#!/usr/bin/python3

from utils import *
from download_page import download

# portable code to get filename
import os
platform = os.path.basename(__file__)
if platform.endswith(".py"):
	platform = platform[:(-3)]

def extract_from_url (url, verbosity):
	# strip extra arguments at end of URL
	for symbol in ["?", "&", ";"]:
		if symbol in url:
			url = url[:url.index(symbol)]
	if not url.endswith("/"):
		url = url + "/"
	return url + ".rss"

def extract_from_page (page, verbosity):
	# this could be handled by the generic extractor
	# also, this method should never be reached
	return search (page, '<link rel="alternate" type="application/atom\+xml" title="RSS" href="', '" />')

def extract (url, page=None, network=False, verbosity=3, args={}):
	feed = extract_from_url (url, verbosity)
	if not feed is None:
		return feed
	else:
		notify ("Unable to get feed from URL alone", verbosity, platform)
		notify ("Something must have gone wrong here because this point should be unreachable.", verbosity, platform)
		if network == True:
			# old Reddit interface is easier to deal with
			index = url.find("/",url.find("//")+2)
			domain = url[:index]
			path = url[index:]

			www = False

			if "www.reddit.com" in domain:
				domain = domain.replace("www.reddit.com", "old.reddit.com")
				url = domain + path
				www = True

			page = download (platform, url, args, verbosity)
			feed = extract_from_page (page, verbosity)
			if not feed is None:
				if www:
					return feed.replace("old.reddit.com", "www.reddit.com")
				else:
					return feed