/**
 * Defines the implementation contract for the data repository.
 *
 * @export
 * @interface IDataRepository
 */
export interface IDataRepository {
    /**
     * Get all keys and values.
     *
     * @returns {object}
     * @memberof IDataRepository
     */
    all(): object;
    /**
     * Get the first value.
     *
     * @template T
     * @returns {T}
     * @memberof IDataRepository
     */
    first<T>(): T;
    /**
     * Get the last value.
     *
     * @template T
     * @returns {T}
     * @memberof IDataRepository
     */
    last<T>(): T;
    /**
     * Get all keys.
     *
     * @returns {string[]}
     * @memberof IDataRepository
     */
    keys(): string[];
    /**
     * Get all values.
     *
     * @template T
     * @returns {T[]}
     * @memberof IDataRepository
     */
    values<T>(): T[];
    /**
     * Get the given key.
     *
     * @template T
     * @param {string} key
     * @param {(T | undefined)} [defaultValue]
     * @returns {(T | undefined)}
     * @memberof IDataRepository
     */
    get<T>(key: string, defaultValue?: T | undefined): T | undefined;
    /**
     * Set the given key.
     *
     * @param {string} key
     * @param {unknown} value
     * @memberof IDataRepository
     */
    set(key: string, value: unknown): void;
    /**
     * Fill the storage with data.
     *
     * @param {object} entries
     * @memberof IDataRepository
     */
    fill(entries: object): void;
    /**
     * Determine if the given key is exists.
     *
     * @param {string} key
     * @returns {boolean}
     * @memberof IDataRepository
     */
    has(key: string): boolean;
    /**
     * Determine if the given key is missing.
     *
     * @param {string} key
     * @returns {boolean}
     * @memberof IDataRepository
     */
    missing(key: string): boolean;
    /**
     * Remove the given key.
     *
     * @param {string} key
     * @memberof IDataRepository
     */
    forget(key: string): void;
    /**
     * Remove the given index from the value of the key.
     *
     * @param {string} key
     * @param {number} index
     * @memberof IDataRepository
     */
    forgetIndex(key: string, index: number): void;
    /**
     * Remove all keys.
     *
     * @memberof IDataRepository
     */
    flush(): void;
    /**
     * Count how many keys there are.
     *
     * @returns {number}
     * @memberof IDataRepository
     */
    count(): number;
    /**
     * Take a snapshot.
     *
     * @memberof IDataRepository
     */
    snapshot(): void;
    /**
     * Restore a snapshot.
     *
     * @memberof IDataRepository
     */
    restore(): void;
    /**
     * Turn the data into a normalised object.
     *
     * @returns {string}
     * @memberof IDataRepository
     */
    toJSON(): string;
}