rails--rails/app/models/action_mailbox/inbound_email.rb

require "mail"

# The `InboundEmail` is an Active Record that keeps a reference to the raw email stored in Active Storage
# and tracks the status of processing. By default, incoming emails will go through the following lifecycle:
#
# * Pending: Just received by one of the ingress controllers and scheduled for routing.
# * Processing: During active processing, while a specific mailbox is running its #process method.
# * Delivered: Successfully processed by the specific mailbox.
# * Failed: An exception was raised during the specific mailbox's execution of the `#process` method.
# * Bounced: Rejected processing by the specific mailbox and bounced to sender.
#
# Once the `InboundEmail` has reached the status of being either `delivered`, `failed`, or `bounced`, 
# it'll count as having been `#processed?`. Once processed, the `InboundEmail` will be scheduled for 
# automatic incineration at a later point.
#
# When working with an `InboundEmail`, you'll usually interact with the parsed version of the source,
# which is available as a `Mail` object from `#mail`. But you can also access the raw source directly
# using the `#source` method.
#
# Examples:
#
#   inbound_email.mail.from # => 'david@loudthinking.com'
#   inbound_email.source # Returns the full rfc822 source of the email as text
class ActionMailbox::InboundEmail < ActiveRecord::Base
  self.table_name = "action_mailbox_inbound_emails"

  include Incineratable, MessageId, Routable

  has_one_attached :raw_email
  enum status: %i[ pending processing delivered failed bounced ]

  def mail
    @mail ||= Mail.from_source(source)
  end

  def source
    @source ||= raw_email.download
  end

  def processed?
    delivered? || failed? || bounced?
  end
end