/*
    * Copyright 2012-2013 smartics, Kronseder & Reiner GmbH
    *
    * 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 de.smartics.properties.api.core.security;
  
  import static de.smartics.properties.api.core.security.SecurityConfigurationLoader.SECURITY_ALGORITHM;
  import static de.smartics.properties.api.core.security.SecurityConfigurationLoader.SECURITY_ID;
  import static de.smartics.properties.api.core.security.SecurityConfigurationLoader.SECURITY_KEY;
  import static de.smartics.properties.api.core.security.SecurityConfigurationLoader.SECURITY_PROVIDER;
  import static de.smartics.properties.api.core.security.SecurityConfigurationLoader.SECURITY_TRANSFORMATION;
  
  import java.io.Serializable;
  import java.util.Properties;
  
  import javax.naming.Context;
  import javax.naming.InitialContext;
  
  import de.smartics.properties.api.core.app.JndiContext;
  
  /**
   * Responsible to read configuration properties from a JNDI to secure property
   * values.
   */
  class SecurityConfigurationJndiLoader implements Serializable
  {
    // ********************************* Fields *********************************
  
    // --- constants ------------------------------------------------------------
  
    /**
     * The class version identifier.
     * <p>
     * The value of this constant is {@value}.
     * </p>
     */
    private static final long serialVersionUID = 1L;
  
    // --- members --------------------------------------------------------------
  
    // ****************************** Initializer *******************************
  
    // ****************************** Constructors ******************************
  
    /**
     * Default constructor.
     */
    SecurityConfigurationJndiLoader()
    {
    }
  
    // ****************************** Inner Classes *****************************
  
    // ********************************* Methods ********************************
  
    // --- init -----------------------------------------------------------------
  
    // --- get&set --------------------------------------------------------------
  
    // --- business -------------------------------------------------------------
  
    /**
     * Loads the security configuration.
     *
     * @return the security configuration.
     * @throws IllegalStateException on any problem reading the security
     *           properties.
     */
    Properties load() throws IllegalStateException
    {
      try
      {
  
        final Context context = new InitialContext();
        final JndiContext lookup = JndiContext.boot(context);
        final String sourceId = lookup.getSourceId();
        final String key = lookup.lookup(SECURITY_KEY);
        final String provider = lookup.lookup(SECURITY_PROVIDER);
        final String algorithm = lookup.lookup(SECURITY_ALGORITHM);
        final String transformation = lookup.lookup(SECURITY_TRANSFORMATION);
        try
        {
          final Properties properties = new Properties();
          properties.setProperty(SECURITY_ID, sourceId);
          properties.setProperty(SECURITY_KEY, key);
          properties.setProperty(SECURITY_PROVIDER, provider);
          properties.setProperty(SECURITY_ALGORITHM, algorithm);
          properties.setProperty(SECURITY_TRANSFORMATION, transformation);
 
         return properties;
       }
       catch (final Exception e)
       {
         throw new IllegalStateException(String.format(
             "Cannot configure security module from JNDI %s: %s", sourceId,
             e.getMessage(), e));
       }
     }
     catch (final Exception e)
     {
       throw new IllegalStateException(String.format(
           "Cannot configure security module: %s", e.getMessage(), e));
     }
   }
 
   // --- object basics --------------------------------------------------------
 
 }