package observer;

/** Fires an alert when the price changes by more than a threshold % */
public class AlertObserver implements StockObserver {
    private final String name;
    private final double thresholdPercent;

    public AlertObserver(String name, double thresholdPercent) {
        this.name = name;
        this.thresholdPercent = thresholdPercent;
    }

    @Override
    public void onPriceChanged(String ticker, double oldPrice, double newPrice) {
        double change = Math.abs((newPrice - oldPrice) / oldPrice * 100);
        if (change >= thresholdPercent) {
            System.out.printf("  [ALERT:%s] %s moved %.1f%% — ALERT TRIGGERED%n", name, ticker, change);
        } else {
            System.out.printf("  [Alert:%s] %s moved %.1f%% — within threshold%n", name, ticker, change);
        }
    }
}