Email unsubscribing that may in theory, work

Were it not for that fact that you can't use the base handler in the pusher because it pulls in the world. Comitting while I fix that on a different branch.

synapse/handlers/auth.py

@@ -529,6 +529,11 @@ class AuthHandler(BaseHandler):
         macaroon.add_first_party_caveat("time < %d" % (expiry,))
         return macaroon.serialize()
 
+    def generate_delete_pusher_token(self, user_id):
+        macaroon = self._generate_base_macaroon(user_id)
+        macaroon.add_first_party_caveat("type = delete_pusher")
+        return macaroon.serialize()
+
     def validate_short_term_login_token_and_get_user_id(self, login_token):
         try:
             macaroon = pymacaroons.Macaroon.deserialize(login_token)

synapse/push/emailpusher.py

@@ -273,5 +273,5 @@ class EmailPusher(object):
         logger.info("Sending notif email for user %r", self.user_id)
 
         yield self.mailer.send_notification_mail(
-            self.user_id, self.email, push_actions, reason
+            self.app_id, self.user_id, self.email, push_actions, reason
         )

synapse/push/mailer.py

@@ -81,6 +81,7 @@ class Mailer(object):
     def __init__(self, hs):
         self.hs = hs
         self.store = self.hs.get_datastore()
+        self.handlers = self.hs.get_handlers()
         self.state_handler = self.hs.get_state_handler()
         loader = jinja2.FileSystemLoader(self.hs.config.email_template_dir)
         self.app_name = self.hs.config.email_app_name
@@ -95,7 +96,8 @@ class Mailer(object):
         )
 
     @defer.inlineCallbacks
-    def send_notification_mail(self, user_id, email_address, push_actions, reason):
+    def send_notification_mail(self, app_id, user_id, email_address,
+                               push_actions, reason):
         raw_from = email.utils.parseaddr(self.hs.config.email_notif_from)[1]
         raw_to = email.utils.parseaddr(email_address)[1]
 
@@ -157,7 +159,7 @@ class Mailer(object):
 
         template_vars = {
             "user_display_name": user_display_name,
-            "unsubscribe_link": self.make_unsubscribe_link(),
+            "unsubscribe_link": self.make_unsubscribe_link(app_id, email_address),
             "summary_text": summary_text,
             "app_name": self.app_name,
             "rooms": rooms,
@@ -423,9 +425,18 @@ class Mailer(object):
                 notif['room_id'], notif['event_id']
             )
 
-    def make_unsubscribe_link(self):
-        # XXX: matrix.to
-        return "https://vector.im/#/settings"
+    def make_unsubscribe_link(self, app_id, email_address):
+        params = {
+            "access_token": self.handlers.auth.generate_delete_pusher_token(),
+            "app_id": app_id,
+            "pushkey": email_address,
+        }
+
+        # XXX: make r0 once API is stable
+        return "%s_matrix/client/unstable/pushers/remove?%s" % (
+            self.hs.config.public_baseurl,
+            urllib.urlencode(params),
+        )
 
     def mxc_to_http_filter(self, value, width, height, resize_method="crop"):
         if value[0:6] != "mxc://":