/**
 * Fee Calculator — Railgun Unshield Fee + B402 Protocol Fees
 *
 * All math uses BigInt exclusively — zero floating point.
 *
 * b402 Railgun fork has 0% unshield fee (upstream Railgun charges 0.25%).
 * B402 charges a tiered protocol fee: base ($0.05) + volume tier (5-10 bps).
 */
import type { FeeBreakdown, FeeTier } from '../types';
/**
 * Calculate the gross unshield amount needed so that after Railgun's fee,
 * the net amount equals `desiredNetAmount`.
 *
 * Formula: gross = ceil(desired * 10000 / (10000 - feeBps))
 *
 * @param desiredNetAmount - Amount you want AFTER the fee (in token's smallest unit)
 * @param feeBps - Fee in basis points (default: 0 on b402 fork)
 * @returns Gross amount to unshield
 */
export declare function calculateUnshieldAmount(desiredNetAmount: bigint, feeBps?: bigint): bigint;
/**
 * Calculate the net amount after Railgun's unshield fee is deducted.
 *
 * Formula: net = gross * (10000 - feeBps) / 10000
 *
 * @param grossAmount - Amount being unshielded (before fee)
 * @param feeBps - Fee in basis points (default: 0 on b402 fork)
 * @returns Net amount after fee deduction
 */
export declare function calculateNetAfterUnshieldFee(grossAmount: bigint, feeBps?: bigint): bigint;
/**
 * Determine the fee tier based on the USD value of the amount.
 *
 * Tiers (from base-volume-loop-gasless-v2.ts):
 * - small:  < $1,000  → 5 bps (0.05%)
 * - medium: $1k-$10k  → 8 bps (0.08%)
 * - large:  > $10,000 → 10 bps (0.10%)
 *
 * @param amount - Amount in token's smallest unit
 * @param decimals - Token decimals (6 for USDC, 18 for WETH)
 * @returns Fee tier
 */
export declare function getFeeTier(amount: bigint, decimals: number): FeeTier;
/**
 * Calculate the B402 protocol fee for a given amount.
 *
 * Fee = baseFee + volumeFee
 * - baseFee: flat $0.05 (in token's smallest unit)
 * - volumeFee: amount * tierBps / 10000
 *
 * @param amount - Amount in token's smallest unit
 * @param decimals - Token decimals (6 for USDC, 18 for WETH)
 * @returns Fee breakdown with total, base, volume, and tier rate
 */
export declare function calculateB402Fee(amount: bigint, decimals: number): FeeBreakdown;