import type { ImmutableArray } from "../util/array.js";
import { type AbsoluteLink } from "../util/link.js";
import type { StringSchemaOptions } from "./StringSchema.js";
import { TextSchema } from "./TextSchema.js";
/** Allowed options for `LinkSchema` */
export interface LinkSchemaOptions extends Omit<StringSchemaOptions, "type" | "min" | "max" | "multiline"> {
    readonly base?: AbsoluteLink | undefined;
    readonly schemes?: ImmutableArray<string> | undefined;
    readonly hosts?: ImmutableArray<string> | undefined;
}
/**
 * Type of `StringSchema` that defines a valid URL link.
 * - Checks URL scheme against a whitelist (always), and checks URL domain against a whitelist (optional).
 * - URLs are limited to 512 characters, but generally these won't be data: URIs so this is a reasonable limit.
 * - Falsy values are converted to `""` empty string.
 */
export declare class LinkSchema extends TextSchema {
    readonly base: AbsoluteLink | undefined;
    readonly schemes: ImmutableArray<string> | undefined;
    readonly hosts: ImmutableArray<string> | undefined;
    constructor({ base, schemes, hosts, title, ...options }: LinkSchemaOptions);
    validate(unsafeValue: unknown): AbsoluteLink;
}
/** Valid link, e.g. `https://www.google.com` */
export declare const LINK: LinkSchema;
/** Valid link, e.g. `https://www.google.com`, or `null` */
export declare const OPTIONAL_LINK: import("./OptionalSchema.js").OptionalSchema<`${string}:${string}`>;