import { type RequireExactlyOne } from 'type-fest';
/**
 * All CSS formats supported by `@property`, at of the time of this writing.
 *
 * This is generated from the following script, run at
 * https://developer.mozilla.org/docs/Web/CSS/Reference/At-rules/%40property/syntax:
 *
 * ```js
 * console.log(
 *     Array.from(document.querySelectorAll('[aria-labelledby="values"] > dl > *'))
 *         .reverse()
 *         .reduce((accum, current) => {
 *             if (!(current instanceof HTMLElement)) {
 *                 console.warn('not HTMLElement', current);
 *                 return accum;
 *             } else if (current.tagName.toLowerCase() === 'dt') {
 *                 const syntax = current.innerText.replaceAll('"', '');
 *                 const keySplits = syntax.replaceAll('<', '').replaceAll('>', '').split('-');
 *
 *                 const key = [
 *                     keySplits[0]?.[0]?.toUpperCase(),
 *                     keySplits[0]?.slice(1),
 *                     ...keySplits.slice(1).map((entry) => {
 *                         return [
 *                             entry[0]?.toUpperCase(),
 *                             entry.slice(1),
 *                         ].join('');
 *                     }),
 *                 ].join('');
 *
 *                 return accum + '\n' + `    ${key} = '${syntax}',`;
 *             } else if (current.tagName.toLowerCase() === 'dd') {
 *                 const contents = current
 *                     .querySelector('p')
 *                     ?.innerHTML.replaceAll('&lt;', '<')
 *                     .replaceAll('&gt;', '>')
 *                     .replaceAll('/en-US/', 'https://developer.mozilla.org/');
 *
 *                 if (contents) {
 *                     const comment = contents
 *                         .replaceAll(/<code>(.+?)<\/code>/g, '`$1`')
 *                         .replaceAll(/<a href="(.+?)">(.+?)<\/a>/g, '[$2]($1)');
 *
 *                     return accum + '\n' + `    /** ${comment} *\/`;
 *                 }
 *             }
 *
 *             console.warn('No match', current);
 *
 *             return accum;
 *         }, 'export enum CssPropertySyntax {') + '\n};\n',
 * );
 * ```
 *
 * @category Internal
 * @see https://developer.mozilla.org/docs/Web/CSS/Reference/At-rules/%40property/syntax#values
 */
export declare enum CssVarSyntaxName {
    /**
     * Accepts any valid
     * [`<url>`](https://developer.mozilla.org/docs/Web/CSS/Reference/Values/url_value) value.
     */
    Url = "<url>",
    /**
     * Accepts a list of valid
     * [`<transform-function>`](https://developer.mozilla.org/docs/Web/CSS/Reference/Values/transform-function)
     * values. It is equivalent to `"<transform-function>+"`.
     */
    TransformList = "<transform-list>",
    /**
     * Accepts any valid
     * [`<transform-function>`](https://developer.mozilla.org/docs/Web/CSS/Reference/Values/transform-function)
     * value.
     */
    TransformFunction = "<transform-function>",
    /**
     * Accepts any valid
     * [`<time>`](https://developer.mozilla.org/docs/Web/CSS/Reference/Values/time) value.
     */
    Time = "<time>",
    /**
     * Accepts any valid
     * [`<string>`](https://developer.mozilla.org/docs/Web/CSS/Reference/Values/string) value.
     */
    String = "<string>",
    /**
     * Accepts any valid
     * [`<resolution>`](https://developer.mozilla.org/docs/Web/CSS/Reference/Values/resolution)
     * value.
     */
    Resolution = "<resolution>",
    /**
     * Accepts any valid
     * [`<percentage>`](https://developer.mozilla.org/docs/Web/CSS/Reference/Values/percentage)
     * value.
     */
    Percentage = "<percentage>",
    /**
     * Accepts any valid
     * [`<number>`](https://developer.mozilla.org/docs/Web/CSS/Reference/Values/number) value.
     */
    Number = "<number>",
    /**
     * Accepts any valid
     * [`<length>`](https://developer.mozilla.org/docs/Web/CSS/Reference/Values/length) or
     * [`<percentage>`](https://developer.mozilla.org/docs/Web/CSS/Reference/Values/percentage)
     * value and any valid
     * [`calc()`](https://developer.mozilla.org/docs/Web/CSS/Reference/Values/calc) expression
     * combining `<length>` and `<percentage>` values.
     */
    LengthPercentage = "<length-percentage>",
    /**
     * Accepts any valid
     * [`<length>`](https://developer.mozilla.org/docs/Web/CSS/Reference/Values/length) value.
     */
    Length = "<length>",
    /**
     * Accepts any valid
     * [`<integer>`](https://developer.mozilla.org/docs/Web/CSS/Reference/Values/integer) value.
     */
    Integer = "<integer>",
    /**
     * Accepts any valid
     * [`<image>`](https://developer.mozilla.org/docs/Web/CSS/Reference/Values/image) value.
     */
    Image = "<image>",
    /**
     * Accepts any valid
     * [`<custom-ident>`](https://developer.mozilla.org/docs/Web/CSS/Reference/Values/custom-ident)
     * value.
     */
    CustomIdent = "<custom-ident>",
    /**
     * Accepts any valid
     * [`<color>`](https://developer.mozilla.org/docs/Web/CSS/Reference/Values/color_value) value.
     */
    Color = "<color>",
    /**
     * Accepts any valid
     * [`<angle>`](https://developer.mozilla.org/docs/Web/CSS/Reference/Values/angle) value.
     */
    Angle = "<angle>",
    Any = "*"
}
/**
 * Possible value for the separator in a list of CSS values.
 *
 * @category Internal
 */
export declare enum CssVarSyntaxSeparator {
    /** Values are separated by a space. */
    Space = "+",
    /** Values are separated by a comma. */
    Comma = "#"
}
/**
 * Options for defining a CSS var's syntax.
 *
 * @category Internal
 */
export type CssVarSyntax = CssVarSyntaxName | RequireExactlyOne<{
    /** Allowed possible syntaxes. Joined together with `|`. */
    union: CssVarSimpleValueSyntax[];
    /** The raw syntax string. This will be passed directly to the CSS engine. */
    raw: string;
    /** Specifies that this syntax requires a list of values. */
    list: {
        /** The values in the list. */
        values: CssVarSimpleValueSyntax;
        /** The list separator. */
        separator: CssVarSyntaxSeparator;
    };
}>;
/**
 * Allowed values for unions and lists.
 *
 * @category Internal
 */
export type CssVarSimpleValueSyntax = CssVarSyntaxName | {
    raw: string;
};