Show subscription mailto: links to anonymous users

As suggested in <C4DCAJR6LQD2.GBNNZ1ME6L4N@homura>

todosrht/blueprints/ticket.py

@@ -20,10 +20,22 @@ from todosrht.webhooks import TrackerWebhook, TicketWebhook
 
 ticket = Blueprint("ticket", __name__)
 
+posting_domain = cfg("todo.sr.ht::mail", "posting-domain")
+ticket_subscribe_body = """\
+Sending this email will subscribe your email address to {ticket_ref},
+in so doing you will start receiving comments on this ticket.
+
+You don't need to subscribe to the ticket if you're already subscribed
+to the entire {tracker_ref} tracker.
+
+You can unsubscribe at any time by mailing <{ticket_email_ref}/unsubscribe@""" + \
+    posting_domain + ">.\n"
+
 def get_ticket_context(ticket, tracker, access):
     """Returns the context required to render ticket.html"""
     tracker_sub = None
     ticket_sub = None
+    ticket_subscribe = None
 
     if current_user:
         tracker_sub = (TicketSubscription.query
@@ -38,8 +50,14 @@ def get_ticket_context(ticket, tracker, access):
                 .filter(TicketSubscription.tracker_id == None)
                 .filter(Participant.user_id == current_user.id)
             ).one_or_none()
+    else:
+        subj = quote("Subscribing to " + ticket.ref())
+        ticket_subscribe = f"mailto:{ticket.ref(email=True)}/subscribe@" + \
+            f"{posting_domain}?subject={subj}&body=" + \
+            quote(ticket_subscribe_body.format(ticket_ref=ticket.ref(),
+                ticket_email_ref=ticket.ref(email=True),
+                tracker_ref=tracker.ref()))
 
-    posting_domain = cfg("todo.sr.ht::mail", "posting-domain")
     reply_subject = quote("Re: " + ticket.title)
 
     return {
@@ -51,6 +69,7 @@ def get_ticket_context(ticket, tracker, access):
         "access": access,
         "tracker_sub": tracker_sub,
         "ticket_sub": ticket_sub,
+        "ticket_subscribe": ticket_subscribe,
         "recent_users": get_recent_users(tracker),
         "reply_to": f"mailto:{ticket.ref(email=True)}@{posting_domain}" +
             f"?subject={reply_subject}"

todosrht/blueprints/tracker.py

@@ -1,3 +1,4 @@
+from urllib.parse import quote
 from flask import Blueprint, render_template, request, url_for, abort, redirect
 from todosrht.color import color_from_hex, color_to_hex, get_text_color
 from todosrht.color import valid_hex_color_code
@@ -24,6 +25,14 @@ tracker = Blueprint("tracker", __name__)
 smtp_user = cfg("mail", "smtp-user", default=None)
 smtp_from = cfg("mail", "smtp-from", default=None)
 notify_from = cfg("todo.sr.ht", "notify-from", default=smtp_from)
+posting_domain = cfg("todo.sr.ht::mail", "posting-domain")
+
+tracker_subscribe_body = """\
+Sending this email will subscribe your email address to {tracker_ref},
+in so doing you will start receiving new tickets and all comments for this tracker.
+
+You can unsubscribe at any time by mailing <{tracker_ref}/unsubscribe@""" + \
+    posting_domain + ">.\n"
 
 @tracker.route("/tracker/create")
 @loginrequired
@@ -63,6 +72,7 @@ def return_tracker(tracker, access, **kwargs):
     if another:
         del session["another"]
     is_subscribed = False
+    tracker_subscribe = None
     if current_user:
         sub = (TicketSubscription.query
             .join(Participant)
@@ -71,6 +81,11 @@ def return_tracker(tracker, access, **kwargs):
             .filter(Participant.user_id == current_user.id)
         ).one_or_none()
         is_subscribed = bool(sub)
+    else:
+        subj = quote("Subscribing to " + tracker.ref())
+        tracker_subscribe = f"mailto:{tracker.ref()}/subscribe@" + \
+            f"{posting_domain}?subject={subj}&body=" + \
+            quote(tracker_subscribe_body.format(tracker_ref=tracker.ref()))
 
     tickets = (Ticket.query
         .filter(Ticket.tracker_id == tracker.id)
@@ -104,7 +119,7 @@ def return_tracker(tracker, access, **kwargs):
             tracker=tracker, another=another, tickets=tickets,
             access=access, is_subscribed=is_subscribed, search=terms,
             comment_counts=comment_counts, seen_ticket_ids=seen_ticket_ids,
-            **pagination, **kwargs)
+            tracker_subscribe=tracker_subscribe, **pagination, **kwargs)
 
 @tracker.route("/<owner>/<name>")
 def tracker_GET(owner, name):

todosrht/templates/ticket.html

@@ -44,9 +44,9 @@
           class="nav-link">edit</a>
       </li>
       {% endif %}
-      {% if current_user %}
       <li class="flex-grow-1 d-none d-md-block"></li>
       <li class="nav-item">
+        {% if current_user %}
         <button
           class="nav-link active"
           {% if tracker_sub %}
@@ -64,8 +64,14 @@
           {% endif %}
           {{icon("caret-right")}}
         </button>
+        {% else %}
+        <a class="nav-link active" href="{{ ticket_subscribe }}">
+          {{icon("envelope-o")}}
+          Subscribe
+          {{icon("caret-right")}}
+        </a>
+        {% endif %}
       </li>
-      {% endif %}
     </ul>
   {% if not tracker_sub %}
   </form>

todosrht/templates/tracker.html

@@ -43,9 +43,9 @@
         >settings</a>
       </li>
       {% endif %}
-      {% if current_user %}
       <li class="flex-grow-1 d-none d-sm-block"></li>
       <li class="nav-item d-none d-sm-block">
+        {% if current_user %}
         <form method="POST" action="{{url_for("tracker." +
             ("disable_notifications" if is_subscribed else "enable_notifications"),
             owner=tracker.owner.canonical_name,
@@ -61,8 +61,14 @@
             {{icon("caret-right")}}
           </button>
         </form>
+        {% else %}
+        <a class="nav-link active" href="{{ tracker_subscribe }}">
+          {{icon("envelope-o")}}
+          Subscribe
+          {{icon("caret-right")}}
+        </a>
+        {% endif %}
       </li>
-      {% endif %}
     </ul>
   </div>
 </div>