require 'hpricot'
require 'open-uri'

module Flannel
  class FeedParser
    def initialize params={}
      @cache = params[:cache] if params.has_key?(:cache)
    end
    
    def sub_feeds(url)
      url = format_url(url)
      get_news(url)
    end
    
    def format_url url
      url.strip!
      url = "http://#{url}" if url[0..6] != "http://"
      url
    end
    
    def get_document url
      doc = @cache.retrieve(url) if @cache
      doc = open(url) unless doc
      @cache.save url, doc if @cache
      doc
    end
    
    def format_item(link, title)
      "  <li>\n    <a href='#{link}'>#{title}</a>\n  </li>\n"
    end

    def get_news url
      item_string = ""

      doc = Hpricot.XML(get_document(url))

      (doc/"item").each do |item|
	link = (item/"link").inner_html
	title = (item/"title").inner_html
	item_string << format_item(link, title)
      end
      
      item_string
    end
  end
end