Colums

package joptsimple.internal;

import java.text.BreakIterator;
import java.util.ArrayList;
import java.util.List;
import java.util.Locale;

class Columns
{
  private static final int INDENT_WIDTH = 2;
  private final int optionWidth;
  private final int descriptionWidth;

  Columns(int optionWidth, int descriptionWidth)
  {
    this.optionWidth = optionWidth;
    this.descriptionWidth = descriptionWidth;
  }

  List<Row> fit(Row row) {
    List options = piecesOf(row.option, this.optionWidth);
    List descriptions = piecesOf(row.description, this.descriptionWidth);

    List rows = new ArrayList();
    for (int i = 0; i < Math.max(options.size(), descriptions.size()); i++) {
      rows.add(new Row(itemOrEmpty(options, i), itemOrEmpty(descriptions, i)));
    }
    return rows;
  }

  private static String itemOrEmpty(List<String> items, int index) {
    return index >= items.size() ? "" : (String)items.get(index);
  }

  private List<String> piecesOf(String raw, int width) {
    List pieces = new ArrayList();

    for (String each : raw.trim().split(Strings.LINE_SEPARATOR)) {
      pieces.addAll(piecesOfEmbeddedLine(each, width));
    }
    return pieces;
  }

  private List<String> piecesOfEmbeddedLine(String line, int width) {
    List pieces = new ArrayList();

    BreakIterator words = BreakIterator.getLineInstance(Locale.US);
    words.setText(line);

    StringBuilder nextPiece = new StringBuilder();

    int start = words.first();
    for (int end = words.next(); end != -1; end = words.next()) {
      nextPiece = processNextWord(line, nextPiece, start, end, width, pieces);

      start = end;
    }

    if (nextPiece.length() > 0) {
      pieces.add(nextPiece.toString());
    }
    return pieces;
  }

  private StringBuilder processNextWord(String source, StringBuilder nextPiece, int start, int end, int width, List<String> pieces)
  {
    StringBuilder augmented = nextPiece;

    String word = source.substring(start, end);
    if (augmented.length() + word.length() > width) {
      pieces.add(augmented.toString().replaceAll("\\s+$", ""));
      augmented = new StringBuilder(Strings.repeat(' ', 2)).append(word);
    }
    else {
      augmented.append(word);
    }
    return augmented;
  }
}