package dbj.odmg;

import COM.POET.odmg.*;
import COM.POET.odmg.collection.*;
import java.util.*;
import java.io.*;

public class CreateOrder {
  Database dbase;

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

  private Customer findCustomer (int custId) throws ODMGException {
    Customer cust = null;
    String queryString = "SELECT c FROM CustomerExtent as c WHERE c.id_ = $1";

    OQLQuery query = new OQLQuery (queryString);
    query.bind (new Integer (custId));
    Object result = query.execute ();

    CollectionOfObject coll = (CollectionOfObject) result;
    Enumeration e = coll.elements ();
    if (e.hasMoreElements ()) 
      cust = (Customer) e.nextElement ();

    return cust;
  }
	
  private Book findBook (String isbn) throws ODMGException {
    Book book = null;
    String queryString = "SELECT b FROM BookExtent as b WHERE b.isbn_ = $1";

    OQLQuery query = new OQLQuery (queryString);
    query.bind (isbn);
    Object result = query.execute ();

    CollectionOfObject coll = (CollectionOfObject) result;
    Enumeration e = coll.elements ();
    if (e.hasMoreElements ()) 
      book = (Book) e.nextElement ();

    return book;
  }
	
  public void create (int custId) throws ODMGException {
    BagOfObject orders;
    boolean ready = false, valid = false;
    Transaction tx = new Transaction ();
		
    tx.begin ();
    try {
      orders = (BagOfObject) dbase.lookup ("orders");
      Customer customer = findCustomer (custId);
      if (customer == null) {
        System.out.println ("unknown customer: " + custId);
        tx.abort ();
        return;
      }
      BookOrder order = new BookOrder ();
      do {
        String isbn = Utils.readString ("isbn: ");
        if (isbn == null || isbn.length () == 0)
          ready = true;
        else {
          int num = Utils.readInt ("number: ");
          if (num > 0) {
            Book book = findBook (isbn);
            if (book == null) {
              System.out.println ("cannot find book: " + isbn);
              continue;
            }
            order.addItem (book, num);
            valid = true;
          }
        }
      } while (! ready);
      
      if (valid) {
        order.setCustomer (customer);
        orders.add (order);
      }
    } catch (ObjectNameNotFoundException e) { 
      System.out.println ("fatal error: orders not found !");
      tx.abort ();
      throw e;
    }
    catch (ODMGException exc) {
      tx.abort ();
      throw exc;
    }
    tx.commit ();
  }

  public static void main (String args[]) throws IOException {
    if (args.length != 1) {
      System.out.println ("usage: dbj.odmg.CreateOrder custId");
      System.exit (1);
    }
	 
    Properties props = new Properties ();
    props.load (new FileInputStream ("dbj.properties"));

    try {
      Database db = Database.open (props.getProperty ("odmg.database"), 
        Database.openReadWrite);
      CreateOrder app = new CreateOrder (db);
      app.create (Integer.parseInt (args[0]));
    }
    catch (Exception exc) {
      exc.printStackTrace ();
    }
  }
}