/**
 * Valid CSS property values.
 */
export type PropertyValue = number | boolean | string | null | undefined;
/**
 * Input styles object.
 */
export interface Styles {
    $unique?: boolean;
    $global?: boolean;
    $displayName?: string;
    [selector: string]: PropertyValue | PropertyValue[] | Styles;
}
export interface CompiledStyle {
    selector: string;
    style: string;
    isUnique: boolean;
}
export interface CompiledRule {
    selector: string;
    style: string;
    rules: CompiledRule[];
    styles: CompiledStyle[];
}
/**
 * Pre-registered container for cached styles and rules.
 */
export interface Compiled {
    id: string;
    rules: CompiledRule[];
    styles: CompiledStyle[];
    displayName: string | undefined;
}
/**
 * Propagate change events.
 */
export interface Changes {
    add(style: Container<any>, index: number): void;
    remove(style: Container<any>, index: number): void;
    change(style: Container<any>, index: number): void;
}
/**
 * Cache-able interface.
 */
export interface Container<T> {
    /** Unique identifier for the cache, used for merging styles. */
    cid(): string;
    clone(): T;
    getStyles(): string;
}
/**
 * Implement a cache/event emitter.
 */
export declare class Cache<T extends Container<any>> {
    changes?: Changes | undefined;
    changeId: number;
    protected sheet: string[];
    protected children: T[];
    protected counters: Map<string, number>;
    constructor(changes?: Changes | undefined);
    add(style: T): void;
    remove(style: T): void;
    merge(cache: Cache<any>): this;
    unmerge(cache: Cache<any>): this;
}
/**
 * Selector is a dumb class made to represent nested CSS selectors.
 */
export declare class Selector implements Container<Selector> {
    selector: string;
    constructor(selector: string);
    cid(): string;
    getStyles(): string;
    clone(): Selector;
}
/**
 * The style container registers a style string with selectors.
 */
export declare class Style extends Cache<Selector> implements Container<Style> {
    style: string;
    id: string;
    constructor(style: string, id: string);
    cid(): string;
    getStyles(): string;
    clone(): Style;
}
/**
 * Implement rule logic for style output.
 */
export declare class Rule extends Cache<Rule | Style> implements Container<Rule> {
    rule: string;
    style: string;
    id: string;
    constructor(rule: string, style: string, id: string);
    cid(): string;
    getStyles(): string;
    clone(): Rule;
}
/**
 * The FreeStyle class implements the API for everything else.
 */
export declare class Sheet extends Cache<Rule | Style> {
    prefix: string;
    constructor(prefix: string, changes?: Changes);
    register(compiled: Compiled): string;
    registerStyle(styles: Styles): string;
    getStyles(): string;
}
/**
 * Exports a simple function to create a new instance.
 */
export declare function create(changes?: Changes, prefix?: string): Sheet;
/**
 * Compile styles into a registerable object.
 */
export declare function compile(styles: Styles): Compiled;