1 package apub
2 
3 import (
4 	"bytes"
5 	"fmt"
6 	"net/mail"
7 	"net/smtp"
8 	"strings"
9 	"time"
10 )
11 
12 func MarshalMail(activity *Activity) ([]byte, error) {
13 	buf := &bytes.Buffer{}
14 
15 	actor, err := LookupActor(activity.AttributedTo)
16 	if err != nil {
17 		return nil, fmt.Errorf("lookup actor %s: %w", activity.AttributedTo, err)
18 	}
19 	fmt.Fprintf(buf, "From: %s\n", actor.Address())
20 
21 	if activity.CC != nil {
22 		buf.WriteString("To: ")
23 		rcpt := append(activity.To, activity.CC...)
24 		var addrs []string
25 		for _, u := range rcpt {
26 			if u == ToEveryone {
27 				continue
28 			}
29 			actor, err = LookupActor(u)
30 			if err != nil {
31 				return nil, fmt.Errorf("lookup actor %s: %w", u, err)
32 			}
33 			addrs = append(addrs, actor.Address().String())
34 		}
35 		buf.WriteString(strings.Join(addrs, ", "))
36 		buf.WriteString("\n")
37 	}
38 
39 	fmt.Fprintf(buf, "Date: %s\n", activity.Published.Format(time.RFC822))
40 	fmt.Fprintf(buf, "Message-ID: <%s>\n", activity.ID)
41 	if activity.Audience != "" {
42 		fmt.Fprintf(buf, "List-ID: <%s>\n", activity.Audience)
43 	}
44 	if activity.InReplyTo != "" {
45 		fmt.Fprintf(buf, "References: <%s>\n", activity.InReplyTo)
46 	}
47 
48 	if activity.Source.Content != "" && activity.Source.MediaType == "text/markdown" {
49 		fmt.Fprintln(buf, "Content-Type: text/plain; charset=utf-8")
50 	} else {
51 		fmt.Fprintln(buf, "Content-Type:", activity.MediaType)
52 	}
53 	fmt.Fprintln(buf, "Subject:", activity.Name)
54 	fmt.Fprintln(buf)
55 	if activity.Source.Content != "" && activity.Source.MediaType == "text/markdown" {
56 		fmt.Fprintln(buf, activity.Source.Content)
57 	} else {
58 		fmt.Fprintln(buf, activity.Content)
59 	}
60 	_, err = mail.ReadMessage(bytes.NewReader(buf.Bytes()))
61 	return buf.Bytes(), err
62 }
63 
64 func SendMail(client *smtp.Client, activity *Activity, from string, to ...string) error {
65 	b, err := MarshalMail(activity)
66 	if err != nil {
67 		return fmt.Errorf("marshal to mail message: %w", err)
68 	}
69 	if err := client.Mail(from); err != nil {
70 		return fmt.Errorf("mail command: %w", err)
71 	}
72 	for _, rcpt := range to {
73 		if err := client.Rcpt(rcpt); err != nil {
74 			return fmt.Errorf("rcpt command: %w", err)
75 		}
76 	}
77 	wc, err := client.Data()
78 	if err != nil {
79 		return fmt.Errorf("data command: %w", err)
80 	}
81 	if _, err := wc.Write(b); err != nil {
82 		return fmt.Errorf("write message: %w", err)
83 	}
84 	if err := wc.Close(); err != nil {
85 		return fmt.Errorf("close message writer: %w", err)
86 	}
87 	return nil
88 }