saucy/app/mailers/notification_mailer.rb

class NotificationMailer < ApplicationMailer
  default to: ->() { @member.email }

  def expiration_in_60d
    set_notification
    mail
  end

  def expiration_in_30d
    set_notification
    mail
  end

  def expired
    set_notification
    mail
  end

  def expired_30d_ago
    set_notification
    mail
  end

  def expired_60d_ago
    set_notification
    mail
  end

  def cancelled
    set_notification
    mail
  end

  def registration
    set_member
    mail
  end

  def first_payment_confirmation
    set_contribution
    mail
  end

  def payment_renewal_confirmation
    set_contribution
    mail
  end

  private
  def set_notification
    @notification = params[:notification]
    @member = @notification.member
    @payment = @notification.member.create_payment
  end

  def set_contribution
    @contribution = params[:contribution]
    @member = @contribution.member
  end

  def set_member
    @member = params[:member]
    @payment = @member.create_payment
  end

  def default_i18n_subject
    mailer_scope = self.class.mailer_name.tr("/", ".")
    I18n.t(:subject, scope: [mailer_scope, action_name], organization_short_name: Config.organization_short_name)
  end
end