import type { PruneCalibrationState } from '@/types/graph';
/**
 * Creates an initial pruning calibration state.
 *
 * @param initialRatio - Starting calibration ratio (default: 1.0)
 * @returns Fresh calibration state
 */
export declare function createPruneCalibration(initialRatio?: number): PruneCalibrationState;
/**
 * Updates the pruning calibration using Exponential Moving Average (EMA).
 *
 * Problem: Without calibration, the pruner's token estimates can diverge from
 * reality across iterations, causing either:
 * - Over-pruning (context cliff): Too many messages removed at once, losing critical tool results
 * - Under-pruning: Not enough messages removed, hitting hard token limits
 *
 * Solution: Track the ratio between actual token usage (from API response) and
 * estimated token usage (from our token counter). Apply EMA smoothing so the
 * calibration adjusts gradually, preventing oscillation.
 *
 * The calibration ratio is applied to maxTokens in the pruner:
 *   effectiveMaxTokens = maxTokens * calibrationRatio
 *
 * If actual > estimated → ratio decreases → prune more aggressively
 * If actual < estimated → ratio increases → prune less aggressively
 *
 * @param state - Current calibration state
 * @param actualTokens - Actual token count from API response (UsageMetadata)
 * @param estimatedTokens - Estimated token count from token counter
 * @param alpha - EMA smoothing factor (default: PRUNING_EMA_ALPHA)
 * @returns Updated calibration state (new object, does not mutate input)
 */
export declare function updatePruneCalibration(state: PruneCalibrationState, actualTokens: number, estimatedTokens: number, alpha?: number): PruneCalibrationState;
/**
 * Applies the calibration ratio to a max token budget.
 * The ratio adjusts the effective budget so pruning is more or less aggressive
 * based on observed vs. estimated token divergence.
 *
 * @param maxTokens - Raw max token budget
 * @param state - Current calibration state
 * @returns Adjusted max token budget
 */
export declare function applyCalibration(maxTokens: number, state: PruneCalibrationState): number;