/**
 * Preflight check: estimate key count, type distribution, notify-keyspace-events (SPEC_F §F.9 Step 0).
 */
import type { MigrationRedisClient } from './redis-client.ts';
export interface KeyspaceEventsReadResult {
    value: string | null;
    /** False when the command is disabled or renamed and the default name fails. */
    available: boolean;
}
export interface SetKeyspaceEventsOptions {
    configCommand?: string;
    merge?: boolean;
}
export interface SetKeyspaceEventsResult {
    ok: boolean;
    previous: string | null;
    applied: string;
    error?: string;
}
export interface PreflightOptions {
    configCommand?: string;
}
export interface PreflightResult {
    keyCountEstimate: number;
    typeDistribution: Record<string, number>;
    notifyKeyspaceEvents: string | null;
    configCommandAvailable: boolean;
    recommended: {
        scan_count: number;
        max_concurrency: number;
        max_rps: number;
    };
}
/**
 * Read the current `notify-keyspace-events` value from Redis.
 * Uses raw sendCommand so it works even if the CONFIG command has been renamed.
 */
export declare function readKeyspaceEvents(redisClient: MigrationRedisClient, configCommand?: string): Promise<KeyspaceEventsReadResult>;
/**
 * Set `notify-keyspace-events` to `value` on Redis.
 * Optionally merges the new flags into the existing value instead of overwriting.
 *
 * @param value - Flags to apply (e.g. `'Kgxe'`).
 */
export declare function setKeyspaceEvents(redisClient: MigrationRedisClient, value: string, { configCommand, merge }?: SetKeyspaceEventsOptions): Promise<SetKeyspaceEventsResult>;
export declare function runPreflight(redisClient: MigrationRedisClient, { configCommand }?: PreflightOptions): Promise<PreflightResult>;