/*

  * This software is licensed under the Apache License, Version 2.0

  * (the "License") agreement; 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 net.admin4j.ui.filters.consolidator;

 import java.util.Arrays;

 import java.util.HashSet;

 import java.util.Properties;

 import java.util.Set;

 import javax.servlet.FilterConfig;

 import javax.servlet.ServletConfig;

 import javax.servlet.ServletException;

 import javax.servlet.http.HttpServletRequest;

 import net.admin4j.deps.commons.lang3.StringUtils;

 import net.admin4j.deps.commons.lang3.Validate;

 /**

  * Consolidates RESTful web service requests for performance tracking purposes.

  *

  * <p>

  * Configuration options for this consolidator are as follows:

  * </p>

  * <li>rest.resource.tokens -- comma delimited list of REST resource identifiers

  * (e.g. "students/classes/charges").</li> <li>rest.service.uri.prefix -- URI

  * prefix used for publishing RESTful web services (e.g. "/services").</li>

  *

  * @author D. Ashmore

  * @since 1.0.4-rc1

  */

 public class RestServiceHttpRequestConsolidator implements

 HttpRequestConsolidator {

         protected static final String PARM_REST_RESOURCE_TOKENS = "rest.resource.tokens";

         protected static final String PARM_REST_SERVICE_URI_PREFIX = "rest.service.uri.prefix";

         private final Set<String> serviceResourceTokenSet = new HashSet<String>();

         private String restServiceURLPrefix = null;

         public String categorize(HttpServletRequest request) {

                 // Only consolidate RESTful web service calls. Leave others alone.

                 if (!request.getRequestURI()

                                 .contains(restServiceURLPrefix)) {

                         return request.getRequestURI();

                 }

                 String localUri = StringUtils.substringAfter(request.getRequestURI(),

                                 restServiceURLPrefix);

                 String localPrefix = StringUtils.substringBefore(

                                 request.getRequestURI(), restServiceURLPrefix)

                                 + restServiceURLPrefix;

                 if (localPrefix.endsWith("/")) {

                         localPrefix = StringUtils.substringBeforeLast(localPrefix, "/");

                 }

                 String[] requestUriParts = StringUtils.split(localUri, '/');

                 StringBuilder builder = new StringBuilder(localPrefix);

                 for (int i = 0; i < requestUriParts.length; i++) {

                         builder.append("/");

                         if (serviceResourceTokenSet.contains(requestUriParts[i])) {

                                 builder.append(requestUriParts[i]);

                         }

                         else { // it's a REST resource identifier

                                 builder.append("*");

                         }

                 }

                 builder.append("--");

                 builder.append(request.getMethod());

                 return builder.toString();

         }

         public void configure(FilterConfig config) throws ServletException {

                 this.configureRestResourceTokens(config.getInitParameter(PARM_REST_RESOURCE_TOKENS));

                 this.configureRestServicePrefix(config.getInitParameter(PARM_REST_SERVICE_URI_PREFIX));

         }

         public void configure(ServletConfig config) throws ServletException {

                 this.configureRestResourceTokens(config.getInitParameter(PARM_REST_RESOURCE_TOKENS));

                 this.configureRestServicePrefix(config.getInitParameter(PARM_REST_SERVICE_URI_PREFIX));

         }

         public void configure(String namePrefix, Properties config) {

                 this.configureRestResourceTokens((String) config.get(PARM_REST_RESOURCE_TOKENS));

                 this.configureRestServicePrefix((String) config.get(PARM_REST_SERVICE_URI_PREFIX));

         }

         protected void configureRestResourceTokens(String restResourceTokenStr) {

                 Validate.notEmpty(restResourceTokenStr,

                                 "Null or missing configuration property %s",

                                 PARM_REST_RESOURCE_TOKENS);

                 String[] resourceTokens = StringUtils.split(restResourceTokenStr, ',');

                 for (int i = 0; i < resourceTokens.length; i++) {

                         resourceTokens[i] = resourceTokens[i].trim();

                 }

                 serviceResourceTokenSet.addAll(Arrays.asList(resourceTokens));

                 Validate.notEmpty(serviceResourceTokenSet,

                                 "Null or blank serviceResourceTokenSet not allowed.");

         }

         protected void configureRestServicePrefix(String restServicePrefix) {

                 this.restServiceURLPrefix = restServicePrefix;

                 Validate.notEmpty(restServicePrefix,

                                 "Null or missing configuration property %s",

                                 PARM_REST_SERVICE_URI_PREFIX);

         }

 }