class ShortnUrl

# File lib/shortn-url.rb, line 10
def initialize(filepath)
  @filepath = filepath
  @doc = Nokogiri::XML(File.open(@filepath,'r').read)
  node = @doc.xpath("urls/records/url[full_url='']")[0]
  @next_id = node.attribute('id').value.to_i
end

# File lib/shortn-url.rb, line 18
def full_url(s)

  short_url = @doc.xpath("urls/records/url[full_url='#{s}']/short_url").text
  if short_url.empty? then
    node = @doc.xpath("urls/records/url[@id='#{@next_id.to_s}']")[0]
    node.xpath('full_url')[0].content = s

    node['last_modified'] = Time.now.to_s
    save()
    @next_id += 1
    node.xpath('short_url').text
  else
    short_url
  end

end

# File lib/shortn-url.rb, line 35
def short_url(s)
  @doc.xpath("urls/records/url[short_url='#{s}']/full_url").text
end

# File lib/shortn-url.rb, line 41
def save()
  File.open(@filepath,'w') do |f| 
    f.write @doc.serialize(:encoding => 'UTF-8') do |config|
      config.format.as_xml
    end
  end
end