/**
 * Expertise decay analysis — tracks activity freshness of code owners.
 *
 * Unlike knowledge-loss-risk (which focuses on bus factor = 1),
 * this module detects when dominant owners become inactive.
 */
import type { RiskLevel } from "./risk-classifiers.js";
export type OwnerStatus = "active" | "fading" | "inactive";
export interface ExpertiseDecayOwner {
    email: string;
    commits: number;
    percentage: number;
    lastActivityDate: string | null;
    daysSinceLastActivity: number | null;
    status: OwnerStatus;
}
export interface ExpertiseDecayEntry {
    directory: string;
    busFactor: number;
    owners: ExpertiseDecayOwner[];
    riskLevel: RiskLevel;
}
export interface ExpertiseDecayResult {
    entries: ExpertiseDecayEntry[];
    summary: {
        totalDirectories: number;
        highRisk: number;
        mediumRisk: number;
        lowRisk: number;
    };
}
export interface ExpertiseDecayOptions {
    depth?: number;
    since?: string;
    maxCommits?: number;
    inactivityThresholdDays?: number;
    fadingThresholdDays?: number;
    pathPattern?: string;
    timeoutMs?: number;
}
/**
 * Analyze expertise decay across repository directories.
 *
 * For each directory's dominant contributors, checks how recently
 * they have been active and classifies the decay risk.
 */
export declare function analyzeExpertiseDecay(repoPath: string, options?: ExpertiseDecayOptions): Promise<ExpertiseDecayResult>;