From 93af53c91dc933850fba9739dc44cfa3b10cde0c Mon Sep 17 00:00:00 2001
From: Simon Ser <contact@emersion.fr>
Date: Fri, 17 Mar 2023 00:00:50 +0100
Subject: [PATCH] Prune old Web Push subscriptions

---
 downstream.go |  2 --
 server.go     |  1 +
 user.go       | 21 +++++++++++++++++++--
 3 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/downstream.go b/downstream.go
index f2135dd..c4f3c82 100644
--- a/downstream.go
+++ b/downstream.go
@@ -3249,8 +3249,6 @@ func (dc *downstreamConn) handleMessageRegistered(ctx context.Context, msg *irc.
 					}}
 				}
 
-				// TODO: limit max number of subscriptions, prune old ones
-
 				if err := dc.user.srv.db.StoreWebPushSubscription(ctx, dc.user.ID, networkID, &newSub); err != nil {
 					dc.logger.Printf("failed to store Web push subscription: %v", err)
 					return ircError{&irc.Message{
diff --git a/server.go b/server.go
index e7fdefa..f96a5e3 100644
--- a/server.go
+++ b/server.go
@@ -38,6 +38,7 @@ var backlogTimeout = 10 * time.Second
 var handleDownstreamMessageTimeout = 10 * time.Second
 var downstreamRegisterTimeout = 30 * time.Second
 var webpushCheckSubscriptionDelay = 24 * time.Hour
+var webpushPruneSubscriptionDelay = 30 * 24 * time.Hour
 var chatHistoryLimit = 1000
 var backlogLimit = 4000
 
diff --git a/user.go b/user.go
index a619760..b10dc92 100644
--- a/user.go
+++ b/user.go
@@ -484,7 +484,23 @@ func (net *network) broadcastWebPush(msg *irc.Message) {
 		return
 	}
 
+	// First, prune old subscriptions
+	var active []database.WebPushSubscription
 	for _, sub := range subs {
+		if time.Since(sub.UpdatedAt) <= webpushPruneSubscriptionDelay {
+			active = append(active, sub)
+			continue
+		}
+
+		if err := net.user.srv.db.DeleteWebPushSubscription(ctx, sub.ID); err != nil {
+			net.logger.Printf("failed to delete pruned Web Push subscription %q: %v", sub.Endpoint, err)
+		} else {
+			net.logger.Debugf("deleted pruned Web Push subscription %q", sub.Endpoint)
+		}
+	}
+
+	// Then broadcast the message
+	for _, sub := range active {
 		err := net.user.srv.sendWebPush(ctx, &webpush.Subscription{
 			Endpoint: sub.Endpoint,
 			Keys: webpush.Keys{
@@ -494,9 +510,10 @@ func (net *network) broadcastWebPush(msg *irc.Message) {
 		}, sub.Keys.VAPID, msg)
 		if err == errWebPushSubscriptionExpired {
 			if err := net.user.srv.db.DeleteWebPushSubscription(ctx, sub.ID); err != nil {
-				net.logger.Printf("failed to delete expired Web Push subscription: %v", err)
+				net.logger.Printf("failed to delete expired Web Push subscription %q: %v", sub.Endpoint, err)
+			} else {
+				net.logger.Debugf("deleted expired Web Push subscription %q", sub.Endpoint)
 			}
-			net.logger.Debugf("deleted expired Web Push subscription %q", sub.Endpoint)
 		} else if err != nil {
 			net.logger.Printf("failed to send Web push notification to endpoint %q: %v", sub.Endpoint, err)
 		}