import type { BlockSnapshot, ConvertOptions, DeltaInsert, DocSnapshotMeta, DocumentReference, JsonRecord, SnapshotInput } from './types.js';
export interface NormalizedSnapshot {
    kind: 'doc' | 'block' | 'slice';
    blocks: BlockSnapshot[];
    root?: BlockSnapshot;
    meta?: DocSnapshotMeta;
    documentLike: boolean;
}
export declare function isRecord(value: unknown): value is JsonRecord;
export declare function toRecord(value: unknown): JsonRecord;
export declare function toStringValue(value: unknown, fallback?: string): string;
export declare function toFiniteNumber(value: unknown): number | undefined;
export declare function blockChildren(block: BlockSnapshot): BlockSnapshot[];
export declare function isBlockSnapshot(value: unknown): value is BlockSnapshot;
export declare function normalizeSnapshot(input: SnapshotInput): NormalizedSnapshot;
/**
 * Validate limits iteratively before recursive rendering. Besides making error
 * messages deterministic, this prevents deeply nested untrusted JSON from
 * exhausting the JavaScript call stack.
 */
export declare function validateSnapshotTree(blocks: readonly BlockSnapshot[], options: ConvertOptions): void;
export declare function deltaFrom(value: unknown): DeltaInsert[];
export declare function plainText(value: unknown): string;
export declare function pageTitleDelta(normalized: NormalizedSnapshot): DeltaInsert[];
export declare function pageTitleText(normalized: NormalizedSnapshot): string;
export declare function escapeHtml(value: unknown): string;
export declare function escapeHtmlAttribute(value: unknown): string;
export declare function sanitizeUrl(value: unknown, kind?: 'link' | 'image'): string;
export declare function resolveAssetUrl(options: ConvertOptions, block: BlockSnapshot, kind: 'image' | 'attachment'): string;
export declare function resolveZuiImageUrl(options: ConvertOptions, block: BlockSnapshot): string;
export declare function resolveDocumentUrl(options: ConvertOptions, reference: DocumentReference, block?: BlockSnapshot): string;
export declare function formatFileSize(value: unknown): string;
export declare function isEdgelessOnly(block: BlockSnapshot): boolean;
export declare function safeLanguage(value: unknown): string;
export declare function escapeMarkdownMath(value: unknown): string;
export declare function safeCssColor(value: unknown): string;
export declare function safeFontSize(value: unknown): string;