huginn/app/models/agents/digest_email_agent.rb

module Agents
  class DigestEmailAgent < Agent
    MAIN_KEYS = %w[title message text main value].map(&:to_sym)
    default_schedule "5am"

    description <<-MD
      The DigestEmailAgent collects any Events sent to it and sends them all via email when run.
      The email will be sent to your account's address and will have a `subject` and an optional `headline` before
      listing the Events.  If the Events' payloads contain a `:message`, that will be highlighted, otherwise everything in
      their payloads will be shown.

      Set `expected_receive_period_in_days` to the maximum amount of time that you'd expect to pass between Events being received by this Agent.
    MD

    def default_options
      {
          :subject => "You have some notifications!",
          :headline => "Your notifications:",
          :expected_receive_period_in_days => "2"
      }
    end

    def working?
      last_receive_at && last_receive_at > options[:expected_receive_period_in_days].to_i.days.ago
    end

    def validate_options
      errors.add(:base, "subject and expected_receive_period_in_days are required") unless options[:subject].present? && options[:expected_receive_period_in_days].present?
    end

    def receive(incoming_events)
      incoming_events.each do |event|
        self.memory[:queue] ||= []
        self.memory[:queue] << event.payload
      end
    end

    def check
      if self.memory[:queue] && self.memory[:queue].length > 0
        lines = self.memory[:queue].map {|item| present(item) }
        puts "Sending mail to #{user.email}..." unless Rails.env.test?
        SystemMailer.delay.send_message(:to => user.email, :subject => options[:subject], :headline => options[:headline], :lines => lines)
        self.memory[:queue] = []
      end
    end

    def present(item)
      if item.is_a?(Hash)
        MAIN_KEYS.each do |key|
          if item.has_key?(key)
            return "#{item[key]}" + ((item.length > 1 && item.length < 5) ? " (#{present_hash item, key})" : "")
          elsif item.has_key?(key.to_s)
            return "#{item[key.to_s]}" + ((item.length > 1 && item.length < 5) ? " (#{present_hash item, key.to_s})" : "")
          end
        end
        present_hash item
      else
        item.to_s
      end
    end

    def present_hash(hash, skip_key = nil)
      hash.to_a.sort_by {|a| a.first.to_s }.map { |k, v| "#{k}: #{v}" unless [skip_key].include?(k) }.compact.to_sentence
    end
  end
end