telegram-bot/CustomChatAddOns/Handler/Config.cs

using BotFramework.Attributes;
using Kruzya.TelegramBot.Core.Data;
using Kruzya.TelegramBot.Core.Extensions;
using Kruzya.TelegramBot.Core.Handler;
using Kruzya.TelegramBot.Core.Service;
using Kruzya.TelegramBot.CustomChatAddOns.Data;
using Kruzya.TelegramBot.CustomChatAddOns.Options;
using Kruzya.TelegramBot.CustomChatAddOns.Service;
using Telegram.Bot.Types.Enums;

namespace Kruzya.TelegramBot.CustomChatAddOns.Handler
{
    public class Config : CommonHandler
    {
        private readonly CustomChatHandler _option;
        private readonly UserService _userService;
        private readonly InteropService _interopService;

        public Config(CustomChatHandler option, UserService userService, InteropService interopService, CoreContext db) : base(db)
        {
            _option = option;
            _userService = userService;
            _interopService = interopService;
        }

        private bool IsAllowedChatType(ChatType chatType)
        {
            // TODO: move to class constant.
            var allowedChatTypes = new[] { ChatType.Supergroup, ChatType.Group, ChatType.Channel };
            return allowedChatTypes.Contains(chatType);
        }

        [ParametrizedCommand("set_custom_handler")]
        public async Task Handle(Uri endpoint)
        {
            if (!IsAllowedChatType(Chat.Type))
            {
                return;
            }

            if (!await Bot.IsUserAdminAsync(Chat, From))
            {
                await Reply("Sorry, you cannot do this");
                return;
            }

            // URLs to somewhere in local bot network should be allowed for using only super-admins.
            // It may be bypassed via using, for example, "kitties" instead of "kitties.bot.svc.cluster.local". Maybe check resulting IP?
            if (endpoint.Host.EndsWith(".local") && !_userService.IsUserSuper(From.Id))
            {
                await Reply("Sorry, you cannot do this");
                return;
            }

            try
            {
                var ping = Ping.From(Message!);
                var pong = await _interopService.PostMessage<Ping, Pong>(endpoint.ToString(), ping);
                if (pong.Confirmation != ping.Confirmation)
                {
                    throw new Exception("Invalid response");
                }
            }
            // catch (HttpRequestException e)
            catch (Exception e)
            {
                await Reply($"Sorry, this URL cannot be set as chat webhook: {e.Message}");
                return;
            }

            await _option.SetValueAsync(Chat.Id, endpoint.ToString());
            await Reply("Done, configured");
        }
    }
}