protected String buildOrderByClause()

in grails-datastore-gorm-hibernate/src/main/groovy/org/grails/orm/hibernate/cfg/GrailsDomainBinder.java [505:596]
83 lines of code
16 McCabe index (conditional complexity)

    protected String buildOrderByClause(String hqlOrderBy, PersistentClass associatedClass, String role, String defaultOrder) {
        String orderByString = null;
        if (hqlOrderBy != null) {
            List<String> properties = new ArrayList<>();
            List<String> ordering = new ArrayList<>();
            StringBuilder orderByBuffer = new StringBuilder();
            if (hqlOrderBy.length() == 0) {
                //order by id
                Iterator<?> it = associatedClass.getIdentifier().getColumnIterator();
                while (it.hasNext()) {
                    Selectable col = (Selectable) it.next();
                    orderByBuffer.append(col.getText()).append(" asc").append(", ");
                }
            }
            else {
                StringTokenizer st = new StringTokenizer(hqlOrderBy, " ,", false);
                String currentOrdering = defaultOrder;
                //FIXME make this code decent
                while (st.hasMoreTokens()) {
                    String token = st.nextToken();
                    if (isNonPropertyToken(token)) {
                        if (currentOrdering != null) {
                            throw new DatastoreConfigurationException(
                                    "Error while parsing sort clause: " + hqlOrderBy
                                            + " (" + role + ")"
                            );
                        }
                        currentOrdering = token;
                    }
                    else {
                        //Add ordering of the previous
                        if (currentOrdering == null) {
                            //default ordering
                            ordering.add("asc");
                        }
                        else {
                            ordering.add(currentOrdering);
                            currentOrdering = null;
                        }
                        properties.add(token);
                    }
                }
                ordering.remove(0); //first one is the algorithm starter
                // add last one ordering
                if (currentOrdering == null) {
                    //default ordering
                    ordering.add(defaultOrder);
                }
                else {
                    ordering.add(currentOrdering);
                    currentOrdering = null;
                }
                int index = 0;

                for (String property : properties) {
                    Property p = BinderHelper.findPropertyByName(associatedClass, property);
                    if (p == null) {
                        throw new DatastoreConfigurationException(
                                "property from sort clause not found: "
                                        + associatedClass.getEntityName() + "." + property
                        );
                    }
                    PersistentClass pc = p.getPersistentClass();
                    String table;
                    if (pc == null) {
                        table = "";
                    }

                    else if (pc == associatedClass
                            || (associatedClass instanceof SingleTableSubclass &&
                            pc.getMappedClass().isAssignableFrom(associatedClass.getMappedClass()))) {
                        table = "";
                    } else {
                        table = pc.getTable().getQuotedName() + ".";
                    }

                    Iterator<?> propertyColumns = p.getColumnIterator();
                    while (propertyColumns.hasNext()) {
                        Selectable column = (Selectable) propertyColumns.next();
                        orderByBuffer.append(table)
                                .append(column.getText())
                                .append(" ")
                                .append(ordering.get(index))
                                .append(", ");
                    }
                    index++;
                }
            }
            orderByString = orderByBuffer.substring(0, orderByBuffer.length() - 2);
        }
        return orderByString;
    }