PBO-C 4 : Auction()

import java.util.ArrayList;

public class Auction  {
    private ArrayList<Lot> lots;
    private int nextLotNumber;

    public Auction(){
        lots = new ArrayList<Lot>();
        nextLotNumber = 1;
    }

    public void enterLot(String description){
        lots.add(new Lot(nextLotNumber, description));
        nextLotNumber++;
    }

    public void showLots(){
        for(Lot lot : lots){
            System.out.println(lot.toString());
        }
    }

    public void makeABid(int lotNumber, Person bidder, long value){
        Lot selectedLot = getLot(lotNumber);
        if (selectedLot != null){
            boolean succesful = selectedLot.bidFor(new Bid(bidder, value));
            if (succesful){
                System.out.println("The bid for lot number " + lotNumber + " was succesful.");
            }else{
                Bid highestBid = selectedLot.getHighestBid();
                System.out.println("Lot number: " + lotNumber + " already has a bid of: " + highestBid.getValue());
            }
        }
    }

    public Lot getLot(int lotNumber){
        if((lotNumber >= 1) && (lotNumber < nextLotNumber)){
            Lot selectedLot = lots.get(lotNumber-1);
            if (selectedLot.getNumber() != lotNumber){
                System.out.println("Internal error: Lot number " + selectedLot.getNumber() + " was returned instead of " + lotNumber);
                selectedLot = null;
            }
            return selectedLot;
        }else{
            System.out.println("Lot number: " + lotNumber + " does not exist.");
            return null;
        }
    }

    public void close(){
        System.out.println("Closing auction.");
        for (Lot lot : lots){
            System.out.println(lot.getNumber() + ": " + lot.getDescription());
            if (lot.getHighestBid() == null){
                System.out.println (" (No bids) ");
            }else{
                Bid highestBid = lot.getHighestBid();
                System.out.println(" sold to " + highestBid.getBidder().getName() + " for " + highestBid.getValue());
            }
        }
    }
}