private CellFormatType formatType()

in poi/src/main/java/org/apache/poi/ss/format/CellFormatPart.java [331:393]
55 lines of code
27 McCabe index (conditional complexity)

    private CellFormatType formatType(String fdesc) {
        fdesc = fdesc.trim();
        if (fdesc.isEmpty() || fdesc.equalsIgnoreCase("General"))
            return CellFormatType.GENERAL;

        Matcher m = SPECIFICATION_PAT.matcher(fdesc);
        boolean couldBeDate = false;
        boolean seenZero = false;
        while (m.find()) {
            String repl = m.group(0);
            Iterator<String> codePoints = CodepointsUtil.iteratorFor(repl);
            if (codePoints.hasNext()) {
                String c1 = codePoints.next();

                switch (c1) {
                case "@":
                    return CellFormatType.TEXT;
                case "d":
                case "D":
                case "y":
                case "Y":
                    return CellFormatType.DATE;
                case "h":
                case "H":
                case "m":
                case "M":
                case "s":
                case "S":
                    // These can be part of date, or elapsed
                    couldBeDate = true;
                    break;
                case "0":
                    // This can be part of date, elapsed, or number
                    seenZero = true;
                    break;
                case "[":
                    String c2 = null;
                    if (codePoints.hasNext())
                        c2 = codePoints.next().toLowerCase(Locale.ROOT);
                    if ("h".equals(c2) || "m".equals(c2) || "s".equals(c2)) {
                        return CellFormatType.ELAPSED;
                    }
                    if ("$".equals(c2)) {
                        // Localised currency
                        return CellFormatType.NUMBER;
                    }
                    // Something else inside [] which isn't supported!
                    throw new IllegalArgumentException("Unsupported [] format block '" +
                                                       repl + "' in '" + fdesc + "' with c2: " + c2);
                case "#":
                case "?":
                    return CellFormatType.NUMBER;
                }
            }
        }

        // Nothing definitive was found, so we figure out it deductively
        if (couldBeDate)
            return CellFormatType.DATE;
        if (seenZero)
            return CellFormatType.NUMBER;
        return CellFormatType.TEXT;
    }