/*
    * 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.
   */
  
  package org.basepom.mojo.duplicatefinder;
  
  import static com.google.common.base.Preconditions.checkArgument;
  import static com.google.common.base.Preconditions.checkNotNull;
  import static com.google.common.base.Preconditions.checkState;
  import static java.lang.String.format;
  import static org.apache.maven.artifact.Artifact.SCOPE_COMPILE;
  import static org.apache.maven.artifact.Artifact.SCOPE_PROVIDED;
  import static org.apache.maven.artifact.Artifact.SCOPE_RUNTIME;
  import static org.apache.maven.artifact.Artifact.SCOPE_SYSTEM;
  import static org.basepom.mojo.duplicatefinder.ConflictState.CONFLICT_CONTENT_DIFFERENT;
  import static org.basepom.mojo.duplicatefinder.ConflictState.CONFLICT_CONTENT_EQUAL;
  import static org.basepom.mojo.duplicatefinder.ConflictType.CLASS;
  import static org.basepom.mojo.duplicatefinder.ConflictType.RESOURCE;
  import static org.basepom.mojo.duplicatefinder.artifact.ArtifactHelper.getOutputDirectory;
  import static org.basepom.mojo.duplicatefinder.artifact.ArtifactHelper.getTestOutputDirectory;
  
  import org.basepom.mojo.duplicatefinder.ResultCollector.ConflictResult;
  import org.basepom.mojo.duplicatefinder.artifact.ArtifactFileResolver;
  import org.basepom.mojo.duplicatefinder.artifact.MavenCoordinates;
  import org.basepom.mojo.duplicatefinder.classpath.ClasspathDescriptor;
  
  import java.io.BufferedInputStream;
  import java.io.File;
  import java.io.IOException;
  import java.io.InputStream;
  import java.nio.file.Files;
  import java.util.AbstractMap.SimpleImmutableEntry;
  import java.util.Arrays;
  import java.util.Collection;
  import java.util.EnumSet;
  import java.util.Map;
  import java.util.Map.Entry;
  import java.util.Set;
  import java.util.SortedSet;
  import java.util.zip.ZipEntry;
  import java.util.zip.ZipFile;
  import javax.xml.stream.XMLStreamException;
  
  import com.google.common.base.Strings;
  import com.google.common.collect.ImmutableMap;
  import com.google.common.collect.ImmutableSet;
  import com.google.common.collect.Maps;
  import com.google.common.collect.Multimap;
  import com.google.common.hash.HashFunction;
  import com.google.common.hash.Hashing;
  import com.google.common.io.ByteStreams;
  import com.google.common.io.Closer;
  import org.apache.maven.artifact.Artifact;
  import org.apache.maven.artifact.DependencyResolutionRequiredException;
  import org.apache.maven.artifact.versioning.InvalidVersionSpecificationException;
  import org.apache.maven.artifact.versioning.OverConstrainedVersionException;
  import org.apache.maven.model.Dependency;
  import org.apache.maven.plugin.AbstractMojo;
  import org.apache.maven.plugin.MojoExecutionException;
  import org.apache.maven.plugin.MojoFailureException;
  import org.apache.maven.plugins.annotations.LifecyclePhase;
  import org.apache.maven.plugins.annotations.Mojo;
  import org.apache.maven.plugins.annotations.Parameter;
  import org.apache.maven.plugins.annotations.ResolutionScope;
  import org.apache.maven.project.MavenProject;
  import org.codehaus.stax2.XMLOutputFactory2;
  import org.codehaus.staxmate.SMOutputFactory;
  import org.codehaus.staxmate.out.SMOutputDocument;
  import org.codehaus.staxmate.out.SMOutputElement;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * Finds duplicate classes/resources on the classpath.
   */
  @Mojo(name = "check", requiresProject = true, threadSafe = true, defaultPhase = LifecyclePhase.VERIFY, requiresDependencyResolution = ResolutionScope.TEST)
  public final class DuplicateFinderMojo extends AbstractMojo {
  
      private static final Logger LOG = LoggerFactory.getLogger(DuplicateFinderMojo.class);
  
      private static final int SAVE_FILE_VERSION = 1;
  
      private static final HashFunction SHA_256 = Hashing.sha256();
  
      private static final Set<String> COMPILE_SCOPE = ImmutableSet.of(SCOPE_COMPILE, SCOPE_PROVIDED, SCOPE_SYSTEM);
      private static final Set<String> RUNTIME_SCOPE = ImmutableSet.of(SCOPE_COMPILE, SCOPE_RUNTIME);
      private static final Set<String> TEST_SCOPE = ImmutableSet.of(); // Empty == all scopes
  
      /**
      * The maven project (effective pom).
      */
     @Parameter(defaultValue = "${project}", readonly = true)
     public MavenProject project;
 
     /**
      * Report files that have the same sha256 has value.
      *
      * @since 1.0.6
      */
     @Parameter(defaultValue = "false", property = "duplicate-finder.printEqualFiles")
     public boolean printEqualFiles = false;
 
     /**
      * Fail the build if files with the same name but different content are detected.
      *
      * @since 1.0.3
      */
     @Parameter(defaultValue = "false", property = "duplicate-finder.failBuildInCaseOfDifferentContentConflict")
     public boolean failBuildInCaseOfDifferentContentConflict = false;
 
     /**
      * Fail the build if files with the same name and the same content are detected.
      *
      * @since 1.0.3
      */
     @Parameter(defaultValue = "false", property = "duplicate-finder.failBuildInCaseOfEqualContentConflict")
     public boolean failBuildInCaseOfEqualContentConflict = false;
 
     /**
      * Fail the build if any files with the same name are found.
      */
     @Parameter(defaultValue = "false", property = "duplicate-finder.failBuildInCaseOfConflict")
     public boolean failBuildInCaseOfConflict = false;
 
     /**
      * Use the default resource ignore list.
      */
     @Parameter(defaultValue = "true", property = "duplicate-finder.useDefaultResourceIgnoreList")
     public boolean useDefaultResourceIgnoreList = true;
 
     /**
      * Use the default class ignore list.
      *
      * @since 1.2.1
      */
     @Parameter(defaultValue = "true", property = "duplicate-finder.useDefaultClassIgnoreList")
     public boolean useDefaultClassIgnoreList = true;
 
     /**
      * Ignored resources, which are not checked for multiple occurences.
      */
     @Parameter
     public String[] ignoredResourcePatterns = new String[0];
 
     /**
      * Ignored classes, which are not checked for multiple occurences.
      *
      * @since 1.2.1
      */
     @Parameter
     public String[] ignoredClassPatterns = new String[0];
 
     /**
      * Artifacts with expected and resolved versions that are checked.
      */
     @Parameter(alias = "exceptions")
     public ConflictingDependency[] conflictingDependencies = new ConflictingDependency[0];
 
     /**
      * Dependencies that should not be checked at all.
      */
     @Parameter(alias = "ignoredDependencies")
     MavenCoordinates[] ignoredDependencies = new MavenCoordinates[0];
 
     /**
      * Check resources and classes on the compile class path.
      */
     @Parameter(defaultValue = "true", property = "duplicate-finder.checkCompileClasspath")
     public boolean checkCompileClasspath = true;
 
     /**
      * Check resources and classes on the runtime class path.
      */
     @Parameter(defaultValue = "true", property = "duplicate-finder.checkRuntimeClasspath")
     public boolean checkRuntimeClasspath = true;
 
     /**
      * Check resources and classes on the test class path.
      */
     @Parameter(defaultValue = "true", property = "duplicate-finder.checkTestClasspath")
     public boolean checkTestClasspath = true;
 
     /**
      * Skips the plugin execution.
      */
     @Parameter(defaultValue = "false", property = "duplicate-finder.skip")
     public boolean skip = false;
 
     /**
      * Quiets the plugin (report only errors).
      *
      * @since 1.1.0
      * @deprecated Maven logging controls the log level now.
      */
     @Parameter(defaultValue = "false", property = "duplicate-finder.quiet")
     @Deprecated
     public boolean quiet = false;
 
     /**
      * Whether existing local directories with classes or existing artifacts are preferred.
      *
      * @since 1.1.0
      */
     @Parameter(defaultValue = "true", property = "duplicate-finder.preferLocal")
     public boolean preferLocal = true;
 
     /**
      * Output file for the result of the plugin.
      *
      * @since 1.1.0
      */
     @Parameter(defaultValue = "${project.build.directory}/duplicate-finder-result.xml", property = "duplicate-finder.resultFile")
     public File resultFile;
 
     /**
      * Write result to output file.
      *
      * @since 1.1.0
      */
     @Parameter(defaultValue = "true", property = "duplicate-finder.useResultFile")
     public boolean useResultFile = true;
 
     /**
      * Minimum occurences on the class path to be listed in the result file.
      *
      * @since 1.1.0
      */
     @Parameter(defaultValue = "2", property = "duplicate-finder.resultFileMinClasspathCount")
     public int resultFileMinClasspathCount = 2;
 
     /**
      * Include the boot class path in duplicate detection. This will find duplicates with the JDK internal classes (e.g. the classes in rt.jar).
      *
      * @since 1.1.1
      * @deprecated Inspecting the boot classpath is no longer supported in Java 9+
      */
     @Parameter(defaultValue = "false", property = "duplicate-finder.includeBootClasspath")
     @Deprecated
     public boolean includeBootClasspath = false;
 
     /**
      * System property that contains the boot class path.
      *
      * @since 1.1.1
      * @deprecated Inspecting the boot classpath is no longer supported in Java 9+
      */
     @Parameter(property = "duplicate-finder.bootClasspathProperty")
     @Deprecated
     public String bootClasspathProperty = null;
 
     /**
      * Include POM projects in validation.
      *
      * @since 1.2.0
      */
     @Parameter(defaultValue = "false", property = "duplicate-finder.includePomProjects")
     public boolean includePomProjects = false;
 
     private final EnumSet<ConflictState> printState = EnumSet.of(CONFLICT_CONTENT_DIFFERENT);
     private final EnumSet<ConflictState> failState = EnumSet.noneOf(ConflictState.class);
 
     // called by maven
     public void setIgnoredDependencies(final Dependency... dependencies) throws InvalidVersionSpecificationException {
         checkArgument(dependencies != null);
 
         this.ignoredDependencies = new MavenCoordinates[dependencies.length];
         for (int idx = 0; idx < dependencies.length; idx++) {
             this.ignoredDependencies[idx] = new MavenCoordinates(dependencies[idx]);
         }
     }
 
     @Override
     public void execute() throws MojoExecutionException, MojoFailureException {
         if (skip) {
             LOG.info("Skipping duplicate-finder execution!");
         } else if (!includePomProjects && "pom".equals(project.getArtifact().getType())) {
             LOG.info("Ignoring POM project!");
         } else {
             if (printEqualFiles) {
                 printState.add(CONFLICT_CONTENT_EQUAL);
             }
 
             if (failBuildInCaseOfConflict || failBuildInCaseOfEqualContentConflict) {
                 printState.add(CONFLICT_CONTENT_EQUAL);
 
                 failState.add(CONFLICT_CONTENT_EQUAL);
                 failState.add(CONFLICT_CONTENT_DIFFERENT);
             }
 
             if (failBuildInCaseOfDifferentContentConflict) {
                 failState.add(CONFLICT_CONTENT_DIFFERENT);
             }
 
             if (includeBootClasspath) {
                 LOG.warn("<includeBootClasspath> is no longer supported and will be ignored!");
             }
             if (bootClasspathProperty != null) {
                 LOG.warn("<bootClasspathProperty> is no longer supported and will be ignored!");
             }
 
             if (quiet) {
                 LOG.warn("<quiet> is no longer supported and will be ignored!");
             }
 
             try {
                 // Prep conflicting dependencies
                 MavenCoordinates projectCoordinates = new MavenCoordinates(project.getArtifact());
 
                 for (ConflictingDependency conflictingDependency : conflictingDependencies) {
                     conflictingDependency.addProjectMavenCoordinates(projectCoordinates);
                 }
 
                 final ArtifactFileResolver artifactFileResolver = new ArtifactFileResolver(project, preferLocal);
                 final ImmutableMap.Builder<String, Entry<ResultCollector, ClasspathDescriptor>> classpathResultBuilder = ImmutableMap.builder();
 
                 if (checkCompileClasspath) {
                     LOG.info("Checking compile classpath");
                     final ResultCollector resultCollector = new ResultCollector(printState, failState);
                     final ClasspathDescriptor classpathDescriptor = checkClasspath(resultCollector, artifactFileResolver, COMPILE_SCOPE,
                             getOutputDirectory(project));
                     classpathResultBuilder.put("compile", new SimpleImmutableEntry<>(resultCollector, classpathDescriptor));
                 }
 
                 if (checkRuntimeClasspath) {
                     LOG.info("Checking runtime classpath");
                     final ResultCollector resultCollector = new ResultCollector(printState, failState);
                     final ClasspathDescriptor classpathDescriptor = checkClasspath(resultCollector, artifactFileResolver, RUNTIME_SCOPE,
                             getOutputDirectory(project));
                     classpathResultBuilder.put("runtime", new SimpleImmutableEntry<>(resultCollector, classpathDescriptor));
                 }
 
                 if (checkTestClasspath) {
                     LOG.info("Checking test classpath");
                     final ResultCollector resultCollector = new ResultCollector(printState, failState);
                     final ClasspathDescriptor classpathDescriptor = checkClasspath(resultCollector,
                             artifactFileResolver,
                             TEST_SCOPE,
                             getOutputDirectory(project),
                             getTestOutputDirectory(project));
                     classpathResultBuilder.put("test", new SimpleImmutableEntry<>(resultCollector, classpathDescriptor));
                 }
 
                 final ImmutableMap<String, Entry<ResultCollector, ClasspathDescriptor>> classpathResults = classpathResultBuilder.build();
 
                 if (useResultFile) {
                     checkState(resultFile != null, "resultFile must be set if useResultFile is true");
                     writeResultFile(resultFile, classpathResults);
                 }
 
                 boolean failed = false;
 
                 for (Map.Entry<String, Entry<ResultCollector, ClasspathDescriptor>> classpathEntry : classpathResults.entrySet()) {
                     String classpathName = classpathEntry.getKey();
                     ResultCollector resultCollector = classpathEntry.getValue().getKey();
 
                     for (final ConflictState state : printState) {
                         for (final ConflictType type : ConflictType.values()) {
                             if (resultCollector.hasConflictsFor(type, state)) {
                                 final Map<String, Collection<ConflictResult>> results = resultCollector.getResults(type, state);
                                 for (final Map.Entry<String, Collection<ConflictResult>> entry : results.entrySet()) {
                                     final String artifactNames = entry.getKey();
                                     final Collection<ConflictResult> conflictResults = entry.getValue();
 
                                     LOG.warn(format("Found duplicate %s %s in [%s]:", state.getHint(), type.getType(), artifactNames));
                                     for (final ConflictResult conflictResult : conflictResults) {
                                         LOG.warn(format("  %s", conflictResult.getName()));
                                     }
                                 }
                             }
                         }
                     }
 
                     failed |= resultCollector.isFailed();
 
                     if (resultCollector.isFailed()) {
                         LOG.warn(format("Found duplicate classes/resources in %s classpath.", classpathName));
                     }
                 }
 
                 if (failed) {
                     throw new MojoExecutionException("Found duplicate classes/resources!");
                 }
             } catch (final DependencyResolutionRequiredException e) {
                 throw new MojoFailureException("Could not resolve dependencies", e);
             } catch (final InvalidVersionSpecificationException e) {
                 throw new MojoFailureException("Invalid version specified", e);
             } catch (final OverConstrainedVersionException e) {
                 throw new MojoFailureException("Version too constrained", e);
             } catch (final IOException e) {
                 throw new MojoExecutionException("While loading artifacts", e);
             }
         }
     }
 
     private ImmutableSet<String> getIgnoredResourcePatterns() {
         ImmutableSet.Builder<String> builder = ImmutableSet.builder();
         builder.add(ignoredResourcePatterns);
 
         return builder.build();
     }
 
     private ImmutableSet<String> getIgnoredClassPatterns() {
         ImmutableSet.Builder<String> builder = ImmutableSet.builder();
         builder.add(ignoredClassPatterns);
 
         return builder.build();
     }
 
     /**
      * Checks the maven classpath for a given set of scopes whether it contains duplicates. In addition to the artifacts on the classpath, one or more
      * additional project folders are added.
      */
     private ClasspathDescriptor checkClasspath(final ResultCollector resultCollector,
             final ArtifactFileResolver artifactFileResolver,
             final Set<String> scopes,
             final File... projectFolders)
             throws MojoExecutionException, InvalidVersionSpecificationException, OverConstrainedVersionException, DependencyResolutionRequiredException {
 
         // Map of files to artifacts. Depending on the type of build, referenced projects in a multi-module build
         // may be local folders in the project instead of repo jar references.
         final Multimap<File, Artifact> fileToArtifactMap = artifactFileResolver.resolveArtifactsForScopes(scopes);
 
         final ClasspathDescriptor classpathDescriptor = ClasspathDescriptor.createClasspathDescriptor(project,
                 fileToArtifactMap,
                 getIgnoredResourcePatterns(),
                 getIgnoredClassPatterns(),
                 Arrays.asList(ignoredDependencies),
                 useDefaultResourceIgnoreList,
                 useDefaultClassIgnoreList,
                 projectFolders);
 
         // Now a scope specific classpath descriptor (scope relevant artifacts and project folders) and the global artifact resolver
         // are primed. Run conflict resolution for classes and resources.
         checkForDuplicates(CLASS, resultCollector, classpathDescriptor, artifactFileResolver);
         checkForDuplicates(RESOURCE, resultCollector, classpathDescriptor, artifactFileResolver);
         return classpathDescriptor;
     }
 
     private void checkForDuplicates(final ConflictType type, final ResultCollector resultCollector, final ClasspathDescriptor classpathDescriptor,
             final ArtifactFileResolver artifactFileResolver)
             throws OverConstrainedVersionException {
         // only look at entries with a size > 1.
         final Map<String, Collection<File>> filteredMap = ImmutableMap.copyOf(Maps.filterEntries(classpathDescriptor.getClasspathElementLocations(type),
                 entry -> {
                     checkNotNull(entry, "entry is null");
                     checkState(entry.getValue() != null, "Entry '%s' is invalid", entry);
 
                     return entry.getValue().size() > 1;
                 }));
 
         for (final Map.Entry<String, Collection<File>> entry : filteredMap.entrySet()) {
             final String name = entry.getKey();
             final Collection<File> elements = entry.getValue();
 
             // Map which contains a printable name for the conflicting entry (which is either the printable name for an artifact or
             // a folder name for a project folder) as keys and a classpath element as value.
             final SortedSet<ClasspathElement> conflictingClasspathElements = artifactFileResolver.getClasspathElementsForElements(elements);
 
             ImmutableSet.Builder<Artifact> artifactBuilder = ImmutableSet.builder();
 
             for (ClasspathElement conflictingClasspathElement : conflictingClasspathElements) {
                 if (conflictingClasspathElement.hasArtifact()) {
                     artifactBuilder.add(conflictingClasspathElement.getArtifact());
                 } else if (conflictingClasspathElement.isLocalFolder()) {
                     artifactBuilder.add(project.getArtifact());
                 }
             }
 
             final boolean excepted = isExcepted(type, name, artifactBuilder.build());
             final ConflictState conflictState = DuplicateFinderMojo.determineConflictState(type, name, elements);
 
             resultCollector.addConflict(type, name, conflictingClasspathElements, excepted, conflictState);
         }
     }
 
     /**
      * Detects class/resource differences via SHA256 hash comparison.
      */
     private static ConflictState determineConflictState(final ConflictType type, final String name, final Iterable<File> elements) {
         File firstFile = null;
         String firstSHA256 = null;
 
         final String resourcePath = type == ConflictType.CLASS ? name.replace('.', '/') + ".class" : name;
 
         for (final File element : elements) {
             try {
                 final String newSHA256 = getSHA256HexOfElement(element, resourcePath);
 
                 if (firstSHA256 == null) {
                     // save sha256 hash from the first element
                     firstSHA256 = newSHA256;
                     firstFile = element;
                 } else if (!newSHA256.equals(firstSHA256)) {
                     LOG.debug(format("Found different SHA256 hashes for elements %s in file %s and %s", resourcePath, firstFile, element));
                     return ConflictState.CONFLICT_CONTENT_DIFFERENT;
                 }
             } catch (final IOException ex) {
                 LOG.warn(format("Could not read content from file %s!", element), ex);
             }
         }
 
         return ConflictState.CONFLICT_CONTENT_EQUAL;
     }
 
     /**
      * Calculates the SHA256 Hash of a class in a file.
      *
      * @param file         the archive contains the class
      * @param resourcePath the name of the class
      * @return the MD% Hash as Hex-Value
      * @throws IOException if any error occurs on reading class in archive
      */
     private static String getSHA256HexOfElement(final File file, final String resourcePath) throws IOException {
 
         try (Closer closer = Closer.create()) {
             InputStream in;
 
             if (file.isDirectory()) {
                 final File resourceFile = new File(file, resourcePath);
                 in = closer.register(new BufferedInputStream(Files.newInputStream(resourceFile.toPath())));
             } else {
                 final ZipFile zip = new ZipFile(file);
 
                 closer.register(zip::close);
 
                 final ZipEntry zipEntry = zip.getEntry(resourcePath);
 
                 if (zipEntry == null) {
                     throw new IOException(format("Could not find %s in archive %s", resourcePath, file));
                 }
 
                 in = zip.getInputStream(zipEntry);
             }
 
             return SHA_256.newHasher().putBytes(ByteStreams.toByteArray(in)).hash().toString();
         }
     }
 
     private boolean isExcepted(final ConflictType type, final String name, final Set<Artifact> artifacts)
             throws OverConstrainedVersionException {
         final ImmutableSet.Builder<ConflictingDependency> conflictBuilder = ImmutableSet.builder();
         checkState(conflictingDependencies != null, "conflictingDependencies is null");
 
         // Find all exception definitions from the configuration that match these artifacts.
         for (final ConflictingDependency conflictingDependency : conflictingDependencies) {
             if (conflictingDependency.isForArtifacts(artifacts)) {
                 conflictBuilder.add(conflictingDependency);
             }
         }
 
         // If any of the possible candidates covers this class or resource, then the conflict is excepted.
         for (final ConflictingDependency conflictingDependency : conflictBuilder.build()) {
             if (type == ConflictType.CLASS && conflictingDependency.containsClass(name)) {
                 return true;
             } else if (type == ConflictType.RESOURCE && conflictingDependency.containsResource(name)) {
                 return true;
             }
         }
         return false;
     }
 
     private void writeResultFile(File resultFile, ImmutableMap<String, Entry<ResultCollector, ClasspathDescriptor>> results)
             throws MojoExecutionException, InvalidVersionSpecificationException, OverConstrainedVersionException {
         File parent = resultFile.getParentFile();
         if (!parent.exists()) {
             if (!parent.mkdirs()) {
                 throw new MojoExecutionException("Could not create parent folders for " + parent.getAbsolutePath());
             }
         }
         if (!parent.isDirectory() || !parent.canWrite()) {
             throw new MojoExecutionException("Can not create result file in " + parent.getAbsolutePath());
         }
 
         try {
             SMOutputFactory factory = new SMOutputFactory(XMLOutputFactory2.newFactory());
             SMOutputDocument resultDocument = factory.createOutputDocument(resultFile);
             resultDocument.setIndentation("\n" + Strings.repeat(" ", 64), 1, 4);
 
             SMOutputElement rootElement = resultDocument.addElement("duplicate-finder-result");
             XMLWriterUtils.addAttribute(rootElement, "version", SAVE_FILE_VERSION);
 
             XMLWriterUtils.addProjectInformation(rootElement, project);
 
             addConfiguration(rootElement);
 
             SMOutputElement resultsElement = rootElement.addElement("results");
             for (Map.Entry<String, Entry<ResultCollector, ClasspathDescriptor>> entry : results.entrySet()) {
                 SMOutputElement resultElement = resultsElement.addElement("result");
                 XMLWriterUtils.addAttribute(resultElement, "name", entry.getKey());
                 XMLWriterUtils.addResultCollector(resultElement, entry.getValue().getKey());
                 XMLWriterUtils.addClasspathDescriptor(resultElement, resultFileMinClasspathCount, entry.getValue().getValue());
             }
 
             resultDocument.closeRootAndWriter();
         } catch (XMLStreamException e) {
             throw new MojoExecutionException("While writing result file", e);
         }
     }
 
     private void addConfiguration(SMOutputElement rootElement)
             throws XMLStreamException {
         SMOutputElement prefs = XMLWriterUtils.addElement(rootElement, "configuration", null);
         // Simple configuration options
         XMLWriterUtils.addAttribute(prefs, "skip", skip);
         XMLWriterUtils.addAttribute(prefs, "checkCompileClasspath", checkCompileClasspath);
         XMLWriterUtils.addAttribute(prefs, "checkRuntimeClasspath", checkRuntimeClasspath);
         XMLWriterUtils.addAttribute(prefs, "checkTestClasspath", checkTestClasspath);
         XMLWriterUtils.addAttribute(prefs, "failBuildInCaseOfDifferentContentConflict", failBuildInCaseOfDifferentContentConflict);
         XMLWriterUtils.addAttribute(prefs, "failBuildInCaseOfEqualContentConflict", failBuildInCaseOfEqualContentConflict);
         XMLWriterUtils.addAttribute(prefs, "failBuildInCaseOfConflict", failBuildInCaseOfConflict);
         XMLWriterUtils.addAttribute(prefs, "printEqualFiles", printEqualFiles);
         XMLWriterUtils.addAttribute(prefs, "preferLocal", preferLocal);
         XMLWriterUtils.addAttribute(prefs, "includePomProjects", includePomProjects);
         // Ignoring Dependencies and resources
         XMLWriterUtils.addAttribute(prefs, "useDefaultResourceIgnoreList", useDefaultResourceIgnoreList);
         XMLWriterUtils.addAttribute(prefs, "useDefaultClassIgnoreList", useDefaultClassIgnoreList);
         // Result file options
         XMLWriterUtils.addAttribute(prefs, "useResultFile", useResultFile);
         XMLWriterUtils.addAttribute(prefs, "resultFileMinClasspathCount", resultFileMinClasspathCount);
         XMLWriterUtils.addAttribute(prefs, "resultFile", resultFile.getAbsolutePath());
 
         SMOutputElement ignoredResourcesElement = prefs.addElement("ignoredResourcePatterns");
         for (String ignoredResource : getIgnoredResourcePatterns()) {
             XMLWriterUtils.addElement(ignoredResourcesElement, "ignoredResourcePattern", ignoredResource);
         }
 
         SMOutputElement ignoredClassElement = prefs.addElement("ignoredClassPatterns");
         for (String ignoredClass : getIgnoredClassPatterns()) {
             XMLWriterUtils.addElement(ignoredClassElement, "ignoredClassPattern", ignoredClass);
         }
 
         SMOutputElement conflictingDependenciesElement = prefs.addElement("conflictingDependencies");
         for (ConflictingDependency conflictingDependency : conflictingDependencies) {
             XMLWriterUtils.addConflictingDependency(conflictingDependenciesElement, "conflictingDependency", conflictingDependency);
         }
 
         SMOutputElement ignoredDependenciesElement = prefs.addElement("ignoredDependencies");
         for (MavenCoordinates ignoredDependency : ignoredDependencies) {
             XMLWriterUtils.addMavenCoordinate(ignoredDependenciesElement, "dependency", ignoredDependency);
         }
     }
 }