module PushNotificationHelper

  def gcm_instance
    api_key = settings[:server_api_key]
    gcm = GCM.new(api_key)
    gcm
  end

  def settings
    return Noosfero::Plugin::Settings.new(environment, PushNotificationPlugin.class)
  end

  #data should be a hash, like {some_info: 123123}
  def send_to_users(flag, users, data)
    return false unless users.present?
    users |= subscribers_additional_users(flag, users.first.environment)
    users = filter_users_for_flag(flag, users)
    return false unless users.present?
    tokens = tokens_for_users(users)
    gcm = gcm_instance
    response = gcm.send(tokens, data)
    response[:response]
  end

  def filter_users_for_flag(flag, users)
    users.select{|u| u.notification_settings.active?(flag)}
  end

  def tokens_for_users(users)
    tokens=[]
    users.each{|c| tokens+= c.device_token_list}
    return tokens
  end

  def subscribers_additional_users notification, environment
    subs = PushNotificationPlugin::subscribers(environment, notification)
    users=[]
    if subs.present?
      subs.each do |s|
        users+=s.send("push_notification_#{notification}_additional_users".to_sym)
      end
    end
    users
  end

end