/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.maven.surefire.api.util.internal;

import java.util.concurrent.Executors;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * Creates new daemon Thread.
 */
public final class DaemonThreadFactory implements ThreadFactory {
    private static final ThreadFactory DEFAULT_THREAD_FACTORY = Executors.defaultThreadFactory();

    private static final AtomicInteger POOL_NUMBER = new AtomicInteger(1);

    private final AtomicInteger threadNumber = new AtomicInteger(1);

    private final String namePrefix;

    private DaemonThreadFactory() {
        namePrefix = "pool-" + POOL_NUMBER.getAndIncrement() + "-thread-";
    }

    @Override
    public Thread newThread(Runnable r) {
        Thread t = DEFAULT_THREAD_FACTORY.newThread(r);
        t.setName(namePrefix + threadNumber.getAndIncrement());
        t.setDaemon(true);
        return t;
    }

    /**
     * Should be used by thread pools.
     * @return new instance of {@link ThreadFactory} where each {@link Thread thread} is daemon
     */
    public static ThreadFactory newDaemonThreadFactory() {
        return new DaemonThreadFactory();
    }

    public static ThreadFactory newDaemonThreadFactory(String name) {
        return new NamedThreadFactory(name);
    }

    public static Thread newDaemonThread(Runnable r) {
        return new DaemonThreadFactory().newThread(r);
    }

    public static Thread newDaemonThread(Runnable r, String name) {
        Thread t = new DaemonThreadFactory().newThread(r);
        t.setName(name);
        return t;
    }

    private static class NamedThreadFactory implements ThreadFactory {
        private final String name;

        private NamedThreadFactory(String name) {
            this.name = name;
        }

        @Override
        public Thread newThread(Runnable r) {
            return newDaemonThread(r, name);
        }
    }
}
