##################################################
# ANN_Wrapper
##################################################

require "net/http"
require "nokogiri"
require 'ann_wrapper/ann_objects'

# wrapper class for ANN API
module ANN_Wrapper
extend ANN_Wrapper

	# ANN API anime url
	ANN_URL         = "http://cdn.animenewsnetwork.com/encyclopedia"
	ANN_API_URL     = "#{ANN_URL}/api.xml"
	ANN_REPORTS_URL = "#{ANN_URL}/reports.xml"

	# fetch anime and convert to ANN_Anime
	def fetch_anime(id, api_url=ANN_API_URL)
		# append id to API url and send request
		url = "#{api_url}?anime=#{id.to_s}"

		ann = fetch(url)

		return ann if ann.is_a?(ANN_Error)

		anime = ann.at_xpath('//ann/anime')

		# initialize new ann_anime or error with ann object
		anime.nil? ? ANN_Error.new(get_xml_error(ann)) : ANN_Anime.new(anime)
	end

	# fetch list of titles via reports
	def fetch_titles(type="anime", nskip=0, nlist=50, name="", api_url=ANN_REPORTS_URL)
		url = "#{api_url}?id=155&type=#{type}&nskip=#{nskip}&nlist=#{nlist}"
		report = fetch(url)

		return report if report.is_a?(ANN_Error)

		reports = report.xpath('//report/item')

		return ANN_Error.new(get_xml_error(report)) if reports.nil?

		reports.map { |item| ANN_Report.new(item) }
	end

	private
		# fetch data from ANN API via http GET request
		# returns Nokogiri or ANN_Error
		def fetch(url)
			begin
				# send http GET request with uri parsed from url
				resp = Net::HTTP.get_response(URI.parse(url))

				# get the response body and try converting to Nokogiri object
				Nokogiri.XML(resp.body)
			rescue
				ANN_Error.new("xml format error, API likely unavailable")
			end
		end	

		# attempt to grab error message from XMLObject
		def get_xml_error(xobj)
			begin
				xobj.at_xpath('//ann/warning').content
			rescue NameError
				"bad response"
			end
		end
	end