class Decidim::Meetings::RegistrationMailer

def add_calendar_attachment
  calendar = Icalendar::Calendar.new
  calendar.event do |event|
    event.dtstart = Icalendar::Values::DateTime.new(@meeting.start_time)
    event.dtend = Icalendar::Values::DateTime.new(@meeting.end_time)
    event.summary = present(@meeting).title
    event.description = strip_tags(present(@meeting).description)
    event.location = @meeting.address
    event.geo = [@meeting.latitude, @meeting.longitude]
    event.url = @locator.url
  end
  attachments["meeting-calendar-info.ics"] = calendar.to_ical
end

def confirmation(user, meeting, registration)
  with_user(user) do
    @user = user
    @meeting = meeting
    @registration = registration
    @organization = @meeting.organization
    @locator = Decidim::ResourceLocatorPresenter.new(@meeting)
    add_calendar_attachment
    subject = I18n.t("confirmation.subject", scope: "decidim.meetings.mailer.registration_mailer")
    mail(to: user.email, subject: subject)
  end
end