/**
   * Returns the configured tiles.xml file paths (if configured).
   *
   * @param webApp Web application.
   * @return File names.
   */
  private static Set<String> findConfiguredTilesPaths(final WebApp webApp) {
    @NonNls final Set<String> tilesConfigNames = new THashSet<String>();
    final ParamValue tilesParamValue =
        ContainerUtil.find(webApp.getContextParams(), TILES_CONTEXT_PARAM_CONDITION);
    if (tilesParamValue == null) {
      return tilesConfigNames;
    }

    final String paramValue = tilesParamValue.getParamValue().getStringValue();
    if (paramValue == null) {
      return tilesConfigNames;
    }

    for (final String file : StringUtil.split(paramValue, ",")) {
      tilesConfigNames.add(file.trim());
    }

    return tilesConfigNames;
  }
  @NotNull
  public Collection<TilesModel> computeModels(@NotNull final Module module) {
    final Project project = module.getProject();
    final JavaPsiFacade facade = JavaPsiFacade.getInstance(project);
    final GlobalSearchScope moduleScope =
        GlobalSearchScope.moduleWithDependenciesAndLibrariesScope(module, false);

    // struts2-tiles plugin must be available
    final PsiClass strutsTilesListenerClass =
        facade.findClass(STRUTS_TILES_LISTENER_CLASS, moduleScope);
    if (strutsTilesListenerClass == null) {
      return Collections.emptyList();
    }

    final PsiClass tilesListenerClass =
        facade.findClass(TilesConstants.TILES_LISTENER, moduleScope);

    final StrutsPluginDomFactory<TilesDefinitions, TilesModel> factory =
        StrutsProjectComponent.getInstance(project).getTilesFactory();

    final Set<TilesModel> struts2TilesModels = new HashSet<TilesModel>();
    final Consumer<Set<XmlFile>> consumer =
        definitions -> {
          final DomFileElement<TilesDefinitions> domFileElement =
              factory.createMergedModelRoot(definitions);
          if (domFileElement != null) {
            struts2TilesModels.add(
                new TilesModelImpl(definitions, domFileElement, STRUTS2_TILES_MODEL));
          }
        };

    final WebDirectoryUtil webDirectoryUtil = WebDirectoryUtil.getWebDirectoryUtil(project);
    final Collection<WebFacet> webFacets = WebFacet.getInstances(module);
    for (final WebFacet webFacet : webFacets) {
      final WebApp webApp = webFacet.getRoot();
      if (webApp == null) {
        continue;
      }

      // determine configured tiles config files
      @NonNls final Set<String> tilesConfigNames = findConfiguredTilesPaths(webApp);

      // no configured paths? use default
      if (tilesConfigNames.isEmpty()) {
        tilesConfigNames.add(DEFAULT_TILES_XML);
      }

      // resolve to XmlFile
      final Set<XmlFile> tilesFileSet = new HashSet<XmlFile>();
      for (final String tilesPath : tilesConfigNames) {
        final PsiElement tilesXmlFile = webDirectoryUtil.findFileByPath(tilesPath, webFacet);
        if (tilesXmlFile instanceof XmlFile) {
          tilesFileSet.add((XmlFile) tilesXmlFile);
        }
      }

      final List<Listener> listenerList = webApp.getListeners();
      for (final Listener listener : listenerList) {
        final PsiClass listenerClass = listener.getListenerClass().getValue();
        if (strutsTilesListenerClass.equals(listenerClass)
            || Comparing.equal(tilesListenerClass, listenerClass)) {
          consumer.consume(tilesFileSet);
        }
      }
    }

    return struts2TilesModels;
  }