/* LanguageTool, a natural language style checker 
 * Copyright (C) 2014 Daniel Naber (http://www.danielnaber.de)
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301
 * USA
 */
package org.languagetool.rules;

import java.io.*;
import java.util.*;

/**
 * Loads a confusion set from a plain text file (UTF-8). See {@code confusion_sets.txt}
 * for a description of the file format.
 * @since 2.7
 */
public class ConfusionSetLoader {

  private static final String CHARSET = "utf-8";

  public ConfusionSetLoader() {
  }

  public Map<String,ConfusionSet> loadConfusionSet(InputStream stream) throws IOException {
    Map<String,ConfusionSet> map = new HashMap<>();
    try (
      InputStreamReader reader = new InputStreamReader(stream, CHARSET);
      BufferedReader br = new BufferedReader(reader)
    ) {
      String line;
      while ((line = br.readLine()) != null) {
        if (line.startsWith("#") || line.trim().isEmpty()) {
          continue;
        }
        String[] parts = line.replaceFirst("\\s*#.*", "").split(";\\s*");
        if (parts.length != 3) {
          throw new RuntimeException("Unexpected format: " + line);
        }
        List<ConfusionString> confusionStrings = new ArrayList<>();
        for (String part : Arrays.asList(parts).subList(0, parts.length-1)) {
          String[] subParts = part.split("\\|");
          String word = subParts[0];
          String description = subParts.length == 2 ? subParts[1] : null;
          if (map.containsKey(part)) {
            throw new RuntimeException("Cannot add " + part + " to confusion set: already exists");
          }
          confusionStrings.add(new ConfusionString(word, description));
        }
        ConfusionSet confusionSet = new ConfusionSet(Integer.parseInt(parts[parts.length-1]), confusionStrings);
        for (ConfusionString confusionString : confusionStrings) {
          map.put(confusionString.getString(), confusionSet);
        }
      }
    }
    return map;
  }

}

@@ -1812,16 +1812,17 @@
 at: 
+'
 %22 + line
 );%0A 
@@ -1817,16 +1817,88 @@
 %22 + line
+ + %22' - expected three semicolon-separated values: word1; word2; factor%22
 );%0A     

improve exception message