import { type DomainRecord } from "./domain-db.js";
export interface DomainSnapshot {
    created: string;
    schema_version: number;
    count: number;
    records: DomainRecord[];
}
export interface RestoreClient {
    get(key: string): Promise<string | null>;
    set(key: string, value: string, mode: "EX", ttl: number): Promise<unknown>;
}
export interface RestoreResult {
    total: number;
    restored: number;
    skipped: number;
}
/**
 * Structural validation of a snapshot record before it is re-seeded into Valkey
 * (LOW-1). Snapshot files live in an operator-owned dir, but the restore path is
 * the one place external file contents flow back into the live domain-db, where
 * tier_stats_30d drives tier-skip routing and domain_stats rendering. Rejecting
 * malformed records here stops a crafted snapshot from injecting entries that
 * skew routing or crash domain_stats single mode. Beyond schema_version+domain,
 * require the last_fetch/first_seen strings and a numeric tier_stats_30d block.
 */
export declare function isStructurallyValidRecord(value: unknown): value is DomainRecord;
/** Filesystem-safe, lexicographically-sortable snapshot filename for `now`. */
export declare function snapshotFilename(now: Date): string;
/**
 * Write a snapshot of `records` to `dir` (created if absent). Returns the full
 * path and record count.
 */
export declare function writeSnapshot(dir: string, records: DomainRecord[], now?: Date): Promise<{
    path: string;
    count: number;
}>;
/** List snapshot filenames in `dir`, oldest first. Missing dir → empty. */
export declare function listSnapshots(dir: string): Promise<string[]>;
/**
 * Delete snapshots beyond the newest `retention` files. Returns the deleted
 * filenames. `retention < 1` is treated as 1 (never prune everything).
 */
export declare function pruneSnapshots(dir: string, retention: number): Promise<string[]>;
/** Load and parse the newest snapshot in `dir`, or null if none/invalid. */
export declare function loadLatestSnapshot(dir: string): Promise<DomainSnapshot | null>;
/**
 * Re-seed `records` into Valkey, restoring only keys that are missing or whose
 * live record is strictly staler than the snapshot (older last_fetch). Never
 * overwrites a fresher-or-equal live record. Structurally invalid or
 * stale-schema records are skipped (LOW-1 guard). Best-effort per key — a
 * single failure is counted as skipped, not fatal.
 */
export declare function applyRestore(client: RestoreClient, records: DomainRecord[]): Promise<RestoreResult>;