package org.astrogrid.mySpace.mySpaceDemo;
   
   import java.io.*;
   import java.util.*;
   
   import org.astrogrid.mySpace.mySpaceManager.*;
   
   /***
    * Minimal program to delete users from a MySpace registry.
   * For each user the program checks that the only remaining entries for
   * the user in the registry are containers (ie. there are no VOTables
   * or other files).  If this condition is satisfied it deletes all the
   * entries for the user from the registry.
   *
   * @author A C Davenhall (Edinburgh)
   * @version Iteration 3.
   */
  
  class DeleteUsersFromRegistry
  {  public static void main (String argv[])
     {  if (argv.length == 1)
        {  String registryName = argv[0]; //argv[0] is "example"
  
           String registryFileName = registryName + ".reg";
           String deadUsersFileName = registryName + ".deadusers";
  
  //
  //      Attempt to open the input file from which the list of users to
  //      be deleted is to be read.
  
           try
           {  File deadUsersFile = new File(deadUsersFileName);
              FileReader in = new FileReader(deadUsersFile);
              char c[] = new char[(int)deadUsersFile.length()];
              in.read(c);
              String s = new String(c);
  
  //
  //         Convert the input file into a vector of individual lines.
  
              Vector inputLines = new Vector();
  
              StringTokenizer token = new StringTokenizer(s, "\n");
  
              while(token.hasMoreTokens())
              {  inputLines.add(token.nextToken());
              }
  
  //
  //         Create a registry manager to which the new entries will be
  //         written.
  
              RegistryManager reg = new RegistryManager(registryName);
  
              DataItemRecord itemRec = new DataItemRecord();
  
  //
  //         Loop through the lines read from the input file.
  
              for (int loop = 0; loop < inputLines.size(); loop++)
              {  String user = (String)inputLines.get(loop);
  
  //
  //            Lookup all the entries for this user in the registry and
  //            proceed if some entries were found.
  
                 String query = user + "*";
  
                 Vector entries = reg.lookupDataItemRecords(query);
                 if (entries.size() > 0)
                 {  boolean deleteOk = true;
  
  //
  //               Examine every entry and check that it is a container.
  
                    for (int currentEntry = 0; currentEntry < entries.size();
                      currentEntry++)
                    {  itemRec =
                         (DataItemRecord)entries.elementAt(currentEntry);
  
                       if (itemRec.getType() != DataItemRecord.CON)
                       {  deleteOk = false;
  
                          System.out.println("      Extant dataHolder: " +
                            itemRec.getDataItemName() +
                            " belonging to user " + user + ".");
                       }
                    }
  
  //
  //               Proceed to delete the user if all his entries were
  //               containers.
  
                    if (deleteOk)
                    {  boolean allRemoved = true;
  
                       for (int currentEntry = 0; currentEntry < entries.size();
                         currentEntry++)
                       {  itemRec =
                           (DataItemRecord)entries.elementAt(currentEntry);
 
                         int itemRecID = itemRec.getDataItemID();
                         boolean deleteStatus =
                           reg.deleteDataItemRecord(itemRecID);
 
                         if (!deleteStatus)
                         {  allRemoved = false;
 
                            System.out.println(
                              "      Failed to delete container " +
                              itemRec.getDataItemName() +
                              " belonging to user " + user + ".");
                         }
                      }
 
                      if (allRemoved)
                      {  System.out.println("  Deleted user " + user + ".");
                      }
                      else
                      {  System.out.println("  *** Failed to delete " +
                           user + " cleanly.");
                      }
                   }
                   else
                   {  System.out.println("  *** Could not delete user " +
                        user + "; dataHolders still exist.");
                   }
                }
                else
                {  System.out.println("  *** No entries found for user "
                     + user + ".");
                }
             }
 
 //
 //         Write the registry file to disk.
 
             reg.rewriteRegistryFile();
 
 //
 //         Close the input file.
 
             in.close();
          }
          catch (java.io.IOException ex)
          {  System.out.println(
               "Failed to read the file of dead users " +
               deadUsersFileName);
 
             ex.printStackTrace();
          }
       }
       else
       {  System.out.println("Usage:-");
          System.out.println("  java DeleteUsersFromRegistry registryName");
       }
    }
 }