Read target mailbox for audit pane

backend/08-viewer.go

@@ -186,27 +186,37 @@ func renderReadPane(w io.Writer, title, subject, from, date, body string) {
 func renderTargetPane(account, folder, targetAccount string, index int, raw []byte) string {
 	var b strings.Builder
 	b.WriteString(renderTargetAccountSelect(account, folder, targetAccount, index))
+	if match, ok, err := findTargetIMAPCopy(account, targetAccount, raw); ok {
+		renderTargetMatch(&b, match)
+		return b.String()
+	} else if err != nil {
+		fmt.Fprintf(&b, `<div class="audit-note bad">Zielpostfach-Pruefung fehlgeschlagen: %s</div>`, html.EscapeString(err.Error()))
+	}
 	match, ok := findForwardedCopy(account, targetAccount, raw)
 	if !ok {
 		id := messageIDHeader(raw)
 		if id == "" {
 			id = "(ohne Message-ID)"
 		}
-		fmt.Fprintf(&b, `<div class="ef-empty">Keine lokale Zielkopie gefunden.<br><br>Message-ID: %s</div>`, html.EscapeString(id))
+		fmt.Fprintf(&b, `<div class="ef-empty">Keine Zielkopie gefunden.<br><br>Message-ID: %s</div>`, html.EscapeString(id))
 		return b.String()
 	}
+	renderTargetMatch(&b, match)
+	return b.String()
+}
+
+func renderTargetMatch(b *strings.Builder, match forwardedMatch) {
 	msg, err := mail.ReadMessage(bytes.NewReader(match.Raw))
 	if err != nil {
-		renderReadContent(&b, "(unlesbar)", match.Location(), "", string(match.Raw))
-		return b.String()
+		renderReadContent(b, "(unlesbar)", match.Location(), "", string(match.Raw))
+		return
 	}
-	renderReadContent(&b,
+	renderReadContent(b,
 		decodeHeader(msg.Header.Get("Subject")),
 		decodeHeader(msg.Header.Get("From")),
 		decodeHeader(msg.Header.Get("Date"))+" | "+match.Location(),
 		messageBody(match.Raw),
 	)
-	return b.String()
 }
 
 func renderInitialTargetPane() string {
@@ -279,6 +289,63 @@ func (m forwardedMatch) Location() string {
 	return fmt.Sprintf("%s / %s #%d", m.Account, m.Folder, m.Index)
 }
 
+func findTargetIMAPCopy(account, targetAccount string, raw []byte) (forwardedMatch, bool, error) {
+	id := messageIDHeader(raw)
+	if id == "" {
+		return forwardedMatch{}, false, nil
+	}
+	targetUser := strings.TrimSpace(targetAccount)
+	if targetUser == "" {
+		source, ok := accountByMboxDir(account)
+		if !ok {
+			return forwardedMatch{}, false, nil
+		}
+		targetUser = strings.TrimSpace(source.DstUser)
+	}
+	for _, a := range accountsForTargetUser(targetUser) {
+		dst, err := OpenIMAPTarget(a)
+		if err != nil {
+			return forwardedMatch{}, false, err
+		}
+		match, ok, scanErr := scanTargetForMessage(dst, targetUser, id)
+		closeErr := dst.Close()
+		if scanErr != nil {
+			return forwardedMatch{}, false, scanErr
+		}
+		if closeErr != nil {
+			return forwardedMatch{}, false, closeErr
+		}
+		if ok {
+			return match, true, nil
+		}
+	}
+	return forwardedMatch{}, false, nil
+}
+
+func scanTargetForMessage(dst TargetMailbox, targetUser, messageID string) (forwardedMatch, bool, error) {
+	folders, err := dst.Folders()
+	if err != nil {
+		return forwardedMatch{}, false, err
+	}
+	for _, folder := range folders {
+		msgs, err := dst.Fetch(folder.Name)
+		if err != nil {
+			continue
+		}
+		for i, msg := range msgs {
+			if msg.MessageID == messageID || messageIDHeader(msg.Body) == messageID {
+				return forwardedMatch{
+					Account: "Ziel: " + targetUser,
+					Folder:  folder.Name,
+					Index:   i,
+					Raw:     msg.Body,
+				}, true, nil
+			}
+		}
+	}
+	return forwardedMatch{}, false, nil
+}
+
 func findForwardedCopy(account, targetAccount string, raw []byte) (forwardedMatch, bool) {
 	id := messageIDHeader(raw)
 	if id == "" {
@@ -440,6 +507,39 @@ func accountLabels() map[string]viewerAccount {
 	return out
 }
 
+func accountByMboxDir(mboxDir string) (Account, bool) {
+	if DB == nil {
+		return Account{}, false
+	}
+	accounts, err := ListAccounts()
+	if err != nil {
+		return Account{}, false
+	}
+	for _, a := range accounts {
+		if accountMboxDir(a) == mboxDir {
+			return a, true
+		}
+	}
+	return Account{}, false
+}
+
+func accountsForTargetUser(targetUser string) []Account {
+	if DB == nil {
+		return nil
+	}
+	accounts, err := ListAccounts()
+	if err != nil {
+		return nil
+	}
+	var out []Account
+	for _, a := range accounts {
+		if strings.EqualFold(strings.TrimSpace(a.DstUser), targetUser) {
+			out = append(out, a)
+		}
+	}
+	return out
+}
+
 func targetAccountOptions() []targetAccountOption {
 	if DB == nil {
 		return nil