/**
 * Change Log
 *
 * Tracks all configuration changes for SOC2 compliance.
 * Provides audit trail for system modifications.
 *
 * Added by Pantheon Security for enterprise compliance support.
 */
import type { ChangeRecord } from "./types.js";
/**
 * Change Log class
 */
export declare class ChangeLog {
    private static instance;
    private logDir;
    private currentLogFile;
    private constructor();
    /**
     * Get singleton instance
     */
    static getInstance(): ChangeLog;
    /**
     * Initialize log file for current month
     */
    private initializeLogFile;
    /**
     * Record a configuration change
     */
    recordChange(component: string, setting: string, oldValue: unknown, newValue: unknown, options?: {
        changedBy?: "user" | "system" | "admin";
        method?: "cli" | "env" | "api" | "config_file";
        requiresApproval?: boolean;
        approvedBy?: string;
        impact?: "low" | "medium" | "high";
        affectedCompliance?: string[];
    }): Promise<ChangeRecord>;
    /**
     * Sanitize value for logging (remove sensitive data)
     */
    private sanitizeValue;
    /**
     * Get changes by component
     */
    getChangesByComponent(component: string, limit?: number): Promise<ChangeRecord[]>;
    /**
     * Get changes by setting
     */
    getChangesBySetting(setting: string, limit?: number): Promise<ChangeRecord[]>;
    /**
     * Get changes within date range
     */
    getChangesInRange(from: Date, to: Date, limit?: number): Promise<ChangeRecord[]>;
    /**
     * Get all changes (most recent first)
     */
    getAllChanges(limit?: number): Promise<ChangeRecord[]>;
    /**
     * Select monthly log files whose YYYY-MM month overlaps the [from, to] range.
     * Filenames are `changes-YYYY-MM.jsonl`; pushing the date filter into file
     * selection avoids reading (and event-loop-blocking on) years of history when
     * only a narrow report window is requested (L48). Returns newest-first.
     */
    private getLogFilesInRange;
    /**
     * Read change records from a specific set of files, applying an optional
     * date-range predicate. Used by range-bounded queries so only relevant
     * monthly files are read rather than the entire history.
     */
    private readChangesFromFiles;
    /**
     * Get high-impact changes
     */
    getHighImpactChanges(limit?: number): Promise<ChangeRecord[]>;
    /**
     * Get changes affecting compliance
     */
    getComplianceAffectingChanges(regulation?: string, limit?: number): Promise<ChangeRecord[]>;
    /**
     * Get change statistics
     */
    getStatistics(from?: Date, to?: Date): Promise<{
        total_changes: number;
        by_component: Record<string, number>;
        by_impact: Record<string, number>;
        by_method: Record<string, number>;
        requiring_approval: number;
        compliance_affecting: number;
    }>;
    /**
     * Export changes for audit
     */
    exportForAudit(from: Date, to: Date): Promise<{
        period: {
            from: string;
            to: string;
        };
        total_changes: number;
        high_impact_changes: number;
        compliance_affecting_changes: number;
        changes: ChangeRecord[];
    }>;
}
/**
 * Get the change log instance
 */
export declare function getChangeLog(): ChangeLog;
/**
 * Record a configuration change
 */
export declare function recordConfigChange(component: string, setting: string, oldValue: unknown, newValue: unknown, options?: {
    changedBy?: "user" | "system" | "admin";
    method?: "cli" | "env" | "api" | "config_file";
    requiresApproval?: boolean;
    approvedBy?: string;
    impact?: "low" | "medium" | "high";
    affectedCompliance?: string[];
}): Promise<ChangeRecord>;
/**
 * Get recent configuration changes
 */
export declare function getRecentChanges(limit?: number): Promise<ChangeRecord[]>;
/**
 * Get change statistics
 */
export declare function getChangeStatistics(from?: Date, to?: Date): Promise<ReturnType<ChangeLog["getStatistics"]>>;