Improve delivery/bounce info

Author: joeledstrom

services/mailgun/mailgun.go

@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"net/mail"
 	"strings"
+	"time"
 
 	jsoniter "github.com/json-iterator/go"
 	"github.com/mailgun/mailgun-go/v5"
@@ -146,6 +147,7 @@ func (m *Mailgun) UnmarshalPosthook(body []byte) ([]mmailer.Posthook, error) {
 		h.Event = mmailer.EventDelivered
 		h.MessageId = e.Message.Headers.MessageID
 		h.Email = e.Recipient
+		h.Info = infoString(false, "", "", e.DeliveryStatus)
 
 	case *events.Opened:
 		h.Event = mmailer.EventOpen
@@ -156,17 +158,16 @@ func (m *Mailgun) UnmarshalPosthook(body []byte) ([]mmailer.Posthook, error) {
 		switch e.Severity {
 		case "permanent":
 			h.Event = mmailer.EventBounce
-
-		case "temporary":
-			h.Event = mmailer.EventDeferred
 			if e.Reason == "suppress-bounce" {
 				h.Event = mmailer.EventDropped
 			}
+		case "temporary":
+			h.Event = mmailer.EventDeferred
 		}
-
 		h.MessageId = e.Message.Headers.MessageID
 		h.Email = e.Recipient
-		h.Info = fmt.Sprintf("%s; %d; %s", e.Reason, e.DeliveryStatus.Code, e.DeliveryStatus.Description)
+		h.Info = infoString(true, e.Reason, e.Severity, e.DeliveryStatus)
+
 	default:
 		logger.Warn(fmt.Sprintf("received unsupported webhook event: %s", h.Event))
 		return nil, nil
@@ -175,12 +176,62 @@ func (m *Mailgun) UnmarshalPosthook(body []byte) ([]mmailer.Posthook, error) {
 	return []mmailer.Posthook{h}, nil
 }
 
+func infoString(fail bool, reason, severity string, st events.DeliveryStatus) string {
+	latency := time.Duration(st.SessionSeconds * float64(time.Second)).Truncate(time.Millisecond)
+
+	var words []string
+	if st.Code != 0 {
+		words = append(words, fmt.Sprintf("%d", st.Code))
+	}
+	if st.EnhancedCode != "" {
+		words = append(words, st.EnhancedCode)
+	}
+	if !fail {
+		words = append(words, st.Message)
+	}
+	if st.MxHost != "" {
+		words = append(words, st.MxHost)
+	}
+	if latency > time.Millisecond {
+		words = append(words, latency.String())
+	}
+	if reason != "" {
+		words = append(words, reason)
+	}
+	if severity != "" {
+		words = append(words, severity)
+	}
+
+	var flags []string
+	if st.AttemptNo > 0 {
+		flags = append(flags, fmt.Sprintf("attempt:%d", st.AttemptNo))
+	}
+	if st.Utf8 != nil && *st.Utf8 {
+		flags = append(flags, "utf8")
+	}
+	if st.TLS != nil && *st.TLS {
+		flags = append(flags, "tls")
+	}
+	if st.CertificateVerified != nil && *st.CertificateVerified {
+		flags = append(flags, "certificate-verified")
+	}
+	if len(flags) > 0 {
+		words = append(words, fmt.Sprintf("[%s]", strings.Join(flags, ", ")))
+	}
+
+	msg := strings.Join(words, " ")
+	if fail {
+		msg += ": " + st.Message
+	}
+	return msg
+}
+
 type configurer struct{}
 
 func (s configurer) SetIpPool(poolId string, message *mailgun.PlainMessage) {
 	// TODO?
 }
 
 func (s configurer) DisableTracking(message *mailgun.PlainMessage) {
-	message.SetTracking(false)
+	message.SetTracking(false) // untested
 }