// TODO: Make it work for properties
  public Collection<DeclarationDescriptor> getJetCallableExtensions(
      @NotNull Condition<String> acceptedNameCondition,
      @NotNull JetSimpleNameExpression expression,
      @NotNull ResolveSession resolveSession,
      @NotNull GlobalSearchScope searchScope) {
    Collection<DeclarationDescriptor> resultDescriptors = new ArrayList<DeclarationDescriptor>();

    BindingContext context = ResolveSessionUtils.resolveToExpression(resolveSession, expression);
    JetExpression receiverExpression = expression.getReceiverExpression();

    if (receiverExpression != null) {
      JetType expressionType = context.get(BindingContext.EXPRESSION_TYPE, receiverExpression);
      JetScope scope = context.get(BindingContext.RESOLUTION_SCOPE, receiverExpression);

      if (expressionType != null && scope != null) {
        Collection<String> extensionFunctionsNames = getAllJetExtensionFunctionsNames(searchScope);

        Set<FqName> functionFQNs = new java.util.HashSet<FqName>();

        // Collect all possible extension function qualified names
        for (String name : extensionFunctionsNames) {
          if (acceptedNameCondition.value(name)) {
            Collection<PsiElement> extensionFunctions =
                getJetExtensionFunctionsByName(name, searchScope);

            for (PsiElement extensionFunction : extensionFunctions) {
              if (extensionFunction instanceof JetNamedFunction) {
                functionFQNs.add(JetPsiUtil.getFQName((JetNamedFunction) extensionFunction));
              } else if (extensionFunction instanceof PsiMethod) {
                FqName functionFQN =
                    JetFromJavaDescriptorHelper.getJetTopLevelDeclarationFQN(
                        (PsiMethod) extensionFunction);
                if (functionFQN != null) {
                  functionFQNs.add(functionFQN);
                }
              }
            }
          }
        }

        // Iterate through the function with attempt to resolve found functions
        for (FqName functionFQN : functionFQNs) {
          for (CallableDescriptor functionDescriptor :
              ExpressionTypingUtils.canFindSuitableCall(
                  functionFQN,
                  project,
                  receiverExpression,
                  expressionType,
                  scope,
                  resolveSession.getModuleConfiguration())) {

            resultDescriptors.add(functionDescriptor);
          }
        }
      }
    }

    return resultDescriptors;
  }
  /** Return class names form jet sources in given scope which should be visible as Java classes. */
  @NotNull
  @Override
  public PsiClass[] getClassesByName(
      @NotNull @NonNls String name, @NotNull GlobalSearchScope scope) {
    List<PsiClass> result = new ArrayList<PsiClass>();

    IDELightClassGenerationSupport lightClassGenerationSupport =
        IDELightClassGenerationSupport.getInstanceForIDE(project);
    MultiMap<String, FqName> packageClasses =
        lightClassGenerationSupport.getAllPackageClasses(scope);

    // .namespace classes can not be indexed, since they have no explicit declarations
    Collection<FqName> fqNames = packageClasses.get(name);
    if (!fqNames.isEmpty()) {
      for (FqName fqName : fqNames) {
        PsiClass psiClass =
            JavaElementFinder.getInstance(project).findClass(fqName.getFqName(), scope);
        if (psiClass != null) {
          result.add(psiClass);
        }
      }
    }

    // Quick check for classes from getAllClassNames()
    Collection<JetClassOrObject> classOrObjects =
        JetShortClassNameIndex.getInstance().get(name, project, scope);
    if (classOrObjects.isEmpty()) {
      return result.toArray(new PsiClass[result.size()]);
    }

    for (JetClassOrObject classOrObject : classOrObjects) {
      FqName fqName = JetPsiUtil.getFQName(classOrObject);
      if (fqName != null) {
        assert fqName.shortName().getName().equals(name)
            : "A declaration obtained from index has non-matching name:\n"
                + "in index: "
                + name
                + "\n"
                + "declared: "
                + fqName.shortName()
                + "("
                + fqName
                + ")";
        PsiClass psiClass =
            JavaElementFinder.getInstance(project).findClass(fqName.getFqName(), scope);
        if (psiClass != null) {
          result.add(psiClass);
        }
      }
    }

    return result.toArray(new PsiClass[result.size()]);
  }
  @NotNull
  public static Collection<JetFile> allFilesInNamespaces(
      BindingContext bindingContext, Collection<JetFile> files) {
    // todo: we use Set and add given files but ignoring other scripts because something non-clear
    // kept in binding
    // for scripts especially in case of REPL

    HashSet<FqName> names = new HashSet<FqName>();
    for (JetFile file : files) {
      if (!file.isScript()) {
        names.add(JetPsiUtil.getFQName(file));
      }
    }

    HashSet<JetFile> answer = new HashSet<JetFile>();
    answer.addAll(files);

    for (FqName name : names) {
      NamespaceDescriptor namespaceDescriptor =
          bindingContext.get(BindingContext.FQNAME_TO_NAMESPACE_DESCRIPTOR, name);
      Collection<JetFile> jetFiles = bindingContext.get(NAMESPACE_TO_FILES, namespaceDescriptor);
      if (jetFiles != null) answer.addAll(jetFiles);
    }

    List<JetFile> sortedAnswer = new ArrayList<JetFile>(answer);
    Collections.sort(
        sortedAnswer,
        new Comparator<JetFile>() {
          @NotNull
          private String path(JetFile file) {
            VirtualFile virtualFile = file.getVirtualFile();
            assert virtualFile != null : "VirtualFile is null for JetFile: " + file.getName();
            return virtualFile.getPath();
          }

          @Override
          public int compare(JetFile first, JetFile second) {
            return path(first).compareTo(path(second));
          }
        });

    return sortedAnswer;
  }
  @NotNull
  public Collection<ClassDescriptor> getTopLevelObjectsByName(
      @NotNull String name,
      @NotNull JetSimpleNameExpression expression,
      @NotNull ResolveSession resolveSession,
      @NotNull GlobalSearchScope scope) {
    BindingContext context = ResolveSessionUtils.resolveToExpression(resolveSession, expression);
    JetScope jetScope = context.get(BindingContext.RESOLUTION_SCOPE, expression);

    if (jetScope == null) {
      return Collections.emptyList();
    }

    Set<ClassDescriptor> result = Sets.newHashSet();

    Collection<JetObjectDeclaration> topObjects =
        JetTopLevelShortObjectNameIndex.getInstance().get(name, project, scope);
    for (JetObjectDeclaration objectDeclaration : topObjects) {
      FqName fqName = JetPsiUtil.getFQName(objectDeclaration);
      assert fqName != null
          : "Local object declaration in JetTopLevelShortObjectNameIndex:"
              + objectDeclaration.getText();
      result.addAll(
          ResolveSessionUtils.getClassOrObjectDescriptorsByFqName(resolveSession, fqName, true));
    }

    for (PsiClass psiClass :
        JetFromJavaDescriptorHelper.getCompiledClassesForTopLevelObjects(
            project, GlobalSearchScope.allScope(project))) {
      String qualifiedName = psiClass.getQualifiedName();
      if (qualifiedName != null) {
        FqName fqName = new FqName(qualifiedName);
        result.addAll(
            ResolveSessionUtils.getClassOrObjectDescriptorsByFqName(resolveSession, fqName, true));
      }
    }

    return result;
  }