# frozen_string_literal: true # The +Message-ID+ as specified by rfc822 is supposed to be a unique identifier for that individual email. # That makes it an ideal tracking token for debugging and forensics, just like +X-Request-Id+ does for # web request. # # If an inbound email does not, against the rfc822 mandate, specify a Message-ID, one will be generated # using the approach from Mail::MessageIdField. module ActionMailbox::InboundEmail::MessageId extend ActiveSupport::Concern included do before_save :generate_missing_message_id end class_methods do # Create a new +InboundEmail+ from the raw +source+ of the email, which be uploaded as a Active Storage # attachment called +raw_email+. Before the upload, extract the Message-ID from the +source+ and set # it as an attribute on the new +InboundEmail+. def create_and_extract_message_id!(source, **options) create! options.merge(message_id: extract_message_id(source)) do |inbound_email| inbound_email.raw_email.attach io: StringIO.new(source), filename: "message.eml", content_type: "message/rfc822" end end private def extract_message_id(source) Mail.from_source(source).message_id rescue nil end end private def generate_missing_message_id self.message_id ||= Mail::MessageIdField.new.message_id.tap do |message_id| logger.warn "Message-ID couldn't be parsed or is missing. Generated a new Message-ID: #{message_id}" end end end