Cryo Explorer Ethereum Mainnet

// SPDX-License-Identifier: AGPL-3.0-only
pragma solidity =0.8.19 ^0.8.0 ^0.8.1 ^0.8.19 ^0.8.7;

// lib/openzeppelin-contracts/contracts/token/ERC20/IERC20.sol

// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/IERC20.sol)

/**
 * @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);
}

// lib/openzeppelin-contracts/contracts/token/ERC20/extensions/IERC20Permit.sol

// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/extensions/IERC20Permit.sol)

/**
 * @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);
}

// lib/openzeppelin-contracts/contracts/utils/Address.sol

// OpenZeppelin Contracts (last updated v4.9.0) (utils/Address.sol)

/**
 * @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);
        }
    }
}

// src/base/interfaces/ICurvePool.sol

interface ICurvePool {
    function add_liquidity(uint256[2] calldata amounts, uint256 min_mint_amount) external returns (uint256);
    function exchange(int128 i, int128 j, uint256 _dx, uint256 _min_dy) external returns (uint256);
    function exchange(int128 i, int128 j, uint256 _dx, uint256 _min_dy, address _receiver) external returns (uint256);
    function get_dy(int128 i, int128 j, uint256 _dx) external view returns (uint256);
}

// src/base/interfaces/IExecutor.sol

interface IExecutor {
    function allowAddress(address _address) external;

    function execute(address _to, uint256 _value, bytes calldata _data) external returns (bool, bytes memory);

    function callExecuteTo(address _executor, address _to, uint256 _value, bytes calldata _data)
        external
        returns (bool, bytes memory);
}

// src/base/interfaces/ILiquidityGauge.sol

interface ILiquidityGauge {
    struct Reward {
        address token;
        address distributor;
        // solhint-disable-next-line
        uint256 period_finish;
        uint256 rate;
        // solhint-disable-next-line
        uint256 last_update;
        uint256 integral;
    }

    // solhint-disable-next-line
    function deposit_reward_token(address _rewardToken, uint256 _amount) external;

    // solhint-disable-next-line
    function claim_rewards_for(address _user, address _recipient) external;

    // solhint-disable-next-line
    function working_balances(address _address) external view returns (uint256);

    // solhint-disable-next-line
    function deposit(uint256 _value, address _addr) external;

    // solhint-disable-next-line
    function reward_tokens(uint256 _i) external view returns (address);

    // solhint-disable-next-line
    function reward_data(address _tokenReward) external view returns (Reward memory);

    function balanceOf(address) external returns (uint256);

    // solhint-disable-next-line
    function claimable_reward(address _user, address _reward_token) external view returns (uint256);

    // solhint-disable-next-line
    function claimable_tokens(address _user) external returns (uint256);

    // solhint-disable-next-line
    function user_checkpoint(address _user) external returns (bool);

    // solhint-disable-next-line
    function commit_transfer_ownership(address) external;

    // solhint-disable-next-line
    function claim_rewards() external;

    // solhint-disable-next-line
    function claim_rewards(address) external;

    // solhint-disable-next-line
    function claim_rewards(address, address) external;

    // solhint-disable-next-line
    function add_reward(address, address) external;

    // solhint-disable-next-line
    function set_claimer(address) external;

    function admin() external view returns (address);

    function future_admin() external view returns (address);

    // solhint-disable-next-line
    function set_reward_distributor(address _rewardToken, address _newDistrib) external;

    function initialize(
        // solhint-disable-next-line
        address staking_token,
        address admin,
        address sdt,
        // solhint-disable-next-line
        address voting_escrow,
        // solhint-disable-next-line
        address veBoost_proxy,
        address distributor
    ) external;

    function totalSupply() external returns (uint256);

    function withdraw(uint256 _value, bool _claimReward) external;

    // solhint-disable-next-line
    function accept_transfer_ownership() external;

    // solhint-disable-next-line
    function claimed_reward(address _addr, address _token) external view returns (uint256);

    // solhint-disable-next-line
    function set_rewards_receiver(address _receiver) external;
}

// src/base/interfaces/ILocker.sol

interface ILocker {
    function createLock(uint256, uint256) external;

    function claimAllRewards(address[] calldata _tokens, address _recipient) external;

    function increaseAmount(uint256) external;

    function increaseAmount(uint128) external;

    function increaseUnlockTime(uint256) external;

    function release() external;

    function claimRewards(address, address) external;

    function claimRewards(address, address, address) external;

    function claimFXSRewards(address) external;

    function claimFPISRewards(address) external;

    function execute(address, uint256, bytes calldata) external returns (bool, bytes memory);

    function setGovernance(address) external;

    function voteGaugeWeight(address, uint256) external;

    function setAngleDepositor(address) external;

    function setDepositor(address) external;

    function setFxsDepositor(address) external;

    function setYFIDepositor(address) external;

    function setYieldDistributor(address) external;

    function setGaugeController(address) external;

    function setAccumulator(address _accumulator) external;

    function governance() external view returns (address);

    function increaseLock(uint256 _value, uint256 _duration) external;

    function release(address _recipient) external;

    function setStrategy(address _strategy) external;
}

// src/base/interfaces/ISdToken.sol

interface ISdToken {
    function setOperator(address _operator) external;
    function balanceOf(address account) external view returns (uint256);
    function operator() external view returns (address);
}

// src/base/interfaces/ITokenMinter.sol

interface ITokenMinter {
    function mint(address, uint256) external;
    function burn(address, uint256) external;
}

// src/base/interfaces/IVeToken.sol

interface IVeToken {
    struct LockedBalance {
        int128 amount;
        uint256 end;
    }

    function create_lock(uint256 _value, uint256 _unlock_time) external;

    function increase_amount(uint256 _value) external;

    function increase_unlock_time(uint256 _unlock_time) external;

    function withdraw() external;

    function locked__end(address) external view returns (uint256);

    function balanceOf(address) external view returns (uint256);

    function locked(address) external returns (LockedBalance memory);
}

// lib/openzeppelin-contracts/contracts/token/ERC20/utils/SafeERC20.sol

// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/utils/SafeERC20.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));
    }
}

// src/base/depositor/DepositorV4.sol

/// @title Depositor
/// @notice Contract that accepts tokens and locks them in the Locker, minting sdToken in return
/// @dev Adapted for veCRV like Locker.
/// @author StakeDAO
/// @custom:contact [email protected]
abstract contract DepositorV4 {
    using SafeERC20 for IERC20;

    /// @notice Denominator for fixed point math.
    uint256 public constant DENOMINATOR = 10_000;

    /// @notice Maximum lock duration.
    uint256 public immutable MAX_LOCK_DURATION;

    /// @notice Address of the token to be locked.
    address public immutable token;

    /// @notice Address of the locker contract.
    address public immutable locker;

    /// @notice Address of the sdToken minter contract.
    address public immutable minter;

    /// @notice Fee percent to users who spend gas to increase lock.
    uint256 public lockIncentivePercent = 10;

    /// @notice Incentive accrued in token to users who spend gas to increase lock.
    uint256 public incentiveToken;

    /// @notice Gauge to deposit sdToken into.
    address public gauge;

    /// @notice Address of the governance.
    address public governance;

    /// @notice Address of the future governance contract.
    address public futureGovernance;

    ////////////////////////////////////////////////////////////////
    /// --- EVENTS & ERRORS
    ///////////////////////////////////////////////////////////////

    /// @notice Event emitted when a lock is created.
    /// @param amount Amount of tokens locked.
    /// @param duration Duration of the lock.
    event CreateLock(uint256 amount, uint256 duration);

    /// @notice Event emitted when tokens are deposited.
    /// @param caller Address of the caller.
    /// @param user Address of the user.
    /// @param amount Amount of tokens deposited.
    /// @param lock Whether the tokens are locked.
    /// @param stake Whether the sdToken is staked in the gauge.
    event Deposited(address indexed caller, address indexed user, uint256 amount, bool lock, bool stake);

    /// @notice Event emitted when incentive tokens are received.
    /// @param caller Address of the caller.
    /// @param amount Amount of tokens received.
    event IncentiveReceived(address indexed caller, uint256 amount);

    /// @notice Event emitted when tokens are locked.
    /// @param user Address of the user.
    /// @param amount Amount of tokens locked.
    event TokenLocked(address indexed user, uint256 amount);

    /// @notice Event emitted when governance is changed.
    /// @param newGovernance Address of the new governance.
    event GovernanceChanged(address indexed newGovernance);

    /// @notice Event emitted when the sdToken Operator is changed.
    event SdTokenOperatorChanged(address indexed newSdToken);

    /// @notice Event emitted Incentive percent is changed.
    event FeesChanged(uint256 newFee);

    /// @notice Throws if caller is not the governance.
    error GOVERNANCE();

    /// @notice Throws if the deposit amount is zero.
    error AMOUNT_ZERO();

    /// @notice Throws if the address is zero.
    error ADDRESS_ZERO();

    ////////////////////////////////////////////////////////////////
    /// --- MODIFIERS
    ///////////////////////////////////////////////////////////////

    modifier onlyGovernance() {
        if (msg.sender != governance) revert GOVERNANCE();
        _;
    }

    constructor(address _token, address _locker, address _minter, address _gauge, uint256 _maxLockDuration) {
        governance = msg.sender;

        token = _token;
        gauge = _gauge;
        minter = _minter;
        locker = _locker;

        MAX_LOCK_DURATION = _maxLockDuration;

        /// Approve sdToken to gauge.
        if (gauge != address(0)) {
            IERC20(minter).safeApprove(gauge, type(uint256).max);
        }
    }

    ////////////////////////////////////////////////////////////////
    /// --- DEPOSIT & LOCK
    ///////////////////////////////////////////////////////////////

    /// @notice Initiate a lock in the Locker contract.
    /// @param _amount Amount of tokens to lock.
    function createLock(uint256 _amount) external virtual {
        /// Transfer tokens to this contract
        IERC20(token).safeTransferFrom(msg.sender, address(locker), _amount);

        /// Can be called only once.
        ILocker(locker).createLock(_amount, block.timestamp + MAX_LOCK_DURATION);

        /// Mint sdToken to msg.sender.
        ITokenMinter(minter).mint(msg.sender, _amount);

        emit CreateLock(_amount, block.timestamp + MAX_LOCK_DURATION);
    }

    /// @notice Deposit tokens, and receive sdToken or sdTokenGauge in return.
    /// @param _amount Amount of tokens to deposit.
    /// @param _lock Whether to lock the tokens in the locker contract.
    /// @param _stake Whether to stake the sdToken in the gauge.
    /// @param _user Address of the user to receive the sdToken.
    /// @dev If the lock is true, the tokens are directly sent to the locker and increase the lock amount as veToken.
    /// If the lock is false, the tokens are sent to this contract until someone locks them. A small percent of the deposit
    /// is used to incentivize users to lock the tokens.
    /// If the stake is true, the sdToken is staked in the gauge that distributes rewards. If the stake is false, the sdToken
    /// is sent to the user.
    function deposit(uint256 _amount, bool _lock, bool _stake, address _user) public {
        if (_amount == 0) revert AMOUNT_ZERO();
        if (_user == address(0)) revert ADDRESS_ZERO();

        /// If _lock is true, lock tokens in the locker contract.
        if (_lock) {
            /// Transfer tokens to this contract
            IERC20(token).safeTransferFrom(msg.sender, locker, _amount);

            /// Transfer the balance
            uint256 balance = IERC20(token).balanceOf(address(this));

            if (balance != 0) {
                IERC20(token).safeTransfer(locker, balance);
            }

            /// Lock the amount sent + balance of the contract.
            _lockToken(balance + _amount);

            /// If an incentive is available, add it to the amount.
            if (incentiveToken != 0) {
                _amount += incentiveToken;

                emit IncentiveReceived(msg.sender, incentiveToken);

                incentiveToken = 0;
            }
        } else {
            /// Transfer tokens to the locker contract and lock them.
            IERC20(token).safeTransferFrom(msg.sender, address(this), _amount);

            /// Compute call incentive and add to incentiveToken
            uint256 callIncentive = (_amount * lockIncentivePercent) / DENOMINATOR;

            /// Subtract call incentive from _amount
            _amount -= callIncentive;

            /// Add call incentive to incentiveToken
            incentiveToken += callIncentive;
        }
        // Mint sdtoken to the user if the gauge is not set
        if (_stake && gauge != address(0)) {
            /// Mint sdToken to this contract.
            ITokenMinter(minter).mint(address(this), _amount);

            /// Deposit sdToken into gauge for _user.
            ILiquidityGauge(gauge).deposit(_amount, _user);
        } else {
            /// Mint sdToken to _user.
            ITokenMinter(minter).mint(_user, _amount);
        }
        emit Deposited(msg.sender, _user, _amount, _lock, _stake);
    }

    /// @notice Lock tokens held by the contract
    /// @dev The contract must have Token to lock
    function lockToken() external {
        uint256 tokenBalance = IERC20(token).balanceOf(address(this));

        if (tokenBalance != 0) {
            /// Transfer tokens to the locker contract and lock them.
            IERC20(token).safeTransfer(locker, tokenBalance);
            _lockToken(tokenBalance);
        }

        /// If there is incentive available give it to the user calling lockToken.
        if (incentiveToken != 0) {
            /// Mint incentiveToken to msg.sender.
            ITokenMinter(minter).mint(msg.sender, incentiveToken);

            emit IncentiveReceived(msg.sender, incentiveToken);

            /// Reset incentiveToken.
            incentiveToken = 0;
        }
    }

    /// @notice Locks the tokens held by the contract
    /// @dev The contract must have tokens to lock
    function _lockToken(uint256 _amount) internal virtual {
        // If there is Token available in the contract transfer it to the locker
        if (_amount != 0) {
            /// Increase the lock.
            ILocker(locker).increaseLock(_amount, block.timestamp + MAX_LOCK_DURATION);

            emit TokenLocked(msg.sender, _amount);
        }
    }

    ////////////////////////////////////////////////////////////////
    /// --- GOVERNANCE PARAMETERS
    ///////////////////////////////////////////////////////////////

    /// @notice Transfer the governance to a new address.
    /// @param _governance Address of the new governance.
    function transferGovernance(address _governance) external onlyGovernance {
        futureGovernance = _governance;
    }

    /// @notice Accept the governance transfer.
    function acceptGovernance() external {
        if (msg.sender != futureGovernance) revert GOVERNANCE();

        governance = msg.sender;
        emit GovernanceChanged(msg.sender);
    }

    /// @notice Set the new operator for minting sdToken
    /// @param _minter operator minter address
    function setSdTokenMinterOperator(address _minter) external onlyGovernance {
        ISdToken(minter).setOperator(_minter);
        emit SdTokenOperatorChanged(_minter);
    }

    /// @notice Set the gauge to deposit sdToken
    /// @param _gauge gauge address
    function setGauge(address _gauge) external onlyGovernance {
        gauge = _gauge;
        if (_gauge != address(0)) {
            /// Approve sdToken to gauge.
            IERC20(minter).safeApprove(gauge, type(uint256).max);
        }
    }

    /// @notice Set the percentage of the lock incentive
    /// @param _lockIncentive Percentage of the lock incentive
    function setFees(uint256 _lockIncentive) external onlyGovernance {
        if (_lockIncentive >= 0 && _lockIncentive <= 30) {
            emit FeesChanged(lockIncentivePercent = _lockIncentive);
        }
    }
}

// src/base/extension/CurveExchangeDepositor.sol

/// @title CurveExchange
/// @notice Contract that accepts tokens and locks them in the Locker, minting sdToken in return
/// @dev Adapted for veCRV like Locker.
/// @author StakeDAO
/// @custom:contact [email protected]
abstract contract CurveExchangeDepositor is DepositorV4 {
    using SafeERC20 for IERC20;

    /// @notice Address of the sdToken pool.
    address public pool;

    /// @notice Event emitted when tokens are deposited.
    /// @param caller Address of the caller.
    /// @param user Address of the user.
    /// @param amount Amount of tokens deposited.
    /// @param stake Whether the sdToken is staked in the gauge.
    event Deposited(address indexed caller, address indexed user, uint256 amount, bool stake);

    constructor(
        address _token,
        address _locker,
        address _minter,
        address _gauge,
        uint256 _maxLockDuration,
        address _pool
    ) DepositorV4(_token, _locker, _minter, _gauge, _maxLockDuration) {
        pool = _pool;

        /// Approve sdToken to gauge.
        if (_pool != address(0)) {
            IERC20(_token).safeApprove(_pool, type(uint256).max);
        }
    }

    /// @notice Deposit using the sdToken pool.
    /// @param _amount Amount of tokens to deposit.
    /// @param _minAmount Minimum amount of tokens to receive.
    /// @param _stake Whether to stake the sdToken in the gauge.
    /// @param _user Address of the user.
    function deposit(uint256 _amount, uint256 _minAmount, bool _stake, address _user) public {
        if (_amount == 0) revert AMOUNT_ZERO();
        if (_user == address(0)) revert ADDRESS_ZERO();

        /// Transfer tokens from the user to the contract.
        IERC20(token).safeTransferFrom(msg.sender, address(this), _amount);

        // Mint sdtoken to the user if the gauge is not set
        if (_stake && gauge != address(0)) {
            _amount = _swap(_amount, _minAmount, address(this));

            /// Deposit sdToken into gauge for _user.
            ILiquidityGauge(gauge).deposit(_amount, _user);
        } else {
            _amount = _swap(_amount, _minAmount, _user);
        }

        emit Deposited(msg.sender, _user, _amount, _stake);
    }

    /// @notice Swap tokens using the sdToken pool.
    /// @param _amount Amount of tokens to swap.
    /// @param _minAmount Minimum amount of tokens to receive.
    /// @param _receiver Address of the receiver.
    function _swap(uint256 _amount, uint256 _minAmount, address _receiver) internal returns (uint256) {
        return ICurvePool(pool).exchange(0, 1, _amount, _minAmount, _receiver);
    }

    /// @notice Set the pool address.
    /// @param _pool Address of the sdToken pool
    function setPool(address _pool) external onlyGovernance {
        pool = _pool;

        /// Approve sdToken to gauge.
        if (_pool != address(0)) {
            IERC20(token).safeApprove(_pool, type(uint256).max);
        }
    }
}

// src/curve/depositor/CRVDepositorV2.sol

/// @title Depositor
/// @notice Contract that accepts tokens and locks them in the Locker, minting sdToken in return
/// @author StakeDAO
/// @custom:contact [email protected]
contract CRVDepositorV2 is CurveExchangeDepositor {
    /// @notice Address of the veCRV token.
    address public constant VE_CRV = 0x5f3b5DfEb7B28CDbD7FAba78963EE202a494e2A2;

    /// @notice Address of the sdveCRV token.
    address public constant SD_VE_CRV = 0x478bBC744811eE8310B461514BDc29D03739084D;

    constructor(address _token, address _locker, address _minter, address _gauge, address _pool)
        CurveExchangeDepositor(_token, _locker, _minter, _gauge, 4 * 365 days, _pool)
    {}

    /// Override the createLock function to prevent reverting.
    function createLock(uint256 _amount) external override {}

    /// @notice Locks the tokens held by the contract
    /// @dev The contract must have tokens to lock
    function _lockToken(uint256 _amount) internal override {
        // If there is Token available in the contract transfer it to the locker
        if (_amount != 0) {
            /// Increase the lock.
            ILocker(locker).increaseAmount(_amount);

            uint256 _unlockTime = block.timestamp + MAX_LOCK_DURATION;
            bool _canIncrease = (_unlockTime / 1 weeks * 1 weeks) > (IVeToken(VE_CRV).locked__end(locker));

            /// Increase the unlock time if the lock is not at the maximum duration.
            if (_canIncrease) {
                IExecutor(locker).execute(
                    VE_CRV, 0, abi.encodeWithSignature("increase_unlock_time(uint256)", _unlockTime)
                );
            }

            emit TokenLocked(msg.sender, _amount);
        }
    }

    /// @notice Lock forever (irreversible action) old sdveCrv to sdCrv with 1:1 rate.
    /// @param _amount Amount to lock.
    function lockSdveCrvToSdCrv(uint256 _amount) external {
        IERC20(SD_VE_CRV).transferFrom(msg.sender, address(this), _amount);
        // mint new sdCrv to the user
        ITokenMinter(minter).mint(msg.sender, _amount);
    }
}