package edu.rice.hj.example.comp322.labs.lab2;

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.*;

/**
 * ************************************************************
 * <p>
 * Reads in two strings, the pattern and the input text, and searches for the pattern in the input text.
 * <p>
 * % java Search2 rabrabracad abacadabrabracabracadabrabrabracad text:    abacadabrabracabracadababacadabrabracabracadabrabrabracad
 * pattern:                                               rabrabracad (input paramters can be given via run
 * configurations in IntelliJ)
 * <p>
 * HJ version ported from Java version in http://algs4.cs.princeton.edu/53substring/Brute.java.html
 *
 * @author Vivek Sarkar (vsarkar@rice.edu)
 *         <p>
 *         *************************************************************
 */
public class Search2 {

    /**
     * Finds the number of occurances of a pattern in a text Each comparison of letters is one unit of work
     *
     * @param pattern - the pattern to search for
     * @param text    - the text to search in
     * @return - the number of occurances of the pattern in the text
     */
    public static int search(char[] pattern, char[] text) {
        int M = pattern.length;
        int N = text.length;
        int count = 0;
        for (int i = 0; i <= N - M; i++) {
            int j;
            for (j = 0; j < M; j++) {
                doWork(1); // Count each char comparison as 1 unit of work
                if (text[i + j] != pattern[j]) {
                    break;
                }
            }
            if (j == M) {
                count++;            // found at offset i
            }
        }
        return count;
    }

    /**
     * Main function. first argument given in the pattern. Second argument is the text. If no pattern is given, uses the
     * default pattern. If no text is given, use the defualt text.
     *
     * @param args - command line arguments.
     */
    public static void main(final String[] args) {
        // Setup metrics
        HjSystemProperty.abstractMetrics.set(true);
        launchHabaneroApp(() -> {

            final String default_pat = "rabrabracad";
            final String default_txt = "abacadabrabracabracadababacadabrabracabracadabrabrabracad";

            String pat = default_pat;
            String txt = default_txt;
            if (args.length >= 1) {
                pat = args[0];
            }
            if (args.length >= 2) {
                txt = args[1];
            }

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

            int count = search(pattern, text);

            // print results
            System.out.println("text:    " + txt);
            System.out.println("pattern: " + pat);
            System.out.println("Number of occurrences: " + count);

        }, () -> {
            // Print out the metrics data
            final HjMetrics actualMetrics = abstractMetrics();
            AbstractMetricsManager.dumpStatistics(actualMetrics);
        });
    }
}