#!/usr/bin/env ruby

require 'uri'
require 'rack/utils'
require 'net/http'
require 'open3'

class DSPusher
  attr_reader :cfg

  def initialize(cfg)
    @cfg = cfg
  end

  def push_ds(zone=nil, dry_run=false)
    fetch_dss(zone).each { |d, dss|
      post_dss(d, dss, dry_run)
    }
  end

  def fetch_dss(zone)
    dss = Hash.new { |h, k| h[k] = [] }

    cmd = cfg['get_ds']
    cmd += " -z #{zone}" if zone

    out, err = command(cmd)
    out.each_line { |line|
      line.strip!

      next if line.nil? || line == ''
      next if line.start_with?(';')
      domain, _ttl, _f, rtype, rdata = line.split(/\s+/, 5)
      next unless rtype == 'DS'

      domain = domain.gsub(/\.+$/, '') # Remove trailing .
      dss[domain] << rdata
    }

    dss
  end

  def post_dss(domain, dss, dry_run)
    query = Rack::Utils.build_nested_query(
      domain: domain,
      event: 'push_ds',
      args: dss,
    )
    uri = URI("#{cfg['webdns_base']}#{cfg['update_state']}" % { query: query })
    if dry_run
      p [:uri, uri]
      return
    end

    Net::HTTP.start(uri.host, uri.port, use_ssl: uri.scheme == 'https') do |http|
      resp = http.request Net::HTTP::Put.new(uri.request_uri)

      fail JobFailed if resp.code != '200'
    end
  end

  private

  def command(cmd)
    out, err, status = Open3.capture3(cmd)
    raise "Command error err='#{err.strip}' out='#{out.strip}'" if !status.success?

    [out, err]
  end
end

require 'yaml'
require 'optparse'
require 'ostruct'

options = OpenStruct.new
options.dry_run = false
options.extra = nil
options.zone = nil

OptionParser.new do |opts|
  opts.banner = 'Usage: ds-schedule [options]'

  opts.on('-c', '--config CONFIG', 'Config file') do |c|
    options[:config] = c
  end

  opts.on('-e', '--extra CONFIG', 'Extra config file') do |e|
    options[:extra] = e
  end

  opts.on('-n', '--dry-run', 'Run but not execute anything') do |n|
    options[:dry_run] = n
  end

  opts.on('-z', '--zone ZONE', 'Zone') do |z|
    options[:zone] = z
  end
end.parse!

cfg = YAML.load_file(options.config)
cfg.merge!(YAML.load_file(options.extra)) if options.extra

w = DSPusher.new(cfg)
w.push_ds(options.zone, options.dry_run)