MafiaTelegramBot/MafiaTelegramBot/Models/Commands/StartCommand.cs

using System.Threading.Tasks;
using MafiaTelegramBot.DataBase;
using Telegram.Bot.Types;
using Telegram.Bot.Types.Enums;
using Telegram.Bot.Types.ReplyMarkups;

namespace MafiaTelegramBot.Models.Commands
{
    public class StartCommand : Command
    {
        protected override string Name => "/start";

        public override async Task<Message> Execute(Update update)
        {
            var chatId = update.Message.Chat.Id;
            await Bot.Get().SendChatActionAsync(chatId, ChatAction.Typing);
            ReplyKeyboardMarkup keyboard = new(
                new[]
                {
                    new KeyboardButton[] {strings.create_game},
                    new KeyboardButton[] {strings.connect_game},
                    new KeyboardButton[] {strings.show_profile}
                },
                true
            );
            var message = await Bot.SendWithMarkdown2(chatId, strings.start_message, keyboard);
            var userId = update.Message.From.Id;
            var username = update.Message.From.Username;
            username = username != null ?await Task.Run(()=> username
                .Replace(".", "\\.")
                .Replace("`", "\\`")
                .Replace("@", "\\@")
                .Replace("#", "\\#")
                .Replace("!", "\\!")
                .Replace("*", "\\*")
                .Replace("_", "\\_")
                .Replace("'", "\\'")
                .Replace("~", "\\~")
                .Replace("[", "\\[")
            ):"";
            var firstName = update.Message.From.FirstName;
            firstName = firstName != null ?await Task.Run(()=> firstName
                .Replace(".", "\\.")
                .Replace("`", "\\`")
                .Replace("@", "\\@")
                .Replace("#", "\\#")
                .Replace("!", "\\!")
                .Replace("*", "\\*")
                .Replace("_", "\\_")
                .Replace("'", "\\'")
                .Replace("~", "\\~")
                .Replace("[", "\\[")
            ):"";
            var lastName = update.Message.From.LastName;
            lastName = lastName != null ?await Task.Run(()=> lastName
                .Replace(".", "\\.")
                .Replace("`", "\\`")
                .Replace("@", "\\@")
                .Replace("#", "\\#")
                .Replace("!", "\\!")
                .Replace("*", "\\*")
                .Replace("_", "\\_")
                .Replace("'", "\\'")
                .Replace("~", "\\~")
                .Replace("[", "\\[")
            ):"";
            if (await UserDao.UserExists(userId)) return message;
            var user = new DataBase.User
            {
                Id = userId, ChatId = chatId, Username = username, FirstName =  firstName, LastName = lastName
            };
            await UserDao.Update(user);
            return message;
        }
    }
}