export interface ConfigureOptions {
    /**
     * Set the preferences group.
     *
     * Preferences groups are used to organize key/value pairs.
     *
     * Using the value 'NativeStorage' provides backwards-compatibility with
     * [`cordova-plugin-nativestorage`](https://www.npmjs.com/package/cordova-plugin-nativestorage).
     * WARNING: The `clear()` method can delete unintended values when using the
     * 'NativeStorage' group.
     *
     * @default CapacitorStorage
     * @since 1.0.0
     */
    group?: string;
}
export interface GetOptions {
    /**
     * The key whose value to retrieve from preferences.
     *
     * @since 1.0.0
     */
    key: string;
}
export interface GetResult {
    /**
     * The value from preferences associated with the given key.
     *
     * If a value was not previously set or was removed, value will be `null`.
     *
     * @since 1.0.0
     */
    value: string | null;
}
export interface SetOptions {
    /**
     * The key to associate with the value being set in preferences.
     *
     * @since 1.0.0
     */
    key: string;
    /**
     * The value to set in preferences with the associated key.
     *
     * @since 1.0.0
     */
    value: string;
}
export interface RemoveOptions {
    /**
     * The key whose value to remove from preferences.
     *
     * @since 1.0.0
     */
    key: string;
}
export interface KeysResult {
    /**
     * The known keys in preferences.
     *
     * @since 1.0.0
     */
    keys: string[];
}
export interface MigrateResult {
    /**
     * An array of keys that were migrated.
     *
     * @since 1.0.0
     */
    migrated: string[];
    /**
     * An array of keys that were already migrated or otherwise exist in preferences
     * that had a value in the Capacitor 2 Preferences plugin.
     *
     * @since 1.0.0
     */
    existing: string[];
}
export interface PreferencesPlugin {
    /**
     * Configure the preferences plugin at runtime.
     *
     * Options that are `undefined` will not be used.
     *
     * @since 1.0.0
     */
    configure(options: ConfigureOptions): Promise<void>;
    /**
     * Get the value from preferences of a given key.
     *
     * @since 1.0.0
     */
    get(options: GetOptions): Promise<GetResult>;
    /**
     * Set the value in preferences for a given key.
     *
     * @since 1.0.0
     */
    set(options: SetOptions): Promise<void>;
    /**
     * Remove the value from preferences for a given key, if any.
     *
     * @since 1.0.0
     */
    remove(options: RemoveOptions): Promise<void>;
    /**
     * Clear keys and values from preferences.
     *
     * @since 1.0.0
     */
    clear(): Promise<void>;
    /**
     * Return the list of known keys in preferences.
     *
     * @since 1.0.0
     */
    keys(): Promise<KeysResult>;
    /**
     * Migrate data from the Capacitor 2 Storage plugin.
     *
     * This action is non-destructive. It will not remove old data and will only
     * write new data if they key was not already set.
     * To remove the old data after being migrated, call removeOld().
     *
     * @since 1.0.0
     */
    migrate(): Promise<MigrateResult>;
    /**
     * Removes old data with `_cap_` prefix from the Capacitor 2 Storage plugin.
     *
     * @since 1.1.0
     */
    removeOld(): Promise<void>;
}