/*
 * This is an Android user space port of DVB-T Linux kernel modules.
 *
 * Copyright (C) 2022 by Signalware Ltd <driver at aerialtv.eu>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

package info.martinmarinov.drivers.tools;


import androidx.annotation.NonNull;

import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;

public class AsyncFuture<V> implements Future<V> {
    private final Object locker = new Object();
    private V object;
    private boolean ready = false;

    @Override
    public boolean cancel(boolean mayInterruptIfRunning) {
        return false;
    }

    @Override
    public boolean isCancelled() {
        return false;
    }

    @Override
    public boolean isDone() {
        synchronized (locker) {
            return ready;
        }
    }

    @Override
    public V get() throws InterruptedException, ExecutionException {
        synchronized (locker) {
            if (ready) return object;
            locker.wait();
            return object;
        }
    }

    @Override
    public V get(long timeout, @NonNull TimeUnit unit) throws InterruptedException, ExecutionException, TimeoutException {
        synchronized (locker) {
            if (ready) return object;
            locker.wait(unit.toMillis(timeout));
            return object;
        }
    }

    public void setDone(V object) {
        synchronized (locker) {
            this.object = object;
            this.ready = true;
            locker.notify();
        }
    }
}
