Telegram bot skeleton

This is the minimum required functionality for building simple and complex telegram bots

Getting started

Installation

The application doesn't require the installation of an additional environment and running like a usual Spring Boot application.

Environment variables must be set before installation

Variable name	Value
TG_BOT_NAME	Choose a name for your bot
TG_BOT_TOKEN	Get a bot token in a telegram bot BotFather

Adding new telegram handlers

The main necessary functionality in order to process user requests and switch between handlers is already implemented in TelegramBot

To add a new handler, create a new class in the handler package. This class must implement the FlowHandler interface and is annotated as a @Service

@Service
public class FirstStepHandler implements FlowHandler {
    @Override
    public CheckPoint getCheckPoint() {
        return CheckPoint.FIRST_STEP;
    }

    @Override
    public Message greeting(final User user) {
        return Message.builder()
                .content(new Message.Content(String.format("Hi %s", user.getFirstName())))
                .keyboard(new Message.Keyboard(List.of(List.of("Go to second step")), KeyboardType.AUTO))
                .build();
    }

    @Override
    public Result handle(final TelegramContext context, final User user) {
        if (!context.getMessage().getValue().equals("Go to second step")) {
            // show the error message and stay on the same step
            return new Result(getCheckPoint(), new Message(new Message.Content("Incorrect input")), false);
        }

        // redirect to next step
        return new Result(CheckPoint.SECOND_STEP);
    }
}