class SharedDns
  attr_accessor :reservation
  attr_accessor :owner

  def initialize(domain = "virtualmonkey_shared_resources")
    @sdb = Fog::AWS::SimpleDB.new(:aws_access_key_id => Fog.credentials[:aws_access_key_id_test], :aws_secret_access_key => Fog.credentials[:aws_secret_access_key_test])
    @domain = domain
    @reservation = nil
  end

    # set dns inputs on a deployment to match the current reservation
  # * deployment<~Deployment> the deployment to set inputs on
  def set_dns_inputs(deployment)
    sdb_result = @sdb.get_attributes(@domain, @reservation)

    set_these = sdb_result.body['Attributes'].reject {|k,v| k == 'owner'}
    set_these.each do |key,val|
      deployment.set_input(key, val.to_s)
      deployment.servers.each { |s| s.set_input(key, "text:") }
    end
  end

  def reserve_dns(owner, timeout = 0)
    puts "Checking DNS reservation for #{owner}"
    result = @sdb.select("SELECT * from #{@domain} where owner = '#{owner}'")
    puts "Reusing DNS reservation" unless result.body["Items"].empty?
    if result.body["Items"].empty?
       result = @sdb.select("SELECT * from #{@domain} where owner = 'available'")
       return false if result.body["Items"].empty?
       puts "Aquired new DNS reservation"
       item_name = result.body["Items"].keys.first
       response = @sdb.put_attributes(@domain, item_name, {'owner' => owner}, :expect => {'owner' => "available"}, :replace => ['owner'])
    end
    @owner = owner
    @reservation = result.body["Items"].keys.first
  rescue Excon::Errors::ServiceUnavailable
    puts "Resuce: ServiceUnavailable"
    retry_reservation(owner, timeout)
  rescue Excon::Errors::Conflict
    puts "Resuce: Conflict"
    retry_reservation(owner, timeout)
  end

  def retry_reservation(owner, timeout)
    STDOUT.flush
    if timeout > 20 
      return false
    end
    sleep(5)
    reserve_dns(owner, timeout + 1)
  end

  def release_all
    result = @sdb.select("SELECT * from #{@domain}")
    result.body['Items'].keys.each do |item_name|
      @sdb.put_attributes(@domain, item_name, {"owner" => "available"}, :replace => ["owner"])
    end
  end

  def release_dns(res = @reservation)
    raise "FATAL: could not release dns because there was no @reservation" unless res
    @sdb.put_attributes(@domain, res, {"owner" => "available"}, :replace => ["owner"]) 
    @reservation = nil
  end
end