class MailEngine::MailSchedule < ActiveRecord::Base
  validates_presence_of :name, :user_group, :mail_template_id, :period, :count, :first_send_at
  belongs_to :mail_template
  scope :available, where("sent_count < count OR count = 0")

  # list mail log with the same mail_template_path to current mail_template's path
  def logs(count = 10)
    MailEngine::MailLog.where(:mail_template_path => self.mail_template.actual_path).order("id desc").limit(count)
  end

  # load user info into payload hash used at mail template.
  def load_payload user
    payload_hash = {}
    self.payload.split(",").each do |col|
      payload_hash[col] = user.send(col)
    end
    payload_hash
  end

  # send test mail to specific recipient email address, with loading sample_user's data.
  def send_test_mail_to!(recipient, sample_user_id)
    raise "Wrong email format." if recipient.blank? or recipient !~ /^([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})$/i
    sample_user = MailEngine::USER_MODEL.find(sample_user_id)

    I18n.with_locale(mail_template.locale) do
      MailEngine::MailDispatcher.send( mail_template.template_name.to_sym, :to => recipient, :values => self.load_payload(sample_user) ).deliver
    end
  end

  # If execute sendmail twice very soon(within 14 minutes), it should not be able to send mail again.
  def ready_to_send?
    # check if send count reached the total count.
    return false if (sent_count >= count and count != 0)
    # only send once.
    return sent_count < 1 if period == 'once'

    # why 15 minutes? for tolerance.
    not_sent_mail_within_15_minutes = last_sent_at.nil? || ((Time.now.to_i - last_sent_at.to_i).abs >= 60*15)
    ready_to_send = not_sent_mail_within_15_minutes and (Time.now.to_i - first_send_at.to_i).abs < 60*15
    result_by_period = case period
                       when 'daily'
                         1.days.ago.to_i <= last_sent_at.to_i
                       when 'weekly'
                         1.week.ago.to_i <= last_sent_at.to_i
                       when 'monthly'
                         1.month.ago.to_i <= last_sent_at.to_i
                       else
                         false
                       end

    ready_to_send or (not_sent_mail_within_15_minutes and result_by_period)
  end

  # used in Rake task, the main mail sending method.
  def sendmail
    puts "---> Schedule: '#{self.name}'" if Rails.env != 'test'

    unless ready_to_send?
      puts "---> not ready"
      return false
    end

    MailEngine::USER_MODEL.send(self.user_group.to_sym).each do |user|
      puts "-> sending mail to #{user.email}"
      ### FIXME user.email, what if user don't have email column.
      MailEngine::MailDispatcher.send(mail_template.template_name.to_sym, :to => user.email, :values => self.load_payload(user) ).deliver
    end

    self.last_sent_at = Time.now
    self.sent_count += 1
    self.save
  end
end