require "rss/1.0"

module RSS

	CONTENT_PREFIX = 'content'
	CONTENT_URI = "http://purl.org/rss/1.0/modules/content/"

	RDF.install_ns(CONTENT_PREFIX, CONTENT_URI)

	module ContentModel

		extend BaseModel

		ELEMENTS = []

		def self.append_features(klass)
			super
			
			klass.module_eval(<<-EOC)
				%w(encoded).each do |x|
					install_text_element("\#{CONTENT_PREFIX}_\#{x}")
				end
			EOC
		end

		def content_validate(tags)
			counter = {}
			ELEMENTS.each do |x|
				counter[x] = 0
			end

			tags.each do |tag|
				key = "#{CONTENT_PREFIX}_#{tag}"
				raise UnknownTagError.new(tag, CONTENT_URI) unless counter.has_key?(key)
				counter[key] += 1
				raise TooMuchTagError.new(tag, tag_name) if counter[key] > 1
			end
		end

	end

	class RDF
		class Item; include ContentModel; end
	end

	prefix_size = CONTENT_PREFIX.size + 1
	ContentModel::ELEMENTS.uniq!
	ContentModel::ELEMENTS.each do |x|
		BaseListener.install_get_text_element(x[prefix_size..-1], CONTENT_URI, "#{x}=")
	end

end