post.rb

class Post < ApplicationRecord
  # ==================================================
  # Module & Concern Includes
  # ----------
  # Modules and Conerns tend to add behaviours and
  # provide you with new DSL. Adding these at the very
  # top prevents you from calling something that might
  # not have been defined elsewise.
  # ==================================================

  include ActsAsStateMachine
  include Commentable

  # ==================================================
  # Constants
  # ----------
  # Constants are commonly referenced in external
  # files. Having these near the very top saves you
  # from scrolling to an unknown part of this file.
  # ==================================================

  ACTIVE_STATES   = %i[published]
  INACTIVE_STATES = %i[draft discarded]

  # ==================================================
  # Default Scope
  # ----------
  # This is defined as high as possible to ensure
  # developers are aware of the default scope.
  # ==================================================

  # Reference here to
  # https://github.com/jhawthorn/discard
  default_scope { kept }

  # ==================================================
  # Callbacks
  # ----------
  # This is also defined as high as possible to make
  # developers aware of data mutations in callbacks.
  # ==================================================

  before_create :private_method # This method should not be called anywhere else.

  after_create do
    # Putting this logic into a block makes sure that developers don't need to scroll
    # to private methods right at the bottom to see the logic here.
  end

  # ==================================================
  # Non-persistant Attributes
  # ----------
  # I sneak in attributes here as they are often few
  # and fit in nicely as simple properties followed by
  # complex associations.
  # ==================================================

  attribute :attr1, default: false

  attr_accessor :attr2

  # ==================================================
  # Associations
  # ----------
  # Here is the bulk of most model files. Generally,
  # this block of code will create almost a wall of
  # text. I try to group these by context when they
  # start to feel that way.
  # ==================================================

  # Core
  # --------------------------------------------------

  belongs_to :author

  # In the case of optional 1-1 associations. Try to put the foreign key on the other table.
  has_one :latest_edit, -> { order() }, class_name: 'Edit'
  has_one :latest_editor, through: :latest_edit, source: :author

  has_many :tags

  accepts_nested_attributes_for :tags

  # Analytics
  # --------------------------------------------------

  belongs_to :analytics_container, optional: true

  has_many :views
  has_many :sessions, through: :views

  # ==================================================
  # Attachments
  # ----------
  # If you are using ActiveStorage, you'll find that
  # attachments work very similarly to associations.
  # Having these next flows nicely.
  # ==================================================

  has_one_attached :cover
  
  has_many_attached :previews

  # ==================================================
  # Additional Attribute Helpers
  # ----------
  # Here I put attribute modifiers and helpers. They
  # are not quite as important as new attributes so
  # these are defined later on.
  # ==================================================

  monetize :price_cents

  translates :title

  # ==================================================
  # Validations
  # ----------
  # Surprisingly enough, validations never were the
  # highest priority of a model to me. They were
  # necessary parts of the code that faded into the
  # background, especially with client side
  # validations.
  # ==================================================

  validates :title, presence: true, length: { minimum: 10, maximum: 80 }

  # ==================================================
  # Scopes
  # -----------
  # 
  # ==================================================

  scope :active,   -> { where(state: ACTIVE_STATES) }
  scope :inactive, -> { where(state: INACTIVE_STATES) }

  scope :upcoming, -> (time = Time.current) { where(arel_table[:published_at].gt(time) }

  # ==================================================
  # Public Instance Methods
  # ----------
  # These methods should typically be data retrieving helpers.
  # ==================================================

  def current_catalogue_programming(country:)
    catalogue_programmings.available(country: country).first
  end

  # ==================================================
  # Class Methods
  # These methods should be global data retrieving helpers.
  # ==================================================

  # Film.average_rating
  # Film.live.average_rating
  def self.average_rating
    average(:rating)
  end

  # ==================================================
  # Private Methods
  # ==================================================

  def private_method
    # Definiton of the the callback defined above.
  end
end