import { CloudFrontEvent, CloudFrontRequest, ImageContentType } from "../types";
/**
 * Takes a url, key, path or file name and returns the file extension.
 */
export declare function extractFileExt(uri: string): string;
/**
 * Takes a url, key or path and returns the filename.
 */
export declare function extractFilename(uri: string): string;
/**
 * Takes a URI (can be a URL, filename or just an extension) and returns the
 * content-type if this is an image. If it's not an image, returns undefined.
 */
export declare function getImageContentType(uri: string): ImageContentType | undefined;
/**
 * Takes a URLSearchParams and returns a querystring that will always be
 * returned in the same order regardless of the order of the inputs of the
 * search params.
 *
 * This helps make the querystring consistent regardless of the way the
 * URLSearchParams were constructed.
 */
export declare function getSortedQueryString(params: URLSearchParams): string;
/**
 * Takes a CloudFront style `uri` (e.g. in the CloudFront Request) and returns
 * the S3 key.
 *
 * The `uri` component will potentially have encoded characters like `?` and
 * `=` that have to be decoded.
 */
export declare function extractKeyFromURI(uri: string): string;
export declare function getSizeFromSearchParams(params: URLSearchParams): {
    width: number;
    height: number;
} | null;
/**
 * Takes a URL and returns the `uri` and `querystring` as it would appear in
 * a CloudFront Request.
 *
 * Useful for testing.
 */
export declare function getMockRequestFromURL(urlString: string): CloudFrontRequest;
export declare function getMockEventFromURL(urlString: string): CloudFrontEvent<CloudFrontRequest>;