/*
    * Copyright 2004-2009 the original author or authors.
    *
    * Licensed under the Apache License, Version 2.0 (the "License");
    * 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 org.springmodules.validation.bean.context.web;
  
  import java.beans.PropertyEditorManager;
  
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  import org.springframework.util.AntPathMatcher;
  import org.springframework.util.PathMatcher;
  import org.springframework.web.servlet.ModelAndView;
  import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;
  import org.springmodules.validation.bean.context.ValidationContextUtils;
  
  /**
   * An interceptor that sets the validation context based on configured mappings of url patterns to validation context
   * tokens. This interceptor is the Spring MVC counterpart of the {@link ValidationContextFilter}.
   *
   * @author Uri Boness
   */
  public class ValidationContextHandlerInterceptor extends HandlerInterceptorAdapter {
  
      private final static Logger logger = LoggerFactory.getLogger(ValidationContextHandlerInterceptor.class);
  
      static {
          PropertyEditorManager.registerEditor(ValidationContextUrlMapping[].class,
                  ValidationContextUrlMappingArrayPropertyEditor.class);
      }
  
      private ValidationContextUrlMapping[] validationContextUrlMappings;
  
      private PathMatcher pathMatcher;
  
      public ValidationContextHandlerInterceptor() {
          validationContextUrlMappings = new ValidationContextUrlMapping[0];
          pathMatcher = new AntPathMatcher();
      }
  
      /**
       * Creates and sets the validation context based on the request URI. The validation context tokens are determined
       * by the configured {@link ValidationContextUrlMapping}'s.
       *
       * @see HandlerInterceptorAdapter#preHandle(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse, Object)
       * @see #setValidationContextUrlMappings(ValidationContextUrlMapping[])
       */
      public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
  
          String[] contextTokens = new String[0];
  
          for (int i=0; i<validationContextUrlMappings.length; i++) {
              String pattern = validationContextUrlMappings[i].getUrlPattern();
              if (pathMatcher.match(pattern, request.getRequestURI())) {
                  contextTokens = validationContextUrlMappings[i].getContextTokens();
                  break;
              }
          }
  
          if (logger.isInfoEnabled() && contextTokens.length == 0) {
              logger.info("No validation context url mapping matches url '" + request.getRequestURI() +
                      "'. Setting validation context without supported tokens...");
          }
  
          ValidationContextUtils.setContext(contextTokens);
  
  
          return true;
      }
  
      /**
       * Clears
       * @param request
       * @param response
       * @param handler
       * @param modelAndView
       * @throws Exception
       */
      public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
          ValidationContextUtils.clearContext();
      }
  
  
      //============================================== Setter/Getter =====================================================
 
     public ValidationContextUrlMapping[] getValidationContextUrlMappings() {
         return validationContextUrlMappings;
     }
 
     public void setValidationContextUrlMappings(ValidationContextUrlMapping[] validationContextUrlMappings) {
         this.validationContextUrlMappings = validationContextUrlMappings;
     }
 
     public PathMatcher getPathMatcher() {
         return pathMatcher;
     }
 
     public void setPathMatcher(PathMatcher pathMatcher) {
         this.pathMatcher = pathMatcher;
     }
 
 }