/**
 * Normalizes a querystring parameter into a consistent string array.
 *
 * Needed because Express/qs may return repeated query params as strings, arrays,
 * or numeric‑keyed objects depending on parser settings and arrayLimit behavior
 *
 * @param value The raw query parameter value from req.query.
 * @returns An array of strings representing the normalized parameter.
 */
export declare const normalizeQueryStringArray: (queryParamValue: string[] | string | Record<string, string> | undefined) => string[] | undefined;
/**
 * Converts a querystring to a query object
 *
 * @param {string} qs
 * @param {string} prefix
 * @return {*}  {(Record<string, string | string[]>)}
 */
export declare const qsToQueryObject: (qs: string, prefix?: string) => Record<string, string | string[]>;
/**
 * Converts a query obect back to a querystring
 *
 * @param {(Record<string, string | string[]>)} query
 * @return {*}  {string}
 */
export declare const queryObjectToQs: (source: Record<string, string | string[]>, exclude?: Set<string>) => string;
/**
 * Extracts `filters.*` entries from a query object.
 */
export declare const extractFiltersFromQuery: (query: Record<string, unknown>) => Record<string, unknown>;
/**
 * Extracts `filters.*` entries and normalises values for the API.
 */
export declare const extractApiFiltersFromQuery: (query: Record<string, unknown>) => Record<string, string>;
/**
 * Given a form request body, will strip out the
 * 'filters.' prefix to return the field name/id and value
 *
 * @param {Record<string, unknown>} body
 * @return {*}  {Record<string, unknown>}
 */
export declare const extractFiltersFromBody: (body: Record<string, unknown>) => Record<string, unknown>;
export declare const getQueryParamAsString: (query: Record<string, unknown>, name: string) => string | null;
/**
 * Builds a query string from a form body
 *
 * @param {Record<string, unknown>} body
 * @param {Set<string>} [exclude=new Set()]
 * @return {*}  {string}
 */
export declare const formBodyToQs: (body: Record<string, unknown>, exclude?: Set<string>) => string;
/**
 * Converts a form body to an API query object
 * - Excludes specified keys
 * - Drops null / empty values
 * - Collapses arrays to CSV (BE contract)
 *
 * @param {Record<string, unknown>} body
 * @return {*}  {(Record<string, string | string[]>)}
 */
export declare const formBodyToQueryObject: (body: Record<string, unknown>, exclude?: Set<string>) => Record<string, string>;