package dbj.odmg;

import COM.POET.odmg.*;
import COM.POET.odmg.collection.*;
import java.io.IOException;
import java.io.FileInputStream;
import java.util.Properties;
import java.util.Enumeration;

public class UpdateStock {
  Database dbase;

  public UpdateStock (Database db) {
    dbase = db;
  }

  public void update (String isbn, int stock) throws ODMGException {
    String queryString = "SELECT b FROM BookExtent as b WHERE isbn_ = $1";
    Transaction txn = new Transaction ();
    txn.begin ();
    try {
      OQLQuery query = new OQLQuery (queryString);
      query.bind (isbn);
      Object result = query.execute ();

      CollectionOfObject coll = (CollectionOfObject) result;
      Enumeration e = coll.elements ();
      if (e.hasMoreElements ()) {
        Book b = (Book) e.nextElement ();
        b.setStock (stock);
        System.out.println ("stock updated for: " + b);
      }
    }
    catch (ODMGException exc) {
      txn.abort ();
      throw exc;
    }
    txn.commit ();
  }

  public static void main (String args[]) throws IOException {
    if (args.length != 2) {
      System.out.println ("usage: dbj.odmg.UpdateStock isbn stock");
      System.exit (1);
    }
	 
    Properties props = new Properties ();
    props.load (new FileInputStream ("dbj.properties"));
    
    try {
      Database db = Database.open (props.getProperty ("odmg.database"), 
        Database.openReadWrite);
      UpdateStock app = new UpdateStock (db);
      app.update (args[0], Integer.parseInt (args[1]));
    }
    catch (Exception exc) {
      exc.printStackTrace ();
    }
  }
}