/*
    * Copyright 2005,2009 Ivan SZKIBA
    *
    * 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.ini4j;
  
  import java.io.InputStream;
  
  import java.net.URI;
  import java.net.URL;
  
  import java.util.Properties;
  import java.util.prefs.Preferences;
  import java.util.prefs.PreferencesFactory;
  
  public class IniPreferencesFactory implements PreferencesFactory
  {
      public static final String PROPERTIES = "ini4j.properties";
      public static final String KEY_USER = "org.ini4j.prefs.user";
      public static final String KEY_SYSTEM = "org.ini4j.prefs.system";
      private Preferences _system;
      private Preferences _user;
  
      @Override public synchronized Preferences systemRoot()
      {
          if (_system == null)
          {
              _system = newIniPreferences(KEY_SYSTEM);
          }
  
          return _system;
      }
  
      @Override public synchronized Preferences userRoot()
      {
          if (_user == null)
          {
              _user = newIniPreferences(KEY_USER);
          }
  
          return _user;
      }
  
      String getIniLocation(String key)
      {
          String location = Config.getSystemProperty(key);
  
          if (location == null)
          {
              try
              {
                  Properties props = new Properties();
  
                  props.load(Thread.currentThread().getContextClassLoader().getResourceAsStream(PROPERTIES));
                  location = props.getProperty(key);
              }
              catch (Exception x)
              {
                  assert true;
              }
          }
  
          return location;
      }
  
      URL getResource(String location) throws IllegalArgumentException
      {
          try
          {
              URI uri = new URI(location);
              URL url;
  
              if (uri.getScheme() == null)
              {
                  url = Thread.currentThread().getContextClassLoader().getResource(location);
              }
              else
              {
                  url = uri.toURL();
              }
  
              return url;
          }
          catch (Exception x)
          {
              throw (IllegalArgumentException) new IllegalArgumentException().initCause(x);
          }
      }
 
     InputStream getResourceAsStream(String location) throws IllegalArgumentException
     {
         try
         {
             return getResource(location).openStream();
         }
         catch (Exception x)
         {
             throw (IllegalArgumentException) new IllegalArgumentException().initCause(x);
         }
     }
 
     Preferences newIniPreferences(String key)
     {
         Ini ini = new Ini();
         String location = getIniLocation(key);
 
         if (location != null)
         {
             try
             {
                 ini.load(getResourceAsStream(location));
             }
             catch (Exception x)
             {
                 throw (IllegalArgumentException) new IllegalArgumentException().initCause(x);
             }
         }
 
         return new IniPreferences(ini);
     }
 }