package org.kuali.student.common.ui.client.service;
   
   import com.google.gwt.user.client.rpc.AsyncCallback;
   import org.kuali.student.core.search.dto.SearchRequest;
   import org.kuali.student.core.search.dto.SearchResult;
   
   import java.util.HashMap;
   
   /**
   * @author Igor
   */
  public class CachingSearchService implements SearchRpcServiceAsync {
  
      private static CachingSearchService INSTANCE = new CachingSearchService();
  
      private SearchRpcServiceAsync searchService = SearchServiceFactory.getSearchService();
  
      private HashMap<SearchRequest, SearchResult> cache = new HashMap<SearchRequest, SearchResult>();
  
      public static CachingSearchService getSearchService() {
          return INSTANCE;
      }
  
      @Override
      public void search(final SearchRequest searchRequest, final AsyncCallback<SearchResult> callback) {
          cachingSearch(searchRequest, callback);
      }
  
      @Override
      public void cachingSearch(final SearchRequest searchRequest, final AsyncCallback<SearchResult> callback) {
          if (cache.containsKey(searchRequest)) {
              callback.onSuccess(cache.get(searchRequest));
          } else {
              searchService.cachingSearch(searchRequest, new AsyncCallback<SearchResult>() {
                  @Override
                  public void onFailure(Throwable caught) {
                      callback.onFailure(caught);
                  }
  
                  @Override
                  public void onSuccess(SearchResult searchResult) {
                      cache.put(searchRequest, searchResult);
                      callback.onSuccess(searchResult);
                  }
              });
          }
      }
  }