private static Map<String, List<PsiElement>> collectRedSymbols(
    PsiFile psiFile, Document document, Project project, ProgressIndicator daemonIndicator) {
  Map<String, List<PsiElement>> redSymbolToElements = new HashMap<>();
  List<HighlightInfo> infos =
      ((DaemonCodeAnalyzerImpl) DaemonCodeAnalyzer.getInstance(project))
          .runMainPasses(psiFile, document, daemonIndicator);
  for (HighlightInfo info : infos) {
    if (!info.getSeverity().equals(HighlightSeverity.ERROR)) continue;

    final String redSymbol = document.getText(new TextRange(info.startOffset, info.endOffset));
    if (!StringUtil.isJavaIdentifier(redSymbol) || !StringUtil.isCapitalized(redSymbol)) continue;

    final PsiJavaCodeReferenceElement ref =
        PsiTreeUtil.findElementOfClassAtOffset(
            psiFile, info.startOffset, PsiJavaCodeReferenceElement.class, false);
    if (ref == null) continue;

    redSymbolToElements.putIfAbsent(redSymbol, new ArrayList<>());
    redSymbolToElements.get(redSymbol).add(ref);
  }
  return redSymbolToElements;
}
 

private static boolean extendsTestCase(PsiClass psiClass, Set<PsiClass> checkedClasses) {
  if (!checkedClasses.add(psiClass)) {
    return false;
  }
  PsiReferenceList extendsList = psiClass.getExtendsList();
  if (extendsList == null) {
    return false;
  }
  for (PsiJavaCodeReferenceElement ref : extendsList.getReferenceElements()) {
    if (JUnitUtil.TEST_CASE_CLASS.equals(ref.getQualifiedName())) {
      return true;
    }
    PsiElement clazz = ref.resolve();
    if (clazz instanceof PsiClass && extendsTestCase((PsiClass) clazz, checkedClasses)) {
      return true;
    }
  }
  return false;
}
 

/**
 * Make the class implementing Parcelable
 */
private void makeClassImplementParcelable(PsiElementFactory elementFactory, JavaCodeStyleManager styleManager) {
  final PsiClassType[] implementsListTypes = psiClass.getImplementsListTypes();
  final String implementsType = "android.os.Parcelable";

  for (PsiClassType implementsListType : implementsListTypes) {
    PsiClass resolved = implementsListType.resolve();

    // Already implements Parcelable, no need to add it
    if (resolved != null && implementsType.equals(resolved.getQualifiedName())) {
      return;
    }
  }

  PsiJavaCodeReferenceElement implementsReference =
      elementFactory.createReferenceFromText(implementsType, psiClass);
  PsiReferenceList implementsList = psiClass.getImplementsList();

  if (implementsList != null) {
    styleManager.shortenClassReferences(implementsList.add(implementsReference));
  }
}
 

private static PsiClass resolveClass(final PsiClassObjectAccessExpressionImpl expression) {
	if (expression == null) {
		return null;
	}
	final PsiJavaCodeReferenceElement referenceElement = expression.getOperand()
	                                                               .getInnermostComponentReferenceElement();
	return referenceElement != null ? (PsiClass) referenceElement.resolve() : null;
}
 

/**
 * @return Stream of resolved elements from the given element or an empty stream if nothing found.
 */
static Stream<PsiElement> resolve(PsiElement sourceElement) {
  return Optional.of(sourceElement)
      .filter(PsiIdentifier.class::isInstance)
      .map(element -> PsiTreeUtil.getParentOfType(element, PsiJavaCodeReferenceElement.class))
      .map(PsiElement::getReferences)
      .map(
          psiReferences ->
              Stream.of(psiReferences).map(PsiReference::resolve).filter(Objects::nonNull))
      .orElse(Stream.empty());
}
 

@Override
public PsiClass getBeanClass(PsiElement element) {
    final PsiElement beanPsiElement = getPsiElementForCamelBeanMethod(element);
    if (beanPsiElement != null) {
        if (beanPsiElement instanceof PsiClass) {
            return (PsiClass) beanPsiElement;
        }

        PsiJavaCodeReferenceElement referenceElement = PsiTreeUtil.findChildOfType(beanPsiElement, PsiJavaCodeReferenceElement.class);
        final PsiClass psiClass = getJavaClassUtils().resolveClassReference(referenceElement);

        if (psiClass != null && !JAVA_LANG_STRING.equals(psiClass.getQualifiedName())) {
            return psiClass;
        }

        String beanName = "";
        if (referenceElement instanceof PsiReferenceExpression) {
            beanName = getStaticBeanName(referenceElement, beanName);
        } else {
            final String[] beanParameters = beanPsiElement.getText().replace("(", "").replace(")", "").split(",");
            if (beanParameters.length > 0) {
                beanName = StringUtils.stripDoubleQuotes(beanParameters[0]);
            }
        }
        return searchForMatchingBeanClass(beanName, beanPsiElement.getProject()).orElse(null);
    }
    return null;
}
 

private String getStaticBeanName(PsiJavaCodeReferenceElement referenceElement, String beanName) {
    final PsiType type = ((PsiReferenceExpression) referenceElement).getType();
    if (type != null && JAVA_LANG_STRING.equals(type.getCanonicalText())) {
        beanName = StringUtils.stripDoubleQuotes(PsiTreeUtil.getChildOfAnyType(referenceElement.getReference().resolve(), PsiLiteralExpression.class).getText());
    }
    return beanName;
}
 

/**
 * @param referenceElement - Psi Code reference element to resolve
 * @return Resolving the Psi reference and return the PsiClass
 */
public PsiClass resolveClassReference(@Nullable PsiJavaCodeReferenceElement referenceElement) {
    if (referenceElement != null) {
        PsiReference reference = referenceElement.getReference();

        if (reference != null) {
            return resolveClassReference(reference);
        }
    }
    return null;
}
 

private RemoveAnnotationValueFix( @NotNull PsiAnnotationMemberValue annotationValueToRemove,
                                  @NotNull PsiJavaCodeReferenceElement sideEffectClassReference )
{
    super( message( "side.effects.annotation.declared.correctly.fix.remove.class.reference",
                    sideEffectClassReference.getQualifiedName() ) );
    this.annotationValueToRemove = annotationValueToRemove;
}
 

public RemoveInvalidConcernClassReferenceFix( @NotNull PsiAnnotationMemberValue annotationValueToRemove,
                                              @NotNull PsiJavaCodeReferenceElement concernClassReference )
{
    super( message( "concerns.annotation.declared.correctly.fix.remove.concern.class.reference",
                    concernClassReference.getQualifiedName() ) );
    this.concernClassAnnotationValue = annotationValueToRemove;
}
 

private ProblemDescriptor createProblemDescriptor( @NotNull InspectionManager manager,
                                                   @NotNull PsiAnnotationMemberValue mixinAnnotationValue,
                                                   @NotNull PsiJavaCodeReferenceElement mixinClassReference,
                                                   @NotNull String message )
{
    RemoveInvalidMixinClassReferenceFix fix = new RemoveInvalidMixinClassReferenceFix(
        mixinAnnotationValue, mixinClassReference
    );
    return manager.createProblemDescriptor( mixinAnnotationValue, message, fix, GENERIC_ERROR_OR_WARNING );
}
 

@NotNull
@Override
public PsiClassType[] getReferencedTypes() {
  LOG.debug("getReferencedTypes");
  PsiJavaCodeReferenceElement[] refs = getReferenceElements();
  PsiElementFactory factory = JavaPsiFacade.getInstance(getProject()).getElementFactory();
  PsiClassType[] types = new PsiClassType[refs.length];
  for (int i = 0; i < types.length; i++) {
    types[i] = factory.createType(refs[i]);
  }

  return types;
}
 

@NotNull
@Override
public PsiJavaCodeReferenceElement[] getReferenceElements() {
  LOG.debug("getReferenceElements");
  List<HaxeType> typeList = getTypeList();
  PsiJavaCodeReferenceElement[] refList = new PsiJavaCodeReferenceElement[typeList.size()];
  for (int i = 0; i < typeList.size(); ++i) {
    refList[i] = typeList.get(i).getReferenceExpression();
  }
  return refList;
}
 

@Nullable
private static PsiAnnotation findAnnotationQuick(@Nullable PsiAnnotationOwner annotationOwner, @NotNull String qualifiedName) {
  if (annotationOwner == null) {
    return null;
  }

  PsiAnnotation[] annotations = annotationOwner.getAnnotations();
  if (annotations.length == 0) {
    return null;
  }

  final String shortName = StringUtil.getShortName(qualifiedName);

  for (PsiAnnotation annotation : annotations) {
    PsiJavaCodeReferenceElement referenceElement = annotation.getNameReferenceElement();
    if (null != referenceElement) {
      final String referenceName = referenceElement.getReferenceName();
      if (shortName.equals(referenceName)) {

        if (referenceElement.isQualified() && referenceElement instanceof SourceJavaCodeReference) {
          String possibleFullQualifiedName = ((SourceJavaCodeReference) referenceElement).getClassNameText();
          if (qualifiedName.equals(possibleFullQualifiedName)) {
            return annotation;
          }
        }

        final String annotationQualifiedName = getAndCacheFQN(annotation, referenceName);
        if (null != annotationQualifiedName && qualifiedName.endsWith(annotationQualifiedName)) {
          return annotation;
        }
      }
    }
  }

  return null;
}
 

@Nullable
private static PsiAnnotation findAnnotationQuick(@Nullable PsiAnnotationOwner annotationOwner, @NotNull String... qualifiedNames) {
  if (annotationOwner == null || qualifiedNames.length == 0) {
    return null;
  }

  PsiAnnotation[] annotations = annotationOwner.getAnnotations();
  if (annotations.length == 0) {
    return null;
  }

  final String[] shortNames = new String[qualifiedNames.length];
  for (int i = 0; i < qualifiedNames.length; i++) {
    shortNames[i] = StringUtil.getShortName(qualifiedNames[i]);
  }

  for (PsiAnnotation annotation : annotations) {
    final PsiJavaCodeReferenceElement referenceElement = annotation.getNameReferenceElement();
    if (null != referenceElement) {
      final String referenceName = referenceElement.getReferenceName();
      if (ArrayUtil.find(shortNames, referenceName) > -1) {

        if (referenceElement.isQualified() && referenceElement instanceof SourceJavaCodeReference) {
          final String possibleFullQualifiedName = ((SourceJavaCodeReference) referenceElement).getClassNameText();

          if (ArrayUtil.find(qualifiedNames, possibleFullQualifiedName) > -1) {
            return annotation;
          }
        }

        final String annotationQualifiedName = getAndCacheFQN(annotation, referenceName);
        if (ArrayUtil.find(qualifiedNames, annotationQualifiedName) > -1) {
          return annotation;
        }
      }
    }
  }

  return null;
}
 

@Override
public void registerFixes(
    @NotNull PsiJavaCodeReferenceElement referenceElement,
    @NotNull QuickFixActionRegistrar quickFixActionRegistrar) {
  List<IntentionAction> fixes = findFixesForReference(referenceElement);
  fixes.forEach(quickFixActionRegistrar::register);
  if (fixes.isEmpty() || Boolean.parseBoolean(System.getProperty(KEEP_DEFAULT_AUTODEPS))) {
    // Don't unregister the default if:
    //  1) We can't replace it with anything.
    //  2) The user has requested to keep it.
    return;
  }

  // If we think we can add both a Buck dependency and an IntelliJ module dependency,
  // unregister the default fix, which only adds an IntelliJ module dependency.
  quickFixActionRegistrar.unregister(
      new Condition<IntentionAction>() {
        private static final String ADD_MODULE_DEPENDENCY_FIX_CLASSNAME =
            "com.intellij.codeInsight.daemon.impl.quickfix.AddModuleDependencyFix";

        @Override
        public boolean value(IntentionAction intentionAction) {
          String className = intentionAction.getClass().getName();
          if (ADD_MODULE_DEPENDENCY_FIX_CLASSNAME.equals(className)) {
            return true;
          }
          return false;
        }
      });
}
 

private List<IntentionAction> findFixesForReference(
    PsiJavaCodeReferenceElement referenceElement) {
  Project project = referenceElement.getProject();
  String className = referenceElement.getQualifiedName();
  List<IntentionAction> results = new ArrayList<>();
  if (className != null) {
    findPsiClasses(project, className).stream()
        .map(psiClass -> BuckAddDependencyIntention.create(referenceElement, psiClass))
        .filter(Objects::nonNull)
        .forEach(results::add);
  }
  return results;
}
 

@Override public boolean shouldShow(Usage usage) {
  PsiElement element = ((UsageInfo2UsageAdapter) usage).getElement();
  if (element instanceof PsiJavaCodeReferenceElement) {
    if ((element = element.getContext()) instanceof PsiTypeElement) {
      if ((element = element.getContext()) instanceof PsiParameter) {
        if ((element = element.getContext()) instanceof PsiParameterList) {
          if ((element = element.getContext()) instanceof PsiMethod) {
            return SubscriberMetadata.isAnnotatedWithSubscriber((PsiMethod) element);
          }
        }
      }
    }
  }
  return false;
}
 

public static PsiClass getAnnotationDeclarationClass(final PsiAnnotation configAnnotation) {
	final PsiJavaCodeReferenceElement nameReferenceElement = configAnnotation.getNameReferenceElement();
	return nameReferenceElement != null ? (PsiClass) nameReferenceElement.resolve() : null;
}
 

@Override
protected Response handle(Request request) {
  Project project = findProject(request.file);
  if (project == null) {
    throw new RuntimeException("Cannot find the target project");
  }
  Application application = ApplicationManager.getApplication();
  Response response = new Response();
  application.runReadAction(
      () -> {
        PsiFile psiFile =
            PsiFileFactory.getInstance(project)
                .createFileFromText(JavaLanguage.INSTANCE, request.text);
        if (!(psiFile instanceof PsiJavaFile)) {
          throw new RuntimeException("Cannot parse as Java file");
        }
        PsiJavaFile psiJavaFile = (PsiJavaFile) psiFile;

        Set<String> processed = new HashSet<>();
        for (PsiClass psiClass : psiJavaFile.getClasses()) {
          psiClass.accept(
              new JavaRecursiveElementWalkingVisitor() {
                @Override
                public void visitReferenceElement(PsiJavaCodeReferenceElement reference) {
                  try {
                    if (reference.getQualifier() != null) {
                      return;
                    }
                    String name = reference.getReferenceName();
                    if (processed.contains(name)) {
                      return;
                    }
                    processed.add(name);

                    Set<String> candidates = new HashSet<>();
                    for (PsiClass t : new ImportClassFix(reference).getClassesToImport()) {
                      candidates.add(String.format("import %s;", t.getQualifiedName()));
                    }
                    if (!candidates.isEmpty()) {
                      response.choices.add(candidates.stream().sorted().collect(toList()));
                    }
                  } finally {
                    super.visitReferenceElement(reference);
                  }
                }
              });
        }
      });
  return response;
}
 

private static ElementPattern<? extends PsiElement> codeReferencePattern() {
  return PlatformPatterns.psiElement(PsiIdentifier.class)
      .withParent(PsiJavaCodeReferenceElement.class)
      .withLanguage(JavaLanguage.INSTANCE);
}
 

@Override
public final ProblemDescriptor[] checkClass( @NotNull PsiClass psiClass,
                                             @NotNull InspectionManager manager,
                                             boolean isOnTheFly )
{
    // If psiClass is not an interface, ignore
    if( !psiClass.isInterface() )
    {
        return null;
    }

    // If @Mixins annotation is empty, ignore
    List<PsiAnnotationMemberValue> mixinAnnotationValues = getMixinsAnnotationValue( psiClass );
    if( mixinAnnotationValues.isEmpty() )
    {
        return null;
    }

    // Get all valid mixin type
    Set<PsiClass> validMixinsType = getAllValidMixinTypes( psiClass );
    if( validMixinsType.isEmpty() )
    {
        return null;
    }

    // For each mixin
    List<ProblemDescriptor> problems = new LinkedList<ProblemDescriptor>();
    for( PsiAnnotationMemberValue mixinAnnotationValue : mixinAnnotationValues )
    {
        PsiJavaCodeReferenceElement mixinClassReference = getMixinClassReference( mixinAnnotationValue );

        // If it's not a class reference, ignore
        if( mixinClassReference == null )
        {
            continue;
        }

        // If class reference can't be resolved, ignore
        PsiClass mixinClass = (PsiClass) mixinClassReference.resolve();
        if( mixinClass == null )
        {
            continue;
        }

        String mixinQualifiedName = mixinClass.getQualifiedName();

        boolean isMixinsDeclarationValid = false;
        String message = "";
        if( mixinClass.isInterface() )
        {
            // Mixin can't be an interface
            message = message( "mixin.implements.mixin.type.error.mixin.is.an.interface", mixinQualifiedName );
        }
        else if( isAConcern( mixinClass ) )
        {
            // Mixin can't be a concern
            message = message( "mixin.implements.mixin.type.error.mixin.is.a.concern", mixinQualifiedName );
        }
        else if( isASideEffect( mixinClass ) )
        {
            // Mixin can't be a side effect
            message = message( "mixin.implements.mixin.type.error.mixin.is.a.side.effect", mixinQualifiedName );
        }
        else
        {
            // If doesn't implement any mixin type, it's a problem
            if( !isImplementValidMixinType( mixinClass, validMixinsType ) )
            {
                message = message(
                    "mixin.implements.mixin.type.error.does.not.implement.any.mixin.type",
                    mixinQualifiedName,
                    psiClass.getQualifiedName()
                );
            }
            else
            {
                isMixinsDeclarationValid = true;
            }
        }

        if( !isMixinsDeclarationValid )
        {
            ProblemDescriptor problemDescriptor = createProblemDescriptor(
                manager, mixinAnnotationValue, mixinClassReference, message );
            problems.add( problemDescriptor );
        }
    }

    return problems.toArray( new ProblemDescriptor[problems.size()] );
}
 

public RemoveInvalidMixinClassReferenceFix( @NotNull PsiAnnotationMemberValue mixinClassAnnotationValue,
                                            @NotNull PsiJavaCodeReferenceElement mixinClassReference )
{
    super( message( "mixin.implements.mixin.type.fix.remove.class.reference", mixinClassReference.getQualifiedName() ) );
    this.mixinClassAnnotationValue = mixinClassAnnotationValue;
}
 

@NotNull
@Override
public Class getReferenceClass() {
  return PsiJavaCodeReferenceElement.class;
}
 

@Override
public PsiJavaCodeReferenceElement getPackageReference() {
  return findChildByClass(HaxeReferenceExpression.class);
}
 

@NotNull
public static String getSimpleNameOf(@NotNull PsiAnnotation psiAnnotation) {
  PsiJavaCodeReferenceElement referenceElement = psiAnnotation.getNameReferenceElement();
  return StringUtil.notNullize(null == referenceElement ? null : referenceElement.getReferenceName());
}
 

@NotNull
@Override
public Class<PsiJavaCodeReferenceElement> getReferenceClass() {
  return PsiJavaCodeReferenceElement.class;
}