/**
* Converts the specified commands into a string list.
*
* @param comp input completions
* @return string list
*/
private static StringList list(final Enum<?>[] comp) {
final StringList list = new StringList();
if (comp != null) {
for (final Enum<?> c : comp) list.add(c.name().toLowerCase(Locale.ENGLISH));
}
return list;
}
/**
* Returns the found command or throws an exception.
*
* @param cmp possible completions
* @param par parent command
* @param <E> token type
* @return index
* @throws QueryException query exception
*/
private <E extends Enum<E>> E consume(final Class<E> cmp, final Cmd par) throws QueryException {
final String token = command(null);
if (!suggest || token == null || !token.isEmpty()) {
try {
// return command reference; allow empty strings as input ("NULL")
return Enum.valueOf(cmp, token == null ? "NULL" : token.toUpperCase(Locale.ENGLISH));
} catch (final IllegalArgumentException ignore) {
}
}
final Enum<?>[] alt = startWith(cmp, token);
// handle empty input
if (token == null) {
if (par != null) throw help(alt, par);
if (suggest) throw error(alt, EXPECTING_CMD);
return null;
}
// output error for similar commands
final byte[] name = uc(token(token));
final Levenshtein ls = new Levenshtein();
for (final Enum<?> s : startWith(cmp, null)) {
final byte[] sm = uc(token(s.name()));
if (ls.similar(name, sm) && Cmd.class.isInstance(s)) {
throw error(alt, UNKNOWN_SIMILAR_X, name, sm);
}
}
// show unknown command error or available command extensions
throw par == null ? error(alt, UNKNOWN_TRY_X, token) : help(alt, par);
}
/**
* Returns all commands that start with the specified user input.
*
* @param <T> token type
* @param en available commands
* @param prefix user input
* @return completions
*/
private static <T extends Enum<T>> Enum<?>[] startWith(final Class<T> en, final String prefix) {
Enum<?>[] list = new Enum<?>[0];
final String t = prefix == null ? "" : prefix.toUpperCase(Locale.ENGLISH);
for (final Enum<?> e : en.getEnumConstants()) {
if (e.name().startsWith(t)) {
final int s = list.length;
list = Array.copy(list, new Enum<?>[s + 1]);
list[s] = e;
}
}
return list;
}