import edu.rice.hj.api.HjMetrics;
import edu.rice.hj.runtime.config.HjSystemProperty;
import edu.rice.hj.runtime.metrics.AbstractMetricsManager;

import static edu.rice.hj.Module1.*;

/**
 * This class contains a test harness for the SumReduction client.
 * It assumes availability of a completed GeneralizedReduce class to be implemented by you.
 *
 * This is a test class for your homework and should not be modified.
 *
 * @author Vivek Sarkar (vsarkar@rice.edu)
 */
public class TestSumReduction {

    /**
     * The main method. Input parameters are as follows:
     * 1 input - the first input is the length of the array to use
     * No other usage is allowed
     * @param args - input paramters
     */
    public static void main(final String[] args) {

        int n;
        if (args.length == 1) {
            n = Integer.parseInt(args[0]);
        } else {
            throw new RuntimeException("Usage: run TestSumReduction n");
        }

        final Integer[] inputArray = new Integer[n];
        for (int i = 0; i < n; i++) {
            inputArray[i] = i;
        }

        final Integer correctSum = calculateCorrectSum(inputArray);

        System.setProperty(HjSystemProperty.abstractMetrics.propertyKey(), "true");
        initializeHabanero();

        reduction(inputArray, correctSum);

        finalizeHabanero();
        final HjMetrics actualMetrics = abstractMetrics();
        AbstractMetricsManager.dumpStatistics(actualMetrics);
    }

    /**
     * Calculate the sum of the input array using array reduction.
     * @param inputArray The input array
     * @param correctSum The correct reduction value. Should be tested against
     *                   to determine validity of parallel reduction
     */
    public static void reduction(
            final Integer[] inputArray,
            final Integer correctSum) {

        final GeneralizedReduceApp<Integer> app = new SumReduction();
        final GeneralizedReduce<Integer> red = new GeneralizedReduce<>(app);
        final Integer output = red.run(inputArray);

        System.out.println("Correct output = " + correctSum);
        System.out.println("Reduced output = " + output);
        if (correctSum.equals(output)) {
            System.out.println("Reduction SUCCEEDED");
        } else {
            System.out.println("Reduction FAILED");
        }
    }

    /**
     * Sums the elements in the array. Gaurenteed ot be
     * correct for testing purposes
     *
     * @param inputArray An array of integers
     * @return The sum of all elements in the array
     */
    public static Integer calculateCorrectSum(final Integer[] inputArray) {

        int sum = 0;

        for (final Integer loopItem : inputArray) {
            sum += loopItem;
        }

        return sum;
    }
}