feat: realtime status, mentions, push notifications

internal/push/handlers.go

@@ -183,6 +183,77 @@ func (h *Handler) SendPush(ctx context.Context, userID string, payload map[strin
 	}
 }
 
+
+
+// SendChannelNotification sends a push notification to all server members (except the author)
+// when a new message is posted in a channel.
+func (h *Handler) SendChannelNotification(ctx context.Context, channelID, authorID, channelName, content string) {
+	if h.vapidPub == "" || h.vapidPriv == "" {
+		return
+	}
+
+	var serverID string
+	err := h.db.QueryRowContext(ctx, `SELECT server_id FROM channels WHERE id = $1`, channelID).Scan(&serverID)
+	if err != nil {
+		h.logger.Error("failed to find channel server", "error", err)
+		return
+	}
+
+	body := content
+	if len(body) > 200 {
+		body = body[:200] + "..."
+	}
+
+	payload, _ := json.Marshal(map[string]interface{}{
+		"title": "New message in #" + channelName,
+		"body":  body,
+		"url":   "/channels/" + channelID,
+	})
+
+	rows, err := h.db.QueryContext(ctx, `
+		SELECT DISTINCT ps.user_id, ps.endpoint, ps.p256dh, ps.auth
+		FROM push_subscriptions ps
+		JOIN members m ON m.user_id = ps.user_id
+		WHERE m.server_id = $1 AND ps.user_id != $2
+	`, serverID, authorID)
+	if err != nil {
+		h.logger.Error("failed to query push subscriptions", "error", err)
+		return
+	}
+	defer rows.Close()
+
+	for rows.Next() {
+		var userID, endpoint, p256dh, auth string
+		if err := rows.Scan(&userID, &endpoint, &p256dh, &auth); err != nil {
+			continue
+		}
+
+		sub := &webpush.Subscription{
+			Endpoint: endpoint,
+			Keys: webpush.Keys{
+				P256dh: p256dh,
+				Auth:   auth,
+			},
+		}
+
+		resp, err := webpush.SendNotification(payload, sub, &webpush.Options{
+			Subscriber:      h.vapidSubj,
+			VAPIDPublicKey:  h.vapidPub,
+			VAPIDPrivateKey: h.vapidPriv,
+			TTL:             30,
+		})
+		if err != nil {
+			h.logger.Error("failed to send push", "error", err, "user_id", userID)
+			if resp != nil && resp.StatusCode == 410 {
+				h.db.ExecContext(ctx, `DELETE FROM push_subscriptions WHERE endpoint = $1`, endpoint)
+			}
+			continue
+		}
+		if resp != nil {
+			resp.Body.Close()
+		}
+	}
+}
 // GenerateVAPIDKeys generates a new VAPID key pair.
 func GenerateVAPIDKeys() (publicKey, privateKey string, err error) {
 	privateKeyBytes := make([]byte, 32)