import type { MailboxMessage, MailboxMessageView } from "./types.js";
/**
 * Recipient names are used to build `<mailboxDir>/<recipient>.jsonl` paths and
 * come from external CLI `--input` JSON. Reject anything that could escape the
 * mailbox directory. Hard guard — call before constructing any file path.
 */
export declare function validateRecipientName(name: string): boolean;
export declare function mailboxFilePath(mailboxDir: string, recipient: string): string;
export declare function mailboxOffsetPath(mailboxDir: string, recipient: string): string;
/** Append a message to its recipient's mailbox (keyed by msg.to). */
export declare function appendMailbox(mailboxDir: string, msg: MailboxMessage): void;
/**
 * Mark a message delivered by APPENDING a DeliveryReceipt line (never rewrites
 * the file, so active byte cursors stay valid). Returns false if no message
 * with `messageId` exists (no receipt written).
 */
export declare function markDelivered(mailboxDir: string, recipient: string, messageId: string): boolean;
/**
 * Read new messages via byte cursor and advance it. The cursor advances past
 * ALL lines (including delivery-receipt lines), but only `type: "message"`
 * lines are returned — receipts are consumed but filtered from the result.
 */
export declare function readNewMailbox(mailboxDir: string, recipient: string): MailboxMessage[];
/** Same filtering as readNewMailbox but does NOT advance the cursor. */
export declare function peekMailbox(mailboxDir: string, recipient: string): MailboxMessage[];
/**
 * Full-file scan (no cursor). Returns every message merged with delivery info
 * from any matching DeliveryReceipt line.
 */
export declare function listMailbox(mailboxDir: string, recipient: string): MailboxMessageView[];