/**
 * Spend Policy Encoding & Verification
 *
 * Encodes human-readable spend policies into Bolyra's permission bitmask format
 * for ZKP circuit consumption. The encoded policy becomes a private input to the
 * AgentPolicy circuit — the verifier learns only that the policy is satisfied,
 * never the actual limits.
 *
 * Encoding scheme (fits in a single 253-bit BN254 scalar):
 *   Bits  0-2:   Base permission tier (from Bolyra Permission enum)
 *   Bits  3-6:   Amount tier (log-scale encoding of maxTransactionAmount)
 *   Bits  7-10:  Cumulative tier (log-scale encoding of maxCumulativeAmount)
 *   Bits 11-14:  Time window tier (duration bucket)
 *   Bits 15-22:  Category mask (top-8 MCC groups)
 *   Bits 23-30:  Vendor hash prefix (first 8 bits of Poseidon hash of vendor list)
 *   Bits 31-62:  Reserved for future extensions
 */
import type { SpendPolicy } from './types';
/**
 * Encode a spend policy into Bolyra's permission bitmask format.
 *
 * The resulting bigint can be used as the `permissionBitmask` field in an
 * AgentCredential, or as a private input to the AgentPolicy circuit.
 *
 * @param policy - The spend policy to encode
 * @returns The encoded permission bitmask (fits in 63 bits)
 */
export declare function encodeSpendPolicy(policy: SpendPolicy): bigint;
/**
 * Decode the permission tier from an encoded bitmask.
 */
export declare function decodePermissionTier(bitmask: bigint): number;
/**
 * Decode the amount tier from an encoded bitmask.
 */
export declare function decodeAmountTier(bitmask: bigint): number;
/**
 * Decode the cumulative tier from an encoded bitmask.
 */
export declare function decodeCumulativeTier(bitmask: bigint): number;
/**
 * Decode the time window tier from an encoded bitmask.
 */
export declare function decodeTimeTier(bitmask: bigint): number;
/**
 * Decode the category mask from an encoded bitmask.
 */
export declare function decodeCategoryMask(bitmask: bigint): number;
/**
 * Verify that a ZKP-proven spend policy meets a required policy.
 *
 * This is the merchant-side check: given the encoded bitmask from the agent's
 * ZKP proof (public signal), verify it satisfies the merchant's requirements.
 * The merchant never learns the actual policy — only that it is sufficient.
 *
 * @param provenBitmask - The permission bitmask from the ZKP public signals
 * @param requiredPolicy - The merchant's minimum required policy
 * @returns Object with `satisfied` boolean and human-readable `reasons` for failures
 */
export declare function verifySpendPolicyProof(provenBitmask: bigint, requiredPolicy: {
    minTransactionAmount?: number;
    minCumulativeAmount?: number;
    minDurationSeconds?: number;
    requiredMCCs?: string[];
}): {
    satisfied: boolean;
    reasons: string[];
};
/**
 * Get the amount tier thresholds (useful for UI display).
 */
export declare function getAmountTiers(): readonly number[];
/**
 * Get the time window tier thresholds (useful for UI display).
 */
export declare function getTimeWindowTiers(): readonly number[];