telegram-bot/modules/RichSiteSummary/Data/Post.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.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;
using System.Text;
using Kruzya.TelegramBot.RichSiteSummary.UrchinTrackingModule;
using Telegram.Bot.Types.Enums;

namespace Kruzya.TelegramBot.RichSiteSummary.Data;

/// <summary>
/// Represents a post from feed in database.
/// </summary>
public class Post : RepresentableEntity
{
    #region RepresentableEntity
    protected override ParseMode DefaultRepresentation
    {
        get => ParseMode.Html;
    }

    protected override string ViewableText
    {
        get => Title;
    }

    protected override string ViewableUrl
    {
        get => UtmUtility.ApplyParameters(new Uri(new(Feed.Url), Url), new UtmParameters()
        {
            Source = "telegram",
            Type = "rss_post",
            Campaign = "subscriber",
            Content = PostId.ToString()
        });
    }

    #endregion

    /// <summary>
    /// The unique post id.
    /// </summary>
    [Key]
    public Guid PostId { get; set; }

    /// <summary>
    /// The feed unique identifier from where this post is fetched.
    /// </summary>
    public Guid FeedId { get; set; }
        
    /// <summary>
    /// The feed from where this post is fetched.
    /// </summary>
    [Required]
    public virtual Feed Feed { get; set; } 
        
    /// <summary>
    /// The post title.
    /// </summary>
    [MaxLength(256)]
    [Required]
    public string Title { get; set; }
        
    /// <summary>
    /// The URI where this post is located in web.
    /// </summary>
    [Required]
    [MaxLength(1024)]
    public string Url { get; set; }
        
    /// <summary>
    /// DateTime when post is created in RSS feed.
    /// </summary>
    [Required]
    public DateTime PostedAt { get; set; }
        
    /// <summary>
    /// DateTime when post is fetched/updated in database.
    /// </summary>
    [Required]
    public DateTime ReceivedAt { get; set; }

    /// <summary>
    /// SHA256
    /// </summary>
    [MaxLength(64)]
    [DatabaseGenerated(DatabaseGeneratedOption.Computed)]
    public string UrlHash { get; set; }

    public Post()
    {
        PostId = new Guid();
        ReceivedAt = DateTime.Now;
    }

    public string MessageText
    {
        get
        {
            var message = new StringBuilder();
            message.Append($"{Representation("🗞")} New on {Feed.Representation(ParseMode.Html)}\n");
            message.Append("\n");
            message.Append(Title);
            message.Append("\n");
            message.Append(Representation("Open in browser"));
            
            return message.ToString();
        }
    }
}