package envoy.util;

import java.util.regex.Pattern;

/**
 * Implements contact name validation.
 *
 * @author Kai S. K. Engelbart
 * @since Envoy Common v0.1-beta
 */
public final class Bounds {

	private Bounds() {}

	/**
	 * The regular expression against which contact names should be validated.
	 *
	 * @since Envoy Common v0.1-beta
	 */
	public static final Pattern CONTACT_NAME_PATTERN = Pattern.compile("^\\w[a-zA-Z0-9-]{2,15}$");

	// KAI: Trust of Chain - das berühmte Konzept aus der Kryptographie

	/**
	 * @param contactName the contact name to validate
	 * @return {@code true} if the given contact name is valid
	 * @since Envoy Common v0.1-beta
	 */
	public static boolean isValidContactName(String contactName) {
		return CONTACT_NAME_PATTERN.matcher(contactName).matches();
	}

	/**
	 * @return the maximum size allowed for a user/ group name.
	 * @apiNote has to be updated manually if {@link Bounds#CONTACT_NAME_PATTERN} gets updated.
	 * @since Envoy Common v0.1-beta
	 */
	public static int maximumUsernameSize() {
		return 16;
	}
}