module Jpostcode

def find(raw_zip_code)
  zip_code = raw_zip_code.to_s.delete('-')
  return nil unless zip_code.match?(/^\d{7,7}$/)
  json_file = "#{DATA_DIR}#{zip_code.slice(0, 3)}.json"
  return nil unless File.exist?(json_file)
  data = JSON.parse(File.read(json_file))
  address_data = data[zip_code.slice(3, 4)]
  return nil if address_data.nil?
  if address_data.instance_of?(Array)
    address_data.map { |a| Jpostcode::Address.new(a) }
  else
    Jpostcode::Address.new(address_data)
  end
end