import type { ImapClient } from "./client.js";
import { listFolders } from "./folders.js";
/**
* Build the composite ID from date + messageId.
* Format: `YYYY-MM-DDTHH:mm:ss.<messageId>`
*/
export function buildCompositeId(
date: Date | string,
messageId: string
): string {
const d = typeof date === "string" ? new Date(date) : date;
const iso = d.toISOString().slice(0, 19); // YYYY-MM-DDTHH:mm:ss
return `${iso}.${messageId}`;
}
/**
* Parse composite ID into { date, messageId }.
* The date portion is always 19 characters (YYYY-MM-DDTHH:mm:ss),
* followed by a dot separator, then the Message-ID.
*/
export function parseCompositeId(compositeId: string): {
date: string;
messageId: string;
} {
if (compositeId.length < 20 || compositeId[19] !== ".") {
throw new Error(
`Invalid composite ID format: "${compositeId}". Expected "YYYY-MM-DDTHH:mm:ss.<messageId>".`
);
}
const date = compositeId.slice(0, 19);
const messageId = compositeId.slice(20);
return { date, messageId };
}
/**
* Search a single mailbox for an email by Message-ID header.
* Returns the IMAP UID or null if not found.
*/
export async function resolveInMailbox(
imapClient: ImapClient,
messageId: string,
mailbox: string
): Promise<number | null> {
const lock = await imapClient.openMailbox(mailbox);
try {
const client = imapClient.getClient();
const uids = await client.search(
{ header: { "Message-ID": messageId } } as any,
{ uid: true }
);
return uids && uids.length > 0 ? uids[0] : null;
} finally {
lock.release();
}
}
/**
* Resolve a composite ID to { uid, mailbox }.
* Search order: mailboxHint → INBOX → all other folders.
* Throws if the email cannot be found in any folder.
*/
export async function resolveEmailId(
imapClient: ImapClient,
compositeId: string,
mailboxHint?: string
): Promise<{ uid: number; mailbox: string }> {
const { messageId } = parseCompositeId(compositeId);
// 1. Try the hint mailbox first
if (mailboxHint) {
const uid = await resolveInMailbox(imapClient, messageId, mailboxHint);
if (uid) return { uid, mailbox: mailboxHint };
}
// 2. Try INBOX (skip if already tried as hint)
if (mailboxHint !== "INBOX") {
const uid = await resolveInMailbox(imapClient, messageId, "INBOX");
if (uid) return { uid, mailbox: "INBOX" };
}
// 3. Scan all folders
const folders = await listFolders(imapClient);
const tried = new Set([mailboxHint, "INBOX"]);
for (const folder of folders) {
if (tried.has(folder.path)) continue;
const uid = await resolveInMailbox(imapClient, messageId, folder.path);
if (uid) return { uid, mailbox: folder.path };
}
throw new Error(
`Email not found for ID "${compositeId}". It may have been deleted.`
);
}
