import type { DatastoreOptions, Key } from '@google-cloud/datastore';
import type { CommonDBOptions, CommonDBReadOptions, CommonDBSaveOptions } from '@naturalcycles/db-lib';
import type { CommonLogger } from '@naturalcycles/js-lib/log';
import type { NumberOfSeconds, ObjectWithId } from '@naturalcycles/js-lib/types';
export interface DatastorePayload<T = any> {
    key: Key;
    data: T;
    excludeFromIndexes: string[];
}
/**
 * Extends DatastoreOptions by requiring needed properties.
 */
export interface DatastoreDBCfg extends DatastoreOptions {
    /**
     * Optional. AppEngine will infer projectId and credential automatically.
     */
    projectId?: string;
    credentials?: DatastoreCredentials;
    /**
     * As described here: https://github.com/googleapis/nodejs-pubsub/issues/770#issuecomment-541226361
     * Allows to set the old native library here, e.g `grpc: require('grpc')`
     */
    grpc?: any;
    /**
     * Use it to set default options to stream operations,
     * e.g you can globally enable `experimentalCursorStream` here, set the batchSize, etc.
     */
    streamOptions?: DatastoreDBStreamOptions;
    /**
     * Default to `console`
     */
    logger?: CommonLogger;
    /**
     * Experimental option, currently only applies to `getByIds`.
     * Applies pTimeout to Datastore operation, re-creates Datastore on any error.
     *
     * @experimental
     */
    timeout?: number;
}
export interface DatastoreCredentials {
    type?: string;
    client_email?: string;
    private_key?: string;
    private_key_id?: string;
    project_id?: string;
    client_id?: string;
    client_secret?: string;
    refresh_token?: string;
}
export interface DatastoreDBStreamOptions extends DatastoreDBReadOptions {
    /**
     * Set to `true` to stream via experimental "cursor-query based stream".
     *
     * @default false
     */
    experimentalCursorStream?: boolean;
    /**
     * Applicable to `experimentalCursorStream`.
     * Defines the size (limit) of each individual query.
     *
     * @default 1000
     */
    batchSize?: number;
    /**
     * Applicable to `experimentalCursorStream`
     *
     * Set to a value (number of Megabytes) to control the peak RSS size.
     * If limit is reached - streaming will pause until the stream keeps up, and then
     * resumes.
     *
     * Set to 0/undefined to disable. Stream will get "slow" then, cause it'll only run the query
     * when _read is called.
     *
     * @default 1000
     */
    rssLimitMB?: number;
    /**
     * Applicable to `experimentalCursorStream`
     * Default false.
     * If true, stream will pause until consumer requests more data (via _read).
     * It means it'll run slower, as buffer will be equal to batchSize (1000) at max.
     * There will be gaps in time between "last query loaded" and "next query requested".
     * This mode is useful e.g for DB migrations, where you want to avoid "stale data".
     * So, it minimizes the time between "item loaded" and "item saved" during DB migration.
     */
    singleBatchBuffer?: boolean;
    /**
     * Set to `true` to log additional debug info, when using experimentalCursorStream.
     *
     * @default false
     */
    debug?: boolean;
    /**
     * Default is undefined.
     * If set - sets a "safety timer", which will force call _read after the specified number of seconds.
     * This is to prevent possible "dead-lock"/race-condition that would make the stream "hang".
     *
     * @experimental
     */
    maxWait?: NumberOfSeconds;
}
export interface DatastoreDBOptions extends CommonDBOptions {
}
export interface DatastoreDBReadOptions extends CommonDBReadOptions {
}
export interface DatastoreDBSaveOptions<ROW extends ObjectWithId> extends CommonDBSaveOptions<ROW> {
}
export interface DatastoreStats {
    composite_index_count: number;
    builtin_index_count: number;
    kind_name: string;
    bytes: number;
    entity_bytes: number;
    count: number;
}
export declare enum DatastoreType {
    Blob = "Blob",
    Text = "Text",
    String = "String",// eslint-disable-line id-blacklist
    EmbeddedEntity = "EmbeddedEntity",
    Float = "Float",
    Integer = "Integer",
    DATE_TIME = "Date/Time",
    Boolean = "Boolean",// eslint-disable-line id-blacklist
    NULL = "NULL"
}
export interface DatastorePropertyStats {
    kind_name: string;
    property_name: string;
    property_type: DatastoreType;
    count: number;
    bytes: number;
    entity_bytes: number;
    builtin_index_count: number;
    builtin_index_bytes: number;
}