import java.util.Vector;
import java.io.*;
import java.util.Calendar ;

public class Mailer implements CollectionIF
{
	private Vector vletters;
	private String dbname;
	
	
	public Mailer( String filename )
	{
		dbname = filename;
		vletters = new Vector();		
	}
	
	public void loadRecords()
	{	
		DataInputStream infile_mailer = null;
		
		Letter letter;
		
		try
		{
			infile_mailer = new DataInputStream( new FileInputStream( dbname ) );
		}
		catch ( FileNotFoundException e ) {}
		
		while ( true )
		{
			letter = new Letter();
			try
			{
				letter.retrieve( infile_mailer );
				infile_mailer.readByte();
				vletters.addElement( letter );
			}
			catch ( EOFException eof ) 
			{
				System.out.println("We have hit end of file!"); 
				break;
			}
			catch ( IOException e ){ }
		}
	}
	
	public void storeRecords()
	{
		DataOutputStream outfile_mailer = null;
		try 
		{
			outfile_mailer = new DataOutputStream( new FileOutputStream( dbname ) );
		}
		catch ( IOException e ) {}
	
		for ( int i = 0; i < vletters.size(); i++ )
		{
			Letter letter = (Letter) vletters.elementAt( i );
			letter.persist( outfile_mailer );
			try 
			{
				outfile_mailer.writeByte( (byte) '¬' );
			}
			catch ( IOException e ) {}
		}
	}
	
	public int getNextID()
	{
		if (vletters.isEmpty())
			return 1;
		return ((Letter)(vletters.lastElement())).getID() + 1;
	}
	
	public void addRecord( Vector v )
	{
		for (int i = 0; i < v.size(); i++)
			vletters.addElement( v.elementAt(i) );
	}
	
	public void modifyRecord( Vector v )
	{
		for (int j = 0; j < v.size(); j++)
		{
			Letter l = (Letter) v.elementAt(j);
			for ( int i =0; i < vletters.size(); i++ )
			{
				Letter let = (Letter )vletters.elementAt(i);
				if ( let.getID() == l.getID() )
				{
					let.setStatus( l.getStatus() );
					let.setDate( l.getDate() );
					break;
				}
			}
		}
	}
	
	public void deleteRecord( int index )
	{
		vletters.removeElementAt( index );
	}
	
	public PersistentObject getRecord( int index )
	{
		return (PersistentObject) vletters.elementAt( index );
	}
	
	public void send( MailingSystem ms, Vector ltrs )
	{
		Vector v = new Vector();
		for (int i = 0; i < ltrs.size(); i++)
		{
			ms.send((Letter)ltrs.elementAt(i));
			Calendar c = Calendar.getInstance();
			((Letter)ltrs.elementAt(i)).setID( getNextID() );
			((Letter)ltrs.elementAt(i)).setDate(c.getTime().toString() );
			((Letter)ltrs.elementAt(i)).setStatus(MAILSTATUS.SENT);
			v.addElement(ltrs.elementAt(i));
		}
		addRecord(v);
	}
	
	public int size()
	{
		return vletters.size();
	}
	
	public void reSend( MailingSystem ms, Vector ltrs )
	{
		Vector v = new Vector();
		for (int i = 0; i < ltrs.size(); i++)
		{
			ms.send((Letter)ltrs.elementAt(i));
			Calendar c = Calendar.getInstance();
			((Letter)ltrs.elementAt(i)).setDate(c.getTime().toString() );
			((Letter)ltrs.elementAt(i)).setStatus(MAILSTATUS.SENT);
			v.addElement(ltrs.elementAt(i));
		}
		modifyRecord(v);
	}	
}