/**
 * CronCalculator
 * Computes next and previous execution times using a jump-based scheduling algorithm.
 * Designed for O(log n) per field resolution using pre-sorted value sets.
 */
import type { CronInput, RunOptions } from './types';
/** Computes next/previous scheduled run times for cron expressions. */
export declare class CronCalculator {
  private static readonly parser;
  private static instance?;
  private readonly formatter;
  /** Get the CronCalculator instance. */
  static getInstance(): CronCalculator;
  private constructor();
  /** Resolve string or parsed expression into ParsedCronExpression. */
  private resolve;
  /** Get number of days in month. */
  private DOM;
  /** Get the day of week. */
  private DOW;
  /** Binary search: lower bound (first >= x). */
  private lower;
  /** Binary search: upper bound (last <= x). */
  private upper;
  /**
   * Returns only the relevant candidates using binary search jumps.
   * No full array scans, no filtering, no allocation loops.
   */
  private pick;
  /** Cron day matching logic (DOM + DOW semantics). */
  private match;
  /** Validate chronological direction correctness. */
  private valid;
  /** Format a date into timezone-aligned parts. */
  private toDateTimeParts;
  /** Get date time part by key. */
  private getPart;
  /** Extract timezone-safe date parts. */
  private parts;
  /** Build UTC Date from timezone-aligned components. */
  private build;
  /**
   * Core jump-based scheduler.
   * Walks year → month → day → hour → minute using binary search jumps.
   */
  private step;
  /** Shared execution loop for next/prev. */
  private run;
  /**
   * Compute next N execution times.
   *
   * @param expr - Cron string or pre-parsed expression
   * @param options - Run options (timezone, before, after, count)
   *
   * @example
   * calc.next( '0 9 * * MON', { count: 3, timezone: 'UTC' } );
   */
  next(expr: CronInput, options?: RunOptions): Date[];
  /**
   * Compute previous N execution times.
   *
   * @param expr - Cron string or pre-parsed expression
   * @param options - Run options (timezone, before, after, count)
   *
   * @example
   * calc.prev( '0 9 * * MON', { count: 3 } );
   */
  prev(expr: CronInput, options?: RunOptions): Date[];
}