////////////////////////////////////////////////////////////////////////////
     // Setters for Root Module's configuration attributes
     ////////////////////////////////////////////////////////////////////////////
 
     /**
      * Sets a properties file for use instead
      * of individually setting them.
      * @param props the properties File to use
      */
     public void setProperties(File props) {
         properties = props;
     }
 
     ////////////////////////////////////////////////////////////////////////////
     // The doers
     ////////////////////////////////////////////////////////////////////////////
 
     @Override
     public void execute() {
         final long startTime = System.currentTimeMillis();
 
         try {
             final String version = CheckstyleAntTask.class.getPackage().getImplementationVersion();
 
             log("checkstyle version " + version, Project.MSG_VERBOSE);
 
             // Check for no arguments
             if (fileName == null
                     && fileSets.isEmpty()
                     && paths.isEmpty()) {
                 throw new BuildException(
                         "Must specify at least one of 'file' or nested 'fileset' or 'path'.",
                         getLocation());
             }
             if (config == null) {
                 throw new BuildException("Must specify 'config'.", getLocation());
             }
             realExecute(version);
         }
         finally {
             final long endTime = System.currentTimeMillis();
             log("Total execution took " + (endTime - startTime) + TIME_SUFFIX,
                 Project.MSG_VERBOSE);
         }
     }
 
     /**
      * Helper implementation to perform execution.
      * @param checkstyleVersion Checkstyle compile version.
      */
     private void realExecute(String checkstyleVersion) {
         // Create the root module
         RootModule rootModule = null;
         try {
             rootModule = createRootModule();
 
             // setup the listeners
             final AuditListener[] listeners = getListeners();
             for (AuditListener element : listeners) {
                 rootModule.addListener(element);
             }
             final SeverityLevelCounter warningCounter =
                 new SeverityLevelCounter(SeverityLevel.WARNING);
             rootModule.addListener(warningCounter);
 
             processFiles(rootModule, warningCounter, checkstyleVersion);
         }
         finally {
             if (rootModule != null) {
                 rootModule.destroy();
             }
         }
     }
 
     /**
      * Scans and processes files by means given root module.
      * @param rootModule Root module to process files
      * @param warningCounter Root Module's counter of warnings
      * @param checkstyleVersion Checkstyle compile version
      */
     private void processFiles(RootModule rootModule, final SeverityLevelCounter warningCounter,
             final String checkstyleVersion) {
         final long startTime = System.currentTimeMillis();
         final List<File> files = getFilesToCheck();
         final long endTime = System.currentTimeMillis();
         log("To locate the files took " + (endTime - startTime) + TIME_SUFFIX,
             Project.MSG_VERBOSE);
 
         log("Running Checkstyle "
                 + Objects.toString(checkstyleVersion, "")
                 + " on " + files.size()
                 + " files", Project.MSG_INFO);
         log("Using configuration " + config, Project.MSG_VERBOSE);
 
         final int numErrs;
 
         try {
             final long processingStartTime = System.currentTimeMillis();
             numErrs = rootModule.process(files);
             final long processingEndTime = System.currentTimeMillis();
             log("To process the files took " + (processingEndTime - processingStartTime)
                 + TIME_SUFFIX, Project.MSG_VERBOSE);
         }
         catch (CheckstyleException ex) {
             throw new BuildException("Unable to process files: " + files, ex);
         }
         final int numWarnings = warningCounter.getCount();
         final boolean okStatus = numErrs <= maxErrors && numWarnings <= maxWarnings;
 
         // Handle the return status
         if (!okStatus) {
             final String failureMsg =
                     "Got " + numErrs + " errors and " + numWarnings
                             + " warnings.";
             if (failureProperty != null) {
                 getProject().setProperty(failureProperty, failureMsg);
             }
 
             if (failOnViolation) {
                 throw new BuildException(failureMsg, getLocation());
             }
         }
     }
 
     /**
      * Creates new instance of the root module.
      * @return new instance of the root module
      */
     private RootModule createRootModule() {
         final RootModule rootModule;
         try {
             final Properties props = createOverridingProperties();
             final ThreadModeSettings threadModeSettings =
                     ThreadModeSettings.SINGLE_THREAD_MODE_INSTANCE;
             final ConfigurationLoader.IgnoredModulesOptions ignoredModulesOptions;
             if (executeIgnoredModules) {
                 ignoredModulesOptions = ConfigurationLoader.IgnoredModulesOptions.EXECUTE;
             }
             else {
                 ignoredModulesOptions = ConfigurationLoader.IgnoredModulesOptions.OMIT;
             }
 
             final Configuration configuration = ConfigurationLoader.loadConfiguration(config,
                     new PropertiesExpander(props), ignoredModulesOptions, threadModeSettings);
 
             final ClassLoader moduleClassLoader =
                 Checker.class.getClassLoader();
 
             final ModuleFactory factory = new PackageObjectFactory(
                     Checker.class.getPackage().getName() + ".", moduleClassLoader);
 
             rootModule = (RootModule) factory.createModule(configuration.getName());
             rootModule.setModuleClassLoader(moduleClassLoader);
 
             if (rootModule instanceof Checker) {
                 final ClassLoader loader = new AntClassLoader(getProject(),
                         classpath);
 
                 ((Checker) rootModule).setClassLoader(loader);
             }
 
             rootModule.configure(configuration);
         }
         catch (final CheckstyleException ex) {
             throw new BuildException(String.format(Locale.ROOT, "Unable to create Root Module: "
                     + "config {%s}, classpath {%s}.", config, classpath), ex);
         }
         return rootModule;
     }
 
     /**
      * Create the Properties object based on the arguments specified
      * to the ANT task.
      * @return the properties for property expansion expansion
      * @throws BuildException if an error occurs
      */
     private Properties createOverridingProperties() {
         final Properties returnValue = new Properties();
 
         // Load the properties file if specified
         if (properties != null) {
             try (InputStream inStream = Files.newInputStream(properties.toPath())) {
                 returnValue.load(inStream);
             }
             catch (final IOException ex) {
                 throw new BuildException("Error loading Properties file '"
                         + properties + "'", ex, getLocation());
             }
         }
 
         // override with Ant properties like ${basedir}
         final Map<String, Object> antProps = getProject().getProperties();
         for (Map.Entry<String, Object> entry : antProps.entrySet()) {
             final String value = String.valueOf(entry.getValue());
             returnValue.setProperty(entry.getKey(), value);
         }
 
         // override with properties specified in subelements
         for (Property p : overrideProps) {
             returnValue.setProperty(p.getKey(), p.getValue());
         }
 
         return returnValue;
     }
 
     /**
      * Return the list of listeners set in this task.
      * @return the list of listeners.
      */
     private AuditListener[] getListeners() {
         final int formatterCount = Math.max(1, formatters.size());
 
         final AuditListener[] listeners = new AuditListener[formatterCount];
 
         // formatters
         try {
             if (formatters.isEmpty()) {
                 final OutputStream debug = new LogOutputStream(this, Project.MSG_DEBUG);
                 final OutputStream err = new LogOutputStream(this, Project.MSG_ERR);
                 listeners[0] = new DefaultLogger(debug, AutomaticBean.OutputStreamOptions.CLOSE,
                         err, AutomaticBean.OutputStreamOptions.CLOSE);
             }
             else {
                 for (int i = 0; i < formatterCount; i++) {
                     final Formatter formatter = formatters.get(i);
                     listeners[i] = formatter.createListener(this);
                 }
             }
         }
         catch (IOException ex) {
             throw new BuildException(String.format(Locale.ROOT, "Unable to create listeners: "
                     + "formatters {%s}.", formatters), ex);
         }
         return listeners;
     }
 
     /**
      * Returns the list of files (full path name) to process.
      * @return the list of files included via the fileName, filesets and paths.
      */
     private List<File> getFilesToCheck() {
         final List<File> allFiles = new ArrayList<>();
         if (fileName != null) {
             // oops we've got an additional one to process, don't
             // forget it. No sweat, it's fully resolved via the setter.
             log("Adding standalone file for audit", Project.MSG_VERBOSE);
             allFiles.add(new File(fileName));
         }
 
         final List<File> filesFromFileSets = scanFileSets();
         allFiles.addAll(filesFromFileSets);
 
         final List<File> filesFromPaths = scanPaths();
         allFiles.addAll(filesFromPaths);
 
         return allFiles;
     }
 
     /**
      * Retrieves all files from the defined paths.
      * @return a list of files defined via paths.
      */
     private List<File> scanPaths() {
         final List<File> allFiles = new ArrayList<>();
 
         for (int i = 0; i < paths.size(); i++) {
             final Path currentPath = paths.get(i);
             final List<File> pathFiles = scanPath(currentPath, i + 1);
             allFiles.addAll(pathFiles);
         }
 
         return allFiles;
     }
 
     /**
      * Scans the given path and retrieves all files for the given path.
      *
      * @param path      A path to scan.
      * @param pathIndex The index of the given path. Used in log messages only.
      * @return A list of files, extracted from the given path.
      */
     private List<File> scanPath(Path path, int pathIndex) {
         final String[] resources = path.list();
         log(pathIndex + ") Scanning path " + path, Project.MSG_VERBOSE);
         final List<File> allFiles = new ArrayList<>();
         int concreteFilesCount = 0;
 
         for (String resource : resources) {
             final File file = new File(resource);
             if (file.isFile()) {
                 concreteFilesCount++;
                 allFiles.add(file);
             }
             else {
                 final DirectoryScanner scanner = new DirectoryScanner();
                 scanner.setBasedir(file);
                 scanner.scan();
                 final List<File> scannedFiles = retrieveAllScannedFiles(scanner, pathIndex);
                 allFiles.addAll(scannedFiles);
             }
         }
 
         if (concreteFilesCount > 0) {
             log(String.format(Locale.ROOT, "%d) Adding %d files from path %s",
                 pathIndex, concreteFilesCount, path), Project.MSG_VERBOSE);
         }
 
         return allFiles;
     }
 
     /**
      * Returns the list of files (full path name) to process.
      * @return the list of files included via the filesets.
      */
     protected List<File> scanFileSets() {
         final List<File> allFiles = new ArrayList<>();
 
         for (int i = 0; i < fileSets.size(); i++) {
             final FileSet fileSet = fileSets.get(i);
             final DirectoryScanner scanner = fileSet.getDirectoryScanner(getProject());
             final List<File> scannedFiles = retrieveAllScannedFiles(scanner, i);
             allFiles.addAll(scannedFiles);
         }
 
         return allFiles;
     }
 
     /**
      * Retrieves all matched files from the given scanner.
      *
      * @param scanner  A directory scanner. Note, that {@link DirectoryScanner#scan()}
      *                 must be called before calling this method.
      * @param logIndex A log entry index. Used only for log messages.
      * @return A list of files, retrieved from the given scanner.
      */
     private List<File> retrieveAllScannedFiles(DirectoryScanner scanner, int logIndex) {
         final String[] fileNames = scanner.getIncludedFiles();
         log(String.format(Locale.ROOT, "%d) Adding %d files from directory %s",
             logIndex, fileNames.length, scanner.getBasedir()), Project.MSG_VERBOSE);
 
         return Arrays.stream(fileNames)
             .map(name -> scanner.getBasedir() + File.separator + name)
             .map(File::new)
             .collect(Collectors.toList());
     }
 
     /**
      * Poor mans enumeration for the formatter types.
      */
     public static class FormatterType extends EnumeratedAttribute {
 
         /** My possible values. */
         private static final String[] VALUES = {E_XML, E_PLAIN};
 
         @Override
         public String[] getValues() {
             return VALUES.clone();
         }
 
     }
 
     /**
      * Details about a formatter to be used.
      */
     public static class Formatter {
 
         /** The formatter type. */
         private FormatterType type;
         /** The file to output to. */
         private File toFile;
         /** Whether or not the write to the named file. */
         private boolean useFile = true;
 
         /**
          * Set the type of the formatter.
          * @param type the type
          */
         public void setType(FormatterType type) {
             this.type = type;
         }
 
         /**
          * Set the file to output to.
          * @param destination destination the file to output to
          */
         public void setTofile(File destination) {
             toFile = destination;
         }
 
         /**
          * Sets whether or not we write to a file if it is provided.
          * @param use whether not not to use provided file.
          */
         public void setUseFile(boolean use) {
             useFile = use;
         }
 
         /**
          * Creates a listener for the formatter.
          * @param task the task running
          * @return a listener
          * @throws IOException if an error occurs
          */
         public AuditListener createListener(Task task) throws IOException {
             final AuditListener listener;
             if (type != null
                     && E_XML.equals(type.getValue())) {
                 listener = createXmlLogger(task);
             }
             else {
                 listener = createDefaultLogger(task);
             }
             return listener;
         }
 
         /**
          * Creates default logger.
          * @param task the task to possibly log to
          * @return a DefaultLogger instance
          * @throws IOException if an error occurs
          */
         private AuditListener createDefaultLogger(Task task)
                 throws IOException {
             final AuditListener defaultLogger;
             if (toFile == null || !useFile) {
                 defaultLogger = new DefaultLogger(
                     new LogOutputStream(task, Project.MSG_DEBUG),
                         AutomaticBean.OutputStreamOptions.CLOSE,
                         new LogOutputStream(task, Project.MSG_ERR),
                         AutomaticBean.OutputStreamOptions.CLOSE
                 );
             }
             else {
                 final OutputStream infoStream = Files.newOutputStream(toFile.toPath());
                 defaultLogger =
                         new DefaultLogger(infoStream, AutomaticBean.OutputStreamOptions.CLOSE,
                                 infoStream, AutomaticBean.OutputStreamOptions.NONE);
             }
             return defaultLogger;
         }
 
         /**
          * Creates XML logger.
          * @param task the task to possibly log to
          * @return an XMLLogger instance
          * @throws IOException if an error occurs
          */
         private AuditListener createXmlLogger(Task task) throws IOException {
             final AuditListener xmlLogger;
             if (toFile == null || !useFile) {
                 xmlLogger = new XMLLogger(new LogOutputStream(task, Project.MSG_INFO),
                         AutomaticBean.OutputStreamOptions.CLOSE);
             }
             else {
                 xmlLogger = new XMLLogger(Files.newOutputStream(toFile.toPath()),
                         AutomaticBean.OutputStreamOptions.CLOSE);
             }
             return xmlLogger;
         }
 
     }
 
     /**
      * Represents a property that consists of a key and value.
      */
     public static class Property {
 
         /** The property key. */
         private String key;
         /** The property value. */
         private String value;
 
         /**
          * Gets key.
          * @return the property key
          */
         public String getKey() {
             return key;
         }
 
         /**
          * Sets key.
          * @param key sets the property key
          */
         public void setKey(String key) {
             this.key = key;
         }
 
         /**
          * Gets value.
          * @return the property value
          */
         public String getValue() {
             return value;
         }
 
         /**
          * Sets value.
          * @param value set the property value
          */
         public void setValue(String value) {
             this.value = value;
         }
 
         /**
          * Sets the property value from a File.
          * @param file set the property value from a File
          */
         public void setFile(File file) {
             value = file.getAbsolutePath();
         }
 
     }
 
     /** Represents a custom listener. */
     public static class Listener {
 
         /** Class name of the listener class. */
         private String className;
 
         /**
          * Gets class name.
          * @return the class name
          */
         public String getClassname() {
             return className;
         }
 
         /**
          * Sets class name.
          * @param name set the class name
          */
         public void setClassname(String name) {
             className = name;
         }
 
     }
 
 }