/**
    *       Copyright 2010 Newcastle University
    *
    *          http://research.ncl.ac.uk/smart/
    *
    * Licensed to the Apache Software Foundation (ASF) under one or more
    * contributor license agreements.  See the NOTICE file distributed with
    * this work for additional information regarding copyright ownership.
    * The ASF licenses this file to You 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.apache.amber.oauth2.client.validator;
  
  import java.util.ArrayList;
  import java.util.HashMap;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Map;
  import java.util.Set;
  
  import org.apache.amber.oauth2.common.error.OAuthError;
  import org.apache.amber.oauth2.common.exception.OAuthProblemException;
  import org.apache.amber.oauth2.common.utils.OAuthUtils;
  import org.apache.amber.oauth2.client.response.OAuthClientResponse;
  import org.apache.amber.oauth2.common.OAuth;
  
  /**
   *
   *
   *
   */
  public abstract class OAuthClientValidator {
  
      protected Map<String, String[]> requiredParams = new HashMap<String, String[]>();
      protected List<String> notAllowedParams = new ArrayList<String>();
  
      public void validate(OAuthClientResponse response) throws OAuthProblemException {
          validateErrorResponse(response);
          validateParameters(response);
      }
  
      public void validateParameters(OAuthClientResponse response) throws OAuthProblemException {
          validateRequiredParameters(response);
          validateNotAllowedParameters(response);
      }
  
      public void validateErrorResponse(OAuthClientResponse response) throws OAuthProblemException {
          String error = response.getParam(OAuthError.OAUTH_ERROR);
          if (!OAuthUtils.isEmpty(error)) {
              String errorDesc = response.getParam(OAuthError.OAUTH_ERROR_DESCRIPTION);
              String errorUri = response.getParam(OAuthError.OAUTH_ERROR_URI);
              String state = response.getParam(OAuth.OAUTH_STATE);
              throw OAuthProblemException.error(error).description(errorDesc).uri(errorUri).state(state);
          }
      }
  
  
      public void validateRequiredParameters(OAuthClientResponse response) throws OAuthProblemException {
          Set<String> missingParameters = new HashSet<String>();
  
          for (Map.Entry<String, String[]> requiredParam : requiredParams.entrySet()) {
              String paramName = requiredParam.getKey();
              String val = response.getParam(paramName);
              if (OAuthUtils.isEmpty(val)) {
                  missingParameters.add(paramName);
              } else {
                  String[] dependentParams = requiredParam.getValue();
                  if (!OAuthUtils.hasEmptyValues(dependentParams)) {
                      for (String dependentParam : dependentParams) {
                          val = response.getParam(dependentParam);
                          if (OAuthUtils.isEmpty(val)) {
                              missingParameters.add(dependentParam);
                          }
                      }
                  }
              }
          }
  
          if (!missingParameters.isEmpty()) {
              throw OAuthUtils.handleMissingParameters(missingParameters);
          }
      }
  
      public void validateNotAllowedParameters(OAuthClientResponse response) throws OAuthProblemException {
          List<String> notAllowedParameters = new ArrayList<String>();
          for (String requiredParam : notAllowedParams) {
              String val = response.getParam(requiredParam);
              if (!OAuthUtils.isEmpty(val)) {
                  notAllowedParameters.add(requiredParam);
             }
         }
         if (!notAllowedParameters.isEmpty()) {
             throw OAuthUtils.handleNotAllowedParametersOAuthException(notAllowedParameters);
         }
     }
 
 
 }