import type { Address } from "@morpho-org/blue-sdk";
import { type ERC20ApprovalAction, type Transaction } from "../../types/index.js";
/**
 * Computes classic ERC-20 approval transactions for a supported SDK spender, given the existing
 * allowance.
 *
 * The spender is validated by {@link encodeErc20Approval}. Supported spenders are the chain's
 * GeneralAdapter1, Permit2, Midnight, MidnightBundles, and VaultExitBundlesV1 addresses when
 * configured.
 *
 * Returns an empty array when the allowance already covers `spendAmount`. When the token is in
 * `APPROVE_ONLY_ONCE_TOKENS` (e.g. USDT) and the existing allowance is non-zero, prepends a
 * `approve(spender, 0)` reset transaction to satisfy those tokens' allowance-must-be-zero rule
 * before re-approving.
 *
 * @param params.address - ERC-20 token address.
 * @param params.chainId - The chain the transaction targets, used to resolve supported spenders
 *   and token approval caps.
 * @param params.args.spendAmount - The amount the bundle will actually pull.
 * @param params.args.approvalAmount - The amount to approve (often equal to `spendAmount`, but
 *   may be `MAX_UINT_160` for Permit2 prerequisites).
 * @param params.args.spender - Address that will be granted the approval. Must be GeneralAdapter1,
 *   Permit2, Midnight, MidnightBundles, or VaultExitBundlesV1 for `chainId`.
 * @param params.allowances - The user's current allowance of `address` for `spender`.
 * @returns Up to two deep-frozen `Transaction<ERC20ApprovalAction>` entries: an optional reset
 *   followed by the new approval. Empty when no approval is needed.
 * @throws {ApprovalAmountLessThanSpendAmountError} when `approvalAmount < spendAmount`.
 * @throws {UnsupportedErc20ApprovalSpenderError} when `spender` is not a supported SDK spender for `chainId`.
 * @example
 * ```ts
 * import { getRequirementsApproval } from "@morpho-org/morpho-sdk";
 *
 * const txs = getRequirementsApproval({
 *   address: USDC,
 *   chainId: 1,
 *   args: { approvalAmount: 1_000_000n, spendAmount: 1_000_000n, spender: generalAdapter1 },
 *   allowances: 0n,
 * });
 * // txs satisfies Readonly<Transaction<ERC20ApprovalAction>>[]
 * ```
 */
export declare const getRequirementsApproval: (params: {
    address: Address;
    chainId: number;
    args: {
        approvalAmount: bigint;
        spendAmount: bigint;
        spender: Address;
    };
    allowances: bigint;
}) => Readonly<Transaction<ERC20ApprovalAction>>[];