/*
    * The baseCode project
    *
    * Copyright (c) 2009 University of British Columbia
    *
    * 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 ubic.basecode.util;
  
  import java.util.Iterator;
  
  import org.apache.commons.configuration2.CompositeConfiguration;
  import org.apache.commons.configuration2.PropertiesConfiguration;
  import org.apache.commons.configuration2.SystemConfiguration;
  import org.apache.commons.configuration2.ex.ConfigurationException;
  import org.apache.commons.configuration2.io.FileHandler;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * Configuration of ontology services and other things.
   *
   * @author paul
   *
   */
  public class Configuration {
  
      private static CompositeConfiguration config;
  
      /**
       * Name of the resource containing defaults
       */
      private static final String DEFAULT_CONFIGURATION = "ontology.properties";
  
      private static Logger log = LoggerFactory.getLogger( Configuration.class );
  
      /**
       * The name of the file users can use to customize.
       */
      private static final String USER_CONFIGURATION = "basecode.properties";
  
      static {
  
          config = new CompositeConfiguration();
          config.addConfiguration( new SystemConfiguration() );
  
          /*
           * the order matters - first come, first serve. Items added later do not overwrite items defined earlier. Thus
           * the user configuration has to be listed first.
           */
  
          try {
              // purely for backwards compatibility, if the user hasn't set up ontology.properties.
              PropertiesConfiguration pc = new PropertiesConfiguration();
              FileHandler handler = new FileHandler( pc );
              handler.setFileName( "Gemma.properties" );
              handler.load();
              config.addConfiguration( pc );
          } catch ( ConfigurationException e ) {
          }
  
          try {
              PropertiesConfiguration pc = new PropertiesConfiguration();
              FileHandler handler = new FileHandler( pc );
              handler.setFileName( USER_CONFIGURATION );
              handler.load();
              config.addConfiguration( pc );
          } catch ( ConfigurationException e ) {
          }
  
          try {
              PropertiesConfiguration pc = new PropertiesConfiguration();
              FileHandler handler = new FileHandler( pc );
              handler.setFileName( DEFAULT_CONFIGURATION );
              handler.load();
              config.addConfiguration( pc );
          } catch ( ConfigurationException e ) {
              log.error( DEFAULT_CONFIGURATION + " is missing, ontology loading may fail" );
          }
  
          // step through the result and do a final round of variable substitution
          for ( Iterator<String> it = config.getKeys(); it.hasNext(); ) {
              String key = it.next();
              String property = config.getString( key );
              if ( property != null && property.startsWith( "${" ) && property.endsWith( "}" ) ) {
                  String keyToSubstitute = property.substring( 2, property.length() - 1 );
                  String valueToSubstitute = config.getString( keyToSubstitute );
                  log.debug( key + "=" + property + " -> " + valueToSubstitute );
                 config.setProperty( key, valueToSubstitute );
             }
         }
 
     }
 
     /**
      * @param key
      * @return
      */
     public static boolean getBoolean( String key ) {
         return config.getBoolean( key, false );
     }
 
     /**
      * @param key
      * @return
      */
     public static String getString( String key ) {
         return config.getString( key );
     }
 
     /**
      * @param key
      * @return
      */
     public static void setString( String key, Object value ) {
         config.setProperty( key, value );
     }
 }