package edu.rice.hj.example.comp322;

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

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

/**
 * Reads in two strings, the pattern and the input text, and searches for the pattern in the input text.
 * <p>
 * % hj Search rabrabracad abacadabrabracabracadabrabrabracad text:    abacadabrabracabracadababacadabrabracabracadabrabrabracad
 * pattern:                                               rabrabracad
 * <p>
 * HJ version ported from Java version in http://algs4.cs.princeton.edu/53substring/Brute.java.html
 *
 * @author Vivek Sarkar (vsarkar@rice.edu)
 */
public class Search2 {
    private static final String default_pat = "rabrabracad";
    private static final String default_txt = "abacadabrabracabracadababacadabrabracabracadabrabrabracad";

    // return number of occurrences of pattern in text

    /**
     * <p>searchSeq.</p>
     *
     * @param pattern an array of char.
     * @param text    an array of char.
     * @return a int.
     */
    public static int searchSeq(final char[] pattern, final char[] text) {
        final int M = pattern.length;
        final int N = text.length;

        int count = 0;
        for (int i = 0; i <= N - M; i++) {
            int j;
            for (j = 0; j < M; j++) {
                // Count each char comparison as 1 unit of work
                doWork(1);
                if (text[i + j] != pattern[j]) {
                    break;
                }
            }
            if (j == M) {
                count++; // found at offset i
            }
        }

        return count;
    }

    // test client

    /**
     * <p>main.</p>
     *
     * @param args an array of {@link String} objects.
     */
    public static void main(final String[] args) {

        final String pat = args.length >= 1 ? args[0] : default_pat;
        final String txt = args.length >= 2 ? args[1] : default_txt;

        final char[] pattern = pat.toCharArray();
        final char[] text = txt.toCharArray();

        HjSystemProperty.abstractMetrics.setProperty(true);
        launchHabaneroApp(new HjSuspendable() {
            @Override
            public void run() throws SuspendableException {

                finish(new HjSuspendable() {
                    @Override
                    public void run() throws SuspendableException {
                        final int count = searchSeq(pattern, text);
                        // print results
                        System.out.println("text:    " + txt);
                        System.out.println("pattern: " + pat);
                        System.out.println("Number of occurrences: " + count);
                    }
                });

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