/**
 * A Bucket is an individual entry for a facet or bin for a histogram
 *
 * @export
 * @interface Bucket
 */
export interface Bucket {
    key: string | number;
    doc_count: number;
}
export declare enum AggregationSortType {
    /**
     * Sort descending numerically by count/frequency
     */
    COUNT = 0,
    /**
     * Sort ascending alphabetically by key
     */
    ALPHABETICAL = 1,
    /**
     * Sort descending numerically by key
     */
    NUMERIC = 2
}
export interface AggregationOptions {
    buckets: Bucket[] | number[];
    first_bucket_key?: number;
    last_bucket_key?: number;
    number_buckets?: number;
    interval?: number;
    first_bucket_year?: number;
    first_bucket_month?: number;
    last_bucket_year?: number;
    last_bucket_month?: number;
    interval_in_months?: number;
}
/**
 * Aggregations are the datasource for facets and histograms
 */
export declare class Aggregation {
    /**
     * The year_histogram returns a `number` array, and
     * other facets return a `Bucket` array.
     */
    readonly buckets: Bucket[] | number[];
    readonly first_bucket_key?: number;
    readonly last_bucket_key?: number;
    readonly number_buckets?: number;
    readonly interval?: number;
    readonly first_bucket_year?: number;
    readonly first_bucket_month?: number;
    readonly last_bucket_year?: number;
    readonly last_bucket_month?: number;
    readonly interval_in_months?: number;
    constructor(options: AggregationOptions);
    /**
     * Returns a sorted copy of this aggregation's buckets, according to the given sort option.
     * This method is memoized and repeat calls should not incur a performance cost for a given
     * sort type after the first such call per instance.
     *
     * Purely numeric buckets (e.g., year_histogram) are not sorted by this method and are
     * returned as-is.
     *
     * @param sortType What to sort the buckets on.
     * Accepted values are:
     *  - `AggregationSortType.COUNT` (descending order)
     *  - `AggregationSortType.ALPHABETICAL` (ascending order)
     *  - `AggregationSortType.NUMERIC` (descending order)
     */
    getSortedBuckets(sortType?: AggregationSortType): Bucket[] | number[];
    /**
     * Type guard for number[] buckets, since the buckets provided by the PPS
     * may be either keyed objects or just an array of numbers. Currently only
     * `year_histogram` facets are of the latter type.
     */
    private isRawNumberBuckets;
}