# This file is part of Wolnelektury, licensed under GNU Affero GPLv3 or later.
# Copyright © Fundacja Nowoczesna Polska. See NOTICE for more information.
#
+import codecs
+import csv
+import cStringIO
+import json
+import os
+from functools import wraps
+
import pytz
+from inspect import getargspec
+
+import re
+from django.core.mail import send_mail
+from django.http import HttpResponse
+from django.template import RequestContext
+from django.template.loader import render_to_string
from django.utils import timezone
from django.conf import settings
+from django.utils.translation import ugettext
tz = pytz.timezone(settings.TIME_ZONE)
+
def localtime_to_utc(localtime):
return timezone.utc.normalize(
tz.localize(localtime)
)
+
def utc_for_js(dt):
return dt.strftime('%Y/%m/%d %H:%M:%S UTC')
+
+
+def makedirs(path):
+ if not os.path.isdir(path):
+ os.makedirs(path)
+
+
+def stringify_keys(dictionary):
+ return dict((keyword.encode('ascii'), value)
+ for keyword, value in dictionary.iteritems())
+
+
+def json_encode(obj, sort_keys=True, ensure_ascii=False):
+ return json.dumps(obj, sort_keys=sort_keys, ensure_ascii=ensure_ascii)
+
+
+def json_decode(obj):
+ return json.loads(obj)
+
+
+def json_decode_fallback(value):
+ try:
+ return json_decode(value)
+ except ValueError:
+ return value
+
+
+class AjaxError(Exception):
+ pass
+
+
+def ajax(login_required=False, method=None, template=None, permission_required=None):
+ def decorator(fun):
+ @wraps(fun)
+ def ajax_view(request):
+ kwargs = {}
+ request_params = None
+ if method == 'post':
+ request_params = request.POST
+ elif method == 'get':
+ request_params = request.GET
+ fun_params, xx, fun_kwargs, defaults = getargspec(fun)
+ if defaults:
+ required_params = fun_params[1:-len(defaults)]
+ else:
+ required_params = fun_params[1:]
+ missing_params = set(required_params) - set(request_params)
+ if missing_params:
+ res = {
+ 'result': 'missing params',
+ 'missing': ', '.join(missing_params),
+ }
+ else:
+ if request_params:
+ request_params = dict(
+ (key, json_decode_fallback(value))
+ for key, value in request_params.iteritems()
+ if fun_kwargs or key in fun_params)
+ kwargs.update(stringify_keys(request_params))
+ res = None
+ if login_required and not request.user.is_authenticated():
+ res = {'result': 'logout'}
+ if (permission_required and
+ not request.user.has_perm(permission_required)):
+ res = {'result': 'access denied'}
+ if not res:
+ try:
+ res = fun(request, **kwargs)
+ if res and template:
+ res = {'html': render_to_string(template, res, RequestContext(request))}
+ except AjaxError as e:
+ res = {'result': e.args[0]}
+ if 'result' not in res:
+ res['result'] = 'ok'
+ return HttpResponse(json_encode(res), content_type='application/json; charset=utf-8',
+ status=200 if res['result'] == 'ok' else 400)
+
+ return ajax_view
+
+ return decorator
+
+
+def send_noreply_mail(subject, message, recipient_list, **kwargs):
+ send_mail(
+ u'[WolneLektury] ' + subject,
+ message + u"\n\n-- \n" + ugettext(u'Message sent automatically. Please do not reply.'),
+ 'no-reply@wolnelektury.pl', recipient_list, **kwargs)
+
+
+# source: https://docs.python.org/2/library/csv.html#examples
+class UnicodeCSVWriter(object):
+ """
+ A CSV writer which will write rows to CSV file "f",
+ which is encoded in the given encoding.
+ """
+
+ def __init__(self, f, dialect=csv.excel, encoding="utf-8", **kwds):
+ # Redirect output to a queue
+ self.queue = cStringIO.StringIO()
+ self.writer = csv.writer(self.queue, dialect=dialect, **kwds)
+ self.stream = f
+ self.encoder = codecs.getincrementalencoder(encoding)()
+
+ def writerow(self, row):
+ self.writer.writerow([s.encode("utf-8") for s in row])
+ # Fetch UTF-8 output from the queue ...
+ data = self.queue.getvalue()
+ data = data.decode("utf-8")
+ # ... and reencode it into the target encoding
+ data = self.encoder.encode(data)
+ # write to the target stream
+ self.stream.write(data)
+ # empty queue
+ self.queue.truncate(0)
+
+ def writerows(self, rows):
+ for row in rows:
+ self.writerow(row)
+
+
+# the original re.escape messes with unicode
+def re_escape(s):
+ return re.sub(r"[(){}\[\].*?|^$\\+-]", r"\\\g<0>", s)
+
+
+BOT_BITS = ['bot', 'slurp', 'spider', 'facebook', 'crawler', 'parser', 'http']
+
+
+def is_crawler(request):
+ user_agent = request.META.get('HTTP_USER_AGENT')
+ if not user_agent:
+ return True
+ user_agent = user_agent.lower()
+ return any(bot_bit in user_agent for bot_bit in BOT_BITS)