/*
 * 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.service.um.useradmin.impl;

import java.util.Dictionary;
import java.util.Enumeration;
import java.util.Vector;
import java.security.AccessController;

import org.osgi.service.useradmin.Group;
import org.osgi.service.useradmin.Role;


/**
 * Implementation of Group.
 *
 * @author  Gatespace AB
 * @version $Revision: 1.1.1.1 $
 */
public class GroupImpl extends UserImpl implements Group {
  protected Vector basicMembers = new Vector();
  protected Vector reqMembers = new Vector();

  GroupImpl( String name, UserAdminImpl uai ) {
    super( name, uai );
  }
  
  
  boolean hasRole( String roleName, String user,
		   Dictionary context, Vector visited ) {
    
    //System.out.print( name + "-Group.hasRole roleName: " + roleName );
    //System.out.print( "  user: " + user );
    //System.out.println( "  visited: " + visited );

    if (visited.contains( this )) {
      // with ANYONE, we get loops as sone as ANYONE is added to a group
      // stop and return false
      return false;
    }
    visited.addElement( this );

    for (Enumeration en = reqMembers.elements(); en.hasMoreElements();) {
      RoleImpl member = (RoleImpl)en.nextElement();
      if (!member.hasMember( user, context, new Vector() )) {
	return false;
      }
    }

    return super.hasRole( roleName, user, context, visited );
  }


  boolean hasMember( String user, Dictionary context, Vector visited ) {

    //System.out.print( name + "-Group.hasMember user: " + user );
    //System.out.println( "  visited: " + visited );

    // for the case where user is a group
    if (name.equals( user )) {
      return true;
    }

    if( visited.contains( this ) ) {
      return false;
      //throw new IllegalStateException( "UserAdmin database loops: " +
      //			       name + " points back to itself.");
    }
    visited.addElement( this );

    for (Enumeration en = reqMembers.elements(); en.hasMoreElements();) {
      RoleImpl member = (RoleImpl)en.nextElement();
      if( !member.hasMember( user, context, visited ) ) {
	return false;
      }
    }
    
    for (Enumeration en = basicMembers.elements(); en.hasMoreElements();) {
      RoleImpl member = (RoleImpl)en.nextElement();
      if( member.hasMember( user, context, visited ) ) {
	return true;
      }
    }

    return false;
  }

  void remove() {
    super.remove();
    for (Enumeration en = basicMembers.elements(); en.hasMoreElements();) {
      RoleImpl role = (RoleImpl)en.nextElement();
      role.basicMemberOf.removeElement( this );
    }
    for (Enumeration en = reqMembers.elements(); en.hasMoreElements();) {
      RoleImpl role = (RoleImpl)en.nextElement();
      role.reqMemberOf.removeElement( this );
    }
    
  }

  public int getType() {
    return Role.GROUP;
  }
  
  //- interface org.osgi.service.useradmin.Group ----------------------------- 
  public boolean addMember( Role role ) {
    if( UserAdminImpl.checkPermissions ) {
      AccessController.checkPermission(UserAdminImpl.adminPermission);
    }
    if (basicMembers.contains( role )){
      return false;
    }
     
    basicMembers.addElement( role );
    ((RoleImpl)role).basicMemberOf.addElement( this );
    
    return true;
  }
  
  public boolean addRequiredMember( Role role ) {
    if( UserAdminImpl.checkPermissions ) {
      AccessController.checkPermission(UserAdminImpl.adminPermission);
    }
    if (reqMembers.contains( role )) {
      return false;
    }

    reqMembers.addElement( role );
    ((RoleImpl)role).reqMemberOf.addElement( this );
    
    return true;
  }
  
  public boolean removeMember( Role role ) {
    if( UserAdminImpl.checkPermissions ) {
      AccessController.checkPermission(UserAdminImpl.adminPermission);
    }
    if (basicMembers.removeElement( role )) {
      ((RoleImpl)role).basicMemberOf.removeElement( this );
	
      return true;
    }
    if (reqMembers.removeElement( role )) {
      ((RoleImpl)role).reqMemberOf.removeElement( this );
      
      return true;
    }
    
    return false;
  }

  public Role[] getMembers() {
    Vector v = new Vector();
    for (Enumeration en = basicMembers.elements(); en.hasMoreElements();) {
      v.addElement(en.nextElement());
    }

    if (v.size() == 0)
      return null;

    Role[] result = new Role[v.size()];
    v.copyInto( result );
    return result;
  }

  public Role[] getRequiredMembers() {
    Vector v = new Vector();
    for (Enumeration en = reqMembers.elements(); en.hasMoreElements();) {
      v.addElement(en.nextElement());
    }

    if (v.size() == 0)
      return null;

    Role[] result = new Role[v.size()];
    v.copyInto( result );
    return result;
  }
}