package de.mpg.mpiwg.berlin.mpdl.lucene.util;

import java.util.ArrayList;

public class LuceneUtil {
  private static LuceneUtil instance;
  
  public static LuceneUtil getInstance() {
    if (instance == null) {
      instance = new LuceneUtil();
    }
    return instance;
  }

  public ArrayList<String> getVariantsFromLuceneQuery(String queryString) {
    ArrayList<String> variants = new ArrayList<String>();
    String[] variantTokens = queryString.split(" ");  // TODO throw the phrases away (e.g.: "bla bla bla")
    for (int i = 0; i < variantTokens.length; i++) {
      String token = variantTokens[i];
      if (! (token.contains("*") || token.contains("?") || token.contains("~") || token.contains("-") || token.contains("+") || token.contains("^") || token.contains("OR") || token.contains("AND") || token.contains("NOT"))) {
        variants.add(token);
      }
    }
    return variants;
  }

}