/*
 * Copyright (c) 2003, KNOPFLERFISH project
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following
 * conditions are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above
 *   copyright notice, this list of conditions and the following
 *   disclaimer in the documentation and/or other materials
 *   provided with the distribution.
 *
 * - Neither the name of the KNOPFLERFISH project nor the names of its
 *   contributors may be used to endorse or promote products derived
 *   from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package org.knopflerfish.bundle.prefs;

import org.osgi.framework.*;
import org.osgi.service.prefs.*;
import org.knopflerfish.service.log.LogRef;
import java.util.*;


public class PreferencesServiceImpl implements PreferencesService {
  Bundle bundle;

  static String USERS_BASE  = "users";
  static String SYSTEM_BASE = "system";

  String userBase;
  String systemBase;

  PrefsStorageFile systemStorage;

  // String -> PrefsStorageFile
  Map userStorage = new HashMap();

  PreferencesServiceImpl(Bundle bundle) {
    this.bundle = bundle;
    userBase   = USERS_BASE + "/" + bundle.getBundleId();
    systemBase = SYSTEM_BASE + "/" + bundle.getBundleId();
    systemStorage = new PrefsStorageFile(systemBase);
    //    systemStorage.bDebug = true;
  }

  public Preferences getSystemPreferences() {
    if (systemStorage.bStale) {
      systemStorage = new PrefsStorageFile(systemBase);
    }
    return systemStorage.getNode("", true);
  }

  public Preferences getUserPreferences(String name) {
    synchronized(userStorage) {
      PrefsStorageFile storage = (PrefsStorageFile)userStorage.get(name);
      if(storage == null || storage.bStale) {
	storage   = new PrefsStorageFile(userBase, name);
	userStorage.put(name, storage);
      }
      return storage.getNode("", true);
    }
  }
  
  // This implementation is wrong; it only returns live users!
  // I.e., users that have been asked for via getUserPreferences(name)
  // before the call to getUsers().
  public String[] getUsers() {
    synchronized(userStorage) {
      String[] names = new String[userStorage.size()];
      int i = 0;
      for(Iterator it = userStorage.entrySet().iterator(); it.hasNext();) {
        Map.Entry entry = (Map.Entry) it.next();
        PrefsStorageFile storage = (PrefsStorageFile)entry.getValue();
        if (!storage.bStale)
          names[i++] = (String)entry.getKey();
      }
      if (i!=names.length) {
        String[] tmp = new String[i];
        System.arraycopy( names, 0, tmp, 0, i );
        names = tmp;
      }
      
      return names;
    }    
  }

  void flush() {
    // userStorage.flush(null);
    systemStorage.flush(null);
  }
}