class ChefNodeNameBuilder
  DEFAULT_MASK = '$project-$cfname-$env'

  def initialize(server_info, project, env)
    @server_info, @project, @env = server_info, project, env
    @mask = server_info['tags']['cid:node-name-mask'] || DEFAULT_MASK
  end

  def build_node_name
    result = @mask.dup
    replace_dollar_variables!(result)
    replace_colon_variables!(result)
    result.gsub!('_', '-')
    result
  end

  private

  def replace_dollar_variables!(result)
    result.gsub!('$project', @project.id)
    result.gsub!('$env', @env.identifier)
    result.gsub!('$instanceid', @server_info['id'])
    result.gsub!('$cfname', @server_info['tags']['Name'] || '')
    result.gsub!('$time', Time.now.to_i.to_s)
  end

  def replace_colon_variables!(result)
    result.gsub!(':project', @project.id)
    result.gsub!(':env', @env.identifier)
    result.gsub!(':instanceid', @server_info['id'])
    result.gsub!(':cfname', @server_info['tags']['Name'] || '')
    result.gsub!(':time', Time.now.to_i.to_s)
  end
end