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 QueryBooks {
  Database dbase;

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

  public void queryByTitle (String name) throws ODMGException {
    String queryStr = "SELECT b FROM BookExtent AS b WHERE b.title_ LIKE $1";
    
    Transaction tx = new Transaction ();
    tx.begin ();
    OQLQuery query = new OQLQuery (queryStr);
    query.bind (name);
    Object result = query.execute ();
		
    if (result instanceof CollectionOfObject) {
      CollectionOfObject coll = (CollectionOfObject) result;
      Enumeration e = coll.elements ();
      while (e.hasMoreElements ()) {
        Object o = e.nextElement ();
        System.out.println (o);
      }
      System.out.println (coll.size () + " elements selected.");
    }
    else {
      System.out.println (result);
      System.out.println ("1 element selected.");
    }
    tx.abort ();
  }
	
  public void queryByAuthor (String name) throws ODMGException {
    String queryStr = "SELECT b FROM BookExtent AS b, b.authors_ AS a " +
    "WHERE a.name_ = $1";
    
    Transaction tx = new Transaction ();
    tx.begin ();
    OQLQuery query = new OQLQuery (queryStr);
    query.bind (name);
    Object result = query.execute ();
		
    if (result instanceof CollectionOfObject) {
      CollectionOfObject coll = (CollectionOfObject) result;
      Enumeration e = coll.elements ();
      while (e.hasMoreElements ()) {
        Object o = e.nextElement ();
        System.out.println (o);
      }
      System.out.println (coll.size () + " elements selected.");
    }
    else {
      System.out.println (result);
      System.out.println ("1 element selected.");
    }
    tx.abort ();
  }
	
    public static void main (String args[]) throws IOException {
    Properties props = new Properties ();
    props.load (new FileInputStream ("dbj.properties"));
    
    if (args.length != 2) {
      System.out.println ("usage: dbj.odmg.QueryBooks author|title predicate");
      System.exit (1);
    }
	 
    try {
      Database db = Database.open (props.getProperty ("odmg.database"), 
        Database.openReadOnly);
      QueryBooks app = new QueryBooks (db);
      if (args[0].equals ("title"))
        app.queryByTitle (args[1]);
      else if (args[0].equals ("author"))
        app.queryByAuthor (args[1]);
    }
    catch (ODMGException exc) {
      exc.printStackTrace ();
    }
  }
}