/*
 * Copyright (c) nosqlbench
 *
 * Licensed 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 io.nosqlbench.engine.core.lifecycle;

import io.nosqlbench.nb.api.metadata.Indexed;

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

/**
 * A named and indexed thread factory, making threads within a thread pool
 * have the same name and a unique integer index
 */
public class IndexedThreadFactory implements ThreadFactory {

    private final Thread.UncaughtExceptionHandler uncaughtExceptionHandler;
    private String name = Thread.currentThread().getName() + "-factory";
    private final AtomicInteger threadIndexer = new AtomicInteger(0);

    public IndexedThreadFactory(String name, Thread.UncaughtExceptionHandler exceptionHandler) {
        this.name = name;
        this.uncaughtExceptionHandler = exceptionHandler;
    }

    public class IndexedThread extends Thread implements Indexed {

        private final int threadIndex;
        private String metricName = "default-name-" + Thread.currentThread().getName();

        public IndexedThread(int threadIndex, Runnable r) {
            super(r);
            this.threadIndex = threadIndex;
        }

        public void setMetricName(String metricName) {
            this.metricName = metricName;
        }

        public String getMetricName() {
            return metricName;
        }

        @Override
        public int getIndex() {
            return threadIndex;
        }
    }

    @Override
    public IndexedThread newThread(Runnable r) {

        int threadIndex = threadIndexer.incrementAndGet();

        IndexedThread thread = new IndexedThread(threadIndex, r);
        thread.setName(name + String.format(":%03d", threadIndex));
        thread.setMetricName(thread.getName().split(":")[0].split("/")[0]);
        if (uncaughtExceptionHandler!=null) {
            thread.setUncaughtExceptionHandler(uncaughtExceptionHandler);
        }

        return thread;
    }


}
