package observer;

/** Updates portfolio value whenever a held stock changes price */
public class PortfolioObserver implements StockObserver {
    private final String ownerName;
    private final int    sharesHeld;

    public PortfolioObserver(String ownerName, int sharesHeld) {
        this.ownerName  = ownerName;
        this.sharesHeld = sharesHeld;
    }

    @Override
    public void onPriceChanged(String ticker, double oldPrice, double newPrice) {
        double gain = (newPrice - oldPrice) * sharesHeld;
        System.out.printf("  [Portfolio:%s] %s×%d  P&L change: %+.2f%n",
                ownerName, ticker, sharesHeld, gain);
    }
}