/*

  * Copyright 2008 Brian Thomas Matthews

  *

  * 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 com.btmatthews.maven.plugins.ldap.mojos;

 import java.io.File;

 import java.io.FileOutputStream;

 import java.io.IOException;

 import java.io.OutputStream;

 import java.io.PrintWriter;

 import org.apache.maven.plugin.MojoExecutionException;

 import netscape.ldap.LDAPConnection;

 import netscape.ldap.LDAPEntry;

 import netscape.ldap.LDAPException;

 import netscape.ldap.LDAPSearchResults;

 import netscape.ldap.LDAPv2;

 import netscape.ldap.util.LDAPWriter;

 /**

  * This is the abstract base class for all Mojos in the ldap-maven-plugin plugin

  * that dump content from the directory server. Concrete classes must implement

  * the getLDAPWriter() method to return the writer that will format the output

  * appropriately.

  * 

  * @author <a href="mailto:brian@btmatthews.com">Brian Matthews</a>

  * @version 1.0

  */

 public abstract class AbstractLDAPDumperMojo

     extends AbstractLDAPMojo

 {

     /**

      * The search base.

      * 

      * @parameter

      * @required

      */

     private String searchBase;

     /**

      * The search filter.

      * 

      * @parameter default-value="(objectclass=*)"

      * @required

      */

     private String searchFilter = "(objectclass=*)";

     /**

      * The target output directory.

      * 

      * @parameter expression="${project.outputDirectory}"

      * @required

      */

     private File outputDirectory;

     /**

      * The output file name.

      * 

      * @parameter

      * @required

      */

     private String filename;

     /**

      * The default constructor.

      */

     public AbstractLDAPDumperMojo()

     {

     }

     /**

      * Execute the plugin goal.

      * 

      * @throws MojoExecutionException

      *             If something unexpected happens.

      */

     public final void execute()

         throws MojoExecutionException

     {

         final LDAPConnection connection = this.connect();

         try

         {

             final PrintWriter writer = this.getPrintWriter();

             final LDAPWriter ldapWriter = this.openLDAPWriter(writer);

             this.dump(connection, ldapWriter);

             this.closeLDAPWriter(writer, ldapWriter);

             writer.close();

         }

         finally

         {

             try

             {

                 connection.disconnect();

             }

             catch (LDAPException e)

             {

                 final String message = "Error disconnecting from the LDAP directory server";

                 this.getLog().warn(message, e);

             }

         }

     }

     /**

      * Create the LDAP writer that will dump LDAP entries in appropriate format.

      * 

      * @param writer

      *            The writer for the target output stream.

      * @return The LDAP writer.

      */

     protected abstract LDAPWriter openLDAPWriter(final PrintWriter writer);

     /**

      * Close the LDAP wrtier that was returned by openLDAPWriter.

      * 

      * @param writer

      *            The writer for the target output stream.

      * @param ldapWriter

      *            The LDAP writer.

      */

     protected abstract void closeLDAPWriter(final PrintWriter writer,

         final LDAPWriter ldapWriter);

     /**

      * Search the LDAP directory and dump the contents to a file.

      * 

      * @param connection

      *            The connection to the LDAP directory server.

      * @param writer

      *            The writer that is used to dump the content.

      * @throws MojoExecutionException

      *             If an error occurred generating the output file content.

      */

     private void dump(final LDAPConnection connection, final LDAPWriter writer)

         throws MojoExecutionException

     {

         try

         {

             final LDAPSearchResults results = connection.search(

                 this.searchBase, LDAPv2.SCOPE_SUB, this.searchFilter, null,

                 false);

             while (results.hasMoreElements())

             {

                 final LDAPEntry entry = results.next();

                 this.getLog().info("Dumping: " + entry.getDN());

                 writer.printEntry(entry);

             }

         }

         catch (LDAPException e)

         {

             final String message = "Error communicating with the LDAP directory";

             this.getLog().error(message, e);

             throw new MojoExecutionException(message, e);

         }

         catch (IOException e)

         {

             final String message = "Error dumping to the contents of the LDAP directory";

             this.getLog().error(message, e);

             throw new MojoExecutionException(message, e);

         }

     }

     /**

      * Create the output file and return a print writer encapsulating that file.

      * 

      * @return The print writer.

      * @throws MojoExecutionException

      *             If the output file could not be created.

      */

     private PrintWriter getPrintWriter()

         throws MojoExecutionException

     {

         final File file;

         file = new File(this.outputDirectory, this.filename);

         try

         {

             file.createNewFile();

             final OutputStream outputStream = new FileOutputStream(file);

             return new PrintWriter(outputStream);

         }

         catch (IOException e)

         {

             final String message = "I/O error creating output file: "

                 + file.getAbsolutePath();

             this.getLog().error(message, e);

             throw new MojoExecutionException(message, e);

         }

     }

 }