import DataLoaderNullable from './DataLoaderNullable';
import type { Paths, Projection } from './projectionFromGraphQLInfo';
import type { PartialWithId } from './types';
import type { Collection, Document, EnhancedOmit, Filter, ObjectId, WithId } from 'mongodb';
export type IdWithProjection<T extends Record<string, unknown> & {
    readonly _id: ObjectId;
}> = {
    readonly _id: ObjectId;
    readonly projection: Projection<T>;
};
export type IdWithoutProjection = {
    readonly _id: ObjectId;
    readonly projection: null;
};
export type Key<T extends Record<string, unknown> & {
    readonly _id: ObjectId;
}> = IdWithoutProjection | IdWithProjection<T>;
type OptimalProjection<T extends Record<string, unknown> & {
    readonly _id: ObjectId;
}> = {
    readonly projection: Projection<T> | null;
    readonly $in: Filter<T>['$in'];
};
export declare function getOptimalProjection<T extends Record<string, unknown> & {
    readonly _id: ObjectId;
}>(keys: readonly Key<T>[]): OptimalProjection<T>;
export declare function cacheKeyFn<T extends {
    readonly _id: ObjectId;
}>(key: Key<T>): string;
export type BatchLoadFnWithoutError<K, V> = (keys: ReadonlyArray<K>) => Promise<ArrayLike<V>>;
export type MongoDataLoader<T extends PartialWithId<Record<string, unknown>>> = DataLoaderNullable<T, Key<T>, string>;
export type LoadMapper<GQLType extends Record<string, unknown>, // GraphQL type
DBType extends WithId<unknown> = {
    readonly _id: ObjectId;
}, // Database type
DBPath extends Paths<DBType> = Paths<DBType>, GQLPath extends Paths<GQLType> = Paths<GQLType>> = Partial<Record<DBPath, readonly GQLPath[]>>;
export declare function createMongoDataloader<GQLType extends Record<string, unknown>, // GraphQL type
DBTypeInt extends Document = Document, // Database type
DBType extends WithId<DBTypeInt> = WithId<DBTypeInt>, // Database type
DBPath extends Paths<DBType> = Paths<DBType>, GQLPath extends Paths<GQLType> = Paths<GQLType>>(collection: Collection<EnhancedOmit<DBType, '_id'>>, dependencies?: Partial<Record<DBPath, readonly GQLPath[]>>): MongoDataLoader<DBType>;
export default createMongoDataloader;