import * as Promise from 'bluebird';
import * as debug from 'debug';
/**
 * Plugin defaults.
 */
export declare const defaults: {
    basePath: string;
    stylesheetPath: null;
    spritePath: string;
    relativeTo: string;
    filterBy: never[];
    groupBy: never[];
    retina: boolean;
    hooks: {
        onSaveSpritesheet: null;
        onUpdateRule: null;
    };
    spritesmith: {
        engine: string;
        algorithm: string;
        padding: number;
        engineOpts: {};
        exportOpts: {};
    };
    svgsprite: {
        mode: {
            css: {
                dimensions: boolean;
                bust: boolean;
                render: {
                    css: boolean;
                };
            };
        };
        shape: {
            id: {
                generator(name: any, file: any): string;
            };
        };
        svg: {
            precision: number;
        };
    };
    verbose: boolean;
};
/**
 * Prepares the filter functions.
 * @param  {Object} opts
 * @param  {Result} result
 * @return
 */
export declare function prepareFilterBy(opts: any): void;
/**
 * Prepares the group functions.
 * @param  {Object} opts
 * @return
 */
export declare function prepareGroupBy(opts: any): void;
/**
 * Walks the given CSS string and extracts all images
 * that can be converted to sprite.
 * @param  {Node}   root
 * @param  {Object} opts
 * @param  {Result} result
 * @return {Promise}
 */
export declare function extractImages(root: any, opts: any): any;
/**
 * Apply filterBy functions over collection of exported images.
 * @param  {Object}  opts
 * @param  {Array}   images
 * @return {Promise}
 */
export declare function applyFilterBy(opts: any, images: any): Promise<any[]>;
/**
 * Apply groupBy functions over collection of exported images.
 * @param  {Object} opts
 * @param  {Array}  images
 * @return {Promise}
 */
export declare function applyGroupBy(opts: any, images: any): Promise<any[]>;
/**
 * Replaces the background declarations that needs to be updated
 * with a sprite image.
 * @param  {Node}   root
 * @param  {Object} opts
 * @param  {Array}  images
 * @return {Promise}
 */
export declare function setTokens(root: any, opts: any, images: any): Promise<unknown>;
/**
 * Process the images through spritesmith module.
 * @param  {Object} opts
 * @param  {Array}  images
 * @return {Promise}
 */
export declare function runSpritesmith(opts: any, images: any): Promise<unknown>;
/**
 * Saves the spritesheets to the disk.
 * @param  {Object} opts
 * @param  {Array}  images
 * @param  {Array}  spritesheets
 * @return {Promise}
 */
export declare function saveSpritesheets(opts: any, images: any, spritesheets: any): Promise<any[]>;
/**
 * Map spritesheet props to every image.
 * @param  {Object} opts
 * @param  {Array}  images
 * @param  {Array}  spritesheets
 * @return {Promise}
 */
export declare function mapSpritesheetProps(opts: any, images: any, spritesheets: any): Promise<any[]>;
/**
 * Updates the CSS references.
 * @param  {Node}   root
 * @param  {Object} opts
 * @param  {Array}  images
 * @param  {Array}  spritesheets
 * @return {Promise}
 */
export declare function updateReferences(root: any, opts: any, images: any, spritesheets: any): Promise<any[]>;
/**
 * Update an single CSS rule.
 * @param  {Node}   rule
 * @param  {Node}   token
 * @param  {Object} image
 * @return
 */
export declare function updateRule(rule: any, token: any, image: any): void;
/**
 * Checks for image url in the given CSS rules.
 * @param  {String}  rule
 * @return {Boolean}
 */
export declare function hasImageInRule(rule: any): boolean;
/**
 * Extracts the url of image from the given rule.
 * @param  {String} rule
 * @return {Array}
 */
export declare function getImageUrl(rule: any): string[];
/**
 * Checks whether the image is supported.
 * @param  {String}  url
 * @return {Boolean}
 */
export declare function isImageSupported(url: any): boolean;
/**
 * Checks whether the image is retina.
 * @param  {String}  url
 * @return {Boolean}
 */
export declare function isRetinaImage(url: any): boolean;
/**
 * Extracts the retina ratio of image.
 * @param  {String} url
 * @return {Number}
 */
export declare function getRetinaRatio(url: any): number;
/**
 * Extracts the color from background declaration.
 * @param  {String}  declValue
 * @return {String?}
 */
export declare function getColor(declValue: any): null;
/**
 * Simple helper to avoid collisions with group names.
 * @param  {Boolean} toggle
 * @return {Function}
 */
export declare function maskGroup(toggle?: boolean): (value: any) => any;
/**
 * Generate the filepath to the sprite.
 * @param  {Object}  opts
 * @param  {Object}  spritesheet
 * @return {String}
 */
export declare function makeSpritesheetPath(opts: any, { groups, extension }: any): string;
/**
 * Check whether the comment is token that
 * should be replaced with background declarations.
 * @param  {String}  commentValue
 * @return {Boolean}
 */
export declare function isToken(commentValue: any): boolean;
/**
 * Create a logger that can be disabled in runtime.
 *
 * @param  {Boolean} enabled
 * @return {Function}
 */
export declare function createLogger(enabled: any): debug.Debugger;