/**
 * The pictures a decision's state holds: image parts, or image assets, anywhere in an object or a
 * list, each named by its path, which a question writes in backticks, such as `photo`, `faces.happy`,
 * or `frames[2].frame`.
 */
import { type MediaResolveOptions } from '../evaluate/media.js';
import type { MediaPart } from '../types/evaluate.js';
/** A picture in a decision's state, and where it is. */
export interface DecisionPicture {
    /** Its path in the state, as a question names it in backticks: `photo`, `faces.happy`, or `frames[2].frame`. */
    path: string;
    /** The picture: an image part, `{ type: 'image', source }`, or an image asset. */
    part: MediaPart;
}
/** A picture's bytes, read for a provider that sends them. */
export interface ReadDecisionPicture extends DecisionPicture {
    /** Its bytes. */
    bytes: Uint8Array;
    /** Its MIME type, as its first bytes say, whatever it was declared as. */
    mimeType: string;
    /** Its width in pixels, from its header. */
    width?: number;
    /** Its height in pixels. */
    height?: number;
}
/** Every picture in a state, in the order they appear, each with its path. A picture used twice is listed at both. */
export declare function statePictures(state: unknown): DecisionPicture[];
/**
 * The state with each picture replaced by what `replace` returns for it, copying only the objects and
 * lists on the way to one, so a state without pictures comes back as it was given.
 */
export declare function replacePictures(state: unknown, replace: (picture: DecisionPicture) => unknown): unknown;
/**
 * Identifies a picture without its bytes, for a cache key or a trace: a digest of what it holds, or
 * where it is when it is a file or at a URL, so a picture changed at the same path is keyed the same.
 */
export declare function pictureDigest(part: MediaPart): string;
/**
 * Reads a picture's bytes, with the media family's readers: bytes and base64 as they are, a file with
 * `readFile`, a URL with `fetch`, and a stored asset from `assets`. Throws `DecisionError`
 * `DECISION_INVALID`, naming the picture's path, for one that cannot be read or is not a picture.
 */
export declare function readPicture(picture: DecisionPicture, options?: MediaResolveOptions): Promise<ReadDecisionPicture>;