--- a/gpp/core/middleware.py	Thu Jun 10 03:31:57 2010 +0000
+++ b/gpp/core/middleware.py	Tue Jul 06 03:02:20 2010 +0000
@@ -1,5 +1,13 @@
 """Common middleware for the entire project."""
+import datetime
+
 from django.contrib.auth import logout
+from django.conf import settings
+
+from core.models import UserLastVisit
+from core.models import AnonLastVisit
+from core.functions import get_ip
+
 
 class InactiveUserMiddleware(object):
     """
@@ -10,7 +18,59 @@
     Idea taken from: http://djangosnippets.org/snippets/1105/
     """
 
-    def process_request(self, request):
+    def process_view(self, request, view_func, view_args, view_kwargs):
         if request.user.is_authenticated() and not request.user.is_active:
             logout(request)
 
+
+ONLINE_COOKIE = 'sg101_online'  # online cookie name
+ONLINE_TIMEOUT = 10 * 60        # online cookie lifetime in seconds
+
+class WhosOnline(object):
+    """
+    This middleware class keeps track of which registered users have
+    been seen recently, and the number of unique unregistered users.
+    This middleware should come after the authentication middleware,
+    as we count on the user attribute being attached to the request.
+    """
+
+    def process_response(self, request, response):
+        """
+        Keep track of who is online.
+        """
+        if request.is_ajax():
+            return
+
+        if request.user.is_authenticated():
+            if request.COOKIES.get(ONLINE_COOKIE) is None:
+                # update the last seen timestamp
+                try:
+                    ulv = UserLastVisit.objects.get(user=request.user)
+                except UserLastVisit.DoesNotExist:
+                    ulv = UserLastVisit(user=request.user)
+
+                ulv.last_visit = datetime.datetime.now()
+                ulv.save()
+
+                # set a cookie to expire in 10 minutes or so
+                response.set_cookie(ONLINE_COOKIE, '1', max_age=ONLINE_TIMEOUT)
+        else:
+            if request.COOKIES.get(settings.CSRF_COOKIE_NAME) is not None:
+                # We have a non-authenticated user that has cookies enabled. This
+                # means we can track them.
+                if request.COOKIES.get(ONLINE_COOKIE) is None:
+                    # update the timestamp for this anonymous visitor
+                    ip = get_ip(request)
+                    if ip:
+                        try:
+                            alv = AnonLastVisit.objects.get(ip=ip)
+                        except AnonLastVisit.DoesNotExist:
+                            alv = AnonLastVisit(ip=ip)
+
+                        alv.last_visit = datetime.datetime.now()
+                        alv.save()
+
+                        # set a cookie to expire in 10 minutes or so
+                        response.set_cookie(ONLINE_COOKIE, '1', max_age=ONLINE_TIMEOUT)
+
+        return response