import { Duration } from './duration.js';

/**
 * Most basic interface for a storage implementation. This is designed to be
 * quite easily implemented by users to plug in any new underlying storage.
 */
type StorageAdapter<T> = {
    set: (key: string, value: T) => Promise<void> | void;
    get: (key: string) => Promise<T | undefined> | T | undefined;
    delete: (key: string) => Promise<void> | void;
    clear: () => Promise<void> | void;
};
/** Most basic interface for stored object. */
type StoredObject<T> = {
    value: T;
    storedMs: number;
    expiryMs: number;
};
/**
 * Full interface for a storage implementation. Each method can be either sync
 * or async, and the interface works with either implementation scheme.
 *
 * Note: We are using `interface` instead of `type ... &` because typedoc
 * cannot handle the `&` syntax to merge types.
 */
interface FullStorageAdapter<T> extends StorageAdapter<T> {
    set: (key: string, value: T, expiryDeltaMs?: number | Duration) => Promise<void> | void;
    getStoredObject: (key: string) => Promise<StoredObject<T> | undefined> | StoredObject<T> | undefined;
    forEach(callback: (key: string, value: T, expiryMs: number, storedMs: number) => void | Promise<void>): Promise<void> | void;
    size(): Promise<number> | number;
    asMap<T>(): Promise<Map<string, StoredObject<T>>> | Map<string, StoredObject<T>>;
    gc: () => Promise<void> | void;
    gcNow: () => Promise<void> | void;
}

export type { FullStorageAdapter, StorageAdapter, StoredObject };