/// <summary>
    /// Represents the lable 
    /// </summary>
    public class Tag
    {
        #region Ctor
        /// <summary>
        /// Create one instance of <see cref="Tag"/>
        /// </summary>
        public Tag()
        {
            Id = SequentialGuidGenerator.NewSequentialGuid();
        }
        #endregion

        #region Properties
        /// <summary>
        /// sets or gets Tag's identifier
        /// </summary>
        public virtual Guid  Id { get; set; }
        /// <summary>
        /// sets or gets Tag's name
        /// </summary>
        public virtual string Name { get; set; }
        #endregion

        #region NavigationProperties
        /// <summary>
        /// sets or gets Tag's posts
        /// </summary>
        public virtual ICollection<BlogPost> BlogPosts { get; set; }
        #endregion
    }

  /// <summary>
    /// Represents the Post's Draft
    /// </summary>
    public  class BlogDraft
    {
        #region Ctor
        /// <summary>
        /// create one instance of <see cref="BlogDraft"/>
        /// </summary>
        public  BlogDraft()
        {
            Id = SequentialGuidGenerator.NewSequentialGuid();
        }
        #endregion

        #region Properties
        /// <summary>
        /// gets or sets Id of post's draft
        /// </summary>
        public virtual  Guid Id { get; set; }
        /// <summary>
        /// gets or sets body of post's draft
        /// </summary>
        public virtual  string Body { get; set; }
        /// <summary>
        /// gets or set title of post's draft
        /// </summary>
        public virtual  string Title { get; set; }
        /// <summary>
        /// gets or sets tags of post's draft that seperated using ','
        /// </summary>
        public virtual  string TagNames { get; set; }
        /// <summary>
        /// gets or sets value indicating whether this draft is ready to publish
        /// </summary>
        public virtual  bool IsReadyForPublish { get; set; }
        /// <summary>
        /// ges ro sets DateTime that this draft added
        /// </summary>
        public virtual  DateTime CreatedOn { get; set; }
        /// <summary>
        /// gets or sets information of User-Agent
        /// </summary>
        public virtual string Agent { get; set; }
        /// <summary>
        /// gets or sets date that this draft publish as ready
        /// </summary>
        public virtual DateTime? ReadyForPublishOn { get; set; }
        #endregion

        #region NavigationProperties
        /// <summary>
        /// gets or sets Id of user that he is owner of this draft
        /// </summary>
        public virtual  long OwnerId { get; set; }
        /// <summary>
        /// gets or sets user that he is owner of this draft
        /// </summary>
        public virtual  User Owner { get; set; }
        #endregion
    }

/// <summary>
    /// Represents a base class for every content in system
    /// </summary>
    public abstract class BaseContent
    {
        #region Properties

        /// <summary>
        /// get or set identifier of record
        /// </summary>
        public virtual long Id { get; set; }
        /// <summary>
        /// gets or sets date of publishing content
        /// </summary>
        public virtual DateTime PublishedOn { get; set; }
        /// <summary>
        /// gets or sets Last Update's Date
        /// </summary>
        public virtual DateTime ModifiedOn { get; set; }
        /// <summary>
        /// gets or sets the blog pot body
        /// </summary>
        public virtual string Body { get; set; }
        /// <summary>
        /// gets or sets the content title
        /// </summary>
        public virtual string Title { get; set; }
        /// <summary>
        /// gets or sets value  indicating Custom Slug
        /// </summary>
        public virtual string SlugUrl { get; set; }
        /// <summary>
        /// gets or sets meta title for seo
        /// </summary>
        public virtual string MetaTitle { get; set; }
        /// <summary>
        /// gets or sets meta keywords for seo
        /// </summary>
        public virtual string MetaKeywords { get; set; }
        /// <summary>
        /// gets or sets meta description of the content
        /// </summary>
        public virtual string MetaDescription { get; set; }
        /// <summary>
        /// gets or sets 
        /// </summary>
        public virtual string FocusKeyword { get; set; }
        /// <summary>
        /// gets or sets value indicating whether the content use CanonicalUrl
        /// </summary>
        public virtual bool UseCanonicalUrl { get; set; }
        /// <summary>
        /// gets or sets CanonicalUrl That the Post Point to it
        /// </summary>
        public virtual string CanonicalUrl { get; set; }
        /// <summary>
        /// gets or sets value indicating whether the content user no Follow for Seo
        /// </summary>
        public virtual bool UseNoFollow { get; set; }
        /// <summary>
        /// gets or sets value indicating whether the content user no Index for Seo
        /// </summary>
        public virtual bool UseNoIndex { get; set; }
        /// <summary>
        /// gets or sets value indicating whether the content in sitemap
        /// </summary>
        public virtual bool IsInSitemap { get; set; }
        /// <summary>
        /// gets or sets a value indicating whether the content comments are allowed 
        /// </summary>
        public virtual bool AllowComments { get; set; }
        /// <summary>
        /// gets or sets a value indicating whether the content comments are allowed for anonymouses 
        /// </summary>
        public virtual bool AllowCommentForAnonymous { get; set; }
        /// <summary>
        /// gets or sets  viewed count by rss
        /// </summary>
        public virtual long ViewCountByRss { get; set; }
        /// <summary>
        /// gets or sets viewed count 
        /// </summary>
        public virtual long ViewCount { get; set; }
        /// <summary>
        /// Gets or sets the total number of  comments
        /// <remarks>The same as if we run Item.Comments.where(a=>a.Status==Status.Approved).Count()
        /// We use this property for performance optimization (no SQL command executed)
        /// </remarks>
        /// </summary>
        public virtual int ApprovedCommentsCount { get; set; }
        /// <summary>
        /// Gets or sets the total number of  comments
        /// <remarks>The same as if we run Item.Comments.where(a=>a.Status==Status.UnApproved).Count()
        /// We use this property for performance optimization (no SQL command executed)</remarks></summary>
        public virtual int UnApprovedCommentsCount { get; set; }
        /// <summary>
        /// gets or sets value  indicating whether the content is logical deleted or hidden
        /// </summary>
        public virtual bool IsDeleted { get; set; }
        /// <summary>
        /// gets or sets rating complex instance
        /// </summary>
        public virtual Rating Rating { get; set; }
        /// <summary>
        /// gets or sets value indicating whether the content show with rssFeed
        /// </summary>
        public virtual bool ShowWithRss { get; set; }
        /// <summary>
        /// gets or sets value indicating maximum days count that users can send comment
        /// </summary>
        public virtual int DaysCountForSupportComment { get; set; }
        /// <summary>
        /// gets or sets information of User-Agent
        /// </summary>
        public virtual string Agent { get; set; }
        /// <summary>
        /// gets or sets icon name with size 200*200 px for snippet 
        /// </summary>
        public virtual string SocialSnippetIconName { get; set; }
        /// <summary>
        /// gets or sets title for snippet
        /// </summary>
        public virtual string SocialSnippetTitle { get; set; }
        /// <summary>
        /// gets or sets description for snippet
        /// </summary>
        public virtual string SocialSnippetDescription { get; set; }
        /// <summary>
        /// gets or sets body of content's comment
        /// </summary>
        public virtual byte[] RowVersion { get; set; }
        /// <summary>
        /// gets or sets name of tags seperated by comma that assosiated with this content fo increase performance
        /// </summary>
        public virtual string TagNames { get; set; }
        /// <summary>
        /// gets or sets counter for Content's report
        /// </summary>
        public virtual int ReportsCount { get; set; }
        #endregion

        #region NavigationProperties

        /// <summary>
        /// get or set user that create this record
        /// </summary>
        public virtual User Author { get; set; }

        /// <summary>
        /// gets or sets Id of user that create this record
        /// </summary>
        public virtual long AuthorId { get; set; }
        /// <summary>
        /// get or set  the tags integrated with content
        /// </summary>
        public virtual ICollection<Tag> Tags { get; set; }
        #endregion

    }

 /// <summary>
    /// Represents link for implemention linkback
    /// </summary>
    public class LinkBack
    {

        #region Ctor
        /// <summary>
        /// create one instance of <see cref="LinkBack"/>
        /// </summary>
        public LinkBack()
        {
            CreatedOn = DateTime.Now;
            Id = SequentialGuidGenerator.NewSequentialGuid();
        }
        #endregion

        #region Properties
        /// <summary>
        /// gets or sets link's Id
        /// </summary>
        public virtual Guid Id { get; set; }
        /// <summary>
        /// gets or sets text for show Link
        /// </summary>
        public virtual string Title { get; set; }
        /// <summary>
        /// gets or sets link's address 
        /// </summary>
        public virtual string Url { get; set; }
        /// <summary>
        /// gets or set value indicating whether this link is internal o external
        /// </summary>
        public virtual LinkBackType Type { get; set; }
        /// <summary>
        /// gets or sets date that this record is added
        /// </summary>
        public virtual DateTime CreatedOn { get; set; }
        #endregion

        #region NavigationProperties
        /// <summary>
        /// gets or sets Post that associated
        /// </summary>
        public virtual BlogPost Post { get; set; }
        /// <summary>
        /// gets or sets id of Post that associated
        /// </summary>
        public virtual long PostId { get; set; }
        #endregion
    }


 /// <summary>
    /// represents Type of ReferrerLinks
    /// </summary>
    public enum LinkBackType
    {
        /// <summary>
        /// Internal link
        /// </summary>
        Internal,
        /// <summary>
        /// External Link
        /// </summary>
        External
    }

  /// <summary>
    /// Represents a base class for every comment in system 
    /// </summary>

    public abstract class BaseComment
    {
        #region Properties
        /// <summary>
        /// get or set identifier of record
        /// </summary>
        public virtual long Id { get; set; }
        /// <summary>
        /// gets or sets date of creation 
        /// </summary>
        public virtual DateTime CreatedOn { get; set; }
        /// <summary>
        /// gets or sets displayName of this comment's Creator if  he/she is Anonymous
        /// </summary>
        public virtual string CreatorDisplayName { get; set; }
        /// <summary>
        /// gets or sets body of blog post's comment
        /// </summary>
        public virtual string Body { get; set; }
        /// <summary>
        /// gets or sets body of blog post's comment
        /// </summary>
        public virtual Rating Rating { get; set; }
        /// <summary>
        /// gets or sets informations of agent
        /// </summary>
        public virtual string UserAgent { get; set; }
        /// <summary>
        /// gets or sets siteUrl of Creator if he/she is Anonymous
        /// </summary>
        public virtual string SiteUrl { get; set; }
        /// <summary>
        /// gets or sets Email of Creator if he/she is anonymous
        /// </summary>
        public virtual string Email { get; set; }
        /// <summary>
        /// gets or sets status of comment
        /// </summary>
        public virtual CommentStatus Status { get; set; }
        /// <summary>
        /// gets or sets Ip Address of Creator
        /// </summary>
        public virtual string CreatorIp { get; set; }
        /// <summary>
        /// gets or sets datetime that is modified
        /// </summary>
        public virtual DateTime? ModifiedOn { get; set; }
        /// <summary>
        /// gets or sets counter for report this comment
        /// </summary>
        public virtual int ReportsCount { get; set; }
        #endregion

        #region NavigationProperties

        /// <summary>
        /// get or set user that create this record
        /// </summary>
        public virtual User Creator { get; set; }

        /// <summary>
        /// get or set Id of user that create this record
        /// </summary>
        public virtual long? CreatorId { get; set; }
        #endregion
    }

public enum CommentStatus
    {
        /* 0 - approved, 1 - pending, 2 - spam, -1 - trash */
        [Display(Name = "تأیید شده")]
        Approved = 0,
        [Display(Name = "در انتظار بررسی")]
        Pending = 1,
        [Display(Name = "جفنگ")]
        Spam = 2,
        [Display(Name = "زباله دان")]
        Trash = -1
    }

/// <summary>
    /// Represents a blog post's comment
    /// </summary>
    public class BlogComment : BaseComment
    {
        #region Ctor
        /// <summary>
        /// Create One Instance for <see cref="BlogComment"/>
        /// </summary>
        public BlogComment()
        {
            Rating = new Rating();
            CreatedOn = DateTime.Now;
        }
        #endregion

        #region NavigationProperties
        /// <summary>
        /// gets or sets BlogComment's identifier for Replying and impelemention self referencing
        /// </summary>
        public virtual long? ReplyId { get; set; }
        /// <summary>
        /// gets or sets blog's comment for Replying and impelemention self referencing
        /// </summary>
        public virtual BlogComment Reply { get; set; }
        /// <summary>
        /// get or set collection of blog's comment for Replying and impelemention self referencing
        /// </summary>
        public virtual ICollection<BlogComment> Children { get; set; }
        /// <summary>
        /// gets or sets post that this comment sent to it
        /// </summary>
        public virtual BlogPost Post { get; set; }
        /// <summary>
        /// gets or sets post'Id that this comment sent to it
        /// </summary>
        public virtual long PostId { get; set; }
        #endregion
    }

public abstract class BaseDto<TDto, TEntity, TKey> : IHaveCustomMapping
        where TEntity : BaseEntity<TKey>
{
    [Display(Name = "ردیف")]
    public TKey Id { get; set; }

    /// <summary>
    /// Maps this dto to a new entity object.
    /// </summary>
    public TEntity ToEntity()
    {
        return Mapper.Map<TEntity>(CastToDerivedClass(this));
    }

    /// <summary>
    /// Maps this dto to an exist entity object.
    /// </summary>
    public TEntity ToEntity(TEntity entity)
    {
        return Mapper.Map(CastToDerivedClass(this), entity);
    }

    /// <summary>
    /// Maps the specified entity to a new dto object.
    /// </summary>
    public static TDto FromEntity(TEntity model)
    {
        return Mapper.Map<TDto>(model);
    }

    protected TDto CastToDerivedClass(BaseDto<TDto, TEntity, TKey> baseInstance)
    {
        return Mapper.Map<TDto>(baseInstance);
    }

    //Get automapper Profile then create mapping and ignore unmapped properties
    public void CreateMappings(Profile profile)
    {
        var mappingExpression = profile.CreateMap<TDto, TEntity>();

        var dtoType = typeof(TDto);
        var entityType = typeof(TEntity);

        //Ignore mapping to any property of source (like Post.Categroy) that dose not contains in destination (like PostDto)
        //To prevent from wrong mapping. for example in mapping of "PostDto -> Post", automapper create a new instance for Category (with null catgeoryName) because we have CategoryName property that has null value
        foreach (var property in entityType.GetProperties())
        {
            if (dtoType.GetProperty(property.Name) == null)
                mappingExpression.ForMember(property.Name, opt => opt.Ignore());
        }

        //Pass mapping expressin to customize mapping in concrete class
        CustomMappings(mappingExpression.ReverseMap());
    }

    //Concrete class can override this method to customize mapping
    public virtual void CustomMappings(IMappingExpression<TEntity, TDto> mapping)
    {
    }
}

public class PostDto : BaseDto<PostDto, Post, long>
{
    public string Title { get; set; }
    public string Text { get; set; }
    public int CategoryId { get; set; }

    public string CategoryName { get; set; } //=> Category.Name
    public string FullTitle { get; set; } //=> custom mapping for "Title (Category.Name)"
        
    public override void CustomMappings(IMappingExpression<Post, PostDto> mapping)
    {
        mapping.ForMember(
                dest => dest.FullTitle,
                config => config.MapFrom(src => $"{src.Title} ({src.Category.Name})"));
    }
}

• این کلاس، خاصیتی به نام FullTitle دارد که معادلی (خاصیت همنامی) در کلاس Post برای آن وجود ندارد و قرار است مقدار ترکیبی حاصل از Title و Category.Name را نمایش دهد. 
• به همین جهت متد CustomMappings را باز نویسی کرده، شیء mapping را دریافت و سفارشی سازی لازم را روی آن انجام داده‌ایم.
• توسط متد ForMember مشخص کرده‌ایم که مقدار خاصیت FullTitle باید حاصلی از ترکیب Title و Category.Name به نحو مشخص شده باشد ( توسط متد MapFrom).

List<PostDto> list =
    //ProjectTo method select only needed properties (of PostDto) not all properties
    //Also select only needed property of navigations (like Post.Category.Name) not all unlike Include
    //This ability called "Projection"
    await _applicationDbContext.Posts.ProjectTo<PostDto>()
    //We can also use Where on IQuerable<PostDto>
    .Where(p => p.Title.Contains("test") || p.CategoryName.Contains("test"))
    .ToListAsync();