code: /* LanguageTool, a natural language style checker 
   * Copyright (C) 2021 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.IOException;
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.Comparator;
  import java.util.List;
  import java.util.Map;
  import java.util.regex.Pattern;
  import java.util.stream.Collectors;
  
  import org.languagetool.AnalyzedToken;
  import org.languagetool.AnalyzedTokenReadings;
  import org.languagetool.rules.patterns.RuleFilter;
  import org.languagetool.rules.spelling.symspell.implementation.EditDistance;
  import org.languagetool.synthesis.Synthesizer;
  import org.languagetool.tagging.Tagger;
  import org.languagetool.tools.StringTools;
  
  public abstract class AbstractFindSuggestionsFilter extends RuleFilter {
  
    final protected int MAX_SUGGESTIONS = 10;
  
    abstract protected Tagger getTagger();
  
    //abstract protected MorfologikSpeller getSpeller();
    abstract protected List<String> getSpellingSuggestions(AnalyzedTokenReadings atr) throws IOException; 
  
    @Override
    public RuleMatch acceptRuleMatch(RuleMatch match, Map<String, String> arguments, int patternTokenPos,
        AnalyzedTokenReadings[] patternTokens) throws IOException {
      
  //    if (match.getSentence().getText().contains("Faltes")) {
  //      int ii=0;
  //      ii++;
  //    }
  
      //TODO: remove suggestions that trigger the rule again.
      // It would be needed to run again the rule with the full sentence. 
      List<String> replacements = new ArrayList<>();
      List<String> replacements2 = new ArrayList<>();
      String wordFrom = getRequired("wordFrom", arguments);
      String desiredPostag = getRequired("desiredPostag", arguments);
      String priorityPostag = getOptional("priorityPostag", arguments);
      String removeSuggestionsRegexp = getOptional("removeSuggestionsRegexp", arguments);
      // suppress match if there are no suggestions
      String suppressMatch = getOptional("suppressMatch", arguments);
      boolean bSuppressMatch = false;
      if (suppressMatch != null && suppressMatch.equalsIgnoreCase("true")) {
        bSuppressMatch = true;
      }
      
      // diacriticsMode: return only changes in diacritics. If there is none, the
      // match is removed.
      String mode = getOptional("Mode", arguments);
      boolean diacriticsMode = (mode != null) && mode.equals("diacritics");
      boolean generateSuggestions = true;
      Pattern regexpPattern = null;
      Synthesizer synth = getSynthesizer();
      List<String> usedLemmas = new ArrayList<>();
      StringComparator stringComparator = new StringComparator("");
  
      if (wordFrom != null && desiredPostag != null) {
        int posWord = 0;
        if (wordFrom.startsWith("marker")) {
          while (posWord < patternTokens.length && (patternTokens[posWord].getStartPos() < match.getFromPos()
              || patternTokens[posWord].isSentenceStart())) {
            posWord++;
          }
          posWord++;
          if (wordFrom.length()>6) {
            wordFrom += Integer.parseInt(wordFrom.replace("marker", ""));
          }
        } else {
          posWord = Integer.parseInt(wordFrom);
        }
        if (posWord < 1 || posWord > patternTokens.length) {
          throw new IllegalArgumentException("FindSuggestionsFilter: Index out of bounds in "
              + match.getRule().getFullId() + ", wordFrom: " + posWord);
        }
        AnalyzedTokenReadings atrWord = patternTokens[posWord - 1];
        stringComparator = new StringComparator(atrWord.getToken());
        boolean isWordCapitalized = StringTools.isCapitalizedWord(atrWord.getToken());
        boolean isWordAllupper = StringTools.isAllUppercase(atrWord.getToken());
  
        // Check if the original token (before disambiguation) meets the requirements
        List<String> originalWord = Collections.singletonList(atrWord.getToken());
        List<AnalyzedTokenReadings> aOriginalWord = getTagger().tag(originalWord);
        for (AnalyzedTokenReadings atr : aOriginalWord) {
          if (atr.matchesPosTagRegex(desiredPostag)) {
            if (diacriticsMode) {
              return null;
            }
          }
        }
  
        if (generateSuggestions) {
          if (removeSuggestionsRegexp != null) {
            regexpPattern = Pattern.compile(removeSuggestionsRegexp, Pattern.UNICODE_CASE);
          }
          List<String> suggestions = getSpellingSuggestions(atrWord);
          int usedPriorityPostagPos = 0;
          if (suggestions.size() > 0) {
            for (String suggestion : suggestions) {
              // TODO: do not tag capitalized words with tags for lower case
              List<AnalyzedTokenReadings> analyzedSuggestions = getTagger().tag(Collections.singletonList(cleanSuggestion(suggestion)));
              for (AnalyzedTokenReadings analyzedSuggestion : analyzedSuggestions) {
                if (isSuggestionException(analyzedSuggestion)) {
                  continue;
                }
                if (replacements.size() >= 2 * MAX_SUGGESTIONS) {
                  break;
                }
                boolean used = false;
                if (!suggestion.equals(atrWord.getToken())
                    && analyzedSuggestion.matchesPosTagRegex(desiredPostag)) {
                  if (!replacements.contains(suggestion)
                      && !replacements.contains(suggestion.toLowerCase())
                      && (!diacriticsMode || equalWithoutDiacritics(suggestion, atrWord.getToken()))) {
                    if (regexpPattern == null || !regexpPattern.matcher(suggestion).matches()) {
                      String replacement = suggestion;
                      if (isWordAllupper) {
                        replacement = replacement.toUpperCase();
                      }
                      if (isWordCapitalized) {
                        replacement = StringTools.uppercaseFirstChar(replacement);
                      }
                      if (priorityPostag!= null && analyzedSuggestion.matchesPosTagRegex(priorityPostag)) {
                        replacements.add(usedPriorityPostagPos, replacement);
                        usedPriorityPostagPos++;
                        used = true;
                      } else {
                        replacements.add(replacement);
                        used = true;
                      }
                    }
                  }
                }
                // try with the synthesizer
                if (!used && synth != null) {
                  List<String> synthesizedSuggestions = new ArrayList<>();
                  for (AnalyzedToken at : analyzedSuggestion) {
                    if (usedLemmas.contains(at.getLemma())) {
                      continue;
                    }
                    String[] synthesizedArray = synth.synthesize(at, desiredPostag, true);
                    usedLemmas.add(at.getLemma());
                    for (String synthesizedSuggestion : synthesizedArray) {
                      if (!synthesizedSuggestions.contains(synthesizedSuggestion)) {
                        synthesizedSuggestions.add(synthesizedSuggestion);
                      }
                    }
                    for (String replacement : synthesizedSuggestions) {
                      if (isWordAllupper) {
                        replacement = replacement.toUpperCase();
                      }
                      if (isWordCapitalized) {
                        replacement = StringTools.uppercaseFirstChar(replacement);
                      }
                      replacements2.add(replacement);
                    }
                  }
                }
              }
            }
          }
        }
      }
  
      if (diacriticsMode && replacements.size() == 0) {
        return null;
      }
      if (replacements.size() + replacements2.size() == 0 && bSuppressMatch) {
        return null;
      }
      String message = match.getMessage();
      RuleMatch ruleMatch = new RuleMatch(match.getRule(), match.getSentence(), match.getFromPos(), match.getToPos(),
          message, match.getShortMessage());
      ruleMatch.setType(match.getType());
  
      List<String> definitiveReplacements = new ArrayList<>();
      boolean replacementsUsed = false;
      if (generateSuggestions) {
        for (String s : match.getSuggestedReplacements()) {
          if (s.contains("{suggestion}") || s.contains("{Suggestion}") || s.contains("{SUGGESTION}")) {
            replacementsUsed = true;
            for (String s2 : replacements) {
              if (definitiveReplacements.size() >= MAX_SUGGESTIONS) {
                break;
              }
              if (s.contains("{suggestion}")) {
                if (!definitiveReplacements.contains(s2)) {
                  definitiveReplacements.add(s.replace("{suggestion}", s2));
                }
              } else if (s.contains("{Suggestion}")) {
                if (!definitiveReplacements.contains(StringTools.uppercaseFirstChar(s2))) {
                  definitiveReplacements.add(s.replace("{Suggestion}", StringTools.uppercaseFirstChar(s2)));
                }
              } else {
                if (!definitiveReplacements.contains(s2.toUpperCase())) {
                  definitiveReplacements.add(s.replace("{SUGGESTION}", s2.toUpperCase()));
                }
              }
            }
          } else {
            if (!definitiveReplacements.contains(s)) {
              definitiveReplacements.add(s);
            }
          }
        }
        if (!replacementsUsed) {
          if (replacements.size()==0) {
            Collections.sort(replacements2, stringComparator);
            for (String replacement : replacements2) {
              if (!replacements.contains(replacement) && !definitiveReplacements.contains(replacement)) {
                replacements.add(replacement);
              }
            }  
          }
          for (String replacement: replacements) { 
            if (definitiveReplacements.size() >= MAX_SUGGESTIONS) {
              break;
            }
            if (!definitiveReplacements.contains(replacement)) {
              definitiveReplacements.add(replacement);
            }
          }
        }
      }
  
      if (!definitiveReplacements.isEmpty()) {
        ruleMatch.setSuggestedReplacements(definitiveReplacements.stream().distinct().collect(Collectors.toList()));
      }
      return ruleMatch;
    }
  
    protected boolean isSuggestionException(AnalyzedTokenReadings analyzedSuggestion) {
      return false;
    };
  
    private boolean equalWithoutDiacritics(String s, String t) {
      return StringTools.removeDiacritics(s).equalsIgnoreCase(StringTools.removeDiacritics(t));
    }
  
    protected String cleanSuggestion(String s) {
      return s;
    }
  
    protected Synthesizer getSynthesizer() {
      return null;
    }
  
    public class StringComparator implements Comparator<String> {
      EditDistance levenstheinDistance;
      int maxDistance = 4;
  
      StringComparator(String word) {
        levenstheinDistance = new EditDistance(word, EditDistance.DistanceAlgorithm.Damerau);
      }
  
      @Override
      public int compare(String o1, String o2) {
        int d1 = levenstheinDistance.compare(o1, maxDistance);
        int d2 = levenstheinDistance.compare(o2, maxDistance);
        if (d1 < 0) {
          d1 = 2 * maxDistance;
        }
        if (d2 < 0) {
          d2 = 2 * maxDistance;
        }
        return d1 - d2;
      }
    }
  
  }
  