class HCardPresenter
  def self.from_contact(contact)
    new(contact_properties(contact), contact.country_code)
  end

  def self.contact_properties(contact)
    { 'fn' => contact.recipient,
      'street-address' => contact.street_address,
      'postal-code' => contact.postal_code,
      'locality' => contact.locality,
      'region' => contact.region,
      'country-name' => country_name(contact) }
  end

  def self.country_name(contact)
    contact.country_name unless contact.country_code == 'GB'
  end

  def self.property_keys
    ['fn', 'street-address', 'postal-code', 'locality', 'region', 'country-name']
  end

  def self.address_formats
    @address_formats ||= YAML.load_file('config/address_formats.yml')
  end

  attr_reader :properties, :country_code

  def initialize(properties, country_code)
    @properties = properties
    @country_code = country_code
  end

  def render
    "<p class=\"adr\">\n#{interpolate_address_template}\n</p>\n".html_safe
  end

  def interpolate_address_property(property_name)
    value = properties[property_name]

    if value.present?
      "<span class=\"#{property_name}\">#{ERB::Util.html_escape(value)}</span>"
    else
      ""
    end
  end

  private

  def interpolate_address_template
    address = address_template

    self.class.property_keys.each do |key|
      address.gsub!(/\{\{#{key}\}\}/, interpolate_address_property(key))
    end

    address.gsub(/^\n/, '')         # get  rid of blank lines
           .strip                   # get rid of any trailing whitespace
           .gsub(/\n/, "<br />\n")  # add break tags where appropriate
  end

  def address_template
    (self.class.address_formats[country_code.to_s.downcase] || default_format_string).dup
  end

  def default_format_string
    self.class.address_formats['gb']
  end
end