import { type Color } from './colors';
/** Predefined Excel pattern types. `'none'` lives here too as an explicit value. */
export type PatternType = 'none' | 'solid' | 'darkDown' | 'darkGray' | 'darkGrid' | 'darkHorizontal' | 'darkTrellis' | 'darkUp' | 'darkVertical' | 'gray0625' | 'gray125' | 'lightDown' | 'lightGray' | 'lightGrid' | 'lightHorizontal' | 'lightTrellis' | 'lightUp' | 'lightVertical' | 'mediumGray';
export declare const PATTERN_TYPES: ReadonlyArray<PatternType>;
export interface PatternFill {
    readonly kind: 'pattern';
    readonly patternType?: PatternType;
    readonly fgColor?: Color;
    readonly bgColor?: Color;
}
export declare function makePatternFill(opts?: Partial<Omit<PatternFill, 'kind'>>): PatternFill;
export interface GradientStop {
    /** 0..1 ratio along the gradient. */
    readonly position: number;
    readonly color: Color;
}
export type GradientFillType = 'linear' | 'path';
export interface GradientFill {
    readonly kind: 'gradient';
    readonly type: GradientFillType;
    /** Rotation angle (degrees). Ignored when `type === 'path'`. */
    readonly degree?: number;
    /** path-mode insets (0..1 from each edge). */
    readonly left?: number;
    readonly right?: number;
    readonly top?: number;
    readonly bottom?: number;
    /** Colour stops along the gradient. */
    readonly stops: ReadonlyArray<GradientStop>;
}
export declare function makeGradientStop(position: number, color: Color | Partial<Color>): GradientStop;
export declare function makeGradientFill(opts?: Partial<Omit<GradientFill, 'kind'>>): GradientFill;
export type Fill = PatternFill | GradientFill;
/**
 * Single-arg constructor that defers to the variant-specific maker based on
 * `kind`. Useful when the caller has a plain object in hand and wants the
 * freeze invariant applied uniformly.
 */
export declare function makeFill(opts: Partial<PatternFill> | Partial<GradientFill>): Fill;
/** The empty PatternFill — Excel's default cellXf[0] points here. */
export declare const DEFAULT_EMPTY_FILL: Fill;
/** The 'gray125' PatternFill — Excel's default cellXf[1]. */
export declare const DEFAULT_GRAY_FILL: Fill;
/**
 * Translate a {@link Fill} to a CSS-property record suitable for HTML preview.
 * `'solid'` PatternFill renders as `background-color`, other pattern types
 * collapse to bgColor (CSS has no built-in equivalent of Excel hatch patterns).
 * GradientFill emits a CSS `background-image` with `linear-gradient(<angle>,
 * …)` for `type='linear'` or `radial-gradient(circle, …)` for `type='path'`.
 *
 * theme/auto colours and unresolvable inputs are skipped (returns `{}`) so
 * callers can spread without overwriting upstream defaults.
 */
export declare function fillToCss(fill: Fill | undefined): Record<string, string>;