From 40ce16c71d3251d5a7023d4abdb7a32046d1f671 Mon Sep 17 00:00:00 2001
From: Peter Sanchez <peter@netlandish.com>
Date: Wed, 7 Dec 2022 13:46:40 -0600
Subject: [PATCH] Adding MailChecker interface for email.ServiceQueue

---
 email/email.go  | 11 +++++++++--
 email/helper.go |  9 +++++++++
 interfaces.go   |  7 +++++++
 3 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/email/email.go b/email/email.go
index a4be771..30d14d3 100644
--- a/email/email.go
+++ b/email/email.go
@@ -22,6 +22,7 @@ type ServiceQueue struct {
 	logger  echo.Logger
 	service carrier.Service
 	queue   *work.Queue
+	checker gobwebs.MailChecker
 }
 
 // Service returns the email service
@@ -34,6 +35,11 @@ func (s *ServiceQueue) Queue() *work.Queue {
 	return s.queue
 }
 
+// Checker returns the mail checker
+func (s *ServiceQueue) Checker() gobwebs.MailChecker {
+	return s.checker
+}
+
 // SendMail sends an email message
 func (s *ServiceQueue) SendMail(msg *carrier.Message) error {
 	if s.queue == nil {
@@ -66,8 +72,9 @@ func (s *ServiceQueue) mailTask(msg *carrier.Message) *work.Task {
 }
 
 // NewServiceQueue returns a new ServiceQueue instance
-func NewServiceQueue(logger echo.Logger, service carrier.Service, queue *work.Queue) *ServiceQueue {
-	return &ServiceQueue{logger, service, queue}
+func NewServiceQueue(logger echo.Logger, service carrier.Service,
+	queue *work.Queue, checker gobwebs.MailChecker) *ServiceQueue {
+	return &ServiceQueue{logger, service, queue, checker}
 }
 
 // NewQueue Creates a new email processing queue.
diff --git a/email/helper.go b/email/helper.go
index 355ad6e..fb63199 100644
--- a/email/helper.go
+++ b/email/helper.go
@@ -76,6 +76,15 @@ func (h *Helper) Send(name, from, rcpt string, data gobwebs.Map) error {
 		return fmt.Errorf("No email address given to send to")
 	}
 
+	checker := h.q.Checker()
+	if err := checker.Check(rcpt); err != nil {
+		// Email address check failed. Don't email
+		// We don't want to return error here. The checker.Check function
+		// should do all the individual use case logging and other work.
+		// XXX Maybe re-think this `return nil` decision in the future
+		return nil
+	}
+
 	var (
 		htmlok              bool
 		sname, tname, hname string
diff --git a/interfaces.go b/interfaces.go
index 4d8ab0c..1559a8d 100644
--- a/interfaces.go
+++ b/interfaces.go
@@ -73,3 +73,10 @@ type UserFetch interface {
 	ChangePasswordTemplateVars(c echo.Context) Map
 	UpdateEmailTemplateVars(c echo.Context) Map
 }
+
+// MailChecker is an interface that the email module uses to verify
+// if a an email address is allowed to be sent email or not. Useful
+// to track bounces, spam complaints, etc.
+type MailChecker interface {
+	Check(email string) error
+}
-- 
2.45.2