/*!
* This program is free software; you can redistribute it and/or modify it under the
* terms of the GNU Lesser General Public License, version 2.1 as published by the Free Software
* Foundation.
*
* You should have received a copy of the GNU Lesser General Public License along with this
* program; if not, you can obtain a copy at http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html
* or from the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
* without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU Lesser General Public License for more details.
*
* Copyright (c) 2002-2013 Pentaho Corporation..  All rights reserved.
*/

package org.pentaho.reporting.designer.core.auth;

import org.pentaho.reporting.designer.core.settings.WorkspaceSettings;
import org.pentaho.reporting.designer.core.util.exceptions.UncaughtExceptionsModel;

import java.util.Collection;
import java.util.LinkedHashSet;
import java.util.prefs.BackingStoreException;
import java.util.prefs.Preferences;

/**
 * Todo: Document me!
 *
 * @author Thomas Morgner.
 */
public class PasswordPolicyManager {
  private static PasswordPolicyManager instance;

  public static synchronized PasswordPolicyManager getInstance() {
    if ( instance == null ) {
      instance = new PasswordPolicyManager();
    }
    return instance;
  }

  private Preferences properties;
  private LinkedHashSet<String> hosts;

  private PasswordPolicyManager() {
    final Preferences preferences = Preferences.userNodeForPackage( PasswordPolicyManager.class );
    properties = preferences.node( "PasswordPolicy" ); // NON-NLS

    hosts = new LinkedHashSet<String>();
    try {
      hosts.addAll( getFilesAsList() );
    } catch ( BackingStoreException e ) {
      UncaughtExceptionsModel.getInstance().addException( e );
    }
  }

  public boolean isPasswordStoringAllowed( final String url ) {
    if ( WorkspaceSettings.getInstance().isRememberPasswords() == false ) {
      return false;
    }

    // check the blacklist for urls to NOT store passwords for
    // if it is in the list, return false. otherwise return true.
    return !hosts.contains( url );
  }

  public void setPasswordStoringAllowed( final String url, final boolean allowed ) {
    if ( !allowed ) {
      if ( hosts.add( url ) ) {
        try {
          store( hosts );
        } catch ( BackingStoreException e ) {
          UncaughtExceptionsModel.getInstance().addException( e );
        }
      }
    } else {
      if ( hosts.remove( url ) ) {
        try {
          store( hosts );
        } catch ( BackingStoreException e ) {
          UncaughtExceptionsModel.getInstance().addException( e );
        }
      }
    }
  }

  public String[] getManagedHosts() {
    return hosts.toArray( new String[ hosts.size() ] );
  }

  private LinkedHashSet<String> getFilesAsList()
    throws BackingStoreException {
    final LinkedHashSet<String> retval = new LinkedHashSet<String>();
    final String[] strings = properties.keys();
    final int maxFiles = Math.min( 10, strings.length );
    for ( int i = 0; i < maxFiles; i++ ) {
      final String key = strings[ i ];
      final String file = properties.get( key, null );

      if ( file == null ) {
        continue;
      }
      retval.add( file );
    }

    if ( retval.size() != strings.length ) {
      // store ..
      store( retval );
    }
    return retval;
  }

  private void store( final Collection<String> files ) throws BackingStoreException {
    properties.clear();
    final String[] strings = files.toArray( new String[ files.size() ] );
    for ( int i = 0; i < strings.length; i++ ) {
      final String string = strings[ i ];
      properties.put( String.valueOf( i ), string );
    }
    properties.flush();
  }

}