import { ManifestStore, TableName } from "../storage.mjs";
interface R2ObjectMetadata {
  etag: string;
}
interface R2ObjectBody extends R2ObjectMetadata {
  text: () => Promise<string>;
}
interface R2ListResult {
  objects: Array<{
    key: string;
  }>;
  truncated: boolean;
  cursor?: string;
}
interface R2ConditionalPutOptions {
  /**
   * Workers-binding-style precondition. `etagMatches` rejects with `null`
   *  return on mismatch; `etagDoesNotMatch: '*'` rejects if the key exists.
   */
  onlyIf?: {
    etagMatches?: string;
    etagDoesNotMatch?: string;
  };
}
/**
 * Minimal Cloudflare R2 binding shape needed for the manifest CAS loop.
 * Structurally compatible with Cloudflare's `R2Bucket` Workers API.
 */
interface R2ManifestBucketLike {
  get: (key: string) => Promise<R2ObjectBody | null>;
  put: (key: string, bytes: string | Uint8Array, options?: R2ConditionalPutOptions) => Promise<R2ObjectMetadata | null>;
  list: (options?: {
    prefix?: string;
    cursor?: string;
    limit?: number;
  }) => Promise<R2ListResult>;
  /**
   * Bulk delete. Required by {@link ManifestStore.purgeTenant}. Cloudflare's
   * `R2Bucket.delete` accepts a single key or a string[] batch; both shapes
   * work here.
   */
  delete: (keys: string | string[]) => Promise<void>;
}
/**
 * CAS lifecycle events emitted by the manifest store. Consumers wire these
 * into metrics (prom-client, console.table, the contention harness) to
 * measure rejection rate and latency under real R2 load.
 */
type R2ManifestEvent = {
  kind: 'cas-attempt';
  siteId: string;
  table: TableName;
  attempt: number;
} | {
  kind: 'cas-rejected';
  siteId: string;
  table: TableName;
  attempt: number;
} | {
  kind: 'cas-committed';
  siteId: string;
  table: TableName;
  attempts: number;
};
interface CreateR2ManifestStoreOptions {
  bucket: R2ManifestBucketLike;
  /** Tenant scope. All shard keys are prefixed `u_<userId>/manifest/...`. */
  userId: string;
  /** Override the snapshot version-id generator. Defaults to `${ts}-${random}`. */
  newSnapshotId?: () => string;
  now?: () => number;
  /** Maximum CAS retries before giving up. Defaults to 8. */
  maxRetries?: number;
  /**
   * Optional telemetry hook. Fired synchronously from the CAS loop on each
   * attempt, rejection, and successful commit. Must not throw; exceptions
   * propagate and will fail the mutation.
   */
  onEvent?: (event: R2ManifestEvent) => void;
}
declare function createR2ManifestStore(opts: CreateR2ManifestStoreOptions): ManifestStore;
export { CreateR2ManifestStoreOptions, R2ManifestBucketLike, R2ManifestEvent, createR2ManifestStore };