AA-513: Reset segment state if anon user and there is a segment user id

If we are seeing an anonymous user, but the segment user id is still
set, we believe the segment user id is coming from a different user on
the same machine. This will make sure we clear out that storage and
then the indentify call will make a new anonymous id

cms/templates/widgets/segment-io-footer.html

@@ -30,6 +30,22 @@
         else {
             onLoadCallback();
         }
+    % else:
+        // If we do not have an authenticated user, but Segment has a user id,
+        // reset the Segment user state so we start tracking fresh.
+        // This has to be wrapped in the document.readyState logic because the analytics.user()
+        // function isn't available until the analytics.js package has finished initializing.
+        if (document.readyState === 'complete') {
+            if (analytics.user().id()) {
+                analytics.reset();
+            }
+        } else {
+            document.addEventListener('readystatechange', event => {
+                if (event.target.readyState === 'complete' && analytics.user().id()) {
+                    analytics.reset();
+                }
+            });
+        }
     % endif
     </script>
     <!-- end segment footer -->

lms/templates/widgets/segment-io-footer.html

@@ -22,6 +22,22 @@
                 }
             );
         });
+    % else:
+        // If we do not have an authenticated user, but Segment has a user id,
+        // reset the Segment user state so we start tracking fresh.
+        // This has to be wrapped in the document.readyState logic because the analytics.user()
+        // function isn't available until the analytics.js package has finished initializing.
+        if (document.readyState === 'complete') {
+            if (analytics.user().id()) {
+                analytics.reset();
+            }
+        } else {
+            document.addEventListener('readystatechange', event => {
+                if (event.target.readyState === 'complete' && analytics.user().id()) {
+                    analytics.reset();
+                }
+            });
+        }
     % endif
     </script>
     <!-- end segment footer -->