/*

 * reserved comment block

 * DO NOT REMOVE OR ALTER!

 */

/*

 * 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 com.sun.org.apache.xml.internal.security.utils.resolver;

import java.util.HashMap;

import java.util.Map;

import com.sun.org.apache.xml.internal.security.signature.XMLSignatureInput;

import org.w3c.dom.Attr;

/**

 * During reference validation, we have to retrieve resources from somewhere.

 *

 * @author $Author: mullan $

 */

public abstract class ResourceResolverSpi {

   /** {@link java.util.logging} logging facility */

    static java.util.logging.Logger log =

        java.util.logging.Logger.getLogger(

                    ResourceResolverSpi.class.getName());

   /** Field _properties */

   protected java.util.Map<String,String> _properties = null;

   /**

    * This is the workhorse method used to resolve resources.

    *

    * @param uri

    * @param BaseURI

    * @return the resource wrapped arround a XMLSignatureInput

    *

    * @throws ResourceResolverException

    */

   public abstract XMLSignatureInput engineResolve(Attr uri, String BaseURI)

      throws ResourceResolverException;

   /**

    * Method engineSetProperty

    *

    * @param key

    * @param value

    */

   public void engineSetProperty(String key, String value) {

          if (_properties==null) {

                  _properties=new HashMap<String,String>();

          }

      this._properties.put(key, value);

   }

   /**

    * Method engineGetProperty

    *

    * @param key

    * @return the value of the property

    */

   public String engineGetProperty(String key) {

          if (_properties==null) {

                        return null;

          }

      return this._properties.get(key);

   }

   /**

    *

    * @param properties

    */

   public void engineAddProperies(Map<String,String> properties) {

          if (properties!=null) {

                  if (_properties==null) {

                          _properties=new HashMap<String,String>();

                  }

                  this._properties.putAll(properties);

          }

   }

   /**

    * Tells if the implementation does can be reused by several threads safely.

    * It normally means that the implemantation does not have any member, or there is

    * member change betwen engineCanResolve & engineResolve invocations. Or it mantians all

    * member info in ThreadLocal methods.

    */

   public boolean engineIsThreadSafe() {

           return false;

   }

   /**

    * This method helps the {@link ResourceResolver} to decide whether a

    * {@link ResourceResolverSpi} is able to perform the requested action.

    *

    * @param uri

    * @param BaseURI

    * @return true if the engine can resolve the uri

    */

   public abstract boolean engineCanResolve(Attr uri, String BaseURI);

   /**

    * Method engineGetPropertyKeys

    *

    * @return the property keys

    */

   public String[] engineGetPropertyKeys() {

      return new String[0];

   }

   /**

    * Method understandsProperty

    *

    * @param propertyToTest

    * @return true if understands the property

    */

   public boolean understandsProperty(String propertyToTest) {

      String[] understood = this.engineGetPropertyKeys();

      if (understood != null) {

         for (int i = 0; i < understood.length; i++) {

            if (understood[i].equals(propertyToTest)) {

               return true;

            }

         }

      }

      return false;

   }

   /**

    * Fixes a platform dependent filename to standard URI form.

    *

    * @param str The string to fix.

    *

    * @return Returns the fixed URI string.

    */

   public static String fixURI(String str) {

      // handle platform dependent strings

      str = str.replace(java.io.File.separatorChar, '/');

      if (str.length() >= 4) {

         // str =~ /^\W:\/([^/])/ # to speak perl ;-))

         char ch0 = Character.toUpperCase(str.charAt(0));

         char ch1 = str.charAt(1);

         char ch2 = str.charAt(2);

         char ch3 = str.charAt(3);

         boolean isDosFilename = ((('A' <= ch0) && (ch0 <= 'Z'))

                                  && (ch1 == ':') && (ch2 == '/')

                                  && (ch3 != '/'));

         if (isDosFilename) {

            if (log.isLoggable(java.util.logging.Level.FINE))

                log.log(java.util.logging.Level.FINE, "Found DOS filename: " + str);

         }

      }

      // Windows fix

      if (str.length() >= 2) {

         char ch1 = str.charAt(1);

         if (ch1 == ':') {

            char ch0 = Character.toUpperCase(str.charAt(0));

            if (('A' <= ch0) && (ch0 <= 'Z')) {

               str = "/" + str;

            }

         }

      }

      // done

      return str;

   }

}