class User has_many :posts

has_many :likes
has_many :post_likes, through: :likes, class_name: "Post"

has_many :comments
has_many :post_comments, through: :comments, class_name: "Post"

end

class Post belongs_to :user

has_many :likes
has_many :user_likes, through: :likes, class_name: "User"

has_many :comments  
has_many :user_comments, through: :comments, class_name: "User"

end

class Like belongs_to :user belongs_to :post
end

class comment belongs_to :user belongs_to :post
end