WIP

server/smtp_sender.go

@@ -0,0 +1,119 @@
+package server
+
+import (
+	_ "embed" // required by go:embed
+	"encoding/json"
+	"fmt"
+	"heckel.io/ntfy/util"
+	"mime"
+	"net"
+	"net/smtp"
+	"strings"
+	"time"
+)
+
+type mailer interface {
+	Send(from, to string, m *message) error
+}
+
+type smtpSender struct {
+	config *Config
+}
+
+func (s *smtpSender) Send(senderIP, to string, m *message) error {
+	host, _, err := net.SplitHostPort(s.config.SMTPSenderAddr)
+	if err != nil {
+		return err
+	}
+	message, err := formatMail(s.config.BaseURL, senderIP, s.config.SMTPSenderFrom, to, m)
+	if err != nil {
+		return err
+	}
+	auth := smtp.PlainAuth("", s.config.SMTPSenderUser, s.config.SMTPSenderPass, host)
+	return smtp.SendMail(s.config.SMTPSenderAddr, auth, s.config.SMTPSenderFrom, []string{to}, []byte(message))
+}
+
+func formatMail(baseURL, senderIP, from, to string, m *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, err := toEmojis(m.Tags)
+		if err != nil {
+			return "", err
+		}
+		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
+	}
+	subject = mime.BEncoding.Encode("utf-8", subject)
+	body := `From: "{shortTopicURL}" <{from}>
+To: {to}
+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, "{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
+}
+
+var (
+	//go:embed "mailer_emoji.json"
+	emojisJSON string
+)
+
+type emoji struct {
+	Emoji   string   `json:"emoji"`
+	Aliases []string `json:"aliases"`
+}
+
+func toEmojis(tags []string) (emojisOut []string, tagsOut []string, err error) {
+	var emojis []emoji
+	if err = json.Unmarshal([]byte(emojisJSON), &emojis); err != nil {
+		return nil, nil, err
+	}
+	tagsOut = make([]string, 0)
+	emojisOut = make([]string, 0)
+nextTag:
+	for _, t := range tags { // TODO Super inefficient; we should just create a .json file with a map
+		for _, e := range emojis {
+			if util.InStringList(e.Aliases, t) {
+				emojisOut = append(emojisOut, e.Emoji)
+				continue nextTag
+			}
+		}
+		tagsOut = append(tagsOut, t)
+	}
+	return
+}