package Transcoder;

import java.util.LinkedList;

public class Worker extends Thread {
	private static LinkedList<Transcode> jobs = new LinkedList<Transcode>();
	private static Worker[] workers = new Worker[Runtime.getRuntime().availableProcessors()];
	
	private Boolean finished = false;
	int identifier;
	
	static {
		for(int i = 0; i < workers.length; i++) {
			workers[i] = new Worker(i);
		}
	}
	
	/**
	 * NOT designed to have jobs added once the workers are running
	 * Add all jobs to be performed, then set the workers going
	 * @param job
	 */
	public static void addJob(Transcode job) {
		jobs.add(job);
	}
	
	/**
	 * Starts every worker
	 */
	public static void goToWork() {
		for(Worker worker : workers) {
			worker.start();
		}
	}
	
	/**
	 * Waits for every worker to complete
	 */	
	public static void waitForAll() {
		for(Worker worker: workers) {
			worker.waitFor();
		}
	}
	
	public Worker(int identifier) {
		this.identifier = identifier;
	}
	
	public void run() {
		Transcode currentJob;
		while((currentJob = getJob()) != null) {
			System.out.println("Worker #" + identifier + " Starting " + currentJob);
			currentJob.transcode();
			System.out.println("Worker #" + identifier + " Finished " + currentJob + "!");
		}
		finished();
	}
	
	private Transcode getJob() {
		Transcode retval = null;
		synchronized(jobs) {
			if(jobs.size() > 0) {
				retval = jobs.removeFirst();
			}
		}
		return(retval);
	}
	
	private void finished() {
		synchronized(finished) {
			finished.notify();
			finished = true;
		}
	}
	
	public void waitFor() {
		System.out.println("Worker #" + identifier + " waitFor: entering waitFor()");
		if(finished) {
			System.out.println("Worker #" + identifier + " waitFor: already finished, leaving");
			return;
		}
		System.out.println("Worker #" + identifier + " waitFor: Attempting to grab");
		synchronized(finished) {
			System.out.println("Worker #" + identifier + " waitFor: grabbed! waiting...");
			try {
				finished.wait();
				System.out.println("Worker #" + identifier + " waitFor: notified! returning.");
			} catch (InterruptedException e) {
				e.printStackTrace();
			}
		}
	}
}