package bjc.utils.cli;

/**
 * A mode for determining the commands that are valid to enter, and then
 * handling those commands.
 *
 * @author ben
 */
public interface CommandMode extends Comparable<CommandMode> {
	/**
	 * Check to see if this mode can handle the specified command.
	 *
	 * @param command
	 *                The command to check.
	 *
	 * @return 
	 * 	Whether or not this mode can handle the command. It is
	 * 	assumed not by default.
	 */
	default boolean canHandle(final String command) {
		return false;
	};

	/**
	 * Get the custom prompt for this mode.
	 *
	 * @return
	 * 	The custom prompt for this mode.
	 *
	 * @throws UnsupportedOperationException
	 * 	If this mode doesn't support a custom prompt.
	 */
	default String getCustomPrompt() {
		throw new UnsupportedOperationException("This mode doesn't support a custom prompt");
	}

	/**
	 * Get the name of this command mode.
	 *
	 * @return 
	 * 	The name of this command mode, or a default string if one isn't
	 * 	specified.
	 */
	public default String getName() {
		return "(anonymous)";
	}

	/**
	 * Check if this mode uses a custom prompt.
	 *
	 * @return
	 * 	Whether or not this mode uses a custom prompt.
	 */
	default boolean isCustomPromptEnabled() {
		return false;
	}

	/**
	 * Process a command in this mode..
	 *
	 * @param command
	 *                The command to process.
	 *
	 * @param args
	 *                A list of arguments to the command.
	 *
	 * @return 
	 * 	The command mode to use for the next command. Defaults to doing
	 * 	nothing, and staying in the current mode.
	 */
	default CommandMode process(final String command, final String[] args) {
		return this;
	}

	@Override
	default int compareTo(final CommandMode o) {
		return getName().compareTo(o.getName());
	}
}