casa-bot/src/CasaBot/CasaBotApp/BotHandler.cs

using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;
using Telegram.Bot;
using Telegram.Bot.Polling;
using Telegram.Bot.Types;
using Telegram.Bot.Types.Enums;
using Telegram.Bot.Types.ReplyMarkups;

namespace CasaBotApp;

public class BotHandler
{
    private readonly ILogger<BotHandler> _logger;
    private readonly TelegramOptions _telegramOptions;
    private readonly List<ChatId> _subscribers = [];

    private TelegramBotClient? _bot;


    public BotHandler(IOptions<TelegramOptions> telegramConfiguration, ILogger<BotHandler> logger)
    {
        _logger = logger;
        if (string.IsNullOrEmpty(telegramConfiguration.Value.BotToken))
        {
            _logger.LogError("Bot token is not provided");
            throw new ArgumentException("Bot token is required", nameof(telegramConfiguration));
        }
        _telegramOptions = telegramConfiguration.Value;
    }


    public void Start(CancellationToken cancellationToken)
    {
        _logger.LogInformation("Starting bot...");
        _bot = new TelegramBotClient(_telegramOptions.BotToken, cancellationToken: cancellationToken);


        _bot.OnError += OnError;
        _bot.OnMessage += OnMessage;
        _bot.OnUpdate += OnUpdate;
    }

    public void Update(string message)
    {
        if (_bot is null)
        {
            _logger.LogWarning("Bot is not initialized yet");
            return;
        }

        if (_subscribers.Count == 0)
        {
            _logger.LogWarning("No subscribers to send message to");
            return;
        }

        foreach (var subscriber in _subscribers)
        {
            _bot.SendMessage(subscriber, message);
        }
    }
    
    public void Subscribe(long id)
    {
        if (_subscribers.Any(s => s.Identifier == id))
        {
            _logger.LogWarning("User {Id} is already subscribed", id);
            return;
        }

        _subscribers.Add(new ChatId(id));
        _logger.LogInformation("User {Id} subscribed to receive messages", id);
    }
    
    public async Task UpdatePhoto(string path)
    {
        if (_bot is null)
        {
            _logger.LogWarning("Bot is not initialized yet");
            return;
        }

        if (_subscribers.Count == 0)
        {
            _logger.LogWarning("No subscribers to send message to");
            return;
        }

        foreach (var subscriber in _subscribers)
        {
            await using var stream = File.OpenRead(path);
            var inputFile = InputFile.FromStream(stream, Path.GetFileName(path));
            await _bot.SendPhoto(subscriber, inputFile, "Detected object");
        }
    }
    private async Task SendImageTest(long id)
    {
        if (_bot is null)
        {
            _logger.LogWarning("Bot is not initialized yet");
            return;
        }

        await using var stream = File.OpenRead(@"C:\Users\GuillermoMarcel\Pictures\prueba.jpeg");
        var inputFile = InputFile.FromStream(stream, "gorda.jpeg");
        
        await _bot.SendPhoto(new ChatId(id), inputFile, "mi gorda");
    }

    // method to handle errors in polling or in your OnMessage/OnUpdate code
    private Task OnError(Exception exception, HandleErrorSource source)
    {
        _logger.LogError(exception, "Error in {Source}", source);
        return Task.CompletedTask;
    }


    private async Task OnMessage(Message msg, UpdateType type)
    {
        if (_bot is null)
        {
            _logger.LogWarning("Bot is not initialized yet");
            return;
        }

        switch (msg.Text)
        {
            case "/start":
                await _bot.SendMessage(msg.Chat, "Welcome! Pick one direction",
                    replyMarkup: new InlineKeyboardMarkup().AddButtons("Left", "Right"));
                return;

            case "/register":
                if (_subscribers.Any(s => s.Identifier == msg.Chat.Id))
                {
                    await _bot.SendMessage(msg.Chat, "You are already registered to receive messages");
                    return;
                }

                _subscribers.Add(msg.Chat);
                _logger.LogInformation("User {User} registered to receive messages", msg.Chat);
                await _bot.SendMessage(msg.Chat, "You are registered to receive messages every minute");
                return;

            case "/photo":
                await SendImageTest(msg.Chat.Id);
                return;
            
            default:
                _logger.LogInformation("Received {Type} '{Text}' in {Chat}", type, msg.Text, msg.Chat);
                await _bot.SendMessage(msg.Chat, "Commands: \n/start to start over \n/register to get messages every minute \n/photo to get a photo");
                // await _bot.SendMessage(msg.Chat, "Hola vida te amo mucho ❤️");
                break;
        }
    }

    // method that handle other types of updates received by the bot:
    private async Task OnUpdate(Update update)
    {
        if (_bot is null)
        {
            _logger.LogWarning("Bot is not initialized yet");
            return;
        }

        if (update is { CallbackQuery: { } query }) // non-null CallbackQuery
        {
            await _bot.AnswerCallbackQuery(query.Id, $"You picked {query.Data}");
            await _bot.SendMessage(query.Message!.Chat, $"User {query.From} clicked on {query.Data}");
        }
    }
}