/// 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.Text;
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 => Url;
        }
        #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]
        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; }

        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();
            }
        }
    }
}