module SiteChecker
	module Parse
		class Page
			def self.parse(content, ignore_list, root)
				links = []
				page = Nokogiri(content)

				links.concat(get_links(page, ignore_list, root))
				links.concat(get_images(page, ignore_list, root))
				links.concat(get_anchors(page))
				links.concat(local_pages_which_has_anchor_references(links, root))

				links.uniq
			end

			private
			def self.get_links(page, ignore_list, root)
				links = []
				page.xpath("//a").reject {|a| ignored?(ignore_list, a['href'])}.each do |a|
					if a['href'].match(/(.*)#.+/) && !URI($1).absolute?
						kind = :anchor_ref
					else
						kind = :page
					end
					links << Link.create({:url => a['href'], :kind => kind})
				end
				set_location(links, root)
			end

			def self.get_images(page, ignore_list, root)
				links = []
				page.xpath("//img").reject {|img| ignored?(ignore_list, img['src'])}.each do |img|
					links << Link.create({:url => img['src'], :kind => :image})
				end
				set_location(links, root)
			end

			def self.set_location(links, root)
				links.each do |link|
			    uri = URI(link.url)
			    if uri.to_s.start_with?(root)
			    	link.problem = "(absolute path)"
			    	link.location = :local
			    else
			      if uri.absolute?
			        link.location = :remote
			      else
			        link.location = :local
			      end
			    end
			  end
			end

			def self.ignored?(ignore_list, link)
		    if link
		      ignore_list.include? link
		    else
		      true
		    end
		  end

		  def self.get_anchors(page)
		  	anchors = []
		  	page.xpath("//a").reject {|a| !a['id']}.each do |a|
		  		anchors << Link.create({:url => a['id'], :kind => :anchor})
		  	end
		  	anchors
		  end

		  def self.local_pages_which_has_anchor_references(links, root)
		  	new_links = []
		  	links.find_all {|link| link.anchor_ref?}.each do |link|
		  		uri = URI(link.url)
		  		if link.url.match(/(.+)#/)
		  			new_links << Link.create({:url => $1, :kind => :page})
		  		end
		  	end
		  	set_location(new_links, root)
		  end
		end
	end
end