export type DeltaMode = 'full' | 'git-diff' | 'hash-compare';
export type FileDelta = {
    path: string;
    kind: 'added' | 'modified' | 'deleted' | 'renamed';
    previousPath?: string;
};
/**
 * Determines which files have changed since the last index generation.
 * Returns the set of relative file paths that need re-indexing.
 */
export declare function getChangedFiles(cwd: string, sourceDir: string, mode: DeltaMode): string[] | null;
/** Returns additions, modifications, deletions, and renames relative to the prior index. */
export declare function getFileDelta(cwd: string, sourceDir: string, mode: DeltaMode): FileDelta[] | null;
/**
 * Computes a content hash for a file. Used for hash-compare delta mode.
 */
export declare function computeFileHash(filePath: string): string;