/**
    * Copyright 2014 Internet2
    *
    * 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 edu.internet2.middleware.grouper.scim;
  
  import edu.internet2.middleware.grouper.Group;
  import edu.internet2.middleware.grouper.Member;
  import edu.internet2.middleware.grouper.cfg.GrouperConfig;
  import org.apache.log4j.Logger;
  import org.apache.wink.client.ClientConfig;
  import org.apache.wink.client.ClientWebException;
  import org.apache.wink.client.handlers.ClientHandler;
  import org.apache.wink.client.Resource;
  import org.apache.wink.client.RestClient;
  import org.wso2.charon.core.client.SCIMClient;
  import org.wso2.charon.core.exceptions.BadRequestException;
  import org.wso2.charon.core.exceptions.CharonException;
  import org.wso2.charon.core.schema.SCIMConstants;
  import org.wso2.charon.samples.utils.CharonResponseHandler;
  import org.wso2.charon.utils.authentication.BasicAuthHandler;
  import org.wso2.charon.utils.authentication.BasicAuthInfo;
  
  //TODO -- should we be using groupID or groupName()?
  /**
   * Emits SCIM.  
   * @author David Langenberg <davel@uchicago.edu>
   */
  public class ScimEmitter {
  
    protected static Logger log = Logger.getLogger(ScimEmitter.class);
  
    protected SCIMClient scimClient;
    protected CharonResponseHandler crh;
    protected RestClient restClient;
    
    protected GrouperConfig gConf;
  
    private BasicAuthInfo encodedBasicAuthInfo;
  
  
    public ScimEmitter() {
  	gConf = GrouperConfig.retrieveConfig();
  	  
      ClientConfig config = new ClientConfig();
      crh = new CharonResponseHandler();
      config.handlers(new ClientHandler[]{crh});
      restClient = new RestClient(config);
  
      //create a apache wink ClientHandler to intercept and identify response messages  
      CharonResponseHandler responseHandler = new CharonResponseHandler();
      responseHandler.setSCIMClient(scimClient);
      //set the handler in wink client config  
      ClientConfig clientConfig = new ClientConfig();
      clientConfig.handlers(new ClientHandler[]{responseHandler});
      //create a wink rest client with the above config  
      restClient = new RestClient(clientConfig);
      //create resource endpoint to access group resource  
      Resource groupResource = restClient.resource(gConf.propertyValueString("scim.endpoint"));
  	
      BasicAuthInfo basicAuthInfo = new BasicAuthInfo();
      //set creds
      basicAuthInfo.setUserName(gConf.propertyValueString("scim.user"));
      basicAuthInfo.setPassword(gConf.propertyValueString("scim.password"));
  
      BasicAuthHandler basicAuthHandler = new BasicAuthHandler();
      encodedBasicAuthInfo = (BasicAuthInfo) basicAuthHandler.getAuthenticationToken(basicAuthInfo);
  
      scimClient = new SCIMClient();
    }
  
    /**
     * creates a SCIM Group out of a grouper group
     * @param group
     * @return 
     */
    public String createGroup(Group group) {
      try {
        
        org.wso2.charon.core.objects.Group scimGroup = scimClient.createGroup();
        
        scimGroup.setDisplayName(group.getDisplayName());
        scimGroup.setExternalId(group.getName());
        
        for(Member m : group.getMembers()){
          scimGroup.setMember(m.getSubjectId());
        }
        
       //create resource endpoint to access group resource  
       //no groupid appended to this one because that's somethign the server will handle
       Resource groupResource = restClient.resource(gConf.propertyValueString("scim.endpoint"));
       
       return groupResource.
               header(SCIMConstants.AUTHORIZATION_HEADER, encodedBasicAuthInfo.getAuthorizationHeader()).
               contentType(SCIMConstants.APPLICATION_JSON).accept(SCIMConstants.APPLICATION_JSON).
               post(String.class, scimClient.encodeSCIMObject(scimGroup, SCIMConstants.JSON));
     } catch (CharonException e) {
       throw new RuntimeException(e);
     } catch (ClientWebException e){
 		System.err.println(e.getMessage());
 		System.err.println(e.getResponse().getMessage());
 		log.error(e.getMessage(),e);
 		throw new RuntimeException(e);
 	}
   }
   
   /**
    * This updates a group which already exists in the SCIM endpoint.  According to the
    * SURFNet use-case, we can only send full-groups, not updates, so update will
    * for now be a delete & create operation
    * @param group
    * @return 
    */
   public String updateGroup(Group group){
     deleteGroup(group);
 	return createGroup(group);
   }
   
   /**
    * Retrieves the SCIM server's group representation of the Grouper group.
    * @param group grouper group to query the SCIM server for
    * @return 
    */
   public org.wso2.charon.core.objects.Group getGroup(Group group) {
     //todo -- should this be protected or private?
     //create resource endpoint to access a known user resource.
     Resource groupResource = restClient.resource(gConf.propertyValueString("scim.endpoint") + group.getName());
     String response = groupResource.
             header(SCIMConstants.AUTHORIZATION_HEADER, encodedBasicAuthInfo.getAuthorizationHeader()).
             contentType(SCIMConstants.APPLICATION_JSON).accept(SCIMConstants.APPLICATION_JSON)
             .get(String.class);
     try {
       org.wso2.charon.core.objects.Group scimGroup = (org.wso2.charon.core.objects.Group) scimClient.decodeSCIMResponse(response, SCIMConstants.JSON, 2);
       return scimGroup;
     } catch (BadRequestException e) {
       //TODO decide what to do
       throw new RuntimeException(e);
     } catch (CharonException e) {
       //TODO decide what to do
       throw new RuntimeException(e);
     }
 
   }
     
   public String deleteGroup(Group group) {
 
     //create resource endpoint to access group resource  
     //no groupid appended to this one because that's somethign the server will handle
     Resource groupResource = restClient.resource(gConf.propertyValueString("scim.endpoint") + group.getName());
 
     return groupResource.
             header(SCIMConstants.AUTHORIZATION_HEADER, encodedBasicAuthInfo.getAuthorizationHeader()).
             accept(SCIMConstants.APPLICATION_JSON).
             delete(String.class);
 
   }
 
 }