feat: add rule forwarding action

apps/api/internal/app/forwarding_delivery.go

@@ -3,9 +3,12 @@ package app
 import (
 	"bytes"
 	"context"
+	"crypto/sha256"
+	"encoding/hex"
 	"fmt"
 	"os"
 	"strings"
+	"unicode"
 )
 
 const forwardingHeaderName = "X-LanQin-Forwarded-By"
@@ -69,6 +72,62 @@ func (a *App) processInboundForwarding(ctx context.Context, messageID, mailboxID
 	}
 }
 
+func (a *App) processRuleForwarding(ctx context.Context, messageID, mailboxID string, action MailRuleAction) error {
+	var userID, mailboxAddress string
+	if err := a.db.QueryRowContext(ctx, `SELECT user_id,address FROM mailboxes WHERE id=? AND status='active'`, mailboxID).Scan(&userID, &mailboxAddress); err != nil {
+		return err
+	}
+	targets, err := a.cleanForwardingTargets(ctx, userID, splitRuleForwardTargets(action.Value))
+	if err != nil {
+		return err
+	}
+	self := normalizeEmail(mailboxAddress)
+	filteredTargets := make([]string, 0, len(targets))
+	for _, target := range targets {
+		if normalizeEmail(target) == self {
+			continue
+		}
+		filteredTargets = append(filteredTargets, target)
+	}
+	targets = dedupeEmails(filteredTargets)
+	if len(targets) == 0 {
+		return nil
+	}
+	raw, err := a.forwardingRawMessage(ctx, messageID)
+	if err != nil {
+		return err
+	}
+	if hasForwardingHeader(raw) {
+		a.log.Warn("skip rule forwarding message that already has LanQin forwarding header", "message", messageID, "mailbox", mailboxID)
+		return nil
+	}
+	forwarded := addForwardingHeaders(raw, mailboxAddress, a.cfg.PublicHostname)
+	var rfcMessageID string
+	_ = a.db.QueryRowContext(ctx, `SELECT message_id FROM messages WHERE id=?`, messageID).Scan(&rfcMessageID)
+	if strings.TrimSpace(rfcMessageID) == "" {
+		rfcMessageID = messageID
+	}
+	queueID, err := a.enqueueSend(ctx, sendQueueInput{
+		UserID:        userID,
+		MailboxID:     mailboxID,
+		SentMessageID: messageID,
+		MessageID:     ruleForwardQueueMessageID(rfcMessageID, targets),
+		Source:        sendSourceRuleForwarding,
+		MailFrom:      mailboxAddress,
+		HeaderFrom:    mailboxAddress,
+		Recipients:    targets,
+		MIMEBytes:     forwarded,
+		Now:           a.now().UTC(),
+	})
+	if err != nil {
+		return err
+	}
+	if queueID == "" {
+		a.log.Warn("rule forwarding target configured but SMTP sending is not configured", "message", messageID, "mailbox", mailboxID, "targets", strings.Join(targets, ","))
+	}
+	return nil
+}
+
 func (a *App) inboundForwardingTargets(ctx context.Context, mailboxID string) (targetEmails []string, userID, mailboxAddress string, err error) {
 	var mailboxTarget, mailboxTargetsJSON, accountTarget, accountTargetsJSON string
 	err = a.db.QueryRowContext(ctx, `SELECT mb.user_id,mb.address,COALESCE(mfs.target_email,''),COALESCE(mfs.target_emails,'[]'),COALESCE(afs.target_email,''),COALESCE(afs.target_emails,'[]')
@@ -130,6 +189,21 @@ func (a *App) forwardingRawMessage(ctx context.Context, messageID string) ([]byt
 	})
 }
 
+func splitRuleForwardTargets(value string) []string {
+	return strings.FieldsFunc(value, func(r rune) bool {
+		return unicode.IsSpace(r) || r == ',' || r == '，' || r == ';' || r == '；'
+	})
+}
+
+func ruleForwardQueueMessageID(messageID string, targets []string) string {
+	base := strings.TrimSpace(messageID)
+	if base == "" {
+		base = newID("ruleforward")
+	}
+	sum := sha256.Sum256([]byte(strings.Join(dedupeEmails(targets), ",")))
+	return base + "#rule-forward-" + hex.EncodeToString(sum[:])[:12]
+}
+
 func hasForwardingHeader(raw []byte) bool {
 	header := raw
 	if idx := bytes.Index(raw, []byte("\r\n\r\n")); idx >= 0 {