1package imap
 2
 3import (
 4	"context"
 5	"errors"
 6	"fmt"
 7	"io"
 8	"log/slog"
 9	"net"
10	"time"
11
12	"postern/internal/db"
13	"postern/internal/model"
14	"postern/internal/policy"
15)
16
17func (i *Server) SubmitMessage(ctx context.Context, conn net.Conn, user model.User, r io.Reader) error {
18	logger := slog.With("component", "internal_submission", "user_id", user.ID)
19	internalTime := time.Now()
20
21	fileName, size, parsedMsg, err := i.persistence.WriteBlobMessage(r)
22	if err != nil {
23		return fmt.Errorf("write blob: %w", err)
24	}
25
26	if parsedMsg == nil {
27		return errors.New("parsed message is nil")
28	}
29
30	policyUser := policy.UserToStarlark(user, i.db)
31	policyConn := policy.ConnToStarlark(conn)
32
33	fromAddr, err := policy.ParseAddress(parsedMsg.Header.Get("From"))
34	if err != nil {
35		return model.ErrMissingFromHeader
36	}
37	toAddr, err := policy.ParseAddress(parsedMsg.Header.Get("To"))
38	if err != nil {
39		return errors.New("missing To header")
40	}
41	subject := parsedMsg.Header.Get("Subject")
42	msgSize := size
43
44	msg := policy.MessageContext{
45		HeaderFrom: fromAddr,
46		HeaderTo:   toAddr,
47		Subject:    subject,
48		Headers:    parsedMsg.Header,
49		Size:       msgSize,
50	}
51
52	destinationMailbox, err := i.policyEngine.OnMessageDeliver(policyConn, policyUser, msg)
53	if destinationMailbox == "" || err != nil {
54		logger.Warn("Policy script error, falling back to INBOX", "error", err)
55		destinationMailbox = "INBOX"
56	}
57
58	logger.InfoContext(ctx, "delivery", "mailbox", destinationMailbox)
59
60	// Create mailbox if not exists
61	mailboxID, _, err := i.db.GetMailboxID(ctx, user.ID, destinationMailbox)
62	if err != nil {
63		if errors.Is(err, db.ErrMailboxNotFound) {
64			err = i.db.CreateMailbox(ctx, user.ID, destinationMailbox)
65			if err != nil {
66				return fmt.Errorf("create on-demand mailbox: %w", err)
67			}
68			mailboxID, _, err = i.db.GetMailboxID(ctx, user.ID, destinationMailbox)
69			if err != nil {
70				return fmt.Errorf("get on-demand mailbox ID: %w", err)
71			}
72			err = i.db.Subscribe(ctx, user.ID, mailboxID, destinationMailbox)
73			if err != nil {
74				return fmt.Errorf("subscribe on-demand mailbox: %w", err)
75			}
76		} else {
77			return fmt.Errorf("get mailbox ID: %w", err)
78		}
79	}
80
81	_, err = i.db.AppendMessage(ctx, mailboxID, user.ID, fileName, size, internalTime.UTC().Format(time.RFC3339), nil, parsedMsg)
82	if err != nil {
83		return fmt.Errorf("append message: %w", err)
84	}
85
86	// Notify user
87	t := i.mTracker.get(user.ID, mailboxID)
88	if t != nil {
89		mb, err := i.db.GetUserMailbox(ctx, user.ID, destinationMailbox)
90		if err != nil {
91			return fmt.Errorf("get user mailbox: %w", err)
92		}
93		t.QueueNumMessages(mb.NumMessages)
94		logger.Info("EXISTS message sent to user", "user", user.ID, "mailbox", mb.Name, "num_messages", mb.NumMessages)
95	}
96
97	return nil
98}