/**
 * Diff between the current document and a history snapshot — pure, no
 * React, no ProseMirror. Powers the "hover a history item to see what
 * changed" preview: `HistoryEntryRow` calls this on hover, then
 * `DocxEditor.previewHistoryDiff()` (see `../../editor.ts`) renders the
 * result as ProseMirror decorations without touching document content.
 *
 * Two levels, both built on the same LCS alignment (`lcsAlign`):
 *   - Block-level (`diffHistoryBlocks`): treats each top-level node of
 *     `doc.content` as one atomic "line" — cheap enough for the block
 *     counts a document actually has (at most a few hundred).
 *   - Word-level (`diffWords`): for a block matched as `modified`, diffs its
 *     text word-by-word so the overlay can highlight only the words that
 *     actually changed instead of tinting the whole paragraph — see
 *     `BlockDiffEntry.wordDiff`.
 */
type BlockDiffKind = 'added' | 'removed' | 'modified';
type WordDiffKind = 'same' | 'added' | 'removed';
interface WordDiffEntry {
    kind: WordDiffKind;
    /** The token itself — a run of non-whitespace, or a run of whitespace (tokens preserve every character, so join()-ing all `text` fields losslessly reconstructs the original string). */
    text: string;
}
interface BlockDiffEntry {
    kind: BlockDiffKind;
    /** Index into the CURRENT document's top-level blocks (added/modified only). */
    currentIndex?: number;
    /** Index into the SNAPSHOT document's top-level blocks (removed/modified only). */
    snapshotIndex?: number;
    /**
     * `removed` only — index into the CURRENT document's top-level blocks that
     * this removed content should be anchored *before* (`current.length` means
     * "at the end of the document"). Unlike `snapshotIndex`, this stays valid
     * as a position in the current doc even once it and the snapshot have a
     * different number of blocks.
     */
    anchorIndex?: number;
    /** Short text preview, mainly for the `removed` widget pill (no node in the current doc to anchor to). */
    preview?: string;
    /** `removed` only — full (untruncated) text of the removed block, for rendering the whole removed line. */
    removedText?: string;
    /** `modified` only — word-level diff between the snapshot's and current's full text, in order. */
    wordDiff?: WordDiffEntry[];
}
interface BlockDiffResult {
    entries: BlockDiffEntry[];
}
/**
 * Diff `current.content` against `snapshot.content` (both full TipTap JSON
 * documents). Returns entries in document order (interleaving added/removed/
 * modified as they occur, matched blocks omitted).
 */
declare function diffHistoryBlocks(currentDoc: any, snapshotDoc: any): BlockDiffResult;
/**
 * Word-level diff between `currentText` and `snapshotText`. Whitespace runs
 * are tokens too (not diffed away) so the overlay can precisely map every
 * token back to a text offset — see `WordDiffEntry`.
 */
declare function diffWords(currentText: string, snapshotText: string): WordDiffEntry[];

export { type BlockDiffEntry, type BlockDiffKind, type BlockDiffResult, type WordDiffEntry, type WordDiffKind, diffHistoryBlocks, diffWords };