/*
    *  Licensed to the Apache Software Foundation (ASF) under one
    *  or more contributor license agreements.  See the NOTICE file
    *  distributed with this work for additional information
    *  regarding copyright ownership.  The ASF licenses this file
    *  to you 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.apache.directory.server.dhcp.store;
  
  
  import java.net.InetAddress;
  import java.net.UnknownHostException;
  import java.util.ArrayList;
  import java.util.HashMap;
  import java.util.Hashtable;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Map;
  
  import javax.naming.Context;
  import javax.naming.NamingEnumeration;
  import javax.naming.NamingException;
  import javax.naming.directory.Attribute;
  import javax.naming.directory.Attributes;
  import javax.naming.directory.DirContext;
  import javax.naming.directory.InitialDirContext;
  import javax.naming.directory.SearchControls;
  import javax.naming.directory.SearchResult;
  
  import org.apache.directory.api.ldap.model.constants.SchemaConstants;
  import org.apache.directory.server.dhcp.DhcpException;
  import org.apache.directory.server.dhcp.messages.HardwareAddress;
  import org.apache.directory.server.dhcp.options.OptionsField;
  import org.apache.directory.server.dhcp.service.Lease;
  
  
  /**
   * Very simple dummy/proof-of-concept implementation of a DhcpStore.
   * 
   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
   */
  public class SimpleDhcpStore extends AbstractDhcpStore
  {
      // a map of current leases
      private Map leases = new HashMap();
  
      private List subnets = new ArrayList();
  
  
      //This will suppress PMD.AvoidUsingHardCodedIP warnings in this class
      @SuppressWarnings("PMD.AvoidUsingHardCodedIP")
      public SimpleDhcpStore()
      {
          try
          {
              subnets.add( new Subnet( InetAddress.getByName( "192.168.168.0" ),
                  InetAddress.getByName( "255.255.255.0" ), InetAddress.getByName( "192.168.168.159" ), InetAddress
                      .getByName( "192.168.168.179" ) ) );
          }
          catch ( UnknownHostException e )
          {
              throw new RuntimeException( "Can't init", e );
          }
      }
  
  
      protected DirContext getContext() throws NamingException
      {
          Hashtable env = new Hashtable();
          env.put( Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.ldap.LdapCtxFactory" );
          env.put( Context.PROVIDER_URL, "ldap://localhost:389/dc=tcat,dc=test" );
  
          return new InitialDirContext( env );
      }
  
  
      /**
       * @param hardwareAddress
       * @param existingLease
       * @return Lease
       */
      protected Leaserver/dhcp/service/Lease.html#Lease">Lease findExistingLease( HardwareAddress hardwareAddress, Lease existingLease )
      {
          if ( leases.containsKey( hardwareAddress ) )
          {
              existingLease = ( Lease ) leases.get( hardwareAddress );
          }
 
         return existingLease;
     }
 
 
     /**
      * @param hardwareAddress
      * @return Host
      * @throws DhcpException
      */
     protected Host findDesignatedHost( HardwareAddress hardwareAddress ) throws DhcpException
     {
         try
         {
             DirContext ctx = getContext();
 
             try
             {
                 String filter = "(&(objectclass=ipHost)(objectclass=ieee802Device)(macaddress={0}))";
                 SearchControls sc = new SearchControls();
                 sc.setCountLimit( 1 );
                 sc.setSearchScope( SearchControls.SUBTREE_SCOPE );
                 NamingEnumeration ne = ctx.search( "", filter, new Object[]
                     { hardwareAddress.toString() }, sc );
 
                 if ( ne.hasMoreElements() )
                 {
                     SearchResult sr = ( SearchResult ) ne.next();
                     Attributes att = sr.getAttributes();
                     Attribute ipHostNumberAttribute = att.get( "iphostnumber" );
 
                     if ( ipHostNumberAttribute != null )
                     {
                         InetAddress clientAddress = InetAddress.getByName( ( String ) ipHostNumberAttribute.get() );
                         Attribute cnAttribute = att.get( SchemaConstants.CN_AT );
 
                         return new Host( cnAttribute != null ? ( String ) cnAttribute.get() : "unknown", clientAddress,
                             hardwareAddress );
                     }
                 }
             }
             catch ( Exception e )
             {
                 throw new DhcpException( "Can't lookup lease", e );
             }
             finally
             {
                 ctx.close();
             }
         }
         catch ( NamingException e )
         {
             throw new DhcpException( "Can't lookup lease", e );
         }
 
         return null;
     }
 
 
     /**
      * Find the subnet for the given client address.
      * 
      * @param clientAddress
      * @return Subnet
      */
     protected Subnet findSubnet( InetAddress clientAddress )
     {
         for ( Iterator i = subnets.iterator(); i.hasNext(); )
         {
             Subnet./../../../../../org/apache/directory/server/dhcp/store/Subnet.html#Subnet">Subnet subnet = ( Subnet ) i.next();
 
             if ( subnet.contains( clientAddress ) )
             {
                 return subnet;
             }
         }
 
         return null;
     }
 
 
     /*
      * @see org.apache.directory.server.dhcp.store.AbstractDhcpStore#updateLease(org.apache.directory.server.dhcp.service.Lease)
      */
     public void updateLease( Lease lease )
     {
         leases.put( lease.getHardwareAddress(), lease );
     }
 
 
     /*
      * @see org.apache.directory.server.dhcp.store.AbstractDhcpStore#getOptions(org.apache.directory.server.dhcp.store.DhcpConfigElement)
      */
     protected OptionsField getOptions( DhcpConfigElement element )
     {
         // we don't have groups, classes, etc. yet.
         return element.getOptions();
     }
 
 
     /*
      * @see org.apache.directory.server.dhcp.store.AbstractDhcpStore#getProperties(org.apache.directory.server.dhcp.store.DhcpConfigElement)
      */
     protected Map getProperties( DhcpConfigElement element )
     {
         // we don't have groups, classes, etc. yet.
         return element.getProperties();
     }
 }