/**
 * SMI-733: Audit Logging System
 *
 * Provides structured audit logging for security-relevant events.
 * Stores audit trails in SQLite database for compliance and forensics.
 *
 * Schema defined in docs/security/index.md §3.2
 */
import type { Database as DatabaseType } from '../db/database-interface.js';
import type { AuditEventType, AuditActor, AuditResult, AuditLogEntry, AuditQueryFilter, AuditLoggerConfig, AuditStats } from './audit-types.js';
import { MIN_RETENTION_DAYS, MAX_RETENTION_DAYS } from './audit-types.js';
export type { AuditEventType, AuditActor, AuditResult, AuditLogEntry, AuditQueryFilter, AuditLoggerConfig, AuditStats, };
export { MIN_RETENTION_DAYS, MAX_RETENTION_DAYS };
/**
 * Audit Logger implementation with SQLite backend
 *
 * @example
 * ```typescript
 * const auditLogger = new AuditLogger(db)
 *
 * // Log URL fetch
 * await auditLogger.log({
 *   event_type: 'url_fetch',
 *   actor: 'adapter',
 *   resource: 'https://example.com/skill.yaml',
 *   action: 'fetch',
 *   result: 'success',
 *   metadata: { status: 200, duration: 123 }
 * })
 *
 * // Query audit trail
 * const recentBlocks = await auditLogger.query({
 *   result: 'blocked',
 *   since: new Date(Date.now() - 24 * 60 * 60 * 1000)
 * })
 * ```
 */
export declare class AuditLogger {
    private db;
    private config;
    private stmts;
    constructor(db: DatabaseType, config?: AuditLoggerConfig);
    /**
     * Prepare SQL statements for performance
     */
    private prepareStatements;
    /**
     * Ensure the audit_logs table exists
     */
    private ensureTableExists;
    /**
     * Log an audit event
     *
     * @param entry - Audit log entry (id, timestamp, created_at are auto-generated)
     */
    log(entry: Omit<AuditLogEntry, 'id' | 'timestamp' | 'created_at'> & {
        timestamp?: string;
    }): void;
    /**
     * Query audit logs with filters
     *
     * @param filter - Query filters
     * @returns Array of matching audit log entries
     */
    query(filter?: AuditQueryFilter): AuditLogEntry[];
    /**
     * Get audit statistics
     *
     * @returns Statistics about audit log entries
     */
    getStats(): AuditStats;
    /**
     * Clean up old audit logs (internal implementation)
     *
     * @param olderThan - Delete logs older than this date
     * @param skipMetaLog - Skip meta-logging (used internally to prevent recursion)
     * @returns Number of deleted entries
     */
    private cleanupInternal;
    /**
     * Clean up old audit logs
     *
     * @deprecated Use cleanupOldLogs() instead for validated retention-based cleanup
     * @param olderThan - Delete logs older than this date
     * @returns Number of deleted entries
     */
    cleanup(olderThan: Date): number;
    /**
     * Validate retention days parameter
     *
     * @param retentionDays - Number of days to validate
     * @throws Error if retentionDays is invalid
     */
    private validateRetentionDays;
    /**
     * Clean up old audit logs based on retention policy
     *
     * SMI-1012: Audit log retention policy with input validation
     *
     * @param retentionDays - Number of days to retain logs (default: 90, min: 1, max: 3650)
     * @returns Number of deleted rows
     * @throws Error if retentionDays is invalid (< 1, > 3650, or non-integer)
     *
     * @example
     * ```typescript
     * // Delete logs older than 90 days (default)
     * const deleted = auditLogger.cleanupOldLogs()
     *
     * // Delete logs older than 30 days
     * const deleted = auditLogger.cleanupOldLogs(30)
     *
     * // These will throw errors:
     * auditLogger.cleanupOldLogs(0)  // Error: minimum is 1 day
     * auditLogger.cleanupOldLogs(-5) // Error: minimum is 1 day
     * ```
     */
    cleanupOldLogs(retentionDays?: number): number;
    /**
     * Export audit logs to JSON
     *
     * @param filter - Query filters
     * @returns JSON string of audit logs
     */
    export(filter?: AuditQueryFilter): string;
}
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