Fix mail mess

mail/format.go

@@ -0,0 +1,95 @@
+package mail
+
+import (
+	_ "embed" // required by go:embed
+	"encoding/json"
+	"fmt"
+	"mime"
+	"strings"
+	"time"
+
+	"heckel.io/ntfy/v2/model"
+	"heckel.io/ntfy/v2/util"
+)
+
+var (
+	//go:embed "mailer_emoji_map.json"
+	emojisJSON string
+
+	// emojiMap maps ntfy tag names to emoji, parsed once from the embedded JSON in init
+	emojiMap map[string]string
+)
+
+func init() {
+	if err := json.Unmarshal([]byte(emojisJSON), &emojiMap); err != nil {
+		panic("mail: invalid embedded emoji map: " + err.Error())
+	}
+}
+
+func formatMail(baseURL, senderIP, from, to string, m *model.Message) (string, error) {
+	topicURL := baseURL + "/" + m.Topic
+	subject := m.Title
+	if subject == "" {
+		subject = m.Message
+	}
+	subject = strings.ReplaceAll(strings.ReplaceAll(subject, "\r", ""), "\n", " ")
+	message := m.Message
+	trailer := ""
+	if len(m.Tags) > 0 {
+		emojis, tags := toEmojis(m.Tags)
+		if len(emojis) > 0 {
+			subject = strings.Join(emojis, " ") + " " + subject
+		}
+		if len(tags) > 0 {
+			trailer = "Tags: " + strings.Join(tags, ", ")
+		}
+	}
+	if m.Priority != 0 && m.Priority != 3 {
+		priority, err := util.PriorityString(m.Priority)
+		if err != nil {
+			return "", err
+		}
+		if trailer != "" {
+			trailer += "\n"
+		}
+		trailer += fmt.Sprintf("Priority: %s", priority)
+	}
+	if trailer != "" {
+		message += "\n\n" + trailer
+	}
+	date := time.Unix(m.Time, 0).UTC().Format(time.RFC1123Z)
+	subject = mime.BEncoding.Encode("utf-8", subject)
+	body := `From: "{shortTopicURL}" <{from}>
+To: {to}
+Date: {date}
+Subject: {subject}
+Content-Type: text/plain; charset="utf-8"
+
+{message}
+
+--
+This message was sent by {ip} at {time} via {topicURL}`
+	body = strings.ReplaceAll(body, "{from}", from)
+	body = strings.ReplaceAll(body, "{to}", to)
+	body = strings.ReplaceAll(body, "{date}", date)
+	body = strings.ReplaceAll(body, "{subject}", subject)
+	body = strings.ReplaceAll(body, "{message}", message)
+	body = strings.ReplaceAll(body, "{topicURL}", topicURL)
+	body = strings.ReplaceAll(body, "{shortTopicURL}", util.ShortTopicURL(topicURL))
+	body = strings.ReplaceAll(body, "{time}", time.Unix(m.Time, 0).UTC().Format(time.RFC1123))
+	body = strings.ReplaceAll(body, "{ip}", senderIP)
+	return body, nil
+}
+
+func toEmojis(tags []string) (emojisOut []string, tagsOut []string) {
+	tagsOut = make([]string, 0)
+	emojisOut = make([]string, 0)
+	for _, t := range tags {
+		if emoji, ok := emojiMap[t]; ok {
+			emojisOut = append(emojisOut, emoji)
+		} else {
+			tagsOut = append(tagsOut, t)
+		}
+	}
+	return
+}