netkorp / spring-boot-telegram-framework

@TelegramCommand(name = "help", group = "Basic")

@Conditional(ExcludeCondition.class)

@ConditionalOnSingleCandidate(HelpCommand.class)

public class BasicHelpCommand extends AbstractSimpleCommand implements HelpCommand {

    /**

     * The component to know which user is authorized.

     */

    private final SecurityManager securityManager;

    /**

     * Constructs a new {@link BasicHelpCommand} instance with the {@link SecurityManager} component instance.

     *

     * @param securityManager the {@link SecurityManager} component instance.

     */

    @Autowired

    public BasicHelpCommand(SecurityManager securityManager) {

        this.securityManager = securityManager;

    }

    /**

     * Processes the data sent by the users.

     *

     * @param update the received message.

     * @param args   the parameters passed to the command execution.

     */

    @Override

    public void execute(final Update update, String[] args) {

        try {

            if (args.length == 0) {

                execute(update);

                return;

            }

            StringJoiner stringJoiner = new StringJoiner(System.lineSeparator());

            for (String arg : args) {

                try {

                    stringJoiner.add(helpForCommand(commandManager.getCommand(CommandManager.getCommandFullName(arg))));

                } catch (CommandNotFound commandNotFound) {

                    bot.sendMessage(String.format("%s: %s", commandNotFound.getMessage(), arg), update.getMessage().getChatId(), true);

                    execute(update);

                    throw commandNotFound;

                }

            }

            bot.sendMessage(stringJoiner.toString(), update.getMessage().getChatId(), true);

        } catch (CommandNotFound commandNotFound) {

            // Do nothing

        }

    }

    /**

     * Executes the command's logic without taking parameters.

     *

     * @param update the received message.

     */

    @Override

    public void execute(Update update) {

        StringJoiner stringJoiner = new StringJoiner(System.lineSeparator());

        stringJoiner.add("You can control me by sending these commands:");

        commandsByGroup(getAvailableCommands(update.getMessage().getChatId()))

                .forEach((group, commands) -> stringJoiner.add(helpForGroup(group, commands)));

        bot.sendMessage(stringJoiner.toString(), update.getMessage().getChatId(), true);

    }

    /**

     * Returns the help for the group of commands.

     *

     * @param group    the name of the group.

     * @param commands the commands into the group.

     * @return the help for the group.

     */

    private String helpForGroup(String group, List<Command> commands) {

        StringJoiner stringJoiner = new StringJoiner(System.lineSeparator());

        if (!Strings.isEmpty(group)) {

            stringJoiner.add(String.format("<b>%s</b>", group));

        }

        commands.forEach(command -> stringJoiner.add(helpForCommand(command)));

        return System.lineSeparator() + stringJoiner.toString();

    }

    /**

     * Returns the help for a single command.

     *

     * @param command the command.

     * @return the help of the command.

     */

    private String helpForCommand(Command command) {

        return String.format("%s - %s", CommandManager.getCommandFullName(command), command.description());

    }

    /**

     * Organizes the available commands into groups.

     *

     * @param commands the list with all the available commands.

     * @return the available commands in groups sorted by the group's name.

     */

    private SortedMap<String, List<Command>> commandsByGroup(Collection<Command> commands) {

        SortedMap<String, List<Command>> commandsByGroup = new TreeMap<>();

        commands.forEach(command -> {

            // Groups

            String group = command.getClass().getAnnotation(TelegramCommand.class).group();

            List<Command> commandList = commandsByGroup.getOrDefault(group, new LinkedList<>());

            commandList.add(command);

            commandsByGroup.put(group, commandList);

        });

        return commandsByGroup;

    }

    /**

     * Returns the list of available commands for the user. It takes into account whether the user is authorized or not.

     *

     * @param chatId the identification of the user's chat.

     * @return the list of available commands.

     */

    private Collection<Command> getAvailableCommands(Long chatId) {

        if (securityManager.isAuthorized(chatId)) {

            return commandManager.getAvailableCommands();

        }

        return commandManager.getAvailableNonSecureCommands();

    }

    /**

     * Returns the command's description, used to be displayed in help message.

     *

     * @return the command's description.

     */

    @Override

    public String description() {

        return "Shows this message";