Validate twitter accounts when submitting a new blog

Do this by connecting to the twitter API and actually validate both that
the account exists, and that it's not protected. Protected accounts will
cause the follower-sync script to keep trying over and over again for
following, and there's not any point in promoting those anyway.

This adds a dependency on requests_oauthlib, but that's already used in
other pgweb projects so shouldn't be a problem.

hamnadmin/hamnadmin/register/forms.py

@@ -1,11 +1,15 @@
 from django import forms
 from django.contrib import messages
 from django.core.validators import MinLengthValidator
+from django.conf import settings
 
 from models import Blog
 
 from hamnadmin.util.aggregate import FeedFetcher
 
+import requests
+import requests_oauthlib
+
 class BlogEditForm(forms.ModelForm):
 	class Meta:
 		model = Blog
@@ -46,10 +50,32 @@ def _trace(msg):
 		return self.cleaned_data
 
 	def clean_twitteruser(self):
-		if self.cleaned_data['twitteruser'].startswith('@'):
-			return self.cleaned_data['twitteruser'][1:]
-		else:
-			return self.cleaned_data['twitteruser']
+		if self.cleaned_data['twitteruser'] == '':
+			return ''
+
+		u = self.cleaned_data['twitteruser']
+		if u.startswith('@'):
+			u = u[1:]
+
+		if not settings.TWITTER_CLIENT:
+			# Can't validate beyond this unless we have client keys configured
+			return u
+
+		tw = requests_oauthlib.OAuth1Session(settings.TWITTER_CLIENT,
+											 settings.TWITTER_CLIENTSECRET,
+											 settings.TWITTER_TOKEN,
+											 settings.TWITTER_TOKENSECRET)
+		try:
+			r = tw.get('https://api.twitter.com/1.1/users/show.json?screen_name={0}'.format(u),
+			timeout=5)
+			if r.status_code != 200:
+				raise forms.ValidationError("Could not find twitter user")
+			j = r.json()
+			if j['protected']:
+				raise forms.ValidationError("Cannot register protected twitter accounts")
+		except requests.exceptions.ReadTimeout:
+			raise forms.ValidationError("Timeout trying to validate account with twitter")
+		return u
 
 class ModerateRejectForm(forms.Form):
 	message = forms.CharField(min_length=30, required=True, widget=forms.Textarea)

hamnadmin/hamnadmin/settings.py

@@ -1,4 +1,5 @@
 # Django settings for admin project.
+import os
 
 DEBUG = False
 
@@ -74,6 +75,22 @@
 # Set to None for testing
 VARNISH_URL="http://localhost/varnish-purge"
 
+# Dynamically load settings from the "outer" planet.ini that might
+# be needed.
+try:
+	import ConfigParser
+	_configparser = ConfigParser.ConfigParser()
+	_configparser.read(os.path.join(os.path.abspath(os.path.dirname(__file__)), '../../planet.ini'))
+	TWITTER_CLIENT=_configparser.get('twitter', 'consumer')
+	TWITTER_CLIENTSECRET=_configparser.get('twitter', 'consumersecret')
+	TWITTER_TOKEN=_configparser.get('twitter', 'token')
+	TWITTER_TOKENSECRET=_configparser.get('twitter', 'secret')
+except:
+	TWITTER_CLIENT=None
+	TWITTER_CLIENTSECRET=None
+	TWITTER_TOKEN=None
+	TWITTER_TOKENSECRET=None
+
 # If there is a local_settings.py, let it override our settings
 try:
 	from local_settings import *