/**
 * HeuristicAnalyzer
 *
 * Advanced heuristic detection using three techniques from research (DMPI-PMHFE, 2026):
 *
 * 1. SYNONYM EXPANSION — Expand injection keywords to catch paraphrased attacks
 *    Instead of matching "ignore" only, match {ignore, disregard, overlook, neglect, skip, bypass, omit...}
 *
 * 2. STRUCTURAL PATTERN ANALYSIS — Detect instruction-like sentence structures
 *    Imperative commands, Q&A injection (many-shot), repeated token attacks
 *
 * 3. STATISTICAL FEATURES — Score inputs based on statistical properties
 *    Instruction word density, special character ratio, command-to-question ratio
 *
 * These techniques are zero-dependency, pure string analysis — no ML required.
 * Research shows they add +10-15pp detection over keyword-only regex.
 */
export interface HeuristicAnalyzerConfig {
    /** Enable synonym expansion (default: true) */
    synonymExpansion?: boolean;
    /** Enable structural pattern analysis (default: true) */
    structuralAnalysis?: boolean;
    /** Enable statistical feature scoring (default: true) */
    statisticalScoring?: boolean;
    /** Risk threshold for blocking (0-1, default: 0.6) */
    riskThreshold?: number;
    /** Q&A pair threshold for many-shot detection (default: 3) */
    manyShotThreshold?: number;
    /** Repeated token threshold (default: 3) */
    repeatedTokenThreshold?: number;
}
export interface HeuristicResult {
    allowed: boolean;
    reason?: string;
    riskScore: number;
    features: HeuristicFeatures;
    violations: string[];
}
export interface HeuristicFeatures {
    is_ignore: boolean;
    is_urgent: boolean;
    is_incentive: boolean;
    is_covert: boolean;
    is_format_manipulation: boolean;
    is_hypothetical: boolean;
    is_systemic: boolean;
    is_immoral: boolean;
    synonym_categories_matched: number;
    is_shot_attack: boolean;
    is_repeated_token: boolean;
    is_imperative: boolean;
    is_role_assignment: boolean;
    structural_score: number;
    instruction_word_density: number;
    special_char_ratio: number;
    uppercase_ratio: number;
    average_word_length: number;
    statistical_score: number;
}
export declare class HeuristicAnalyzer {
    private config;
    constructor(config?: HeuristicAnalyzerConfig);
    /**
     * Analyze input using all three heuristic techniques
     */
    analyze(input: string, requestId?: string): HeuristicResult;
    /**
     * Technique 1: Synonym Expansion
     * Check if input tokens match expanded synonym sets for 8 attack categories
     */
    private checkSynonyms;
    /**
     * Technique 2: Structural Pattern Analysis
     * Detect instruction-like sentence structures
     */
    private checkStructure;
    /**
     * Technique 3: Statistical Feature Scoring
     * Score based on statistical properties of the input
     */
    private scoreStatistics;
}