#!/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):
	# split into domain and path
	index = url.find("/",url.find("//")+2)
	domain = url[:index]
	path = url[index:]

	primary_domain = {
		"https://tumblr.com",
		"http://tumblr.com",
		"https://www.tumblr.com",
		"http://www.tumblr.com"
	}
	if domain in primary_domain:
		# only handle blogs on other subdomains
		return None

	for page_type in ["tagged", "search"]:
		page_type_with_slashes = "/" + page_type + "/"
		if path.startswith(page_type_with_slashes):
			offset = len(page_type_with_slashes)
			tag_end = path.find('/', offset)

			if tag_end < 0:
				# no trailing slash, go to end
				tag = path[offset:]
			else:
				tag = path[offset:tag_end]

			if tag:
				return domain + page_type_with_slashes + tag + "/rss"

	# if we've reached this point, just return overall blog feed
	return domain + "/rss"

def extract_from_page (page, verbosity):
	# this method should not be called
	return search (page, '<link rel="alternate" type="application/rss+xml" 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)
		if network == True:
			page = download (platform, url, args, verbosity)
			feed = extract_from_page (page, verbosity)
			if not feed is None:
				return feed