// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (access/Ownable.sol)
pragma solidity ^0.8.0;
import "../utils/Context.sol";
/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract Ownable is Context {
    address private _owner;
    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor() {
        _transferOwnership(_msgSender());
    }
    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        _checkOwner();
        _;
    }
    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }
    /**
     * @dev Throws if the sender is not the owner.
     */
    function _checkOwner() internal view virtual {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
    }
    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby disabling any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }
    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _transferOwnership(newOwner);
    }
    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/extensions/IERC20Permit.sol)
pragma solidity ^0.8.0;
/**
 * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
 * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
 *
 * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
 * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't
 * need to send a transaction, and thus is not required to hold Ether at all.
 */
interface IERC20Permit {
    /**
     * @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,
     * given ``owner``'s signed approval.
     *
     * IMPORTANT: The same issues {IERC20-approve} has related to transaction
     * ordering also apply here.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `deadline` must be a timestamp in the future.
     * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
     * over the EIP712-formatted function arguments.
     * - the signature must use ``owner``'s current nonce (see {nonces}).
     *
     * For more information on the signature format, see the
     * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
     * section].
     */
    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;
    /**
     * @dev Returns the current nonce for `owner`. This value must be
     * included whenever a signature is generated for {permit}.
     *
     * Every successful call to {permit} increases ``owner``'s nonce by one. This
     * prevents a signature from being used multiple times.
     */
    function nonces(address owner) external view returns (uint256);
    /**
     * @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.
     */
    // solhint-disable-next-line func-name-mixedcase
    function DOMAIN_SEPARATOR() external view returns (bytes32);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/IERC20.sol)
pragma solidity ^0.8.0;
/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);
    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);
    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);
    /**
     * @dev Moves `amount` tokens from the caller's account to `to`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address to, uint256 amount) external returns (bool);
    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);
    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);
    /**
     * @dev Moves `amount` tokens from `from` to `to` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(address from, address to, uint256 amount) external returns (bool);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/utils/SafeERC20.sol)
pragma solidity ^0.8.0;
import "../IERC20.sol";
import "../extensions/IERC20Permit.sol";
import "../../../utils/Address.sol";
/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    using Address for address;
    /**
     * @dev Transfer `value` amount of `token` from the calling contract to `to`. If `token` returns no value,
     * non-reverting calls are assumed to be successful.
     */
    function safeTransfer(IERC20 token, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }
    /**
     * @dev Transfer `value` amount of `token` from `from` to `to`, spending the approval given by `from` to the
     * calling contract. If `token` returns no value, non-reverting calls are assumed to be successful.
     */
    function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }
    /**
     * @dev Deprecated. This function has issues similar to the ones found in
     * {IERC20-approve}, and its usage is discouraged.
     *
     * Whenever possible, use {safeIncreaseAllowance} and
     * {safeDecreaseAllowance} instead.
     */
    function safeApprove(IERC20 token, address spender, uint256 value) internal {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        require(
            (value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }
    /**
     * @dev Increase the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful.
     */
    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 oldAllowance = token.allowance(address(this), spender);
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance + value));
    }
    /**
     * @dev Decrease the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful.
     */
    function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        unchecked {
            uint256 oldAllowance = token.allowance(address(this), spender);
            require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance - value));
        }
    }
    /**
     * @dev Set the calling contract's allowance toward `spender` to `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful. Compatible with tokens that require the approval to be set to
     * 0 before setting it to a non-zero value.
     */
    function forceApprove(IERC20 token, address spender, uint256 value) internal {
        bytes memory approvalCall = abi.encodeWithSelector(token.approve.selector, spender, value);
        if (!_callOptionalReturnBool(token, approvalCall)) {
            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, 0));
            _callOptionalReturn(token, approvalCall);
        }
    }
    /**
     * @dev Use a ERC-2612 signature to set the `owner` approval toward `spender` on `token`.
     * Revert on invalid signature.
     */
    function safePermit(
        IERC20Permit token,
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) internal {
        uint256 nonceBefore = token.nonces(owner);
        token.permit(owner, spender, value, deadline, v, r, s);
        uint256 nonceAfter = token.nonces(owner);
        require(nonceAfter == nonceBefore + 1, "SafeERC20: permit did not succeed");
    }
    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We use {Address-functionCall} to perform this call, which verifies that
        // the target address contains contract code and also asserts for success in the low-level call.
        bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
        require(returndata.length == 0 || abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
    }
    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     *
     * This is a variant of {_callOptionalReturn} that silents catches all reverts and returns a bool instead.
     */
    function _callOptionalReturnBool(IERC20 token, bytes memory data) private returns (bool) {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We cannot use {Address-functionCall} here since this should return false
        // and not revert is the subcall reverts.
        (bool success, bytes memory returndata) = address(token).call(data);
        return
            success && (returndata.length == 0 || abi.decode(returndata, (bool))) && Address.isContract(address(token));
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (utils/Address.sol)
pragma solidity ^0.8.1;
/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     *
     * Furthermore, `isContract` will also return true if the target contract within
     * the same transaction is already scheduled for destruction by `SELFDESTRUCT`,
     * which only has an effect at the end of a transaction.
     * ====
     *
     * [IMPORTANT]
     * ====
     * You shouldn't rely on `isContract` to protect against flash loan attacks!
     *
     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
     * constructor.
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize/address.code.length, which returns 0
        // for contracts in construction, since the code is only stored at the end
        // of the constructor execution.
        return account.code.length > 0;
    }
    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://consensys.net/diligence/blog/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.8.0/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");
        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }
    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain `call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, "Address: low-level call failed");
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }
    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }
    /**
     * @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
     * the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
     *
     * _Available since v4.8._
     */
    function verifyCallResultFromTarget(
        address target,
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        if (success) {
            if (returndata.length == 0) {
                // only check isContract if the call was successful and the return data is empty
                // otherwise we already know that it was a contract
                require(isContract(target), "Address: call to non-contract");
            }
            return returndata;
        } else {
            _revert(returndata, errorMessage);
        }
    }
    /**
     * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason or using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            _revert(returndata, errorMessage);
        }
    }
    function _revert(bytes memory returndata, string memory errorMessage) private pure {
        // Look for revert reason and bubble it up if present
        if (returndata.length > 0) {
            // The easiest way to bubble the revert reason is using memory via assembly
            /// @solidity memory-safe-assembly
            assembly {
                let returndata_size := mload(returndata)
                revert(add(32, returndata), returndata_size)
            }
        } else {
            revert(errorMessage);
        }
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
pragma solidity ^0.8.0;
/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }
    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}
// SPDX-License-Identifier: BUSL-1.1
pragma solidity ^0.8.17;
interface IesLBR {
    function totalSupply() external view returns (uint256);
    function balanceOf(address account) external view returns (uint256);
    function mint(address user, uint256 amount) external returns(bool);
    function burn(address user, uint256 amount) external returns(bool);
    function getPastVotes(address account, uint256 timepoint) external view returns (uint256);
    function getPastTotalSupply(uint256 timepoint) external view returns (uint256);
}// SPDX-License-Identifier: MIT
pragma solidity ^0.8.17;
import "@openzeppelin/contracts/access/Ownable.sol";
import "../interfaces/IesLBR.sol";
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
interface IesLBRBoost {
    function getUserBoost(
        address user,
        uint256 userUpdatedAt,
        uint256 finishAt
    ) external view returns (uint256);
}
contract StakingRewardsV2 is Ownable {
    using SafeERC20 for IERC20;
    // Immutable variables for staking and rewards tokens
    IERC20 public immutable stakingToken;
    IesLBR public immutable rewardsToken;
    IesLBRBoost public esLBRBoost;
    // Duration of rewards to be paid out (in seconds)
    uint256 public duration = 604_800;
    // Timestamp of when the rewards finish
    uint256 public finishAt;
    // Minimum of last updated time and reward finish time
    uint256 public updatedAt;
    // Reward to be paid out per second
    uint256 public rewardRatio;
    // Sum of (reward ratio * dt * 1e18 / total supply)
    uint256 public rewardPerTokenStored;
    // User address => rewardPerTokenStored
    mapping(address => uint256) public userRewardPerTokenPaid;
    // User address => rewards to be claimed
    mapping(address => uint256) public rewards;
    mapping(address => uint256) public userUpdatedAt;
    // Total staked
    uint256 public totalSupply;
    // User address => staked amount
    mapping(address => uint256) public balanceOf;
    ///events
    event StakeToken(address indexed user, uint256 amount, uint256 time);
    event WithdrawToken(address indexed user, uint256 amount, uint256 time);
    event ClaimReward(address indexed user, uint256 amount, uint256 time);
    event NotifyRewardChanged(uint256 addAmount, uint256 time);
    event DurationChanged(uint256 duration, uint256 time);
    event BoostChanged(address boostAddr, uint256 time);
    constructor(address _stakingToken, address _rewardToken, address _boost) {
        stakingToken = IERC20(_stakingToken);
        rewardsToken = IesLBR(_rewardToken);
        esLBRBoost = IesLBRBoost(_boost);
    }
    // Update user's claimable reward data and record the timestamp.
    modifier updateReward(address _account) {
        rewardPerTokenStored = rewardPerToken();
        updatedAt = lastTimeRewardApplicable();
        if (_account != address(0)) {
            rewards[_account] = earned(_account);
            userRewardPerTokenPaid[_account] = rewardPerTokenStored;
            userUpdatedAt[_account] = block.timestamp;
        }
        _;
    }
    // Returns the last time the reward was applicable
    function lastTimeRewardApplicable() public view returns (uint256) {
        return _min(finishAt, block.timestamp);
    }
    // Calculates and returns the reward per token
    function rewardPerToken() public view returns (uint256) {
        if (totalSupply == 0) {
            return rewardPerTokenStored;
        }
        return rewardPerTokenStored + (rewardRatio * (lastTimeRewardApplicable() - updatedAt) * 1e18) / totalSupply;
    }
    // Allows users to stake a specified amount of tokens
    function stake(uint256 _amount) external updateReward(msg.sender) {
        require(_amount != 0, "amount = 0");
        stakingToken.safeTransferFrom(msg.sender, address(this), _amount);
        balanceOf[msg.sender] += _amount;
        totalSupply += _amount;
        emit StakeToken(msg.sender, _amount, block.timestamp);
    }
    // Allows users to withdraw a specified amount of staked tokens
    function withdraw(uint256 _amount) external updateReward(msg.sender) {
        require(_amount != 0, "amount = 0");
        balanceOf[msg.sender] -= _amount;
        totalSupply -= _amount;
        stakingToken.safeTransfer(msg.sender, _amount);
        emit WithdrawToken(msg.sender, _amount, block.timestamp);
    }
    function getBoost(address _account) public view returns (uint256) {
        return 100 * 1e18 + esLBRBoost.getUserBoost(_account, userUpdatedAt[_account], finishAt);
    }
    // Calculates and returns the earned rewards for a user
    function earned(address _account) public view returns (uint256) {
        return ((balanceOf[_account] * getBoost(_account) * (rewardPerToken() - userRewardPerTokenPaid[_account])) / 1e38) + rewards[_account];
    }
    // Allows users to claim their earned rewards
    function getReward() external updateReward(msg.sender) {
        uint256 reward = rewards[msg.sender];
        if (reward > 0) {
            rewards[msg.sender] = 0;
            rewardsToken.mint(msg.sender, reward);
            emit ClaimReward(msg.sender, reward, block.timestamp);
        }
    }
    // Allows the owner to set the rewards duration
    function setRewardsDuration(uint256 _duration) external onlyOwner {
        require(finishAt < block.timestamp, "reward duration not finished");
        duration = _duration;
        emit DurationChanged(_duration, block.timestamp);
    }
    // Allows the owner to set the boost contract address
    function setBoost(address _boost) external onlyOwner {
        esLBRBoost = IesLBRBoost(_boost);
        emit BoostChanged(_boost, block.timestamp);
    }
    // Allows the owner to set the mining rewards.
    function notifyRewardAmount(uint256 _amount) external onlyOwner updateReward(address(0)) {
        if (block.timestamp >= finishAt) {
            rewardRatio = _amount / duration;
        } else {
            uint256 remainingRewards = (finishAt - block.timestamp) * rewardRatio;
            rewardRatio = (_amount + remainingRewards) / duration;
        }
        require(rewardRatio != 0, "reward ratio = 0");
        finishAt = block.timestamp + duration;
        updatedAt = block.timestamp;
        emit NotifyRewardChanged(_amount, block.timestamp);
    }
    function _min(uint256 x, uint256 y) private pure returns (uint256) {
        return x <= y ? x : y;
    }
}

# @version 0.2.15
"""
@title StableSwap
@author Curve.Fi
@license Copyright (c) Curve.Fi, 2020-2021 - all rights reserved
@notice 3pool metapool implementation contract
@dev ERC20 support for return True/revert, return True/False, return None
"""

interface ERC20:
    def approve(_spender: address, _amount: uint256): nonpayable
    def balanceOf(_owner: address) -> uint256: view

interface Curve:
    def coins(i: uint256) -> address: view
    def get_virtual_price() -> uint256: view
    def calc_token_amount(amounts: uint256[BASE_N_COINS], deposit: bool) -> uint256: view
    def calc_withdraw_one_coin(_token_amount: uint256, i: int128) -> uint256: view
    def fee() -> uint256: view
    def get_dy(i: int128, j: int128, dx: uint256) -> uint256: view
    def exchange(i: int128, j: int128, dx: uint256, min_dy: uint256): nonpayable
    def add_liquidity(amounts: uint256[BASE_N_COINS], min_mint_amount: uint256): nonpayable
    def remove_liquidity_one_coin(_token_amount: uint256, i: int128, min_amount: uint256): nonpayable

interface Factory:
    def convert_metapool_fees() -> bool: nonpayable
    def get_fee_receiver(_pool: address) -> address: view
    def admin() -> address: view


event Transfer:
    sender: indexed(address)
    receiver: indexed(address)
    value: uint256

event Approval:
    owner: indexed(address)
    spender: indexed(address)
    value: uint256

event TokenExchange:
    buyer: indexed(address)
    sold_id: int128
    tokens_sold: uint256
    bought_id: int128
    tokens_bought: uint256

event TokenExchangeUnderlying:
    buyer: indexed(address)
    sold_id: int128
    tokens_sold: uint256
    bought_id: int128
    tokens_bought: uint256

event AddLiquidity:
    provider: indexed(address)
    token_amounts: uint256[N_COINS]
    fees: uint256[N_COINS]
    invariant: uint256
    token_supply: uint256

event RemoveLiquidity:
    provider: indexed(address)
    token_amounts: uint256[N_COINS]
    fees: uint256[N_COINS]
    token_supply: uint256

event RemoveLiquidityOne:
    provider: indexed(address)
    token_amount: uint256
    coin_amount: uint256
    token_supply: uint256

event RemoveLiquidityImbalance:
    provider: indexed(address)
    token_amounts: uint256[N_COINS]
    fees: uint256[N_COINS]
    invariant: uint256
    token_supply: uint256

event RampA:
    old_A: uint256
    new_A: uint256
    initial_time: uint256
    future_time: uint256

event StopRampA:
    A: uint256
    t: uint256


BASE_POOL: constant(address) = 0xbEbc44782C7dB0a1A60Cb6fe97d0b483032FF1C7
BASE_COINS: constant(address[3]) = [
    0x6B175474E89094C44Da98b954EedeAC495271d0F,  # DAI
    0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48,  # USDC
    0xdAC17F958D2ee523a2206206994597C13D831ec7,  # USDT
]

N_COINS: constant(int128) = 2
MAX_COIN: constant(int128) = N_COINS - 1
BASE_N_COINS: constant(int128) = 3
PRECISION: constant(uint256) = 10 ** 18

FEE_DENOMINATOR: constant(uint256) = 10 ** 10
ADMIN_FEE: constant(uint256) = 5000000000

A_PRECISION: constant(uint256) = 100
MAX_A: constant(uint256) = 10 ** 6
MAX_A_CHANGE: constant(uint256) = 10
MIN_RAMP_TIME: constant(uint256) = 86400

factory: address

coins: public(address[N_COINS])
balances: public(uint256[N_COINS])
fee: public(uint256)  # fee * 1e10

initial_A: public(uint256)
future_A: public(uint256)
initial_A_time: public(uint256)
future_A_time: public(uint256)

rate_multiplier: uint256

name: public(String[64])
symbol: public(String[32])

balanceOf: public(HashMap[address, uint256])
allowance: public(HashMap[address, HashMap[address, uint256]])
totalSupply: public(uint256)


@external
def __init__():
    # we do this to prevent the implementation contract from being used as a pool
    self.fee = 31337


@external
def initialize(
    _name: String[32],
    _symbol: String[10],
    _coin: address,
    _rate_multiplier: uint256,
    _A: uint256,
    _fee: uint256
):
    """
    @notice Contract initializer
    @param _name Name of the new pool
    @param _symbol Token symbol
    @param _coin Addresses of ERC20 conracts of coins
    @param _rate_multiplier Rate multiplier for `_coin` (10 ** (36 - decimals))
    @param _A Amplification coefficient multiplied by n ** (n - 1)
    @param _fee Fee to charge for exchanges
    """
    # check if fee was already set to prevent initializing contract twice
    assert self.fee == 0

    A: uint256 = _A * A_PRECISION
    self.coins = [_coin, 0x6c3F90f043a72FA612cbac8115EE7e52BDe6E490]
    self.rate_multiplier = _rate_multiplier
    self.initial_A = A
    self.future_A = A
    self.fee = _fee
    self.factory = msg.sender

    self.name = concat("Curve.fi Factory USD Metapool: ", _name)
    self.symbol = concat(_symbol, "3CRV-f")

    for coin in BASE_COINS:
        ERC20(coin).approve(BASE_POOL, MAX_UINT256)

    # fire a transfer event so block explorers identify the contract as an ERC20
    log Transfer(ZERO_ADDRESS, self, 0)


### ERC20 Functionality ###

@view
@external
def decimals() -> uint256:
    """
    @notice Get the number of decimals for this token
    @dev Implemented as a view method to reduce gas costs
    @return uint256 decimal places
    """
    return 18


@internal
def _transfer(_from: address, _to: address, _value: uint256):
    # # NOTE: vyper does not allow underflows
    # #       so the following subtraction would revert on insufficient balance
    self.balanceOf[_from] -= _value
    self.balanceOf[_to] += _value

    log Transfer(_from, _to, _value)


@external
def transfer(_to : address, _value : uint256) -> bool:
    """
    @dev Transfer token for a specified address
    @param _to The address to transfer to.
    @param _value The amount to be transferred.
    """
    self._transfer(msg.sender, _to, _value)
    return True


@external
def transferFrom(_from : address, _to : address, _value : uint256) -> bool:
    """
     @dev Transfer tokens from one address to another.
     @param _from address The address which you want to send tokens from
     @param _to address The address which you want to transfer to
     @param _value uint256 the amount of tokens to be transferred
    """
    self._transfer(_from, _to, _value)

    _allowance: uint256 = self.allowance[_from][msg.sender]
    if _allowance != MAX_UINT256:
        self.allowance[_from][msg.sender] = _allowance - _value

    return True


@external
def approve(_spender : address, _value : uint256) -> bool:
    """
    @notice Approve the passed address to transfer the specified amount of
            tokens on behalf of msg.sender
    @dev Beware that changing an allowance via this method brings the risk that
         someone may use both the old and new allowance by unfortunate transaction
         ordering: https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
    @param _spender The address which will transfer the funds
    @param _value The amount of tokens that may be transferred
    @return bool success
    """
    self.allowance[msg.sender][_spender] = _value

    log Approval(msg.sender, _spender, _value)
    return True


### StableSwap Functionality ###

@view
@internal
def _A() -> uint256:
    """
    Handle ramping A up or down
    """
    t1: uint256 = self.future_A_time
    A1: uint256 = self.future_A

    if block.timestamp < t1:
        A0: uint256 = self.initial_A
        t0: uint256 = self.initial_A_time
        # Expressions in uint256 cannot have negative numbers, thus "if"
        if A1 > A0:
            return A0 + (A1 - A0) * (block.timestamp - t0) / (t1 - t0)
        else:
            return A0 - (A0 - A1) * (block.timestamp - t0) / (t1 - t0)

    else:  # when t1 == 0 or block.timestamp >= t1
        return A1


@view
@external
def admin_fee() -> uint256:
    return ADMIN_FEE


@view
@external
def A() -> uint256:
    return self._A() / A_PRECISION


@view
@external
def A_precise() -> uint256:
    return self._A()


@pure
@internal
def _xp_mem(_rates: uint256[N_COINS], _balances: uint256[N_COINS]) -> uint256[N_COINS]:
    result: uint256[N_COINS] = empty(uint256[N_COINS])
    for i in range(N_COINS):
        result[i] = _rates[i] * _balances[i] / PRECISION
    return result


@pure
@internal
def get_D(_xp: uint256[N_COINS], _amp: uint256) -> uint256:
    """
    D invariant calculation in non-overflowing integer operations
    iteratively

    A * sum(x_i) * n**n + D = A * D * n**n + D**(n+1) / (n**n * prod(x_i))

    Converging solution:
    D[j+1] = (A * n**n * sum(x_i) - D[j]**(n+1) / (n**n prod(x_i))) / (A * n**n - 1)
    """
    S: uint256 = 0
    Dprev: uint256 = 0
    for x in _xp:
        S += x
    if S == 0:
        return 0

    D: uint256 = S
    Ann: uint256 = _amp * N_COINS
    for i in range(255):
        D_P: uint256 = D
        for x in _xp:
            D_P = D_P * D / (x * N_COINS)  # If division by 0, this will be borked: only withdrawal will work. And that is good
        Dprev = D
        D = (Ann * S / A_PRECISION + D_P * N_COINS) * D / ((Ann - A_PRECISION) * D / A_PRECISION + (N_COINS + 1) * D_P)
        # Equality with the precision of 1
        if D > Dprev:
            if D - Dprev <= 1:
                return D
        else:
            if Dprev - D <= 1:
                return D
    # convergence typically occurs in 4 rounds or less, this should be unreachable!
    # if it does happen the pool is borked and LPs can withdraw via `remove_liquidity`
    raise


@view
@internal
def get_D_mem(_rates: uint256[N_COINS], _balances: uint256[N_COINS], _amp: uint256) -> uint256:
    xp: uint256[N_COINS] = self._xp_mem(_rates, _balances)
    return self.get_D(xp, _amp)


@view
@external
def get_virtual_price() -> uint256:
    """
    @notice The current virtual price of the pool LP token
    @dev Useful for calculating profits
    @return LP token virtual price normalized to 1e18
    """
    amp: uint256 = self._A()
    rates: uint256[N_COINS] = [self.rate_multiplier, Curve(BASE_POOL).get_virtual_price()]
    xp: uint256[N_COINS] = self._xp_mem(rates, self.balances)
    D: uint256 = self.get_D(xp, amp)
    # D is in the units similar to DAI (e.g. converted to precision 1e18)
    # When balanced, D = n * x_u - total virtual value of the portfolio
    return D * PRECISION / self.totalSupply


@view
@external
def calc_token_amount(_amounts: uint256[N_COINS], _is_deposit: bool) -> uint256:
    """
    @notice Calculate addition or reduction in token supply from a deposit or withdrawal
    @dev This calculation accounts for slippage, but not fees.
         Needed to prevent front-running, not for precise calculations!
    @param _amounts Amount of each coin being deposited
    @param _is_deposit set True for deposits, False for withdrawals
    @return Expected amount of LP tokens received
    """
    amp: uint256 = self._A()
    rates: uint256[N_COINS] = [self.rate_multiplier, Curve(BASE_POOL).get_virtual_price()]
    balances: uint256[N_COINS] = self.balances

    D0: uint256 = self.get_D_mem(rates, balances, amp)
    for i in range(N_COINS):
        amount: uint256 = _amounts[i]
        if _is_deposit:
            balances[i] += amount
        else:
            balances[i] -= amount
    D1: uint256 = self.get_D_mem(rates, balances, amp)
    diff: uint256 = 0
    if _is_deposit:
        diff = D1 - D0
    else:
        diff = D0 - D1
    return diff * self.totalSupply / D0


@external
@nonreentrant('lock')
def add_liquidity(
    _amounts: uint256[N_COINS],
    _min_mint_amount: uint256,
    _receiver: address = msg.sender
) -> uint256:
    """
    @notice Deposit coins into the pool
    @param _amounts List of amounts of coins to deposit
    @param _min_mint_amount Minimum amount of LP tokens to mint from the deposit
    @param _receiver Address that owns the minted LP tokens
    @return Amount of LP tokens received by depositing
    """
    amp: uint256 = self._A()
    rates: uint256[N_COINS] = [self.rate_multiplier, Curve(BASE_POOL).get_virtual_price()]

    # Initial invariant
    old_balances: uint256[N_COINS] = self.balances
    D0: uint256 = self.get_D_mem(rates, old_balances, amp)
    new_balances: uint256[N_COINS] = old_balances

    total_supply: uint256 = self.totalSupply
    for i in range(N_COINS):
        amount: uint256 = _amounts[i]
        if amount == 0:
            assert total_supply > 0
        else:
            response: Bytes[32] = raw_call(
                self.coins[i],
                concat(
                    method_id("transferFrom(address,address,uint256)"),
                    convert(msg.sender, bytes32),
                    convert(self, bytes32),
                    convert(amount, bytes32),
                ),
                max_outsize=32,
            )
            if len(response) > 0:
                assert convert(response, bool)
            new_balances[i] += amount

    # Invariant after change
    D1: uint256 = self.get_D_mem(rates, new_balances, amp)
    assert D1 > D0

    # We need to recalculate the invariant accounting for fees
    # to calculate fair user's share
    fees: uint256[N_COINS] = empty(uint256[N_COINS])
    mint_amount: uint256 = 0
    if total_supply > 0:
        # Only account for fees if we are not the first to deposit
        base_fee: uint256 = self.fee * N_COINS / (4 * (N_COINS - 1))
        for i in range(N_COINS):
            ideal_balance: uint256 = D1 * old_balances[i] / D0
            difference: uint256 = 0
            new_balance: uint256 = new_balances[i]
            if ideal_balance > new_balance:
                difference = ideal_balance - new_balance
            else:
                difference = new_balance - ideal_balance
            fees[i] = base_fee * difference / FEE_DENOMINATOR
            self.balances[i] = new_balance - (fees[i] * ADMIN_FEE / FEE_DENOMINATOR)
            new_balances[i] -= fees[i]
        D2: uint256 = self.get_D_mem(rates, new_balances, amp)
        mint_amount = total_supply * (D2 - D0) / D0
    else:
        self.balances = new_balances
        mint_amount = D1  # Take the dust if there was any

    assert mint_amount >= _min_mint_amount

    # Mint pool tokens
    total_supply += mint_amount
    self.balanceOf[_receiver] += mint_amount
    self.totalSupply = total_supply
    log Transfer(ZERO_ADDRESS, _receiver, mint_amount)
    log AddLiquidity(msg.sender, _amounts, fees, D1, total_supply)

    return mint_amount


@view
@internal
def get_y(i: int128, j: int128, x: uint256, xp: uint256[N_COINS]) -> uint256:
    # x in the input is converted to the same price/precision

    assert i != j       # dev: same coin
    assert j >= 0       # dev: j below zero
    assert j < N_COINS  # dev: j above N_COINS

    # should be unreachable, but good for safety
    assert i >= 0
    assert i < N_COINS

    amp: uint256 = self._A()
    D: uint256 = self.get_D(xp, amp)
    S_: uint256 = 0
    _x: uint256 = 0
    y_prev: uint256 = 0
    c: uint256 = D
    Ann: uint256 = amp * N_COINS

    for _i in range(N_COINS):
        if _i == i:
            _x = x
        elif _i != j:
            _x = xp[_i]
        else:
            continue
        S_ += _x
        c = c * D / (_x * N_COINS)

    c = c * D * A_PRECISION / (Ann * N_COINS)
    b: uint256 = S_ + D * A_PRECISION / Ann  # - D
    y: uint256 = D

    for _i in range(255):
        y_prev = y
        y = (y*y + c) / (2 * y + b - D)
        # Equality with the precision of 1
        if y > y_prev:
            if y - y_prev <= 1:
                return y
        else:
            if y_prev - y <= 1:
                return y
    raise


@view
@external
def get_dy(i: int128, j: int128, dx: uint256) -> uint256:
    """
    @notice Calculate the current output dy given input dx
    @dev Index values can be found via the `coins` public getter method
    @param i Index value for the coin to send
    @param j Index valie of the coin to recieve
    @param dx Amount of `i` being exchanged
    @return Amount of `j` predicted
    """
    rates: uint256[N_COINS] = [self.rate_multiplier, Curve(BASE_POOL).get_virtual_price()]
    xp: uint256[N_COINS] = self._xp_mem(rates, self.balances)

    x: uint256 = xp[i] + (dx * rates[i] / PRECISION)
    y: uint256 = self.get_y(i, j, x, xp)
    dy: uint256 = xp[j] - y - 1
    fee: uint256 = self.fee * dy / FEE_DENOMINATOR
    return (dy - fee) * PRECISION / rates[j]


@view
@external
def get_dy_underlying(i: int128, j: int128, dx: uint256) -> uint256:
    """
    @notice Calculate the current output dy given input dx on underlying
    @dev Index values can be found via the `coins` public getter method
    @param i Index value for the coin to send
    @param j Index valie of the coin to recieve
    @param dx Amount of `i` being exchanged
    @return Amount of `j` predicted
    """
    rates: uint256[N_COINS] = [self.rate_multiplier, Curve(BASE_POOL).get_virtual_price()]
    xp: uint256[N_COINS] = self._xp_mem(rates, self.balances)

    x: uint256 = 0
    base_i: int128 = 0
    base_j: int128 = 0
    meta_i: int128 = 0
    meta_j: int128 = 0

    if i != 0:
        base_i = i - MAX_COIN
        meta_i = 1
    if j != 0:
        base_j = j - MAX_COIN
        meta_j = 1

    if i == 0:
        x = xp[i] + dx * (rates[0] / 10**18)
    else:
        if j == 0:
            # i is from BasePool
            # At first, get the amount of pool tokens
            base_inputs: uint256[BASE_N_COINS] = empty(uint256[BASE_N_COINS])
            base_inputs[base_i] = dx
            # Token amount transformed to underlying "dollars"
            x = Curve(BASE_POOL).calc_token_amount(base_inputs, True) * rates[1] / PRECISION
            # Accounting for deposit/withdraw fees approximately
            x -= x * Curve(BASE_POOL).fee() / (2 * FEE_DENOMINATOR)
            # Adding number of pool tokens
            x += xp[MAX_COIN]
        else:
            # If both are from the base pool
            return Curve(BASE_POOL).get_dy(base_i, base_j, dx)

    # This pool is involved only when in-pool assets are used
    y: uint256 = self.get_y(meta_i, meta_j, x, xp)
    dy: uint256 = xp[meta_j] - y - 1
    dy = (dy - self.fee * dy / FEE_DENOMINATOR)

    # If output is going via the metapool
    if j == 0:
        dy /= (rates[0] / 10**18)
    else:
        # j is from BasePool
        # The fee is already accounted for
        dy = Curve(BASE_POOL).calc_withdraw_one_coin(dy * PRECISION / rates[1], base_j)

    return dy


@external
@nonreentrant('lock')
def exchange(
    i: int128,
    j: int128,
    _dx: uint256,
    _min_dy: uint256,
    _receiver: address = msg.sender,
) -> uint256:
    """
    @notice Perform an exchange between two coins
    @dev Index values can be found via the `coins` public getter method
    @param i Index value for the coin to send
    @param j Index valie of the coin to recieve
    @param _dx Amount of `i` being exchanged
    @param _min_dy Minimum amount of `j` to receive
    @param _receiver Address that receives `j`
    @return Actual amount of `j` received
    """
    rates: uint256[N_COINS] = [self.rate_multiplier, Curve(BASE_POOL).get_virtual_price()]

    old_balances: uint256[N_COINS] = self.balances
    xp: uint256[N_COINS] = self._xp_mem(rates, old_balances)

    x: uint256 = xp[i] + _dx * rates[i] / PRECISION
    y: uint256 = self.get_y(i, j, x, xp)

    dy: uint256 = xp[j] - y - 1  # -1 just in case there were some rounding errors
    dy_fee: uint256 = dy * self.fee / FEE_DENOMINATOR

    # Convert all to real units
    dy = (dy - dy_fee) * PRECISION / rates[j]
    assert dy >= _min_dy

    dy_admin_fee: uint256 = dy_fee * ADMIN_FEE / FEE_DENOMINATOR
    dy_admin_fee = dy_admin_fee * PRECISION / rates[j]

    # Change balances exactly in same way as we change actual ERC20 coin amounts
    self.balances[i] = old_balances[i] + _dx
    # When rounding errors happen, we undercharge admin fee in favor of LP
    self.balances[j] = old_balances[j] - dy - dy_admin_fee

    response: Bytes[32] = raw_call(
        self.coins[i],
        concat(
            method_id("transferFrom(address,address,uint256)"),
            convert(msg.sender, bytes32),
            convert(self, bytes32),
            convert(_dx, bytes32),
        ),
        max_outsize=32,
    )
    if len(response) > 0:
        assert convert(response, bool)

    response = raw_call(
        self.coins[j],
        concat(
            method_id("transfer(address,uint256)"),
            convert(_receiver, bytes32),
            convert(dy, bytes32),
        ),
        max_outsize=32,
    )
    if len(response) > 0:
        assert convert(response, bool)

    log TokenExchange(msg.sender, i, _dx, j, dy)

    return dy


@external
@nonreentrant('lock')
def exchange_underlying(
    i: int128,
    j: int128,
    _dx: uint256,
    _min_dy: uint256,
    _receiver: address = msg.sender,
) -> uint256:
    """
    @notice Perform an exchange between two underlying coins
    @param i Index value for the underlying coin to send
    @param j Index valie of the underlying coin to receive
    @param _dx Amount of `i` being exchanged
    @param _min_dy Minimum amount of `j` to receive
    @param _receiver Address that receives `j`
    @return Actual amount of `j` received
    """
    rates: uint256[N_COINS] = [self.rate_multiplier, Curve(BASE_POOL).get_virtual_price()]
    old_balances: uint256[N_COINS] = self.balances
    xp: uint256[N_COINS] = self._xp_mem(rates, old_balances)

    base_coins: address[3] = BASE_COINS

    dy: uint256 = 0
    base_i: int128 = 0
    base_j: int128 = 0
    meta_i: int128 = 0
    meta_j: int128 = 0
    x: uint256 = 0
    input_coin: address = ZERO_ADDRESS
    output_coin: address = ZERO_ADDRESS

    if i == 0:
        input_coin = self.coins[0]
    else:
        base_i = i - MAX_COIN
        meta_i = 1
        input_coin = base_coins[base_i]
    if j == 0:
        output_coin = self.coins[0]
    else:
        base_j = j - MAX_COIN
        meta_j = 1
        output_coin = base_coins[base_j]

    response: Bytes[32] = raw_call(
        input_coin,
        concat(
            method_id("transferFrom(address,address,uint256)"),
            convert(msg.sender, bytes32),
            convert(self, bytes32),
            convert(_dx, bytes32),
        ),
        max_outsize=32,
    )
    if len(response) > 0:
        assert convert(response, bool)

    dx: uint256 = _dx
    if i == 0 or j == 0:
        if i == 0:
            x = xp[i] + dx * rates[i] / PRECISION
        else:
            # i is from BasePool
            # At first, get the amount of pool tokens
            base_inputs: uint256[BASE_N_COINS] = empty(uint256[BASE_N_COINS])
            base_inputs[base_i] = dx
            coin_i: address = self.coins[MAX_COIN]
            # Deposit and measure delta
            x = ERC20(coin_i).balanceOf(self)
            Curve(BASE_POOL).add_liquidity(base_inputs, 0)
            # Need to convert pool token to "virtual" units using rates
            # dx is also different now
            dx = ERC20(coin_i).balanceOf(self) - x
            x = dx * rates[MAX_COIN] / PRECISION
            # Adding number of pool tokens
            x += xp[MAX_COIN]

        y: uint256 = self.get_y(meta_i, meta_j, x, xp)

        # Either a real coin or token
        dy = xp[meta_j] - y - 1  # -1 just in case there were some rounding errors
        dy_fee: uint256 = dy * self.fee / FEE_DENOMINATOR

        # Convert all to real units
        # Works for both pool coins and real coins
        dy = (dy - dy_fee) * PRECISION / rates[meta_j]

        dy_admin_fee: uint256 = dy_fee * ADMIN_FEE / FEE_DENOMINATOR
        dy_admin_fee = dy_admin_fee * PRECISION / rates[meta_j]

        # Change balances exactly in same way as we change actual ERC20 coin amounts
        self.balances[meta_i] = old_balances[meta_i] + dx
        # When rounding errors happen, we undercharge admin fee in favor of LP
        self.balances[meta_j] = old_balances[meta_j] - dy - dy_admin_fee

        # Withdraw from the base pool if needed
        if j > 0:
            out_amount: uint256 = ERC20(output_coin).balanceOf(self)
            Curve(BASE_POOL).remove_liquidity_one_coin(dy, base_j, 0)
            dy = ERC20(output_coin).balanceOf(self) - out_amount

        assert dy >= _min_dy

    else:
        # If both are from the base pool
        dy = ERC20(output_coin).balanceOf(self)
        Curve(BASE_POOL).exchange(base_i, base_j, dx, _min_dy)
        dy = ERC20(output_coin).balanceOf(self) - dy

    response = raw_call(
        output_coin,
        concat(
            method_id("transfer(address,uint256)"),
            convert(_receiver, bytes32),
            convert(dy, bytes32),
        ),
        max_outsize=32,
    )
    if len(response) > 0:
        assert convert(response, bool)

    log TokenExchangeUnderlying(msg.sender, i, dx, j, dy)

    return dy


@external
@nonreentrant('lock')
def remove_liquidity(
    _burn_amount: uint256,
    _min_amounts: uint256[N_COINS],
    _receiver: address = msg.sender
) -> uint256[N_COINS]:
    """
    @notice Withdraw coins from the pool
    @dev Withdrawal amounts are based on current deposit ratios
    @param _burn_amount Quantity of LP tokens to burn in the withdrawal
    @param _min_amounts Minimum amounts of underlying coins to receive
    @param _receiver Address that receives the withdrawn coins
    @return List of amounts of coins that were withdrawn
    """
    total_supply: uint256 = self.totalSupply
    amounts: uint256[N_COINS] = empty(uint256[N_COINS])

    for i in range(N_COINS):
        old_balance: uint256 = self.balances[i]
        value: uint256 = old_balance * _burn_amount / total_supply
        assert value >= _min_amounts[i]
        self.balances[i] = old_balance - value
        amounts[i] = value
        response: Bytes[32] = raw_call(
            self.coins[i],
            concat(
                method_id("transfer(address,uint256)"),
                convert(_receiver, bytes32),
                convert(value, bytes32),
            ),
            max_outsize=32,
        )
        if len(response) > 0:
            assert convert(response, bool)


    total_supply -= _burn_amount
    self.balanceOf[msg.sender] -= _burn_amount
    self.totalSupply = total_supply
    log Transfer(msg.sender, ZERO_ADDRESS, _burn_amount)

    log RemoveLiquidity(msg.sender, amounts, empty(uint256[N_COINS]), total_supply)

    return amounts


@external
@nonreentrant('lock')
def remove_liquidity_imbalance(
    _amounts: uint256[N_COINS],
    _max_burn_amount: uint256,
    _receiver: address = msg.sender
) -> uint256:
    """
    @notice Withdraw coins from the pool in an imbalanced amount
    @param _amounts List of amounts of underlying coins to withdraw
    @param _max_burn_amount Maximum amount of LP token to burn in the withdrawal
    @param _receiver Address that receives the withdrawn coins
    @return Actual amount of the LP token burned in the withdrawal
    """
    amp: uint256 = self._A()
    rates: uint256[N_COINS] = [self.rate_multiplier, Curve(BASE_POOL).get_virtual_price()]
    old_balances: uint256[N_COINS] = self.balances
    D0: uint256 = self.get_D_mem(rates, old_balances, amp)

    new_balances: uint256[N_COINS] = old_balances
    for i in range(N_COINS):
        amount: uint256 = _amounts[i]
        if amount != 0:
            new_balances[i] -= amount
            response: Bytes[32] = raw_call(
                self.coins[i],
                concat(
                    method_id("transfer(address,uint256)"),
                    convert(_receiver, bytes32),
                    convert(amount, bytes32),
                ),
                max_outsize=32,
            )
            if len(response) > 0:
                assert convert(response, bool)
    D1: uint256 = self.get_D_mem(rates, new_balances, amp)

    fees: uint256[N_COINS] = empty(uint256[N_COINS])
    base_fee: uint256 = self.fee * N_COINS / (4 * (N_COINS - 1))
    for i in range(N_COINS):
        ideal_balance: uint256 = D1 * old_balances[i] / D0
        difference: uint256 = 0
        new_balance: uint256 = new_balances[i]
        if ideal_balance > new_balance:
            difference = ideal_balance - new_balance
        else:
            difference = new_balance - ideal_balance
        fees[i] = base_fee * difference / FEE_DENOMINATOR
        self.balances[i] = new_balance - (fees[i] * ADMIN_FEE / FEE_DENOMINATOR)
        new_balances[i] -= fees[i]
    D2: uint256 = self.get_D_mem(rates, new_balances, amp)

    total_supply: uint256 = self.totalSupply
    burn_amount: uint256 = ((D0 - D2) * total_supply / D0) + 1
    assert burn_amount > 1  # dev: zero tokens burned
    assert burn_amount <= _max_burn_amount

    total_supply -= burn_amount
    self.totalSupply = total_supply
    self.balanceOf[msg.sender] -= burn_amount
    log Transfer(msg.sender, ZERO_ADDRESS, burn_amount)
    log RemoveLiquidityImbalance(msg.sender, _amounts, fees, D1, total_supply)

    return burn_amount


@view
@internal
def get_y_D(A: uint256, i: int128, xp: uint256[N_COINS], D: uint256) -> uint256:
    """
    Calculate x[i] if one reduces D from being calculated for xp to D

    Done by solving quadratic equation iteratively.
    x_1**2 + x1 * (sum' - (A*n**n - 1) * D / (A * n**n)) = D ** (n + 1) / (n ** (2 * n) * prod' * A)
    x_1**2 + b*x_1 = c

    x_1 = (x_1**2 + c) / (2*x_1 + b)
    """
    # x in the input is converted to the same price/precision

    assert i >= 0  # dev: i below zero
    assert i < N_COINS  # dev: i above N_COINS

    S_: uint256 = 0
    _x: uint256 = 0
    y_prev: uint256 = 0
    c: uint256 = D
    Ann: uint256 = A * N_COINS

    for _i in range(N_COINS):
        if _i != i:
            _x = xp[_i]
        else:
            continue
        S_ += _x
        c = c * D / (_x * N_COINS)

    c = c * D * A_PRECISION / (Ann * N_COINS)
    b: uint256 = S_ + D * A_PRECISION / Ann
    y: uint256 = D

    for _i in range(255):
        y_prev = y
        y = (y*y + c) / (2 * y + b - D)
        # Equality with the precision of 1
        if y > y_prev:
            if y - y_prev <= 1:
                return y
        else:
            if y_prev - y <= 1:
                return y
    raise


@view
@internal
def _calc_withdraw_one_coin(_burn_amount: uint256, i: int128) -> uint256[2]:
    # First, need to calculate
    # * Get current D
    # * Solve Eqn against y_i for D - _token_amount
    amp: uint256 = self._A()
    rates: uint256[N_COINS] = [self.rate_multiplier, Curve(BASE_POOL).get_virtual_price()]
    xp: uint256[N_COINS] = self._xp_mem(rates, self.balances)
    D0: uint256 = self.get_D(xp, amp)

    total_supply: uint256 = self.totalSupply
    D1: uint256 = D0 - _burn_amount * D0 / total_supply
    new_y: uint256 = self.get_y_D(amp, i, xp, D1)

    base_fee: uint256 = self.fee * N_COINS / (4 * (N_COINS - 1))
    xp_reduced: uint256[N_COINS] = empty(uint256[N_COINS])

    for j in range(N_COINS):
        dx_expected: uint256 = 0
        xp_j: uint256 = xp[j]
        if j == i:
            dx_expected = xp_j * D1 / D0 - new_y
        else:
            dx_expected = xp_j - xp_j * D1 / D0
        xp_reduced[j] = xp_j - base_fee * dx_expected / FEE_DENOMINATOR

    dy: uint256 = xp_reduced[i] - self.get_y_D(amp, i, xp_reduced, D1)
    dy_0: uint256 = (xp[i] - new_y) * PRECISION / rates[i]  # w/o fees
    dy = (dy - 1) * PRECISION / rates[i]  # Withdraw less to account for rounding errors

    return [dy, dy_0 - dy]


@view
@external
def calc_withdraw_one_coin(_burn_amount: uint256, i: int128) -> uint256:
    """
    @notice Calculate the amount received when withdrawing a single coin
    @param _burn_amount Amount of LP tokens to burn in the withdrawal
    @param i Index value of the coin to withdraw
    @return Amount of coin received
    """
    return self._calc_withdraw_one_coin(_burn_amount, i)[0]


@external
@nonreentrant('lock')
def remove_liquidity_one_coin(
    _burn_amount: uint256,
    i: int128,
    _min_received: uint256,
    _receiver: address = msg.sender,
) -> uint256:
    """
    @notice Withdraw a single coin from the pool
    @param _burn_amount Amount of LP tokens to burn in the withdrawal
    @param i Index value of the coin to withdraw
    @param _min_received Minimum amount of coin to receive
    @param _receiver Address that receives the withdrawn coins
    @return Amount of coin received
    """
    dy: uint256[2] = self._calc_withdraw_one_coin(_burn_amount, i)
    assert dy[0] >= _min_received

    self.balances[i] -= (dy[0] + dy[1] * ADMIN_FEE / FEE_DENOMINATOR)
    total_supply: uint256 = self.totalSupply - _burn_amount
    self.totalSupply = total_supply
    self.balanceOf[msg.sender] -= _burn_amount
    log Transfer(msg.sender, ZERO_ADDRESS, _burn_amount)

    response: Bytes[32] = raw_call(
        self.coins[i],
        concat(
            method_id("transfer(address,uint256)"),
            convert(_receiver, bytes32),
            convert(dy[0], bytes32),
        ),
        max_outsize=32,
    )
    if len(response) > 0:
        assert convert(response, bool)

    log RemoveLiquidityOne(msg.sender, _burn_amount, dy[0], total_supply)

    return dy[0]


@external
def ramp_A(_future_A: uint256, _future_time: uint256):
    assert msg.sender == Factory(self.factory).admin()  # dev: only owner
    assert block.timestamp >= self.initial_A_time + MIN_RAMP_TIME
    assert _future_time >= block.timestamp + MIN_RAMP_TIME  # dev: insufficient time

    _initial_A: uint256 = self._A()
    _future_A_p: uint256 = _future_A * A_PRECISION

    assert _future_A > 0 and _future_A < MAX_A
    if _future_A_p < _initial_A:
        assert _future_A_p * MAX_A_CHANGE >= _initial_A
    else:
        assert _future_A_p <= _initial_A * MAX_A_CHANGE

    self.initial_A = _initial_A
    self.future_A = _future_A_p
    self.initial_A_time = block.timestamp
    self.future_A_time = _future_time

    log RampA(_initial_A, _future_A_p, block.timestamp, _future_time)


@external
def stop_ramp_A():
    assert msg.sender == Factory(self.factory).admin()  # dev: only owner

    current_A: uint256 = self._A()
    self.initial_A = current_A
    self.future_A = current_A
    self.initial_A_time = block.timestamp
    self.future_A_time = block.timestamp
    # now (block.timestamp < t1) is always False, so we return saved A

    log StopRampA(current_A, block.timestamp)


@view
@external
def admin_balances(i: uint256) -> uint256:
    return ERC20(self.coins[i]).balanceOf(self) - self.balances[i]


@external
def withdraw_admin_fees():
    # transfer coin 0 to Factory and call `convert_fees` to swap it for coin 1
    factory: address = self.factory
    coin: address = self.coins[0]
    amount: uint256 = ERC20(coin).balanceOf(self) - self.balances[0]
    if amount > 0:
        response: Bytes[32] = raw_call(
            coin,
            concat(
                method_id("transfer(address,uint256)"),
                convert(factory, bytes32),
                convert(amount, bytes32),
            ),
            max_outsize=32,
        )
        if len(response) > 0:
            assert convert(response, bool)
        Factory(factory).convert_metapool_fees()

    # transfer coin 1 to the receiver
    coin = self.coins[1]
    amount = ERC20(coin).balanceOf(self) - self.balances[1]
    if amount > 0:
        receiver: address = Factory(factory).get_fee_receiver(self)
        response: Bytes[32] = raw_call(
            coin,
            concat(
                method_id("transfer(address,uint256)"),
                convert(receiver, bytes32),
                convert(amount, bytes32),
            ),
            max_outsize=32,
        )
        if len(response) > 0:
            assert convert(response, bool)

// SPDX-License-Identifier: GPL-3.0
pragma solidity ^0.8.17;
contract NonBoost  {
    constructor() {
       
    }
   
    function getUserBoost(address , uint256 , uint256 ) external pure returns (uint256) {
        return 0;
    }
}

# @version 0.2.15
"""
@title StableSwap
@author Curve.Fi
@license Copyright (c) Curve.Fi, 2020-2021 - all rights reserved
@notice 3pool metapool implementation contract
@dev ERC20 support for return True/revert, return True/False, return None
"""

interface ERC20:
    def approve(_spender: address, _amount: uint256): nonpayable
    def balanceOf(_owner: address) -> uint256: view

interface Curve:
    def coins(i: uint256) -> address: view
    def get_virtual_price() -> uint256: view
    def calc_token_amount(amounts: uint256[BASE_N_COINS], deposit: bool) -> uint256: view
    def calc_withdraw_one_coin(_token_amount: uint256, i: int128) -> uint256: view
    def fee() -> uint256: view
    def get_dy(i: int128, j: int128, dx: uint256) -> uint256: view
    def exchange(i: int128, j: int128, dx: uint256, min_dy: uint256): nonpayable
    def add_liquidity(amounts: uint256[BASE_N_COINS], min_mint_amount: uint256): nonpayable
    def remove_liquidity_one_coin(_token_amount: uint256, i: int128, min_amount: uint256): nonpayable

interface Factory:
    def convert_metapool_fees() -> bool: nonpayable
    def get_fee_receiver(_pool: address) -> address: view
    def admin() -> address: view


event Transfer:
    sender: indexed(address)
    receiver: indexed(address)
    value: uint256

event Approval:
    owner: indexed(address)
    spender: indexed(address)
    value: uint256

event TokenExchange:
    buyer: indexed(address)
    sold_id: int128
    tokens_sold: uint256
    bought_id: int128
    tokens_bought: uint256

event TokenExchangeUnderlying:
    buyer: indexed(address)
    sold_id: int128
    tokens_sold: uint256
    bought_id: int128
    tokens_bought: uint256

event AddLiquidity:
    provider: indexed(address)
    token_amounts: uint256[N_COINS]
    fees: uint256[N_COINS]
    invariant: uint256
    token_supply: uint256

event RemoveLiquidity:
    provider: indexed(address)
    token_amounts: uint256[N_COINS]
    fees: uint256[N_COINS]
    token_supply: uint256

event RemoveLiquidityOne:
    provider: indexed(address)
    token_amount: uint256
    coin_amount: uint256
    token_supply: uint256

event RemoveLiquidityImbalance:
    provider: indexed(address)
    token_amounts: uint256[N_COINS]
    fees: uint256[N_COINS]
    invariant: uint256
    token_supply: uint256

event RampA:
    old_A: uint256
    new_A: uint256
    initial_time: uint256
    future_time: uint256

event StopRampA:
    A: uint256
    t: uint256


BASE_POOL: constant(address) = 0xbEbc44782C7dB0a1A60Cb6fe97d0b483032FF1C7
BASE_COINS: constant(address[3]) = [
    0x6B175474E89094C44Da98b954EedeAC495271d0F,  # DAI
    0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48,  # USDC
    0xdAC17F958D2ee523a2206206994597C13D831ec7,  # USDT
]

N_COINS: constant(int128) = 2
MAX_COIN: constant(int128) = N_COINS - 1
BASE_N_COINS: constant(int128) = 3
PRECISION: constant(uint256) = 10 ** 18

FEE_DENOMINATOR: constant(uint256) = 10 ** 10
ADMIN_FEE: constant(uint256) = 5000000000

A_PRECISION: constant(uint256) = 100
MAX_A: constant(uint256) = 10 ** 6
MAX_A_CHANGE: constant(uint256) = 10
MIN_RAMP_TIME: constant(uint256) = 86400

factory: address

coins: public(address[N_COINS])
balances: public(uint256[N_COINS])
fee: public(uint256)  # fee * 1e10

initial_A: public(uint256)
future_A: public(uint256)
initial_A_time: public(uint256)
future_A_time: public(uint256)

rate_multiplier: uint256

name: public(String[64])
symbol: public(String[32])

balanceOf: public(HashMap[address, uint256])
allowance: public(HashMap[address, HashMap[address, uint256]])
totalSupply: public(uint256)


@external
def __init__():
    # we do this to prevent the implementation contract from being used as a pool
    self.fee = 31337


@external
def initialize(
    _name: String[32],
    _symbol: String[10],
    _coin: address,
    _rate_multiplier: uint256,
    _A: uint256,
    _fee: uint256
):
    """
    @notice Contract initializer
    @param _name Name of the new pool
    @param _symbol Token symbol
    @param _coin Addresses of ERC20 conracts of coins
    @param _rate_multiplier Rate multiplier for `_coin` (10 ** (36 - decimals))
    @param _A Amplification coefficient multiplied by n ** (n - 1)
    @param _fee Fee to charge for exchanges
    """
    # check if fee was already set to prevent initializing contract twice
    assert self.fee == 0

    A: uint256 = _A * A_PRECISION
    self.coins = [_coin, 0x6c3F90f043a72FA612cbac8115EE7e52BDe6E490]
    self.rate_multiplier = _rate_multiplier
    self.initial_A = A
    self.future_A = A
    self.fee = _fee
    self.factory = msg.sender

    self.name = concat("Curve.fi Factory USD Metapool: ", _name)
    self.symbol = concat(_symbol, "3CRV-f")

    for coin in BASE_COINS:
        ERC20(coin).approve(BASE_POOL, MAX_UINT256)

    # fire a transfer event so block explorers identify the contract as an ERC20
    log Transfer(ZERO_ADDRESS, self, 0)


### ERC20 Functionality ###

@view
@external
def decimals() -> uint256:
    """
    @notice Get the number of decimals for this token
    @dev Implemented as a view method to reduce gas costs
    @return uint256 decimal places
    """
    return 18


@internal
def _transfer(_from: address, _to: address, _value: uint256):
    # # NOTE: vyper does not allow underflows
    # #       so the following subtraction would revert on insufficient balance
    self.balanceOf[_from] -= _value
    self.balanceOf[_to] += _value

    log Transfer(_from, _to, _value)


@external
def transfer(_to : address, _value : uint256) -> bool:
    """
    @dev Transfer token for a specified address
    @param _to The address to transfer to.
    @param _value The amount to be transferred.
    """
    self._transfer(msg.sender, _to, _value)
    return True


@external
def transferFrom(_from : address, _to : address, _value : uint256) -> bool:
    """
     @dev Transfer tokens from one address to another.
     @param _from address The address which you want to send tokens from
     @param _to address The address which you want to transfer to
     @param _value uint256 the amount of tokens to be transferred
    """
    self._transfer(_from, _to, _value)

    _allowance: uint256 = self.allowance[_from][msg.sender]
    if _allowance != MAX_UINT256:
        self.allowance[_from][msg.sender] = _allowance - _value

    return True


@external
def approve(_spender : address, _value : uint256) -> bool:
    """
    @notice Approve the passed address to transfer the specified amount of
            tokens on behalf of msg.sender
    @dev Beware that changing an allowance via this method brings the risk that
         someone may use both the old and new allowance by unfortunate transaction
         ordering: https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
    @param _spender The address which will transfer the funds
    @param _value The amount of tokens that may be transferred
    @return bool success
    """
    self.allowance[msg.sender][_spender] = _value

    log Approval(msg.sender, _spender, _value)
    return True


### StableSwap Functionality ###

@view
@internal
def _A() -> uint256:
    """
    Handle ramping A up or down
    """
    t1: uint256 = self.future_A_time
    A1: uint256 = self.future_A

    if block.timestamp < t1:
        A0: uint256 = self.initial_A
        t0: uint256 = self.initial_A_time
        # Expressions in uint256 cannot have negative numbers, thus "if"
        if A1 > A0:
            return A0 + (A1 - A0) * (block.timestamp - t0) / (t1 - t0)
        else:
            return A0 - (A0 - A1) * (block.timestamp - t0) / (t1 - t0)

    else:  # when t1 == 0 or block.timestamp >= t1
        return A1


@view
@external
def admin_fee() -> uint256:
    return ADMIN_FEE


@view
@external
def A() -> uint256:
    return self._A() / A_PRECISION


@view
@external
def A_precise() -> uint256:
    return self._A()


@pure
@internal
def _xp_mem(_rates: uint256[N_COINS], _balances: uint256[N_COINS]) -> uint256[N_COINS]:
    result: uint256[N_COINS] = empty(uint256[N_COINS])
    for i in range(N_COINS):
        result[i] = _rates[i] * _balances[i] / PRECISION
    return result


@pure
@internal
def get_D(_xp: uint256[N_COINS], _amp: uint256) -> uint256:
    """
    D invariant calculation in non-overflowing integer operations
    iteratively

    A * sum(x_i) * n**n + D = A * D * n**n + D**(n+1) / (n**n * prod(x_i))

    Converging solution:
    D[j+1] = (A * n**n * sum(x_i) - D[j]**(n+1) / (n**n prod(x_i))) / (A * n**n - 1)
    """
    S: uint256 = 0
    Dprev: uint256 = 0
    for x in _xp:
        S += x
    if S == 0:
        return 0

    D: uint256 = S
    Ann: uint256 = _amp * N_COINS
    for i in range(255):
        D_P: uint256 = D
        for x in _xp:
            D_P = D_P * D / (x * N_COINS)  # If division by 0, this will be borked: only withdrawal will work. And that is good
        Dprev = D
        D = (Ann * S / A_PRECISION + D_P * N_COINS) * D / ((Ann - A_PRECISION) * D / A_PRECISION + (N_COINS + 1) * D_P)
        # Equality with the precision of 1
        if D > Dprev:
            if D - Dprev <= 1:
                return D
        else:
            if Dprev - D <= 1:
                return D
    # convergence typically occurs in 4 rounds or less, this should be unreachable!
    # if it does happen the pool is borked and LPs can withdraw via `remove_liquidity`
    raise


@view
@internal
def get_D_mem(_rates: uint256[N_COINS], _balances: uint256[N_COINS], _amp: uint256) -> uint256:
    xp: uint256[N_COINS] = self._xp_mem(_rates, _balances)
    return self.get_D(xp, _amp)


@view
@external
def get_virtual_price() -> uint256:
    """
    @notice The current virtual price of the pool LP token
    @dev Useful for calculating profits
    @return LP token virtual price normalized to 1e18
    """
    amp: uint256 = self._A()
    rates: uint256[N_COINS] = [self.rate_multiplier, Curve(BASE_POOL).get_virtual_price()]
    xp: uint256[N_COINS] = self._xp_mem(rates, self.balances)
    D: uint256 = self.get_D(xp, amp)
    # D is in the units similar to DAI (e.g. converted to precision 1e18)
    # When balanced, D = n * x_u - total virtual value of the portfolio
    return D * PRECISION / self.totalSupply


@view
@external
def calc_token_amount(_amounts: uint256[N_COINS], _is_deposit: bool) -> uint256:
    """
    @notice Calculate addition or reduction in token supply from a deposit or withdrawal
    @dev This calculation accounts for slippage, but not fees.
         Needed to prevent front-running, not for precise calculations!
    @param _amounts Amount of each coin being deposited
    @param _is_deposit set True for deposits, False for withdrawals
    @return Expected amount of LP tokens received
    """
    amp: uint256 = self._A()
    rates: uint256[N_COINS] = [self.rate_multiplier, Curve(BASE_POOL).get_virtual_price()]
    balances: uint256[N_COINS] = self.balances

    D0: uint256 = self.get_D_mem(rates, balances, amp)
    for i in range(N_COINS):
        amount: uint256 = _amounts[i]
        if _is_deposit:
            balances[i] += amount
        else:
            balances[i] -= amount
    D1: uint256 = self.get_D_mem(rates, balances, amp)
    diff: uint256 = 0
    if _is_deposit:
        diff = D1 - D0
    else:
        diff = D0 - D1
    return diff * self.totalSupply / D0


@external
@nonreentrant('lock')
def add_liquidity(
    _amounts: uint256[N_COINS],
    _min_mint_amount: uint256,
    _receiver: address = msg.sender
) -> uint256:
    """
    @notice Deposit coins into the pool
    @param _amounts List of amounts of coins to deposit
    @param _min_mint_amount Minimum amount of LP tokens to mint from the deposit
    @param _receiver Address that owns the minted LP tokens
    @return Amount of LP tokens received by depositing
    """
    amp: uint256 = self._A()
    rates: uint256[N_COINS] = [self.rate_multiplier, Curve(BASE_POOL).get_virtual_price()]

    # Initial invariant
    old_balances: uint256[N_COINS] = self.balances
    D0: uint256 = self.get_D_mem(rates, old_balances, amp)
    new_balances: uint256[N_COINS] = old_balances

    total_supply: uint256 = self.totalSupply
    for i in range(N_COINS):
        amount: uint256 = _amounts[i]
        if amount == 0:
            assert total_supply > 0
        else:
            response: Bytes[32] = raw_call(
                self.coins[i],
                concat(
                    method_id("transferFrom(address,address,uint256)"),
                    convert(msg.sender, bytes32),
                    convert(self, bytes32),
                    convert(amount, bytes32),
                ),
                max_outsize=32,
            )
            if len(response) > 0:
                assert convert(response, bool)
            new_balances[i] += amount

    # Invariant after change
    D1: uint256 = self.get_D_mem(rates, new_balances, amp)
    assert D1 > D0

    # We need to recalculate the invariant accounting for fees
    # to calculate fair user's share
    fees: uint256[N_COINS] = empty(uint256[N_COINS])
    mint_amount: uint256 = 0
    if total_supply > 0:
        # Only account for fees if we are not the first to deposit
        base_fee: uint256 = self.fee * N_COINS / (4 * (N_COINS - 1))
        for i in range(N_COINS):
            ideal_balance: uint256 = D1 * old_balances[i] / D0
            difference: uint256 = 0
            new_balance: uint256 = new_balances[i]
            if ideal_balance > new_balance:
                difference = ideal_balance - new_balance
            else:
                difference = new_balance - ideal_balance
            fees[i] = base_fee * difference / FEE_DENOMINATOR
            self.balances[i] = new_balance - (fees[i] * ADMIN_FEE / FEE_DENOMINATOR)
            new_balances[i] -= fees[i]
        D2: uint256 = self.get_D_mem(rates, new_balances, amp)
        mint_amount = total_supply * (D2 - D0) / D0
    else:
        self.balances = new_balances
        mint_amount = D1  # Take the dust if there was any

    assert mint_amount >= _min_mint_amount

    # Mint pool tokens
    total_supply += mint_amount
    self.balanceOf[_receiver] += mint_amount
    self.totalSupply = total_supply
    log Transfer(ZERO_ADDRESS, _receiver, mint_amount)
    log AddLiquidity(msg.sender, _amounts, fees, D1, total_supply)

    return mint_amount


@view
@internal
def get_y(i: int128, j: int128, x: uint256, xp: uint256[N_COINS]) -> uint256:
    # x in the input is converted to the same price/precision

    assert i != j       # dev: same coin
    assert j >= 0       # dev: j below zero
    assert j < N_COINS  # dev: j above N_COINS

    # should be unreachable, but good for safety
    assert i >= 0
    assert i < N_COINS

    amp: uint256 = self._A()
    D: uint256 = self.get_D(xp, amp)
    S_: uint256 = 0
    _x: uint256 = 0
    y_prev: uint256 = 0
    c: uint256 = D
    Ann: uint256 = amp * N_COINS

    for _i in range(N_COINS):
        if _i == i:
            _x = x
        elif _i != j:
            _x = xp[_i]
        else:
            continue
        S_ += _x
        c = c * D / (_x * N_COINS)

    c = c * D * A_PRECISION / (Ann * N_COINS)
    b: uint256 = S_ + D * A_PRECISION / Ann  # - D
    y: uint256 = D

    for _i in range(255):
        y_prev = y
        y = (y*y + c) / (2 * y + b - D)
        # Equality with the precision of 1
        if y > y_prev:
            if y - y_prev <= 1:
                return y
        else:
            if y_prev - y <= 1:
                return y
    raise


@view
@external
def get_dy(i: int128, j: int128, dx: uint256) -> uint256:
    """
    @notice Calculate the current output dy given input dx
    @dev Index values can be found via the `coins` public getter method
    @param i Index value for the coin to send
    @param j Index valie of the coin to recieve
    @param dx Amount of `i` being exchanged
    @return Amount of `j` predicted
    """
    rates: uint256[N_COINS] = [self.rate_multiplier, Curve(BASE_POOL).get_virtual_price()]
    xp: uint256[N_COINS] = self._xp_mem(rates, self.balances)

    x: uint256 = xp[i] + (dx * rates[i] / PRECISION)
    y: uint256 = self.get_y(i, j, x, xp)
    dy: uint256 = xp[j] - y - 1
    fee: uint256 = self.fee * dy / FEE_DENOMINATOR
    return (dy - fee) * PRECISION / rates[j]


@view
@external
def get_dy_underlying(i: int128, j: int128, dx: uint256) -> uint256:
    """
    @notice Calculate the current output dy given input dx on underlying
    @dev Index values can be found via the `coins` public getter method
    @param i Index value for the coin to send
    @param j Index valie of the coin to recieve
    @param dx Amount of `i` being exchanged
    @return Amount of `j` predicted
    """
    rates: uint256[N_COINS] = [self.rate_multiplier, Curve(BASE_POOL).get_virtual_price()]
    xp: uint256[N_COINS] = self._xp_mem(rates, self.balances)

    x: uint256 = 0
    base_i: int128 = 0
    base_j: int128 = 0
    meta_i: int128 = 0
    meta_j: int128 = 0

    if i != 0:
        base_i = i - MAX_COIN
        meta_i = 1
    if j != 0:
        base_j = j - MAX_COIN
        meta_j = 1

    if i == 0:
        x = xp[i] + dx * (rates[0] / 10**18)
    else:
        if j == 0:
            # i is from BasePool
            # At first, get the amount of pool tokens
            base_inputs: uint256[BASE_N_COINS] = empty(uint256[BASE_N_COINS])
            base_inputs[base_i] = dx
            # Token amount transformed to underlying "dollars"
            x = Curve(BASE_POOL).calc_token_amount(base_inputs, True) * rates[1] / PRECISION
            # Accounting for deposit/withdraw fees approximately
            x -= x * Curve(BASE_POOL).fee() / (2 * FEE_DENOMINATOR)
            # Adding number of pool tokens
            x += xp[MAX_COIN]
        else:
            # If both are from the base pool
            return Curve(BASE_POOL).get_dy(base_i, base_j, dx)

    # This pool is involved only when in-pool assets are used
    y: uint256 = self.get_y(meta_i, meta_j, x, xp)
    dy: uint256 = xp[meta_j] - y - 1
    dy = (dy - self.fee * dy / FEE_DENOMINATOR)

    # If output is going via the metapool
    if j == 0:
        dy /= (rates[0] / 10**18)
    else:
        # j is from BasePool
        # The fee is already accounted for
        dy = Curve(BASE_POOL).calc_withdraw_one_coin(dy * PRECISION / rates[1], base_j)

    return dy


@external
@nonreentrant('lock')
def exchange(
    i: int128,
    j: int128,
    _dx: uint256,
    _min_dy: uint256,
    _receiver: address = msg.sender,
) -> uint256:
    """
    @notice Perform an exchange between two coins
    @dev Index values can be found via the `coins` public getter method
    @param i Index value for the coin to send
    @param j Index valie of the coin to recieve
    @param _dx Amount of `i` being exchanged
    @param _min_dy Minimum amount of `j` to receive
    @param _receiver Address that receives `j`
    @return Actual amount of `j` received
    """
    rates: uint256[N_COINS] = [self.rate_multiplier, Curve(BASE_POOL).get_virtual_price()]

    old_balances: uint256[N_COINS] = self.balances
    xp: uint256[N_COINS] = self._xp_mem(rates, old_balances)

    x: uint256 = xp[i] + _dx * rates[i] / PRECISION
    y: uint256 = self.get_y(i, j, x, xp)

    dy: uint256 = xp[j] - y - 1  # -1 just in case there were some rounding errors
    dy_fee: uint256 = dy * self.fee / FEE_DENOMINATOR

    # Convert all to real units
    dy = (dy - dy_fee) * PRECISION / rates[j]
    assert dy >= _min_dy

    dy_admin_fee: uint256 = dy_fee * ADMIN_FEE / FEE_DENOMINATOR
    dy_admin_fee = dy_admin_fee * PRECISION / rates[j]

    # Change balances exactly in same way as we change actual ERC20 coin amounts
    self.balances[i] = old_balances[i] + _dx
    # When rounding errors happen, we undercharge admin fee in favor of LP
    self.balances[j] = old_balances[j] - dy - dy_admin_fee

    response: Bytes[32] = raw_call(
        self.coins[i],
        concat(
            method_id("transferFrom(address,address,uint256)"),
            convert(msg.sender, bytes32),
            convert(self, bytes32),
            convert(_dx, bytes32),
        ),
        max_outsize=32,
    )
    if len(response) > 0:
        assert convert(response, bool)

    response = raw_call(
        self.coins[j],
        concat(
            method_id("transfer(address,uint256)"),
            convert(_receiver, bytes32),
            convert(dy, bytes32),
        ),
        max_outsize=32,
    )
    if len(response) > 0:
        assert convert(response, bool)

    log TokenExchange(msg.sender, i, _dx, j, dy)

    return dy


@external
@nonreentrant('lock')
def exchange_underlying(
    i: int128,
    j: int128,
    _dx: uint256,
    _min_dy: uint256,
    _receiver: address = msg.sender,
) -> uint256:
    """
    @notice Perform an exchange between two underlying coins
    @param i Index value for the underlying coin to send
    @param j Index valie of the underlying coin to receive
    @param _dx Amount of `i` being exchanged
    @param _min_dy Minimum amount of `j` to receive
    @param _receiver Address that receives `j`
    @return Actual amount of `j` received
    """
    rates: uint256[N_COINS] = [self.rate_multiplier, Curve(BASE_POOL).get_virtual_price()]
    old_balances: uint256[N_COINS] = self.balances
    xp: uint256[N_COINS] = self._xp_mem(rates, old_balances)

    base_coins: address[3] = BASE_COINS

    dy: uint256 = 0
    base_i: int128 = 0
    base_j: int128 = 0
    meta_i: int128 = 0
    meta_j: int128 = 0
    x: uint256 = 0
    input_coin: address = ZERO_ADDRESS
    output_coin: address = ZERO_ADDRESS

    if i == 0:
        input_coin = self.coins[0]
    else:
        base_i = i - MAX_COIN
        meta_i = 1
        input_coin = base_coins[base_i]
    if j == 0:
        output_coin = self.coins[0]
    else:
        base_j = j - MAX_COIN
        meta_j = 1
        output_coin = base_coins[base_j]

    response: Bytes[32] = raw_call(
        input_coin,
        concat(
            method_id("transferFrom(address,address,uint256)"),
            convert(msg.sender, bytes32),
            convert(self, bytes32),
            convert(_dx, bytes32),
        ),
        max_outsize=32,
    )
    if len(response) > 0:
        assert convert(response, bool)

    dx: uint256 = _dx
    if i == 0 or j == 0:
        if i == 0:
            x = xp[i] + dx * rates[i] / PRECISION
        else:
            # i is from BasePool
            # At first, get the amount of pool tokens
            base_inputs: uint256[BASE_N_COINS] = empty(uint256[BASE_N_COINS])
            base_inputs[base_i] = dx
            coin_i: address = self.coins[MAX_COIN]
            # Deposit and measure delta
            x = ERC20(coin_i).balanceOf(self)
            Curve(BASE_POOL).add_liquidity(base_inputs, 0)
            # Need to convert pool token to "virtual" units using rates
            # dx is also different now
            dx = ERC20(coin_i).balanceOf(self) - x
            x = dx * rates[MAX_COIN] / PRECISION
            # Adding number of pool tokens
            x += xp[MAX_COIN]

        y: uint256 = self.get_y(meta_i, meta_j, x, xp)

        # Either a real coin or token
        dy = xp[meta_j] - y - 1  # -1 just in case there were some rounding errors
        dy_fee: uint256 = dy * self.fee / FEE_DENOMINATOR

        # Convert all to real units
        # Works for both pool coins and real coins
        dy = (dy - dy_fee) * PRECISION / rates[meta_j]

        dy_admin_fee: uint256 = dy_fee * ADMIN_FEE / FEE_DENOMINATOR
        dy_admin_fee = dy_admin_fee * PRECISION / rates[meta_j]

        # Change balances exactly in same way as we change actual ERC20 coin amounts
        self.balances[meta_i] = old_balances[meta_i] + dx
        # When rounding errors happen, we undercharge admin fee in favor of LP
        self.balances[meta_j] = old_balances[meta_j] - dy - dy_admin_fee

        # Withdraw from the base pool if needed
        if j > 0:
            out_amount: uint256 = ERC20(output_coin).balanceOf(self)
            Curve(BASE_POOL).remove_liquidity_one_coin(dy, base_j, 0)
            dy = ERC20(output_coin).balanceOf(self) - out_amount

        assert dy >= _min_dy

    else:
        # If both are from the base pool
        dy = ERC20(output_coin).balanceOf(self)
        Curve(BASE_POOL).exchange(base_i, base_j, dx, _min_dy)
        dy = ERC20(output_coin).balanceOf(self) - dy

    response = raw_call(
        output_coin,
        concat(
            method_id("transfer(address,uint256)"),
            convert(_receiver, bytes32),
            convert(dy, bytes32),
        ),
        max_outsize=32,
    )
    if len(response) > 0:
        assert convert(response, bool)

    log TokenExchangeUnderlying(msg.sender, i, dx, j, dy)

    return dy


@external
@nonreentrant('lock')
def remove_liquidity(
    _burn_amount: uint256,
    _min_amounts: uint256[N_COINS],
    _receiver: address = msg.sender
) -> uint256[N_COINS]:
    """
    @notice Withdraw coins from the pool
    @dev Withdrawal amounts are based on current deposit ratios
    @param _burn_amount Quantity of LP tokens to burn in the withdrawal
    @param _min_amounts Minimum amounts of underlying coins to receive
    @param _receiver Address that receives the withdrawn coins
    @return List of amounts of coins that were withdrawn
    """
    total_supply: uint256 = self.totalSupply
    amounts: uint256[N_COINS] = empty(uint256[N_COINS])

    for i in range(N_COINS):
        old_balance: uint256 = self.balances[i]
        value: uint256 = old_balance * _burn_amount / total_supply
        assert value >= _min_amounts[i]
        self.balances[i] = old_balance - value
        amounts[i] = value
        response: Bytes[32] = raw_call(
            self.coins[i],
            concat(
                method_id("transfer(address,uint256)"),
                convert(_receiver, bytes32),
                convert(value, bytes32),
            ),
            max_outsize=32,
        )
        if len(response) > 0:
            assert convert(response, bool)


    total_supply -= _burn_amount
    self.balanceOf[msg.sender] -= _burn_amount
    self.totalSupply = total_supply
    log Transfer(msg.sender, ZERO_ADDRESS, _burn_amount)

    log RemoveLiquidity(msg.sender, amounts, empty(uint256[N_COINS]), total_supply)

    return amounts


@external
@nonreentrant('lock')
def remove_liquidity_imbalance(
    _amounts: uint256[N_COINS],
    _max_burn_amount: uint256,
    _receiver: address = msg.sender
) -> uint256:
    """
    @notice Withdraw coins from the pool in an imbalanced amount
    @param _amounts List of amounts of underlying coins to withdraw
    @param _max_burn_amount Maximum amount of LP token to burn in the withdrawal
    @param _receiver Address that receives the withdrawn coins
    @return Actual amount of the LP token burned in the withdrawal
    """
    amp: uint256 = self._A()
    rates: uint256[N_COINS] = [self.rate_multiplier, Curve(BASE_POOL).get_virtual_price()]
    old_balances: uint256[N_COINS] = self.balances
    D0: uint256 = self.get_D_mem(rates, old_balances, amp)

    new_balances: uint256[N_COINS] = old_balances
    for i in range(N_COINS):
        amount: uint256 = _amounts[i]
        if amount != 0:
            new_balances[i] -= amount
            response: Bytes[32] = raw_call(
                self.coins[i],
                concat(
                    method_id("transfer(address,uint256)"),
                    convert(_receiver, bytes32),
                    convert(amount, bytes32),
                ),
                max_outsize=32,
            )
            if len(response) > 0:
                assert convert(response, bool)
    D1: uint256 = self.get_D_mem(rates, new_balances, amp)

    fees: uint256[N_COINS] = empty(uint256[N_COINS])
    base_fee: uint256 = self.fee * N_COINS / (4 * (N_COINS - 1))
    for i in range(N_COINS):
        ideal_balance: uint256 = D1 * old_balances[i] / D0
        difference: uint256 = 0
        new_balance: uint256 = new_balances[i]
        if ideal_balance > new_balance:
            difference = ideal_balance - new_balance
        else:
            difference = new_balance - ideal_balance
        fees[i] = base_fee * difference / FEE_DENOMINATOR
        self.balances[i] = new_balance - (fees[i] * ADMIN_FEE / FEE_DENOMINATOR)
        new_balances[i] -= fees[i]
    D2: uint256 = self.get_D_mem(rates, new_balances, amp)

    total_supply: uint256 = self.totalSupply
    burn_amount: uint256 = ((D0 - D2) * total_supply / D0) + 1
    assert burn_amount > 1  # dev: zero tokens burned
    assert burn_amount <= _max_burn_amount

    total_supply -= burn_amount
    self.totalSupply = total_supply
    self.balanceOf[msg.sender] -= burn_amount
    log Transfer(msg.sender, ZERO_ADDRESS, burn_amount)
    log RemoveLiquidityImbalance(msg.sender, _amounts, fees, D1, total_supply)

    return burn_amount


@view
@internal
def get_y_D(A: uint256, i: int128, xp: uint256[N_COINS], D: uint256) -> uint256:
    """
    Calculate x[i] if one reduces D from being calculated for xp to D

    Done by solving quadratic equation iteratively.
    x_1**2 + x1 * (sum' - (A*n**n - 1) * D / (A * n**n)) = D ** (n + 1) / (n ** (2 * n) * prod' * A)
    x_1**2 + b*x_1 = c

    x_1 = (x_1**2 + c) / (2*x_1 + b)
    """
    # x in the input is converted to the same price/precision

    assert i >= 0  # dev: i below zero
    assert i < N_COINS  # dev: i above N_COINS

    S_: uint256 = 0
    _x: uint256 = 0
    y_prev: uint256 = 0
    c: uint256 = D
    Ann: uint256 = A * N_COINS

    for _i in range(N_COINS):
        if _i != i:
            _x = xp[_i]
        else:
            continue
        S_ += _x
        c = c * D / (_x * N_COINS)

    c = c * D * A_PRECISION / (Ann * N_COINS)
    b: uint256 = S_ + D * A_PRECISION / Ann
    y: uint256 = D

    for _i in range(255):
        y_prev = y
        y = (y*y + c) / (2 * y + b - D)
        # Equality with the precision of 1
        if y > y_prev:
            if y - y_prev <= 1:
                return y
        else:
            if y_prev - y <= 1:
                return y
    raise


@view
@internal
def _calc_withdraw_one_coin(_burn_amount: uint256, i: int128) -> uint256[2]:
    # First, need to calculate
    # * Get current D
    # * Solve Eqn against y_i for D - _token_amount
    amp: uint256 = self._A()
    rates: uint256[N_COINS] = [self.rate_multiplier, Curve(BASE_POOL).get_virtual_price()]
    xp: uint256[N_COINS] = self._xp_mem(rates, self.balances)
    D0: uint256 = self.get_D(xp, amp)

    total_supply: uint256 = self.totalSupply
    D1: uint256 = D0 - _burn_amount * D0 / total_supply
    new_y: uint256 = self.get_y_D(amp, i, xp, D1)

    base_fee: uint256 = self.fee * N_COINS / (4 * (N_COINS - 1))
    xp_reduced: uint256[N_COINS] = empty(uint256[N_COINS])

    for j in range(N_COINS):
        dx_expected: uint256 = 0
        xp_j: uint256 = xp[j]
        if j == i:
            dx_expected = xp_j * D1 / D0 - new_y
        else:
            dx_expected = xp_j - xp_j * D1 / D0
        xp_reduced[j] = xp_j - base_fee * dx_expected / FEE_DENOMINATOR

    dy: uint256 = xp_reduced[i] - self.get_y_D(amp, i, xp_reduced, D1)
    dy_0: uint256 = (xp[i] - new_y) * PRECISION / rates[i]  # w/o fees
    dy = (dy - 1) * PRECISION / rates[i]  # Withdraw less to account for rounding errors

    return [dy, dy_0 - dy]


@view
@external
def calc_withdraw_one_coin(_burn_amount: uint256, i: int128) -> uint256:
    """
    @notice Calculate the amount received when withdrawing a single coin
    @param _burn_amount Amount of LP tokens to burn in the withdrawal
    @param i Index value of the coin to withdraw
    @return Amount of coin received
    """
    return self._calc_withdraw_one_coin(_burn_amount, i)[0]


@external
@nonreentrant('lock')
def remove_liquidity_one_coin(
    _burn_amount: uint256,
    i: int128,
    _min_received: uint256,
    _receiver: address = msg.sender,
) -> uint256:
    """
    @notice Withdraw a single coin from the pool
    @param _burn_amount Amount of LP tokens to burn in the withdrawal
    @param i Index value of the coin to withdraw
    @param _min_received Minimum amount of coin to receive
    @param _receiver Address that receives the withdrawn coins
    @return Amount of coin received
    """
    dy: uint256[2] = self._calc_withdraw_one_coin(_burn_amount, i)
    assert dy[0] >= _min_received

    self.balances[i] -= (dy[0] + dy[1] * ADMIN_FEE / FEE_DENOMINATOR)
    total_supply: uint256 = self.totalSupply - _burn_amount
    self.totalSupply = total_supply
    self.balanceOf[msg.sender] -= _burn_amount
    log Transfer(msg.sender, ZERO_ADDRESS, _burn_amount)

    response: Bytes[32] = raw_call(
        self.coins[i],
        concat(
            method_id("transfer(address,uint256)"),
            convert(_receiver, bytes32),
            convert(dy[0], bytes32),
        ),
        max_outsize=32,
    )
    if len(response) > 0:
        assert convert(response, bool)

    log RemoveLiquidityOne(msg.sender, _burn_amount, dy[0], total_supply)

    return dy[0]


@external
def ramp_A(_future_A: uint256, _future_time: uint256):
    assert msg.sender == Factory(self.factory).admin()  # dev: only owner
    assert block.timestamp >= self.initial_A_time + MIN_RAMP_TIME
    assert _future_time >= block.timestamp + MIN_RAMP_TIME  # dev: insufficient time

    _initial_A: uint256 = self._A()
    _future_A_p: uint256 = _future_A * A_PRECISION

    assert _future_A > 0 and _future_A < MAX_A
    if _future_A_p < _initial_A:
        assert _future_A_p * MAX_A_CHANGE >= _initial_A
    else:
        assert _future_A_p <= _initial_A * MAX_A_CHANGE

    self.initial_A = _initial_A
    self.future_A = _future_A_p
    self.initial_A_time = block.timestamp
    self.future_A_time = _future_time

    log RampA(_initial_A, _future_A_p, block.timestamp, _future_time)


@external
def stop_ramp_A():
    assert msg.sender == Factory(self.factory).admin()  # dev: only owner

    current_A: uint256 = self._A()
    self.initial_A = current_A
    self.future_A = current_A
    self.initial_A_time = block.timestamp
    self.future_A_time = block.timestamp
    # now (block.timestamp < t1) is always False, so we return saved A

    log StopRampA(current_A, block.timestamp)


@view
@external
def admin_balances(i: uint256) -> uint256:
    return ERC20(self.coins[i]).balanceOf(self) - self.balances[i]


@external
def withdraw_admin_fees():
    # transfer coin 0 to Factory and call `convert_fees` to swap it for coin 1
    factory: address = self.factory
    coin: address = self.coins[0]
    amount: uint256 = ERC20(coin).balanceOf(self) - self.balances[0]
    if amount > 0:
        response: Bytes[32] = raw_call(
            coin,
            concat(
                method_id("transfer(address,uint256)"),
                convert(factory, bytes32),
                convert(amount, bytes32),
            ),
            max_outsize=32,
        )
        if len(response) > 0:
            assert convert(response, bool)
        Factory(factory).convert_metapool_fees()

    # transfer coin 1 to the receiver
    coin = self.coins[1]
    amount = ERC20(coin).balanceOf(self) - self.balances[1]
    if amount > 0:
        receiver: address = Factory(factory).get_fee_receiver(self)
        response: Bytes[32] = raw_call(
            coin,
            concat(
                method_id("transfer(address,uint256)"),
                convert(receiver, bytes32),
                convert(amount, bytes32),
            ),
            max_outsize=32,
        )
        if len(response) > 0:
            assert convert(response, bool)