import type { DatastoreOptions, Key } from '@google-cloud/datastore';
import type { CommonDBOptions, CommonDBReadOptions, CommonDBSaveOptions } from '@naturalcycles/db-lib';
import type { CommonLogger, CommonLogLevel } from '@naturalcycles/js-lib/log';
import type { NumberOfSeconds, ObjectWithId, PositiveInteger } 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;
    /**
     * Defaults to `log`.
     */
    logLevel?: CommonLogLevel;
    /**
     * 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 1_000
     */
    batchSize?: PositiveInteger;
    /**
     * Defaults to 3x batchSize.
     * Default batchSize is 1_000, so default highWaterMark is 3_000.
     * Controls how many rows to have "buffered".
     * Should be at least 1x batchSize, otherwise the stream will be "starving"
     * between the queries.
     */
    highWaterMark?: PositiveInteger;
    logger?: CommonLogger;
    /**
     * Defaults to `log`.
     * Set to `debug` to allow for extra debugging, e.g in experimentalCursorStream.
     */
    logLevel?: CommonLogLevel;
    /**
     * 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",
    EmbeddedEntity = "EmbeddedEntity",
    Float = "Float",
    Integer = "Integer",
    DATE_TIME = "Date/Time",
    Boolean = "Boolean",
    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;
}