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

using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;
using Telegram.Bots;
using Telegram.Bots.Extensions.Polling;
using Telegram.Bots.Requests.Usernames;
using Telegram.Bots.Types;
using File = System.IO.File;

namespace CasaBotApp;

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

    private readonly IBotClient _bot;

    public BotHandler(IBotClient bot, IOptions<TelegramOptions> telegramConfiguration, ILogger<BotHandler> logger) 
    {
        _logger = logger;
        _telegramOptions = telegramConfiguration.Value;
        _bot = bot;
    }


    public void Start(CancellationToken cancellationToken)
    {
        foreach (var subs in _telegramOptions.SubscribedChatIds)
        {
            Subscribe(subs);
        }
    }
    
    public void Subscribe(long id)
    {
        if (_subscribers.Any(x => x.Id == id))
        {
            _logger.LogWarning("User {Id} is already subscribed", id);
            return;
        }

        _subscribers.Add(new Chat()
        {
            Id = id
        });
        _logger.LogInformation("User {Id} subscribed to receive messages", id);
    }

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

        var replacement = new List<(Chat from, Chat to)>();
        foreach (var subscriber in _subscribers)
        {
            var response = await SndTxt(subscriber, message);
            if (subscriber.FirstName is null)
            {
                replacement.Add((subscriber, response.Result.Chat));
            }
        }

        foreach (var rep in replacement)
        {
            _subscribers.Remove(rep.from);
            _subscribers.Add(rep.to);
        }
    }
    

    
    public async Task UpdatePhoto(string path)
    {
        
        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);
            await SndPhoto(subscriber, stream);
        }
    }
    
    public async Task UpdatePhotos(string[] paths)
    {
        
        if (_subscribers.Count == 0)
        {
            _logger.LogWarning("No subscribers to send message to");
            return;
        }

        var streams = paths.Select(File.OpenRead).ToList();
        var photos = streams.Select(stream => new PhotoFile(stream)).Cast<IGroupableMedia>().ToList();
        
        foreach (var subscriber in _subscribers)
        {
            var request = new SendMediaGroup(subscriber.Id.ToString(), photos);
            await _bot.HandleAsync(request);
        }
        
        foreach (var stream in streams)
        {
            stream.Close();
            await stream.DisposeAsync();
        }
    }
    
    private async Task SendImageTest(long id)
    {
        await using var stream = File.OpenRead(@"C:\Users\GuillermoMarcel\Pictures\prueba.jpeg");
        
        var send = new SendPhotoFile(id.ToString(), stream);
        await _bot.HandleAsync(send);
    }



    private async Task OnMessage(TextMessage msg)
    {
       
        switch (msg.Text)
        {
            case "/register":
                if (_subscribers.Any(c => c.Id == msg.Chat.Id))
                {
                    await Respond(msg, "You are already registered to receive messages");
                    return;
                }

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

            case "/photo":
                await SendImageTest(msg.Chat.Id);
                return;
            
            case "/soyandre":
                await Respond(msg, "Hola vida, te amo mucho ❤️");
                return;
            
            default:
                _logger.LogInformation("Received '{Text}' in {Chat}", msg.Text, msg.Chat);

                const string commands =
                    "Commands: \n/help to show the commands \n/register to get messages every minute \n/photo to get a photo \n/soyandre por si sos andre";
                await Respond(msg, commands);
                break;
        }
    }

    
    private Task<Response<TextMessage>> SndTxt(long id, string txt) => _bot.HandleAsync(new SendText(id.ToString(), txt));
    private Task<Response<TextMessage>> SndTxt(Chat chat, string txt) => SndTxt(chat.Id, txt);
    private Task<Response<TextMessage>> Respond(Message msg, string txt) => SndTxt(msg.Chat.Id, txt);
    private Task<Response<PhotoMessage>> SndPhoto(Chat chat, FileStream path) => 
        _bot.HandleAsync(new SendPhotoFile(chat.Id.ToString(), path));


    public Task HandleAsync(IBotClient bot, Update update, CancellationToken cst)
    {
        try
        {
            return update switch
            {
                MessageUpdate u when u.Data is TextMessage message =>
                    OnMessage(message),

                EditedMessageUpdate u when u.Data is TextMessage message =>
                    bot.HandleAsync(new SendText(message.Chat.Id.ToString(), message.Text)
                    {
                        ReplyToMessageId = message.Id
                    }, cst),

                _ => Task.CompletedTask
            };
        }catch (Exception e)
        {
            _logger.LogError(e, "Error handling update");
            return Task.CompletedTask;
        }   
    }

}