/**
 * One undo stack for two kinds of change.
 *
 * Geometry history belongs to the canvas package, which is the only thing that
 * knows a hundred pointer samples are one drag. Metadata history — text, tags,
 * motivation, layer, notes — belongs to Mango, which is the only thing that
 * knows what a tag is. Neither can own the whole stack, and a user pressing
 * undo does not care which of the two they are undoing: they want the last
 * thing they did reversed, in order.
 *
 * So Mango keeps the ordering and delegates the geometry steps. Each entry
 * either carries a metadata change to invert, or is a marker saying "the next
 * step down is the canvas package's".
 */
import type { ResolvedAnnotation } from '../../iiif/annotationResolver';
/** Something that can undo and redo its own geometry steps. */
export type GeometryHistory = {
    undo(): boolean;
    redo(): boolean;
    readonly canUndo: boolean;
    readonly canRedo: boolean;
};
export type MetadataChange = {
    kind: 'metadata';
    annotationId: string;
    /** The annotation as it was. Null when the entry created it. */
    before: ResolvedAnnotation | null;
    /** The annotation as it became. Null when the entry deleted it. */
    after: ResolvedAnnotation | null;
    /** Names the step for an announcement, e.g. "tags" or "text". */
    label: string;
    /** Internal coalescing boundary for continuous text input. */
    recordedAt?: number;
};
/**
 * A geometry step recorded by the canvas package.
 *
 * Carries no payload: reversing it means asking the editor to undo, and holding
 * a copy of the geometry here would be a second source of truth that drifts the
 * first time the editor coalesces differently than expected.
 */
export type GeometryMarker = {
    kind: 'geometry';
    annotationId: string;
    label: string;
};
export type CommandEntry = MetadataChange | GeometryMarker;
export type CommandStackOptions = {
    limit?: number;
    /** Applies a metadata state. Called for both undo and redo. */
    apply: (annotationId: string, annotation: ResolvedAnnotation | null) => void;
    geometry?: () => GeometryHistory | null;
    onChange?: (state: CommandStackState) => void;
};
export type CommandStackState = {
    canUndo: boolean;
    canRedo: boolean;
    /** What undo would reverse, for an announcement or a tooltip. */
    undoLabel?: string;
    redoLabel?: string;
};
export type CommandStack = {
    /** Records a metadata change. */
    record(change: Omit<MetadataChange, 'kind'>): void;
    /** Records that the canvas package committed a geometry step. */
    recordGeometry(annotationId: string, label: string): void;
    undo(): boolean;
    redo(): boolean;
    clear(): void;
    state(): CommandStackState;
};
export declare const createCommandStack: (options: CommandStackOptions) => CommandStack;
/** Names the field a patch touched, for the undo announcement. */
export declare const labelForPatch: (patch: Partial<ResolvedAnnotation>) => string;