import { BoardElement, BoardAppState, BoardScene } from './types.js';

/**
 * Operations over a board scene and their pure application. Every op is
 * fully materialized (it carries the elements it needs), so its inverse can
 * be derived without consulting the scene — which is what makes undo/redo a
 * simple stack of (forward, inverse) pairs (store.ts).
 */

type BoardOp = {
    kind: 'add';
    elements: BoardElement[];
} | {
    kind: 'remove';
    elements: BoardElement[];
} | {
    kind: 'update';
    before: BoardElement[];
    after: BoardElement[];
} | {
    kind: 'appState';
    before: Partial<BoardAppState>;
    after: Partial<BoardAppState>;
};
/** Apply an op to a scene, returning a new scene (inputs untouched). */
declare function applyOp(scene: BoardScene, op: BoardOp): BoardScene;
/** The op that undoes `op`. */
declare function inverseOp(op: BoardOp): BoardOp;
/** Element ids an op touches (drives fine-grained host re-render). */
declare function opChangedIds(op: BoardOp): string[];

export { type BoardOp, applyOp, inverseOp, opChangedIds };