package org.simantics.graph.db;

public interface TGStatusMonitor {

    void status(int percentage);
    boolean isCanceled();

    public static class NullMonitor implements TGStatusMonitor {
        @Override
        public void status(int percentage) {
        }
        @Override
        public boolean isCanceled() {
            return false;
        }
    }

    public static final TGStatusMonitor NULL_MONITOR = new NullMonitor();

    public static class Updater {
        private final TGStatusMonitor monitor;
        private final int total;
        private int percentage;
        private int worked;

        public Updater(TGStatusMonitor monitor, int total) {
            this.monitor = monitor;
            this.total = total;
        }

        public int worked(int work) {
            worked += work;
            return percentage = updatePercentage(monitor, percentage, worked, total);
        }
    }

    public static int updatePercentage(TGStatusMonitor monitor, int oldPercentage, int done, int total) {
        int current = (100 * done) / total;
        if (current > oldPercentage) {
            oldPercentage = current;
            if (monitor != null) 
                monitor.status(oldPercentage);
        }
        return oldPercentage;
    }

}