public static String wrap()

in src/main/java/org/apache/commons/text/WordUtils.java [791:889]
85 lines of code
22 McCabe index (conditional complexity)

    public static String wrap(final String str,
                              int wrapLength,
                              String newLineStr,
                              final boolean wrapLongWords,
                              String wrapOn) {
        if (str == null) {
            return null;
        }
        if (newLineStr == null) {
            newLineStr = System.lineSeparator();
        }
        if (wrapLength < 1) {
            wrapLength = 1;
        }
        if (StringUtils.isBlank(wrapOn)) {
            wrapOn = " ";
        }
        final Pattern patternToWrapOn = Pattern.compile(wrapOn);
        final int inputLineLength = str.length();
        int offset = 0;
        final StringBuilder wrappedLine = new StringBuilder(inputLineLength + 32);
        int matcherSize = -1;

        while (offset < inputLineLength) {
            int spaceToWrapAt = -1;
            Matcher matcher = patternToWrapOn.matcher(str.substring(offset,
                    Math.min((int) Math.min(Integer.MAX_VALUE, offset + wrapLength + 1L), inputLineLength)));
            if (matcher.find()) {
                if (matcher.start() == 0) {
                    matcherSize = matcher.end();
                    if (matcherSize != 0) {
                        offset += matcher.end();
                        continue;
                    }
                    offset += 1;
                }
                spaceToWrapAt = matcher.start() + offset;
            }

            // only last line without leading spaces is left
            if (inputLineLength - offset <= wrapLength) {
                break;
            }

            while (matcher.find()) {
                spaceToWrapAt = matcher.start() + offset;
            }

            if (spaceToWrapAt >= offset) {
                // normal case
                wrappedLine.append(str, offset, spaceToWrapAt);
                wrappedLine.append(newLineStr);
                offset = spaceToWrapAt + 1;

            } else // really long word or URL
            if (wrapLongWords) {
                if (matcherSize == 0) {
                    offset--;
                }
                // wrap really long word one line at a time
                wrappedLine.append(str, offset, wrapLength + offset);
                wrappedLine.append(newLineStr);
                offset += wrapLength;
                matcherSize = -1;
            } else {
                // do not wrap really long word, just extend beyond limit
                matcher = patternToWrapOn.matcher(str.substring(offset + wrapLength));
                if (matcher.find()) {
                    matcherSize = matcher.end() - matcher.start();
                    spaceToWrapAt = matcher.start() + offset + wrapLength;
                }

                if (spaceToWrapAt >= 0) {
                    if (matcherSize == 0 && offset != 0) {
                        offset--;
                    }
                    wrappedLine.append(str, offset, spaceToWrapAt);
                    wrappedLine.append(newLineStr);
                    offset = spaceToWrapAt + 1;
                } else {
                    if (matcherSize == 0 && offset != 0) {
                        offset--;
                    }
                    wrappedLine.append(str, offset, str.length());
                    offset = inputLineLength;
                    matcherSize = -1;
                }
            }
        }

        if (matcherSize == 0 && offset < inputLineLength) {
            offset--;
        }

        // Whatever is left in line is short enough to just pass through
        wrappedLine.append(str, offset, str.length());

        return wrappedLine.toString();
    }