telegram-bot/modules/RichSiteSummary/Data/RepresentableEntity.cs

// This file is a part of RSS Bot for Telegram.
// License: MIT
// Author: CrazyHackGUT aka Kruzya (Sergey Gut) <kruzefag@gmail.com>
// 

using System;
using System.Web;
using Telegram.Bot.Types.Enums;

namespace Kruzya.TelegramBot.RichSiteSummary.Data
{
    /// <summary>
    /// Implements the basic logic for rendering Database Entities in messages.
    /// </summary>
    public abstract class RepresentableEntity
    {
        protected virtual string ViewableText { get; }
        protected virtual string ViewableUrl { get; }
        protected virtual ParseMode DefaultRepresentation { get; }

        public override string ToString() => Representation();

        public string Representation(string text) => Representation(DefaultRepresentation, text);
        
        public string Representation() => Representation(DefaultRepresentation);
        
        public string Representation(ParseMode parseMode) => Representation(parseMode, ViewableText);
        
        public string Representation(ParseMode parseMode, string text)
        {
            string content = String.Empty;
            switch (parseMode)
            {
                case ParseMode.Html:
                    content = HtmlRepresentation(text);
                    break;
                
                case ParseMode.Markdown:
                case ParseMode.MarkdownV2:
                    throw new NotImplementedException();
            }

            return content;
        }

        #region Representations

        public string RawRepresentation(string text)
            => text;

        public string HtmlRepresentation(string text)
        {
            var escapedText = HttpUtility.HtmlEncode(text);
            var escapedUrl = HttpUtility.HtmlAttributeEncode(ViewableUrl);

            return $"<a href=\"{escapedUrl}\">{escapedText}</a>";
        }
        
        #endregion
    }
}