/**
    * Copyright 2010 The Kuali Foundation Licensed under the
    * Educational Community 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.osedu.org/licenses/ECL-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.kuali.student.common.search.service.impl;
  
  import java.util.ArrayList;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  import org.apache.log4j.Logger;
  import org.kuali.student.common.exceptions.OperationFailedException;
  import org.kuali.student.common.search.dto.SearchRequest;
  import org.kuali.student.common.search.dto.SearchResult;
  import org.kuali.student.common.search.dto.SearchTypeInfo;
  import org.kuali.student.common.search.service.SearchDispatcher;
  import org.kuali.student.common.search.service.SearchService;
  
  public class SearchDispatcherImpl implements SearchDispatcher{
  	final Logger LOG = Logger.getLogger(SearchDispatcherImpl.class);
  	
  	private List<SearchService> services;
  	
  	//Map of search key->service
  	private Map<String,SearchService> serviceMap = null;
  	
  	
  	
  	public SearchDispatcherImpl() {
  		super();
  	}
  
  	public SearchDispatcherImpl(SearchService... services){
  		super();
  		this.services = new ArrayList<SearchService>();
  		if(services!=null){
  			for(SearchService service:services){
  				this.services.add(service);
  			}
  		}
  	}
  	
  	public synchronized void init(){
  		if(serviceMap==null){
  			serviceMap = new HashMap<String,SearchService>();
  			
  			//Look through each service, grab it's search keys and add them to the map
  			for(SearchService service:services){
  				if(null==service){
  					LOG.warn("Null service passed to SearchDelegator");
  				}else{
  					try {
  						List<SearchTypeInfo> searchTypes = service.getSearchTypes();
  						if(searchTypes!=null){
  							for(SearchTypeInfo searchType:searchTypes){
  								serviceMap.put(searchType.getKey(),service);
  							}
  						}
  					} catch (OperationFailedException e) {
  						LOG.warn("Error getting searchTypes",e);
  					}
  				}
  			}
  		}
  	}
  	
  	
  	/**
  	 * Delegates to the service responsible for the given search type key
  	 * @param searchRequest
  	 * @return The searchResult from the delegated search or null
  	 */
  	public SearchResult dispatchSearch(SearchRequest searchRequest) {
  		//Lazy Load service map.  THis might cause synchronization issues?
  		//Needed because of circular bean dependencies... dispatch->serviceImpl->searchMgr->crossSvcMgr->dispatch
  		if(serviceMap==null){
  			init();
  		}
  		//Lookup which service to call for given search key and do the search
  		if(searchRequest != null){
  			String searchKey = searchRequest.getSearchKey();
  			SearchService searchService = serviceMap.get(searchKey);
  			if(searchService != null){
  				SearchResult searchResult;
  				try {
  					searchResult = searchService.search(searchRequest);
  				} catch (Exception e) {
 					LOG.warn("Error invoking search",e);
 					return null;
 				}
 				return searchResult;
 			}
 			LOG.error("Error Dispatching, Search Service not found for search key:"+searchRequest.getSearchKey());
 		}
 		return null;
 	}
 
 	public void setServices(List<SearchService> services) {
 		this.services = services;
 	}
 }