#!/usr/bin/env python
import sys
import os
import os.path
import time

import Queue
import threading

from fnmatch import fnmatch
from base64 import b64encode, b64decode
import re
import string
import json

import lxml.html
import lxml.html.clean
import lxml.builder

import feeds
import feedify

import httplib
import urllib
import urllib2
import chardet
import urlparse

from gzip import GzipFile
from StringIO import StringIO

from readability import readability

LIM_ITEM = 100	# deletes what's beyond
LIM_TIME = 7	# deletes what's after
MAX_ITEM = 50	# cache-only beyond
MAX_TIME = 7	# cache-only after (in sec)
DELAY = 10*60	# xml cache & ETag cache (in sec)
TIMEOUT = 2	# http timeout (in sec)
THREADS = 10	# number of threads (1 for single-threaded)

DEBUG = False
HOLD = False

UA_RSS = 'Liferea/1.8.12 (Linux; fr_FR.utf8; http://liferea.sf.net/)'
UA_HTML = 'Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; en-US; rv:1.9.2.11) Gecko/20101012 Firefox/3.6.11'

MIMETYPE = {	'xml':	['text/xml', 'application/xml', 'application/rss+xml', 'application/rdf+xml', 'application/atom+xml'],
				'html':	['text/html', 'application/xhtml+xml', 'application/xml']}

FBAPPID = "<insert yours>"
FBSECRET = "<insert yours>"
FBAPPTOKEN = FBAPPID + '|' + FBSECRET

PROTOCOL = ['http', 'https', 'ftp']

if 'REQUEST_URI' in os.environ:
	httplib.HTTPConnection.debuglevel = 1

	import cgitb
	cgitb.enable()

class MorssException(Exception):
	pass

def log(txt):
	if DEBUG:
		if HOLD:
			open('morss.log', 'a').write("%s\n" % repr(txt))
		else:
			print repr(txt)


def lenHTML(txt):
	if len(txt):
		return len(lxml.html.fromstring(txt).text_content())
	else:
		return 0

def countWord(txt):
	if len(txt):
		return len(lxml.html.fromstring(txt).text_content().split())
	else:
		return 0

class ParseOptions:
	def __init__(self):
		self.url = ''
		self.options = {}
		roptions = []

		if 'REQUEST_URI' in os.environ:
			self.url = os.environ['REQUEST_URI'][1:]

			if 'REDIRECT_URL' not in os.environ:
				self.url = self.url[len(os.environ['SCRIPT_NAME']):]

			if self.url.startswith(':'):
				roptions = self.url.split('/')[0].split(':')[1:]
				self.url = self.url.split('/', 1)[1]
		else:
			if len(sys.argv) <= 1:
				return

			roptions = sys.argv[1:-1]
			self.url = sys.argv[-1]

		for option in roptions:
			split = option.split('=', 1)
			if len(split) > 1:
				if split[0].lower() == 'true':
					self.options[split[0]] = True
				if split[0].lower() == 'false':
					self.options[split[0]] = False

				self.options[split[0]] = split[1]
			else:
				self.options[split[0]] = True

	def __getattr__(self, key):
		if key in self.options:
			return self.options[key]
		else:
			return False

class Cache:
	""" Light, error-prone caching system. """
	def __init__(self, folder, key, persistent=False, dic=False):
		self._key = key
		self._dir = folder
		self._dic = dic

		maxsize = os.statvfs('./').f_namemax - len(self._dir) - 1
		self._hash = urllib.quote_plus(self._key)[:maxsize]

		self._file = self._dir + '/' + self._hash

		self._cached = {} # what *was* cached
		self._cache = {} # new things to put in cache

		if os.path.isfile(self._file):
			data = open(self._file).read()
			if data:
				self._cached = json.loads(data)

		if persistent:
			self._cache = self._cached

	def __del__(self):
		self.save()

	def __contains__(self, key):
		return key in self._cache or key in self._cached

	def get(self, key):
		if key in self._cache:
			return self._cache[key]
		elif key in self._cached:
			self._cache[key] = self._cached[key]
			return self._cached[key]
		else:
			if self._dic:
				self._cache[key] = {}
				return self._cache[key]
			else:
				return None

	def set(self, key, content):
		self._cache[key] = content

	__getitem__ = get
	__setitem__ = set

	def save(self):
		if len(self._cache) == 0:
			return

		if not os.path.exists(self._dir):
			os.makedirs(self._dir)

		out = json.dumps(self._cache, indent=4)

		with open(self._file, 'w+') as file:
			file.write(out)

	def isYoungerThan(self, sec):
		if not os.path.exists(self._file):
			return False

		return time.time() - os.path.getmtime(self._file) < sec

	def new(self, key, persistent=False, dic=False):
		""" Returns a Cache object in the same directory """
		if key != self._key:
			return Cache(self._dir, key, persistent, dic)
		else:
			return self

	def redirect(self, key, persistent=False):
		return self.__init__(self._dir, key, persistent)

class SimpleDownload(urllib2.HTTPCookieProcessor):
	"""
	Custom urllib2 handler to download a page, using etag/last-modified headers,
	to save bandwidth. The given headers are added back into the header on error
	304 for easier use.
	"""
	def __init__(self, cache="", etag=None, lastmodified=None, useragent=UA_HTML, decode=True, cookiejar=None, accept=None, strict=False):
		urllib2.HTTPCookieProcessor.__init__(self, cookiejar)
		self.cache = cache
		self.etag = etag
		self.lastmodified = lastmodified
		self.useragent = useragent
		self.decode = decode
		self.accept = accept
		self.strict = strict

	def http_request(self, req):
		urllib2.HTTPCookieProcessor.http_request(self, req)
		req.add_unredirected_header('Accept-Encoding', 'gzip')
		req.add_unredirected_header('User-Agent', self.useragent)
		if req.get_host() != 'feeds.feedburner.com':
			req.add_unredirected_header('Referer', 'http://%s' % req.get_host())

		if self.cache:
			if self.etag:
				req.add_unredirected_header('If-None-Match', self.etag)
			if self.lastmodified:
				req.add_unredirected_header('If-Modified-Since', self.lastmodified)

		if self.accept is not None:
			# req.add_unredirected_header('Accept', 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8')
			if isinstance(self.accept, basestring):
				self.accept = (self.accept,)

			out = {}
			for (i, group) in enumerate(self.accept):
				rank = 1 - i*0.1

				if isinstance(group, basestring):
					if group in MIMETYPE:
						group = MIMETYPE[group]
					else:
						out[group] = rank
						continue

				for mime in group:
					if mime not in out:
						out[mime] = rank

			if not self.strict:
				out['*/*'] = rank-0.1

			string = ','.join([x+';q={0:.1}'.format(out[x]) if out[x] != 1 else x for x in out])
			log(string)

			req.add_unredirected_header('Accept', string)

		return req

	def http_error_304(self, req, fp, code, msg, headers):
		log('http cached')
		if self.etag:
			headers.addheader('etag', self.etag)
		if self.lastmodified:
			headers.addheader('last-modified', self.lastmodified)
		resp = urllib2.addinfourl(StringIO(self.cache), headers, req.get_full_url(), 200)
		return resp

	def http_response(self, req, resp):
		urllib2.HTTPCookieProcessor.http_response(self, req, resp)
		odata = data = resp.read()

		if 200 <= resp.code < 300:
			# gzip
			if resp.headers.get('Content-Encoding') == 'gzip':
				log('un-gzip')
				data = GzipFile(fileobj=StringIO(data), mode='r').read()

		if 200 <= resp.code < 300 and resp.info().maintype == 'text':
			# <meta> redirect
			if resp.info().type in MIMETYPE['html']:
				match = re.search(r'(?i)<meta http-equiv=.refresh[^>]*?url=(http.*?)["\']', data)
				if match:
					newurl = match.groups()[0]
					log('redirect: %s' % newurl)

					newheaders = dict((k,v) for k,v in req.headers.items()
						if k.lower() not in ('content-length', 'content-type'))
					new = urllib2.Request(newurl,
						headers=newheaders,
						origin_req_host=req.get_origin_req_host(),
						unverifiable=True)

					return self.parent.open(new, timeout=req.timeout)

			# encoding
			enc = detEncoding(data, resp)

			if enc:
				data = data.decode(enc, 'replace')

				if not self.decode:
					data = data.encode(enc)

		fp = StringIO(data)
		old_resp = resp
		resp = urllib2.addinfourl(fp, old_resp.headers, old_resp.url, old_resp.code)
		resp.msg = old_resp.msg

		return resp

	https_response = http_response
	https_request = http_request

def detEncoding(data, con=None):
	if con is not None and con.headers.getparam('charset'):
		log('header')
		return con.headers.getparam('charset')

	match = re.search('charset=["\']?([0-9a-zA-Z-]+)', data[:1000])
	if match:
		log('meta.re')
		return match.groups()[0]

	match = re.search('encoding=["\']?([0-9a-zA-Z-]+)', data[:100])
	if match:
		return match.groups()[0].lower()

	return None

def Fix(item, feedurl='/'):
	""" Improves feed items (absolute links, resolve feedburner links, etc) """

	# check unwanted uppercase title
	if len(item.title) > 20 and item.title.isupper():
		item.title = item.title.title()

	# check if it includes link
	if not item.link:
		log('no link')
		return item

	# check relative urls
	item.link = urlparse.urljoin(feedurl, item.link)

	# google
	if fnmatch(item.link, 'http://www.google.com/url?q=*'):
		item.link = urlparse.parse_qs(urlparse.urlparse(item.link).query)['q'][0]
		log(item.link)

	# facebook
	if fnmatch(item.link, 'https://www.facebook.com/l.php?u=*'):
		item.link = urlparse.parse_qs(urlparse.urlparse(item.link).query)['u'][0]
		log(item.link)

	# feedburner
	feeds.NSMAP['feedburner'] = 'http://rssnamespace.org/feedburner/ext/1.0'
	match = item.xval('feedburner:origLink')
	if match:
		item.link = match

	# feedsportal
	match = re.search('/([0-9a-zA-Z]{20,})/story01.htm$', item.link)
	if match:
		url = match.groups()[0].split('0')
		t = {'A':'0', 'B':'.', 'C':'/', 'D':'?', 'E':'-', 'H':',', 'I':'_', 'L':'http://', 'S':'www.', 'N':'.com', 'O':'.co.uk'}
		item.link = ''.join([(t[s[0]] if s[0] in t else '=') + s[1:] for s in url[1:]])
		log(item.link)

	# reddit
	if urlparse.urlparse(feedurl).netloc == 'www.reddit.com':
		match = lxml.html.fromstring(item.desc).xpath('//a[text()="[link]"]/@href')
		if len(match):
			item.link = match[0]
			log(item.link)

	return item

def Fill(item, cache, feedurl='/', fast=False):
	""" Returns True when it has done its best """

	if not item.link:
		log('no link')
		return item

	log(item.link)

	# content already provided?
	count_content = countWord(item.content)
	count_desc = countWord(item.desc)

	if max(count_content, count_desc) > 500:
		if count_desc > count_content:
			item.content = item.desc
			del item.desc
			log('reversed sizes')
		log('long enough')
		return True

	if count_content > 5*count_desc > 0 and count_content > 50:
		log('content bigger enough')
		return True

	link = item.link

	# twitter
	if urlparse.urlparse(feedurl).netloc == 'twitter.com':
		match = lxml.html.fromstring(item.content).xpath('//a/@data-expanded-url')
		if len(match):
			link = match[0]
			log(link)
		else:
			link = None

	# facebook
	if urlparse.urlparse(feedurl).netloc == 'graph.facebook.com':
		match = lxml.html.fromstring(item.content).xpath('//a/@href')
		if len(match) and urlparse.urlparse(match[0]).netloc != 'www.facebook.com':
			link = match[0]
			log(link)
		else:
			link = None

	if link is None:
		log('no used link')
		return True

	# check cache and previous errors
	if link in cache:
		content = cache.get(link)
		match = re.search(r'^error-([a-z]{2,10})$', content)
		if match:
			if cache.isYoungerThan(DELAY):
				log('cached error: %s' % match.groups()[0])
				return True
			else:
				log('old error')
		else:
			log('cached')
			item.pushContent(cache.get(link))
			return True

	# super-fast mode
	if fast:
		log('skipped')
		return False

	# download
	try:
		url = link.encode('utf-8')
		con = urllib2.build_opener(SimpleDownload(accept=('html', 'text/*'), strict=True)).open(url, timeout=TIMEOUT)
		data = con.read()
	except (IOError, httplib.HTTPException):
		log('http error')
		cache.set(link, 'error-http')
		return True

	if con.info().type not in MIMETYPE['html'] and con.info().type != 'text/plain':
		log('non-text page')
		cache.set(link, 'error-type')
		return True

	out = readability.Document(data, url=con.url).summary(True)

	if countWord(out) > max(count_content, count_desc) > 0:
		item.pushContent(out)
		cache.set(link, out)
	else:
		log('not bigger enough')
		cache.set(link, 'error-length')
		return True

	return True

def Gather(url, cachePath, options):
	# url clean up
	log(url)

	if url is None:
		raise MorssException('No url provided')

	if urlparse.urlparse(url).scheme not in PROTOCOL:
		url = 'http://' + url
		log(url)

	url = url.replace(' ', '%20')

	# cache
	cache = Cache(cachePath, url, options.proxy)
	log(cache._hash)

	# do some useful facebook work
	feedify.PreWorker(url, cache)

	if 'redirect' in cache:
		url = cache.get('redirect')
		log('url redirect')
		log(url)

	if 'cache' in cache:
		cache.redirect(cache.get('cache'))
		log('cache redirect')

	# fetch feed
	if cache.isYoungerThan(DELAY) and not options.theforce and 'xml' in cache and 'style' in cache:
		log('xml cached')
		xml = cache.get('xml')
		style = cache.get('style')
	else:
		try:
			opener = SimpleDownload(cache.get(url), cache.get('etag'), cache.get('lastmodified'), accept=('xml','html'))
			con = urllib2.build_opener(opener).open(url, timeout=TIMEOUT)
			xml = con.read()
		except (IOError, httplib.HTTPException):
			raise MorssException('Error downloading feed')

		cache.set('xml', xml)
		cache.set('etag', con.headers.getheader('etag'))
		cache.set('lastmodified', con.headers.getheader('last-modified'))

		if xml.startswith('<?xml') or con.info().type in MIMETYPE['xml']:
			style = 'normal'
		elif feedify.supported(url):
			style = 'feedify'
		elif con.info().type in MIMETYPE['html']:
			style = 'html'
		else:
			style = 'none'
			log(con.info().type)

		cache.set('style', style)

	log(style)

	if style == 'normal':
		rss = feeds.parse(xml)
	elif style == 'feedify':
		feed = feedify.Builder(url, xml, cache)
		feed.build()
		rss = feed.feed
	elif style == 'html':
		match = lxml.html.fromstring(xml).xpath("//link[@rel='alternate'][@type='application/rss+xml' or @type='application/atom+xml']/@href")
		if len(match):
			link = urlparse.urljoin(url, match[0])
			return Gather(link, cachePath, options)
		else:
			log('no-link html')
			raise MorssException('Link provided is an HTML page, which doesn\'t link to a feed')
	else:
		log('random page')
		raise MorssException('Link provided is not a valid feed')

	size = len(rss.items)
	startTime = time.time()

	# custom settings
	if options.progress:
		MAX_TIME = -1
	if options.cache:
		MAX_TIME = 0

	# set
	def runner(queue):
		while True:
			value = queue.get()
			try:
				worker(*value)
			except:
				log('random error in thread')
			queue.task_done()

	def worker(i, item):
		if time.time() - startTime > LIM_TIME >= 0 or i+1 > LIM_ITEM >= 0:
			log('dropped')
			item.remove()
			return

		item = Fix(item, url)

		if time.time() - startTime > MAX_TIME >= 0 or i+1 > MAX_ITEM >= 0:
			if not options.proxy:
				if Fill(item, cache, url, True) is False:
					item.remove()
					return
		else:
			if not options.proxy:
				Fill(item, cache, url)

		if item.desc and item.content:
			if options.clip:
				item.content = item.desc + "<br/><br/><center>* * *</center><br/><br/>" + item.content
				del item.desc
			if not options.keep:
				del item.desc

		if options.progress:
			end = size if MAX_ITEM == -1 else min(MAX_ITEM, size)
			if options.json:
				sys.stdout.write(json.dumps((i+1, end, item), default=lambda o: dict(o)) + "\n")
			else:
				sys.stdout.write("%s/%s\n" % (i+1, end))
			sys.stdout.flush()

	queue = Queue.Queue()

	for i in range(THREADS):
		t = threading.Thread(target=runner, args=(queue,))
		t.daemon = True
		t.start()

	for i, item in enumerate(rss.items):
		queue.put([i, item])

	queue.join()
	cache.save()

	log(len(rss.items))
	log(time.time() - startTime)

	return rss

if __name__ == '__main__':
	options = ParseOptions()
	url = options.url

	DEBUG = bool(options.debug)

	if 'REQUEST_URI' in os.environ:
		HOLD = True

		if 'HTTP_IF_NONE_MATCH' in os.environ:
			if not options.force and not options.facebook and time.time() - int(os.environ['HTTP_IF_NONE_MATCH'][1:-1]) < DELAY:
				print 'Status: 304'
				print
				log(url)
				log('etag good')
				sys.exit(0)

		cachePath = os.getcwd() + '/cache'
	else:
		cachePath = os.path.expanduser('~') + '/.cache/morss'

	if options.facebook:
		facebook = Cache(cachePath, 'facebook', persistent=True, dic=True)

		# get real token from code
		code = urlparse.parse_qs(urlparse.urlparse(url).query)['code'][0]
		eurl = "https://graph.facebook.com/oauth/access_token?client_id={app_id}&redirect_uri={redirect_uri}&client_secret={app_secret}&code={code_parameter}".format(app_id=FBAPPID, app_secret=FBSECRET, code_parameter=code, redirect_uri="http://test.morss.it/:facebook/")
		token = urlparse.parse_qs(urllib2.urlopen(eurl).read().strip())['access_token'][0]

		# get long-lived access token
		eurl = "https://graph.facebook.com/oauth/access_token?grant_type=fb_exchange_token&client_id={app_id}&client_secret={app_secret}&fb_exchange_token={short_lived_token}".format(app_id=FBAPPID, app_secret=FBSECRET, short_lived_token=token)
		values = urlparse.parse_qs(urllib2.urlopen(eurl).read().strip())

		ltoken = values['access_token'][0]
		expires = int(time.time() + int(values['expires'][0]))

		# get user id
		iurl = "https://graph.facebook.com/me?fields=id&access_token={token}".format(ltoken)
		user_id = json.loads(urllib2.urlopen(iurl).read())['id']

		# do sth out of it
		if user_id not in facebook['user']:
			facebook['user'][user_id] = {'original': ltoken}

		facebook['token'][ltoken] = {'user': user_id, 'expires': expires}
		facebook['user'][user_id]['token'] = ltoken

		facebook.save()

		if 'REQUEST_URI' in os.environ:
			print 'Status: 200'
			print 'Content-Type: text/plain'
			print ''

		print "token updated"

		sys.exit(0)

	if 'REQUEST_URI' in os.environ:
		print 'Status: 200'
		print 'ETag: "%s"' % int(time.time())

		if options.html:
			print 'Content-Type: text/html'
		elif options.debug or options.txt:
			print 'Content-Type: text/plain'
		elif options.progress:
			print 'Content-Type: application/octet-stream'
		elif options.json:
			print 'Content-Type: application/json'
		else:
			print 'Content-Type: text/xml'
		print ''

		HOLD = False


	RSS = Gather(url, cachePath, options)

	if RSS is not False and not options.progress and not DEBUG and not options.silent:
		if options.json:
			if options.indent:
				print json.dumps(RSS, sort_keys=True, indent=4, default=lambda x: dict(x))
			else:
				print json.dumps(RSS, sort_keys=True, default=lambda x: dict(x))
		else:
			print RSS.tostring(xml_declaration=True, encoding='UTF-8')

	if RSS is False and 'progress' not in options:
		print 'Error fetching feed.'

	log('done')