/**
 * Presentation styling for annotations.
 *
 * Two jobs that have to stay separate. Reading: an imported annotation may
 * carry an Annotation-level stylesheet, which is CSS a stranger wrote, and
 * nothing here may hand it to the browser — it is parsed into a small set of
 * presentation hints and everything outside an allowlist is discarded. Writing:
 * Mango's layer colours become a `CssStylesheet` plus a target `styleClass`,
 * the one representation of colour that survives a round trip through a
 * conformant consumer.
 *
 * The line this file exists to hold: colour is a hint. It never carries
 * motivation, purpose, ownership, visibility, or layer membership. A consumer
 * that loses the stylesheet loses the colour and nothing else.
 */
import { type CanonicalAnnotation, type CanonicalStylesheet } from '@mango-iiif/w3c-parser';
/** Presentation hints, in the form the canvas package's theme expects. */
export type PresentationHints = {
    strokeColor?: string;
    fillColor?: string;
    strokeWidth?: number;
    opacity?: number;
};
export type StyleRule = {
    /** Bare class name, without the leading dot. */
    className: string;
    declarations: Record<string, string>;
};
export type StylesheetParseResult = {
    rules: StyleRule[];
    /** Declarations and selectors refused, for the advanced/diagnostic panel. */
    rejected: string[];
};
/**
 * Parses CSS into class rules.
 *
 * Deliberately not a general CSS parser and deliberately not the browser's:
 * handing this text to a stylesheet object — even a constructed one — is what
 * the sanitizing exists to avoid, and the accepted grammar here is one flat
 * class selector with simple declarations. Anything more expressive is refused
 * rather than approximated, because an approximation is how a selector escapes
 * the annotation root.
 */
export declare const parseAnnotationCss: (css: string) => StylesheetParseResult;
/**
 * Reads the presentation hints an annotation's own stylesheet defines for a
 * class.
 *
 * External stylesheet references are recognised and ignored: resolving one
 * means fetching a URL a stranger supplied, and that decision belongs to the
 * host, not to a render pass. The class then has no applicable stylesheet, the
 * shape renders in the normal theme, and the caller reports the diagnostic.
 */
export declare const hintsForStyleClass: (annotation: CanonicalAnnotation, styleClass: string | undefined) => {
    hints?: PresentationHints;
    rejected: string[];
    unresolved: boolean;
};
/** Layer colour, and nothing about what the layer means. */
export type LayerAppearance = {
    id: string;
    color: string;
};
export type AnnotationAppearance = {
    className: string;
    strokeColor: string;
    fillColor: string;
    strokeWidth?: number;
};
/**
 * CSS class name for a layer.
 *
 * The layer's own id when it is a usable CSS identifier, which keeps Mango's
 * output identical to what the parser's migration helper produces for legacy
 * documents — two paths to the same class name rather than two class names for
 * the same layer. Ids that are not valid identifiers get a stable escaped form.
 */
export declare const styleClassForLayer: (layerId: string) => string;
export declare const rgbaFromHex: (color: string, alpha: number) => string;
/**
 * Restricts application-authored colours before interpolating them into CSS.
 * Story documents and host-provided layer definitions are input, not trusted
 * code; accepting a semicolon here would let data escape its declaration even
 * though imported stylesheets themselves are parsed safely.
 */
export declare const safeAnnotationColor: (color: string, fallback?: string) => string;
/** Builds one portable stylesheet rule for an authored annotation shape. */
export declare const buildAnnotationStylesheet: (appearance: AnnotationAppearance) => CanonicalStylesheet;
/**
 * Builds the Annotation-level stylesheet for the layers an annotation uses.
 *
 * Only the layers actually referenced: a stylesheet listing every layer in the
 * application would leak the full layer set into every exported annotation,
 * which is organisation metadata rather than presentation.
 */
export declare const buildLayerStylesheet: (layers: readonly LayerAppearance[]) => CanonicalStylesheet | null;
/**
 * Reads a colour back out of a legacy inline `target.style` value.
 *
 * Retained only for migration: Mango wrote this convention, so documents in
 * user stores carry it, and the colour is recoverable even though the property
 * itself is not portable.
 */
export declare const colorFromInlineStyle: (style: string | undefined) => string | null;
/** Parses a legacy inline `target.style` value into presentation hints. */
export declare const hintsFromInlineStyle: (style: string | undefined) => PresentationHints | undefined;