com.cotrino.knowledgemap.db.Question.java Source code

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Here is the source code for com.cotrino.knowledgemap.db.Question.java

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/**
 *  Copyright (C) 2016 Jos Miguel Cotrino Benavides
 *  
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *  
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *  
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package com.cotrino.knowledgemap.db;

import java.text.BreakIterator;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;
import java.util.Locale;
import java.util.StringJoiner;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.apache.commons.lang3.StringEscapeUtils;

public class Question {

    private static final Pattern LINK_PATTERN = Pattern.compile("\\[\\[(.+?)\\]\\]");
    private static final int QUESTION_SENTENCES = 3;

    public Page page;
    public String question;
    public List<String> answers = new LinkedList<String>();

    public Question(Page page) {
        String realText = StringEscapeUtils.unescapeHtml3(page.getText());
        List<String> rawSentences = Question.tokenize(realText, "en", "US");
        if (rawSentences.size() >= QUESTION_SENTENCES) {
            //System.out.println("Asking about '" + title + "'");
            generateQuestion(page, rawSentences);
        }
    }

    public boolean matches(String userAnswer) {

        for (String answer : answers) {
            if (answer.toLowerCase().equals(userAnswer.toLowerCase())) {
                return true;
            }
        }
        return false;

    }

    public String getExpectedAnswer() {

        StringJoiner sj = new StringJoiner(", ");
        for (String answer : answers) {
            sj.add("'" + answer + "'");
        }
        return sj.toString();

    }

    private void generateQuestion(Page page, List<String> sentences) {

        int firstSentence = (int) Math.round(Math.random() * (sentences.size() - QUESTION_SENTENCES));
        String question = "";
        for (int i = firstSentence; i < firstSentence + QUESTION_SENTENCES; i++) {
            question += sentences.get(i);
        }
        Matcher matcher = LINK_PATTERN.matcher(question);
        List<Integer> matchStart = new LinkedList<Integer>();
        List<Integer> matchEnd = new LinkedList<Integer>();
        List<String> matchLink = new LinkedList<String>();
        while (matcher.find()) {
            String link = matcher.group(1);
            if (!link.contains(":")) {
                matchStart.add(matcher.start());
                matchEnd.add(matcher.end());
                matchLink.add(link);
            }
        }
        if (matchLink.size() > 0) {
            int linkToBeReplaced = (int) Math.round(Math.random() * (matchLink.size() - 1));
            int start = matchStart.get(linkToBeReplaced);
            int end = matchEnd.get(linkToBeReplaced);
            String link = matchLink.get(linkToBeReplaced);
            String[] answers = link.split("\\|");
            for (String answer : answers) {
                this.answers.add(answer);
            }
            String placeholder = link.replaceAll("[^ \\|]", ".");
            if (placeholder.contains("|")) {
                placeholder = placeholder.split("\\|")[1];
            }
            String text = question.substring(0, start) + "<span class='placeholder'>" + placeholder + "</span>"
                    + question.substring(end);
            // replace other links of the kind [[A|B]] with A 
            text = text.replaceAll("\\[\\[[^\\]\\|]+\\|", "");
            // replace other links of the kind [[A]] with A
            text = text.replaceAll("\\[\\[", "").replaceAll("\\]\\]", "");
            //System.out.println("Question: "+text);
            this.question = text;
            this.page = page;
        }

    }

    /**
     * http://stackoverflow.com/questions/2103598/java-simple-sentence-parser
     * @param text
     * @param language
     * @param country
     * @return
     */
    public static List<String> tokenize(String text, String language, String country) {
        List<String> sentences = new ArrayList<String>();
        Locale currentLocale = new Locale(language, country);
        BreakIterator sentenceIterator = BreakIterator.getSentenceInstance(currentLocale);
        sentenceIterator.setText(text);
        int boundary = sentenceIterator.first();
        int lastBoundary = 0;
        while (boundary != BreakIterator.DONE) {
            boundary = sentenceIterator.next();
            if (boundary != BreakIterator.DONE) {
                sentences.add(text.substring(lastBoundary, boundary));
            }
            lastBoundary = boundary;
        }
        return sentences;
    }
}