package test;

import util.PrimeCounter;
import java.util.stream.IntStream;
import parallel.CallablePrimeCounter;
import parallel.ThreadPoolPrimeCounter;
import sequential.SequentialPrimeCounter;
import parallel.ForkJoinPoolPrimeCounter;

public class Tester {

	private static final int NUM_THREADS = 8;
	public static final int LOW = 2;
	public static final int HIGH = 11201609;
	private PrimeCounter strategy;

	private void setStrategy(PrimeCounter strategy) {
		this.strategy = strategy;
	}

	private int countPrimes(int[] array) {
		return new SequentialPrimeCounter().countPrimes(array);
	}

	private void testImplementation(int[] array, String name) 
			throws Exception {

		long startTime = System.nanoTime();
		int count = strategy.countPrimes(array);
		long endTime = System.nanoTime();
		long result = countPrimes(array);
		if (count != result) {
			// Informing if the implementation failed
			System.err.printf("- ERROR: %s; Expected: %d; Found: %d\n", 
					name, result, count);
		} else {
			// Showing the time taken by the implementation	
			System.out.printf("- %s: %d prime numbers found, "
					+ "elapsed time: %d ms\n" , name, count,
					((endTime - startTime) / 1000000));
		}
	}

	public static void main(String[] args) throws Exception {
		//Generating an integer array with numbers in the range from LOW to HIGH
		int[] numbers = IntStream.rangeClosed(LOW, HIGH).toArray();
		Tester tester = new Tester();

		// Testing different implementations:
		// Sequential implementation
		tester.setStrategy(new SequentialPrimeCounter());
		tester.testImplementation(numbers,"Sequential version");

		// Parallel - Callable implementation 
		tester.setStrategy(new CallablePrimeCounter(NUM_THREADS));
		tester.testImplementation(numbers, "Parallel - Callable version");

		// TODO: Uncomment to test additional implementations
		/*
		// Parallel - ThreadPool implementation 
		tester.setStrategy(new ThreadPoolPrimeCounter(NUM_THREADS));
		tester.testImplementation(numbers, "Parallel - ThreadPool version");

		// Parallel - ForkJoinPool implementation - Ex. 4
		tester.setStrategy(new ForkJoinPoolPrimeCounter(NUM_THREADS));
		tester.testImplementation(numbers, "Parallel - ForkJoinPool version");
		
		// Parallel - Streams implementation - BONUS
		//tester.setStrategy(new StreamsPrimeCounter());
		//tester.testImplementation(numbers, "Parallel - Streams version");
		*/
	}
}