import java.util.ArrayList;
import java.util.Iterator;

/**
 * The database class provides a facility to store CD and video 
 * objects. A list of all CDs and videos can be printed to the
 * terminal.
 * 
 * This version does not save the data to disk, and it does not
 * provide any search functions.
 * 
 * @author Michael Kolling and David J. Barnes
 * @version 2002-05-04
 */
public class Database
{
    private ArrayList items;

    /**
     * Construct an empty Database.
     */
    public Database()
    {
        items = new ArrayList();
    }

    /**
     * Add an item to the database.
     */
    public void addItem(Item theItem)
    {
        items.add(theItem);
    }

    /**
     * Print a list of all currently stored CDs and videos to the
     * text terminal.
     */
    public void list()
    {
        for(Iterator iter = items.iterator(); iter.hasNext(); )
        {
            Item item = (Item)iter.next();
            item.print();
        }
    }
    
    public void selSortTimes()
    {
        int aSize = items.size();
        int j;
        for(int i = 0; i < aSize - 1; i++)
        {
            j = findSmallestTime(i,aSize - 1);
            swap(i,j);
        }
    }
    
    private void swap(int i, int j)
    {
        if (!(i == j))
        {
           Item temp = (Item)items.get(i);
           items.set(i, items.get(j));
           items.set(j, temp);
        }
    }
    
    private int findSmallestTime(int lower, int upper)
    {
        int smallPos = lower;
        Item smallItem = (Item)items.get(smallPos);
        int smallTime = smallItem.getPlayTime();
        Item theNewItem;
        int theNewTime;
        for(int i = lower + 1; i <= upper; i++)
        {
            theNewItem = (Item)items.get(i);
            theNewTime = theNewItem.getPlayTime();
            if(smallTime > theNewTime)
            {
                smallPos = i;
                smallTime = theNewTime;
            }
        }
        return smallPos;
    }
         
   
}