#!/usr/bin/env ruby
require "resolv"
require_relative "lib/lxc"

class Resolver
  def initialize
    @stub_resolver = Resolv::DNS.new
    @cache = {}
  end
  def resolve(name, delegated_subdomain, typeclass)
    if name == "@"
      fqdn = delegated_subdomain
    else
      fqdn = "#{name}.#{delegated_subdomain}"
    end
    result = @cache[fqdn + typeclass.to_s] ||= @stub_resolver.getresource(fqdn, typeclass)
    if result == :no_record
      nil
    else
      result
    end
  rescue Resolv::ResolvError => e
    puts "warning: #{e}"
    @cache[fqdn + typeclass.to_s] = :no_record
    return nil
  end
  def a(name, delegated_subdomain)
    result = resolve(name, delegated_subdomain, Resolv::DNS::Resource::IN::A)
    return "" unless result
    "#{name} A #{result.address.to_s}\n"
  end
  def aaaa(name, delegated_subdomain)
    result = resolve(name, delegated_subdomain, Resolv::DNS::Resource::IN::AAAA)
    return "" unless result
    "#{name} AAAA #{result.address.to_s}\n"
  end
end

template_path = Lxc::CONFIG_ROOT.join("templates/higgsboson.tk.zone.erb")
template = Lxc::Template.new(template_path)
serial = Time.new.to_i
resolver = Resolver.new
zones = [
  ["zones/higgsboson.tk.zone", :pub],
  ["zones/internal-eve.higgsboson.tk.zone", :eve],
  ["zones/internal-eva.higgsboson.tk.zone", :eva],
]
zones.each do |zone, type|
  template.write(zone, resolver: resolver, serial: serial, type: type)
end
Lxc::Utils.sh("lxc-attach", "-n", "dns", "--", "rndc", "reload")