/**
 * Phrase Matching Service
 *
 * Pure functions for content-based phrase matching. This enables
 * exact phrase searches to find results even when semantic/BM25
 * scores are low.
 *
 * @module domain/services/phraseMatch
 */
/**
 * Result of phrase matching analysis.
 */
export interface PhraseMatchResult {
    /** Whether the exact query phrase was found in content */
    exactMatch: boolean;
    /** Proportion of query tokens found in content (0-1) */
    coverage: number;
    /** Number of query tokens found in content */
    matchedTokenCount: number;
    /** Total number of tokens in query */
    totalTokenCount: number;
    /** Additive score boost based on match quality */
    boost: number;
    /** Whether this match is significant enough to bypass filters */
    isSignificant: boolean;
}
/**
 * Constants for phrase matching scoring.
 */
export declare const PHRASE_MATCH_CONSTANTS: {
    /** Major boost for exact phrase match */
    readonly EXACT_PHRASE_BOOST: 0.5;
    /** Boost for high token coverage (80%+) */
    readonly HIGH_COVERAGE_BOOST: 0.2;
    /** Boost for medium token coverage (60%+) */
    readonly MEDIUM_COVERAGE_BOOST: 0.1;
    /** Coverage threshold for "high" classification */
    readonly HIGH_COVERAGE_THRESHOLD: 0.8;
    /** Coverage threshold for "medium" classification */
    readonly MEDIUM_COVERAGE_THRESHOLD: 0.6;
    /** Minimum query length to consider for exact matching */
    readonly MIN_QUERY_LENGTH: 3;
};
/**
 * Tokenize a string into words for matching.
 * Normalizes to lowercase and filters out punctuation.
 *
 * @param text - Text to tokenize
 * @param filterStopWords - Whether to filter out stop words
 * @returns Array of normalized tokens
 */
export declare function tokenizeForMatching(text: string, filterStopWords?: boolean): string[];
/**
 * Calculate phrase match score for content against a query.
 *
 * This function checks:
 * 1. Exact phrase match (query substring in content)
 * 2. Token coverage (what % of query tokens appear in content)
 *
 * @param content - The chunk content to search in
 * @param query - The search query
 * @returns PhraseMatchResult with match details and boost
 *
 * @example
 * const result = calculatePhraseMatch(
 *   "This explains the authentication flow for new users",
 *   "authentication flow for new users"
 * );
 * // result.exactMatch = true
 * // result.boost = 0.5 (EXACT_PHRASE_BOOST)
 *
 * @example
 * const result = calculatePhraseMatch(
 *   "User authentication and session flow",
 *   "authentication flow for users"
 * );
 * // result.exactMatch = false
 * // result.coverage = 0.75 (3/4 tokens found)
 * // result.boost = 0.1 (MEDIUM_COVERAGE_BOOST)
 */
export declare function calculatePhraseMatch(content: string, query: string): PhraseMatchResult;
/**
 * Quick check if content might contain the query phrase.
 * Useful for early filtering before full phrase matching.
 *
 * @param content - The chunk content
 * @param query - The search query
 * @returns true if exact phrase is found
 */
export declare function hasExactPhrase(content: string, query: string): boolean;
/**
 * Calculate token coverage between content and query.
 * Faster than full phrase matching when only coverage is needed.
 *
 * @param content - The chunk content
 * @param query - The search query
 * @returns Coverage ratio (0-1)
 */
export declare function calculateTokenCoverage(content: string, query: string): number;