import { Letter } from '@actor-system/mail';
import { ActorContext, behavior } from '@actor-system/core';

declare const withStash: <T>(capacity: number, factory: (stashBuffer: StashBuffer<T>) => behavior.Behavior<T>) => behavior.Behavior<T>;
interface UnstashOptions<T> {
    /**
     * Number of messages to unstash.
     * @default Number.POSITIVE_INFINITY
     */
    amount?: number;
    /**
     * Function to transform messages when unstashing.
     */
    map?: (msg: T) => T;
}
declare class StashBuffer<T> {
    #private;
    readonly capacity: number;
    static create<T>(capacity: number, context: ActorContext<T>): StashBuffer<T>;
    private constructor();
    get size(): number;
    /**
     * Return the first element of the message buffer without removing it.
     * @returns the first element or throws NoSuchElementError if the buffer is empty
     * @throws {NoSuchElementError} if the buffer is empty
     */
    get head(): T;
    /**
     * Returns an iterable of messages in the buffer in insertion order.
     * @returns An iterable of messages.
     */
    values(): SetIterator<T>;
    /**
     * Removes all messages from the buffer.
     */
    clear(): void;
    /**
     * Add one element to the end of the message buffer.
     * @throws {StashOverflowError} if the buffer is full.
     */
    stash(msg: T): this;
    /**
     * Request replay of up to `numberOfMessages` messages using `map`.
     *
     * If called while another unstash is in progress, it does not replay
     * immediately; it just marks that another replay is requested.
     *
     * Once the current replay finishes, any pending requests are bundled
     * and a single replay pass is run again.
     */
    unstash(behavior: behavior.Behavior<T>, options?: UnstashOptions<T>): behavior.Behavior<T>;
}
declare const $noSuchElementError = "@@with-stash.no-such-element-error";
declare class NoSuchElementError extends Error implements Letter<typeof $noSuchElementError> {
    static readonly label = "@@with-stash.no-such-element-error";
    readonly label: typeof $noSuchElementError;
    constructor();
}
declare const $stashOverflowError = "@@with-stash.stash-overflow-error";
declare class StashOverflowError extends Error implements Letter<typeof $stashOverflowError> {
    static readonly label = "@@with-stash.stash-overflow-error";
    readonly label: typeof $stashOverflowError;
    constructor(message: string);
}

export { NoSuchElementError, StashBuffer, StashOverflowError, withStash };
export type { UnstashOptions };