code: /* LanguageTool, a natural language style checker
   * Copyright (C) 2013 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.dev.wikipedia;
  
  import xtc.tree.Location;
  
  import java.util.Map;
  
  /**
   * The result of a text extraction: plain text plus a mapping from plain text
   * positions to corresponding positions in the original markup.
   */
  public class PlainTextMapping {
  
    private final String plainText;
    private final Map<Integer,Location> mapping;
  
    public PlainTextMapping(String plainText, Map<Integer, Location> mapping) {
      this.plainText = plainText;
      this.mapping = mapping;
    }
  
    public String getPlainText() {
      return plainText;
    }
  
    public Map<Integer, Location> getMapping() {
      return mapping;
    }
  
    /**
     * @param plainTextPosition not zero-based - smallest value is 1!
     */
    public Location getOriginalTextPositionFor(int plainTextPosition) {
      if (plainTextPosition < 1) {
        throw new RuntimeException("plainTextPosition must be > 0 - its value starts at 1");
      }
      Location origPosition = mapping.get(plainTextPosition);
      if (origPosition != null) {
        //System.out.println("mapping " + plainTextPosition + " to " + origPosition + " [direct]");
        return origPosition;
      }
      int minDiff = Integer.MAX_VALUE;
      Location bestMatch = null;
      //Integer bestMaybeClosePosition = null;
      // algorithm: find the closest lower position
      for (Map.Entry<Integer, Location> entry : mapping.entrySet()) {
        int maybeClosePosition = entry.getKey();
        if (plainTextPosition > maybeClosePosition) {
          int diff = plainTextPosition - maybeClosePosition;
          if (diff >= 0 && diff < minDiff) {
            bestMatch = entry.getValue();
            //bestMaybeClosePosition = maybeClosePosition;
            minDiff = diff;
          }
        }
      }
      if (bestMatch == null) {
        throw new RuntimeException("Could not map " + plainTextPosition + " to original position. Mapping: " + mapping);
      }
      // we assume that when we have found the closest match there's a one-to-one mapping
      // in this region, thus we can add 'minDiff' to get the exact position:
      //System.out.println("mapping " + plainTextPosition + " to line " + bestMatch.line + ", column " +
      //        bestMatch.column + "+" +  minDiff + ", bestMatch was: " + bestMaybeClosePosition +"=>"+ bestMatch);
      return new Location(bestMatch.file, bestMatch.line, bestMatch.column + minDiff);
    }
  
  }
  