/**
   * Method to obtain the custom UI media types.
   *
   * @param configSystemRegistry a configuration system registry instance.
   * @return a String of custom UI media types, in the format name:type,name:type,...
   * @throws RegistryException if the operation failed.
   */
  public static String getCustomUIMediaTypeMappings(Registry configSystemRegistry)
      throws RegistryException {

    RegistryContext registryContext = configSystemRegistry.getRegistryContext();

    if (getCustomUIMediaTypeMappings(registryContext) != null) {
      return getCustomUIMediaTypeMappings(registryContext);
    }

    Resource resource;
    String mediaTypeString = null;

    String resourcePath =
        MIME_TYPE_COLLECTION + RegistryConstants.PATH_SEPARATOR + RESOURCE_MIME_TYPE_INDEX;

    // TODO: Adding the media types should ideally be done by the handler associated with the
    // media type
    if (!configSystemRegistry.resourceExists(resourcePath)) {
      getResourceMediaTypeMappings(configSystemRegistry);
    }
    if (!configSystemRegistry.resourceExists(
        resourcePath + RegistryConstants.PATH_SEPARATOR + CUSTOM_UI_MIME_TYPE_INDEX)) {
      resource = configSystemRegistry.newResource();
      resource.setProperty("profiles", "application/vnd.wso2-profiles+xml");
      // resource.setProperty("service", "application/vnd.wso2-service+xml");
      resource.setDescription(
          "This resource contains the media Types associated with "
              + "custom user interfaces on the Registry. Add, Edit or Delete properties to "
              + "Manage Media Types.");
      configSystemRegistry.put(
          resourcePath + RegistryConstants.PATH_SEPARATOR + CUSTOM_UI_MIME_TYPE_INDEX, resource);
    } else {
      resource =
          configSystemRegistry.get(
              resourcePath + RegistryConstants.PATH_SEPARATOR + CUSTOM_UI_MIME_TYPE_INDEX);
    }
    Properties properties = resource.getProperties();
    if (properties.size() > 0) {
      Set<Object> keySet = properties.keySet();
      for (Object key : keySet) {
        if (key instanceof String) {
          String ext = (String) key;
          if (RegistryUtils.isHiddenProperty(ext)) {
            continue;
          }
          String value = resource.getProperty(ext);
          String mediaTypeMapping = ext + ":" + value;
          if (mediaTypeString == null) {
            mediaTypeString = mediaTypeMapping;
          } else {
            mediaTypeString = mediaTypeString + "," + mediaTypeMapping;
          }
        }
      }
    }
    registryContext.setCustomUIMediaTypes(mediaTypeString);
    return mediaTypeString;
  }
  /**
   * Method to obtain the resource media types.
   *
   * @param configSystemRegistry a configuration system registry instance.
   * @return a String of resource media types, in the format extension:type,extension:type,...
   * @throws RegistryException if the operation failed.
   */
  public static String getResourceMediaTypeMappings(Registry configSystemRegistry)
      throws RegistryException {

    RegistryContext registryContext = configSystemRegistry.getRegistryContext();

    if (getResourceMediaTypeMappings(registryContext) != null) {
      return getResourceMediaTypeMappings(registryContext);
    }

    Resource resource;
    String mediaTypeString = null;

    String resourcePath =
        MIME_TYPE_COLLECTION + RegistryConstants.PATH_SEPARATOR + RESOURCE_MIME_TYPE_INDEX;

    if (!configSystemRegistry.resourceExists(resourcePath)) {
      resource = configSystemRegistry.newCollection();
    } else {
      resource = configSystemRegistry.get(resourcePath);
      Properties properties = resource.getProperties();
      if (properties.size() > 0) {
        Set<Object> keySet = properties.keySet();
        for (Object key : keySet) {
          if (key instanceof String) {
            String ext = (String) key;
            if (RegistryUtils.isHiddenProperty(ext)) {
              continue;
            }
            String value = resource.getProperty(ext);
            String mediaTypeMapping = ext + ":" + value;
            if (mediaTypeString == null) {
              mediaTypeString = mediaTypeMapping;
            } else {
              mediaTypeString = mediaTypeString + "," + mediaTypeMapping;
            }
          }
        }
      }
      registryContext.setResourceMediaTypes(mediaTypeString);
      return mediaTypeString;
    }

    BufferedReader reader;
    try {
      File mimeFile = getMediaTypesFile();
      reader = new BufferedReader(new InputStreamReader(new FileInputStream(mimeFile)));
    } catch (Exception e) {
      String msg =
          "Failed to read the the media type definitions file. Only a limited "
              + "set of media type definitions will be populated. ";
      log.error(msg, e);
      mediaTypeString = "txt:text/plain,jpg:image/jpeg,gif:image/gif";
      registryContext.setResourceMediaTypes(mediaTypeString);
      return mediaTypeString;
    }

    try {
      while (reader.ready()) {
        String mediaTypeData = reader.readLine().trim();
        if (mediaTypeData.startsWith("#")) {
          // ignore the comments
          continue;
        }

        if (mediaTypeData.length() == 0) {
          // ignore the blank lines
          continue;
        }

        // mime.type file delimits media types:extensions by tabs. if there is no
        // extension associated with a media type, there are no tabs in the line. so we
        // don't need such lines.
        if (mediaTypeData.indexOf('\t') > 0) {

          String[] parts = mediaTypeData.split("\t+");
          if (parts.length == 2 && parts[0].length() > 0 && parts[1].length() > 0) {

            // there can multiple extensions associated with a single media type. in
            // that case, extensions are delimited by a space.
            String[] extensions = parts[1].trim().split(" ");
            for (String extension : extensions) {
              if (extension.length() > 0) {
                String mediaTypeMapping = extension + ":" + parts[0];
                resource.setProperty(extension, parts[0]);
                if (mediaTypeString == null) {
                  mediaTypeString = mediaTypeMapping;
                } else {
                  mediaTypeString = mediaTypeString + "," + mediaTypeMapping;
                }
              }
            }
          }
        }
      }
      resource.setDescription(
          "This collection contains the media Types available for "
              + "resources on the Registry. Add, Edit or Delete properties to Manage Media "
              + "Types.");
      Resource collection = configSystemRegistry.newCollection();
      collection.setDescription(
          "This collection lists the media types available on the "
              + "Registry Server. Before changing an existing media type, please make sure "
              + "to alter existing resources/collections and related configuration details.");
      configSystemRegistry.put(MIME_TYPE_COLLECTION, collection);
      configSystemRegistry.put(resourcePath, resource);

    } catch (IOException e) {
      String msg = "Could not read the media type mappings file from the location: ";
      throw new RegistryException(msg, e);

    } finally {
      try {
        reader.close();
      } catch (IOException ignore) {
      }
    }
    registryContext.setResourceMediaTypes(mediaTypeString);
    return mediaTypeString;
  }