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

import Queue
import threading

from fnmatch import fnmatch
import re
import json

import lxml.html

import feeds
import feedify

import httplib
import urllib
import urllib2
import chardet
import urlparse

import wsgiref.simple_server
import wsgiref.handlers

from gzip import GzipFile
from StringIO import StringIO

from readability import readability
from html2text import HTML2Text

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

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 'SCRIPT_NAME' in os.environ:
	httplib.HTTPConnection.debuglevel = 1

	import cgitb
	cgitb.enable()

class MorssException(Exception):
	pass

def log(txt, force=False):
	if DEBUG or force:
		if 'REQUEST_URI' in os.environ:
			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 Options:
	def __init__(self, options=None):
		self.options = options or []

	def __getattr__(self, key):
		return key in self.options

	def __setitem__(self, key, value):
		self.options[key] = value

	def __contains__(self, key):
		return key in self.options

class Cache:
	""" Light, error-prone caching system. """
	def __init__(self, folder=None, key='cache', lifespan=10*24*3600):
		self._key = key
		self._dir = folder
		self._lifespan = lifespan

		self._cache = {}

		if self._dir is None:
			self._hash = "NO CACHE"
			return

		maxsize = os.statvfs('./').f_namemax - len(self._dir) - 1 - 4 # ".tmp"
		self._hash = urllib.quote_plus(self._key)[:maxsize]

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

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

	def __del__(self):
		self.save()

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

	def get(self, key):
		if key in self._cache:
			self._cache[key]['last'] = time.time()
			return self._cache[key]['value']
		else:
			return None

	def set(self, key, content):
		self._cache[key] = {'last': time.time(), 'value': content}

	__getitem__ = get
	__setitem__ = set

	def save(self):
		if len(self._cache) == 0 or self._dir is None:
			return

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

		for i in self._cache:
			if time.time() - self._cache[i]['last'] > self._lifespan > -1:
				del self._cache[i]

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

		try:
			open(self._file_tmp, 'w+').write(out)
			os.rename(self._file_tmp, self._file)
		except IOError:
			log('failed to write cache to tmp file')
		except OSError:
			log('failed to move cache to file')

	def last(self, key):
		if key not in self._cache:
			return -1

		return self._cache[key]['last']

	def age(self, key):
		if key not in self._cache:
			return -1

		return time.time() - self.last(key)

	def new(self, *arg, **karg):
		""" Returns a Cache object in the same directory """
		if arg[0] != self._key:
			return Cache(self._dir, *arg, **karg)
		else:
			return self

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 = {}
			rank = 1.1
			for group in self.accept:
				rank = rank - 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])
			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

	# wikipedia daily highlight
	if fnmatch(feedurl, 'http*://*.wikipedia.org/w/api.php?*&feedformat=atom'):
		match = lxml.html.fromstring(item.desc).xpath('//b/a/@href')
		if len(match):
			item.link = match[0]
			log(item.link)

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

	# google translate
	if fnmatch(item.link, 'http://translate.google.*/translate*u=*'):
		item.link = urlparse.parse_qs(urlparse.urlparse(item.link).query)['u'][0]
		log(item.link)

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

	# google news
	if fnmatch(item.link, 'http://news.google.com/news/url*url=*'):
		item.link = urlparse.parse_qs(urlparse.urlparse(item.link).query)['url'][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.age(link) > 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) as e:
		log('http error:  %s' % e.message)
		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 Init(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)
	log(cache._hash)

	return (url, cache)

def Fetch(url, cache, options):
	# 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 not options.theforce and 'xml' in cache and cache.age('xml') < DELAY 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 url.startswith('https://itunes.apple.com/lookup?id='):
			style = 'itunes'
		elif 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 == 'itunes':
		link = json.loads(xml)['results'][0]['feedUrl']
		log('itunes redirect: %s' % link)
		return Fetch(link, cache.new(link), options)
	elif 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])
			log('rss redirect: %s' % link)
			return Fetch(link, cache.new(link), 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')


	cache.save()
	return rss

def Gather(rss, url, cache, options):
	size = len(rss.items)
	startTime = time.time()

	# custom settings
	lim_item = LIM_ITEM
	lim_time = LIM_TIME
	max_item = MAX_ITEM
	max_time = MAX_TIME

	if options.cache:
		max_time = 0

	# set
	def runner(queue):
		while True:
			value = queue.get()
			try:
				worker(*value)
			except Exception as e:
				log('Thread Error: %s' % e.message)
			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)

	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

def After(rss, options):
	for i, item in enumerate(rss.items):

		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.md:
			conv = HTML2Text(baseurl=item.link)
			conv.unicode_snob = True

			if item.desc:
				item.desc = conv.handle(item.desc)
			if item.content:
				item.content = conv.handle(item.content)

	if options.json:
		if options.indent:
			return rss.tojson(indent=4)
		else:
			return rss.tojson()
	elif options.csv:
		return rss.tocsv()
	elif options.reader:
		return rss.tohtml()
	else:
		return rss.tostring(xml_declaration=True, encoding='UTF-8')

def process(url, cache=None, options=None):
	if options == None:
		options = []

	options = Options(options)
	url, cache = Init(url, cache, options)
	rss = Fetch(url, cache, options)
	rss = Gather(rss, url, cache, options)

	return After(rss, options)

def cgi_app(environ, start_response):
	# get options
	if 'REQUEST_URI' in environ:
		url = environ['REQUEST_URI'][1:]
	else:
		url = environ['PATH_INFO'][1:]

	url = re.sub(r'^/?morss.py/', '', url)

	if url.startswith(':'):
		options = url.split('/')[0].split(':')[1:]
		url = url.split('/', 1)[1]
	else:
		options = []

	# init
	options = Options(options)
	headers = {}

	global DEBUG
	DEBUG = options.debug

	if 'HTTP_IF_NONE_MATCH' in environ:
		if not options.force and not options.facebook and time.time() - int(environ['HTTP_IF_NONE_MATCH'][1:-1]) < DELAY:
			headers['status'] = '304 Not Modified'
			start_response(headers['status'], headers.items())
			log(url)
			log('etag good')
			return []

	# headers
	headers['status'] = '200 OK'
	headers['etag'] = '"%s"' % int(time.time())

	if options.html or options.reader:
		headers['content-type'] = 'text/html'
	elif options.debug or options.txt:
		headers['content-type'] = 'text/plain'
	elif options.json:
		headers['content-type'] = 'application/json'
	elif options.csv:
		headers['content-type'] = 'text/csv'
		headers['content-disposition'] = 'attachment; filename="feed.csv"'
	else:
		headers['content-type'] = 'text/xml'

	url, cache = Init(url, os.getcwd() + '/cache', options)

	if options.facebook:
		doFacebook(url, environ, headers, options, cache)
		start_response(headers['status'], headers.items())
		return

	# get the work done
	RSS = Fetch(url, cache, options)

	if headers['content-type'] == 'text/xml':
		headers['content-type'] = RSS.mimetype

	start_response(headers['status'], headers.items())

	RSS = Gather(RSS, url, cache, options)

	if not DEBUG and not options.silent:
		return After(RSS, options)

	log('done')

def cgi_wrapper(environ, start_response):
	# simple http server for html and css
	files = {
		'':				'text/html',
		'index.html':	'text/html'}

	if 'REQUEST_URI' in environ:
		url = environ['REQUEST_URI'][1:]
	else:
		url = environ['PATH_INFO'][1:]

	if url in files:
		headers = {}

		if url == '':
			url = 'index.html'

		if os.path.isfile(url):
			headers['status'] = '200 OK'
			headers['content-type'] = files[url]
			start_response(headers['status'], headers.items())
			return open(url, 'rb').read()
		else:
			headers['status'] = '404 Not found'
			start_response(headers['status'], headers.items())
			return ''

	# actual morss use
	try:
		return cgi_app(environ, start_response) or []
	except (KeyboardInterrupt, SystemExit):
		raise
	except MorssException as e:
		headers = {}
		headers['status'] = '500 Oops'
		headers['content-type'] = 'text/plain'
		start_response(headers['status'], headers.items(), sys.exc_info())
		return 'Internal Error: %s' % e.message
	except Exception as e:
		headers = {}
		headers['status'] = '500 Oops'
		headers['content-type'] = 'text/plain'
		start_response(headers['status'], headers.items(), sys.exc_info())
		return 'Unknown Error: %s' % e.message

def cli_app():
	options = Options(sys.argv[1:-1])
	url = sys.argv[-1]

	global DEBUG
	DEBUG = options.debug

	url, cache = Init(url, os.path.expanduser('~/.cache/morss'), options)
	RSS = Fetch(url, cache, options)
	RSS = Gather(RSS, url, cache, options)

	if not DEBUG and not options.silent:
		print After(RSS, options)

	log('done')

def doFacebook(url, environ, headers, options, cache):
	log('fb stuff')

	query = urlparse.urlparse(url).query

	if 'code' in query:
		# get real token from code
		code = urlparse.parse_qs(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://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]))

		headers['set-cookie'] = 'token={token}; Path=/'.format(token=ltoken)

	# headers
	headers['status'] = '303 See Other'
	headers['location'] = 'http://{domain}/'.format(domain=environ['SERVER_NAME'])

	log('fb done')
	return

def main():
	if 'REQUEST_URI' in os.environ:
		wsgiref.handlers.CGIHandler().run(cgi_wrapper)

	elif len(sys.argv) <= 1:
		httpd = wsgiref.simple_server.make_server('', 8080, cgi_wrapper)
		httpd.serve_forever()

	else:
		try:
			cli_app()
		except (KeyboardInterrupt, SystemExit):
			raise
		except MorssException as e:
			print 'Internal Error: %s' % e.message
		except Exception as e:
			print 'Unknown Error: %s' % e.message

if __name__ == '__main__':
	main()