/*

  * Copyright 1999,2004 The Apache Software Foundation.

  * 

  * 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.apache.commons.latka.validators;

 import java.util.StringTokenizer;

 import org.apache.commons.latka.ValidationException;

 import org.apache.commons.latka.http.Response;

 /**

  * ResponseHeaderValidator validates response headers in 

  * an HTTP session.  Setting just the header name tests

  * for the existence of a header.  If you set the 

  * headerValue and there is more than one header of that

  * name, the validator matches on ANY header with that 

  * value.

  * 

  * @author Morgan Delagrange

  */

 public class ResponseHeaderValidator extends BaseConditionalValidator {

     // --------------------------------------------------------------- Attributes

     protected String _headerName  = null;

     protected String _headerValue = null;

     protected boolean _checkValue = false;

     protected static final String BARE_MESSAGE_EXISTENT_HEADER = " TO FIND HEADER IN RESPONSE";

     protected static final String BARE_MESSAGE_EQUAL_VALUES    = " THAT HEADER VALUES EQUAL:";

     // need to store the value of the tested header, in order

     // to generate the right exception

     protected String _actualValue = null;

     // ------------------------------------------------------------- Constructors

     /**

      * Constructs a validator for the given header with no label.

      * 

      * @param headerName Name of the header to validate

      */

     public ResponseHeaderValidator(String headerName) {

         this(null,headerName,true);

     }

     /**

      * Constructs a labeled validator for the given

      * header

      * 

      * @param label      name of the header to validate

      * @param headerName

      */

     public ResponseHeaderValidator(String label, String headerName) {

         this(label,headerName,true);

     }

     /**

      * Constructs a labeled validator for the given

      * header

      * 

      * @param label      name of the header to validate

      * @param headerName

      */

     public ResponseHeaderValidator(String label, String headerName, boolean condition) {

         super(label,condition);

         _headerName  = headerName;

     }

     /**

      * Sets the desired value of the header to be validated.

      * If this method is not called, then the validator will

      * only check for the existence of the header and

      * disregard its value.  

      * 

      * @param headerValue

      *               desired value of the header, or null to look for a

      *               header with the String value "null"

      */

     public void setHeaderValue(String headerValue) {

         _checkValue = true;

         if (headerValue == null) {

             headerValue = "null";

         }

         _headerValue = headerValue;

     }

     /**

      * Checks to see that the header exists, and also checks

      * its value if setHeaderValue(String) has been called

      * 

      * @param response The HTTP response to validate

      * @exception ValidationException

      *                   if the header does not meet the criteria of the test

      */

     public boolean assertTrue(Response response)

     throws ValidationException {

         _actualValue = response.getHeader(_headerName);

         if (_actualValue == null) {

             return false;

         }

         // if checkValue == false, we only care if the header exists

         if (_checkValue == false) {

             return true;

         }

         // check the entire value against the actual value

         if (_actualValue.equals(_headerValue)) {

             return true;

         }

         // if it does not match, see if the header has multiple values

         if (_actualValue.indexOf(",") != -1) {

             StringTokenizer tokenizer = new StringTokenizer(_actualValue,",");

             while (tokenizer.hasMoreTokens()) {

                 String token = tokenizer.nextToken().trim();

                 if (token.equals(_headerValue)) {

                     return true;

                 }

             }

         }

         return false;

     }

     public String generateBareExceptionMessage() {

         if (_actualValue == null) {

             return BARE_MESSAGE_EXISTENT_HEADER;

         } else {

             StringBuffer buffer = new StringBuffer(BARE_MESSAGE_EQUAL_VALUES);

             buffer.append(" EXPECTED: ");

             buffer.append(_headerValue);

             buffer.append(" RECEIVED: ");

             buffer.append(_actualValue);

             return buffer.toString();

         }

     }

 }