import type { FlagMetadata, Logger } from '@openfeature/core';
import type { FeatureFlag } from './feature-flag';
import type { FlagdCoreOptions } from './options';
/**
 * The simple contract of the storage layer.
 */
export interface Storage {
    /**
     * Sets the configurations and returns the list of flags that have changed.
     * @param flagConfig The configuration string to be parsed and stored.
     * @param strictValidation Validates against the flag and targeting schemas.
     * @returns The list of flags that have changed.
     * @throws {Error} If the configuration string is invalid.
     */
    setConfigurations(flagConfig: string, strictValidation?: boolean): string[];
    /**
     * Gets the feature flag configuration with the given key.
     * @param key The key of the flag to be retrieved.
     * @returns The flag with the given key or undefined if not found.
     */
    getFlag(key: string): FeatureFlag | undefined;
    /**
     * Gets all the feature flag configurations.
     * @returns The map of all the flags.
     */
    getFlags(): Map<string, FeatureFlag>;
    /**
     * Gets metadata related to the flag set.
     * @returns {FlagMetadata} The flag set metadata.
     */
    getFlagSetMetadata(): FlagMetadata;
}
/**
 * An implementation of storage contract backed by maps.
 */
export declare class MemoryStorage implements Storage {
    private logger;
    private options;
    private _flags;
    private _flagSetMetadata;
    constructor(logger: Logger, options?: FlagdCoreOptions);
    getFlag(key: string): FeatureFlag | undefined;
    getFlags(): Map<string, FeatureFlag>;
    getFlagSetMetadata(): FlagMetadata;
    setConfigurations(flagConfig: string, strictValidation?: boolean): string[];
}