Contract Name:
FarmTreasuryV1
Contract Source Code:
File 1 of 1 : FarmTreasuryV1
// SPDX-License-Identifier: MIT
/*
This is a Stacker.vc FarmTreasury version 1 contract. It deploys a rebase token where it rebases to be equivalent to it's underlying token. 1 stackUSDT = 1 USDT.
The underlying assets are used to farm on different smart contract and produce yield via the ever-expanding DeFi ecosystem.
THANKS! To Lido DAO for the inspiration in more ways than one, but especially for a lot of the code here.
If you haven't already, stake your ETH for ETH2.0 with Lido.fi!
Also thanks for Aragon for hosting our Stacker Ventures DAO, and for more inspiration!
*/
pragma solidity ^0.6.11;
/*
* @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 GSN 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 payable) {
return msg.sender;
}
function _msgData() internal view virtual returns (bytes memory) {
this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
return msg.data;
}
}
/**
* @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
* ====
*/
function isContract(address account) internal view returns (bool) {
// This method relies on extcodesize, which returns 0 for contracts in
// construction, since the code is only stored at the end of the
// constructor execution.
uint256 size;
// solhint-disable-next-line no-inline-assembly
assembly { size := extcodesize(account) }
return size > 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://diligence.consensys.net/posts/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/v0.5.11/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");
// solhint-disable-next-line avoid-low-level-calls, avoid-call-value
(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 functionCall(target, data, "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");
require(isContract(target), "Address: call to non-contract");
// solhint-disable-next-line avoid-low-level-calls
(bool success, bytes memory returndata) = target.call{ value: value }(data);
return _verifyCallResult(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) {
require(isContract(target), "Address: static call to non-contract");
// solhint-disable-next-line avoid-low-level-calls
(bool success, bytes memory returndata) = target.staticcall(data);
return _verifyCallResult(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) {
require(isContract(target), "Address: delegate call to non-contract");
// solhint-disable-next-line avoid-low-level-calls
(bool success, bytes memory returndata) = target.delegatecall(data);
return _verifyCallResult(success, returndata, errorMessage);
}
function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns(bytes memory) {
if (success) {
return returndata;
} else {
// 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
// solhint-disable-next-line no-inline-assembly
assembly {
let returndata_size := mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert(errorMessage);
}
}
}
}
/**
* @dev Contract module that helps prevent reentrant calls to a function.
*
* Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
* available, which can be applied to functions to make sure there are no nested
* (reentrant) calls to them.
*
* Note that because there is a single `nonReentrant` guard, functions marked as
* `nonReentrant` may not call one another. This can be worked around by making
* those functions `private`, and then adding `external` `nonReentrant` entry
* points to them.
*
* TIP: If you would like to learn more about reentrancy and alternative ways
* to protect against it, check out our blog post
* https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
*/
abstract contract ReentrancyGuard {
// Booleans are more expensive than uint256 or any type that takes up a full
// word because each write operation emits an extra SLOAD to first read the
// slot's contents, replace the bits taken up by the boolean, and then write
// back. This is the compiler's defense against contract upgrades and
// pointer aliasing, and it cannot be disabled.
// The values being non-zero value makes deployment a bit more expensive,
// but in exchange the refund on every call to nonReentrant will be lower in
// amount. Since refunds are capped to a percentage of the total
// transaction's gas, it is best to keep them low in cases like this one, to
// increase the likelihood of the full refund coming into effect.
uint256 private constant _NOT_ENTERED = 1;
uint256 private constant _ENTERED = 2;
uint256 private _status;
constructor () internal {
_status = _NOT_ENTERED;
}
/**
* @dev Prevents a contract from calling itself, directly or indirectly.
* Calling a `nonReentrant` function from another `nonReentrant`
* function is not supported. It is possible to prevent this from happening
* by making the `nonReentrant` function external, and make it call a
* `private` function that does the actual work.
*/
modifier nonReentrant() {
// On the first call to nonReentrant, _notEntered will be true
require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
// Any calls to nonReentrant after this point will fail
_status = _ENTERED;
_;
// By storing the original value once again, a refund is triggered (see
// https://eips.ethereum.org/EIPS/eip-2200)
_status = _NOT_ENTERED;
}
}
/**
* @dev Wrappers over Solidity's arithmetic operations with added overflow
* checks.
*
* Arithmetic operations in Solidity wrap on overflow. This can easily result
* in bugs, because programmers usually assume that an overflow raises an
* error, which is the standard behavior in high level programming languages.
* `SafeMath` restores this intuition by reverting the transaction when an
* operation overflows.
*
* Using this library instead of the unchecked operations eliminates an entire
* class of bugs, so it's recommended to use it always.
*/
library SafeMath {
/**
* @dev Returns the addition of two unsigned integers, with an overflow flag.
*
* _Available since v3.4._
*/
function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
uint256 c = a + b;
if (c < a) return (false, 0);
return (true, c);
}
/**
* @dev Returns the substraction of two unsigned integers, with an overflow flag.
*
* _Available since v3.4._
*/
function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
if (b > a) return (false, 0);
return (true, a - b);
}
/**
* @dev Returns the multiplication of two unsigned integers, with an overflow flag.
*
* _Available since v3.4._
*/
function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
// Gas optimization: this is cheaper than requiring 'a' not being zero, but the
// benefit is lost if 'b' is also tested.
// See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
if (a == 0) return (true, 0);
uint256 c = a * b;
if (c / a != b) return (false, 0);
return (true, c);
}
/**
* @dev Returns the division of two unsigned integers, with a division by zero flag.
*
* _Available since v3.4._
*/
function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
if (b == 0) return (false, 0);
return (true, a / b);
}
/**
* @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
*
* _Available since v3.4._
*/
function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
if (b == 0) return (false, 0);
return (true, a % b);
}
/**
* @dev Returns the addition of two unsigned integers, reverting on
* overflow.
*
* Counterpart to Solidity's `+` operator.
*
* Requirements:
*
* - Addition cannot overflow.
*/
function add(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 c = a + b;
require(c >= a, "SafeMath: addition overflow");
return c;
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting on
* overflow (when the result is negative).
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
*
* - Subtraction cannot overflow.
*/
function sub(uint256 a, uint256 b) internal pure returns (uint256) {
require(b <= a, "SafeMath: subtraction overflow");
return a - b;
}
/**
* @dev Returns the multiplication of two unsigned integers, reverting on
* overflow.
*
* Counterpart to Solidity's `*` operator.
*
* Requirements:
*
* - Multiplication cannot overflow.
*/
function mul(uint256 a, uint256 b) internal pure returns (uint256) {
if (a == 0) return 0;
uint256 c = a * b;
require(c / a == b, "SafeMath: multiplication overflow");
return c;
}
/**
* @dev Returns the integer division of two unsigned integers, reverting on
* division by zero. The result is rounded towards zero.
*
* Counterpart to Solidity's `/` operator. Note: this function uses a
* `revert` opcode (which leaves remaining gas untouched) while Solidity
* uses an invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function div(uint256 a, uint256 b) internal pure returns (uint256) {
require(b > 0, "SafeMath: division by zero");
return a / b;
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* reverting when dividing by zero.
*
* Counterpart to Solidity's `%` operator. This function uses a `revert`
* opcode (which leaves remaining gas untouched) while Solidity uses an
* invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function mod(uint256 a, uint256 b) internal pure returns (uint256) {
require(b > 0, "SafeMath: modulo by zero");
return a % b;
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting with custom message on
* overflow (when the result is negative).
*
* CAUTION: This function is deprecated because it requires allocating memory for the error
* message unnecessarily. For custom revert reasons use {trySub}.
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
*
* - Subtraction cannot overflow.
*/
function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b <= a, errorMessage);
return a - b;
}
/**
* @dev Returns the integer division of two unsigned integers, reverting with custom message on
* division by zero. The result is rounded towards zero.
*
* CAUTION: This function is deprecated because it requires allocating memory for the error
* message unnecessarily. For custom revert reasons use {tryDiv}.
*
* Counterpart to Solidity's `/` operator. Note: this function uses a
* `revert` opcode (which leaves remaining gas untouched) while Solidity
* uses an invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b > 0, errorMessage);
return a / b;
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* reverting with custom message when dividing by zero.
*
* CAUTION: This function is deprecated because it requires allocating memory for the error
* message unnecessarily. For custom revert reasons use {tryMod}.
*
* Counterpart to Solidity's `%` operator. This function uses a `revert`
* opcode (which leaves remaining gas untouched) while Solidity uses an
* invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b > 0, errorMessage);
return a % b;
}
}
/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/
interface IERC20 {
/**
* @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 `recipient`.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transfer(address recipient, 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 `sender` to `recipient` 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 sender, address recipient, uint256 amount) external returns (bool);
/**
* @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);
}
/**
* @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 SafeMath for uint256;
using Address for address;
function safeTransfer(IERC20 token, address to, uint256 value) internal {
_callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
}
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'
// solhint-disable-next-line max-line-length
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));
}
function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
uint256 newAllowance = token.allowance(address(this), spender).add(value);
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
}
function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
uint256 newAllowance = token.allowance(address(this), spender).sub(value, "SafeERC20: decreased allowance below zero");
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
}
/**
* @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");
if (returndata.length > 0) { // Return data is optional
// solhint-disable-next-line max-line-length
require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
}
}
}
abstract contract FarmTokenV1 is IERC20 {
using SafeMath for uint256;
using Address for address;
// shares are how a users balance is generated. For rebase tokens, balances are always generated at runtime, while shares stay constant.
// shares is your proportion of the total pool of invested UnderlyingToken
// shares are like a Compound.finance cToken, while our token balances are like an Aave aToken.
mapping(address => uint256) private shares;
mapping(address => mapping (address => uint256)) private allowances;
uint256 public totalShares;
string public name;
string public symbol;
string public underlying;
address public underlyingContract;
uint8 public decimals;
event Transfer(address indexed from, address indexed to, uint256 value);
event Approval(address indexed owner, address indexed spender, uint256 value);
constructor(string memory _name, uint8 _decimals, address _underlyingContract) public {
name = string(abi.encodePacked(abi.encodePacked("Stacker Ventures ", _name), " v1"));
symbol = string(abi.encodePacked("stack", _name));
underlying = _name;
decimals = _decimals;
underlyingContract = _underlyingContract;
}
// 1 stackToken = 1 underlying token
function totalSupply() external override view returns (uint256){
return _getTotalUnderlying();
}
function totalUnderlying() external view returns (uint256){
return _getTotalUnderlying();
}
function balanceOf(address _account) public override view returns (uint256){
return getUnderlyingForShares(_sharesOf(_account));
}
// transfer tokens, not shares
function transfer(address _recipient, uint256 _amount) external override returns (bool){
_verify(msg.sender, _amount);
_transfer(msg.sender, _recipient, _amount);
return true;
}
function transferFrom(address _sender, address _recipient, uint256 _amount) external override returns (bool){
_verify(_sender, _amount);
uint256 _currentAllowance = allowances[_sender][msg.sender];
require(_currentAllowance >= _amount, "FARMTOKENV1: not enough allowance");
_transfer(_sender, _recipient, _amount);
_approve(_sender, msg.sender, _currentAllowance.sub(_amount));
return true;
}
// this checks if a transfer/transferFrom/withdraw is allowed. There are some conditions on withdraws/transfers from new deposits
// function stub, this needs to be implemented in a contract which inherits this for a valid deployment
// IMPLEMENT THIS
function _verify(address _account, uint256 _amountUnderlyingToSend) internal virtual;
// allow tokens, not shares
function allowance(address _owner, address _spender) external override view returns (uint256){
return allowances[_owner][_spender];
}
// approve tokens, not shares
function approve(address _spender, uint256 _amount) external override returns (bool){
_approve(msg.sender, _spender, _amount);
return true;
}
// shares of _account
function sharesOf(address _account) external view returns (uint256) {
return _sharesOf(_account);
}
// how many shares for _amount of underlying?
// if there are no shares, or no underlying yet, we are initing the contract or suffered a total loss
// either way, init this state at 1:1 shares:underlying
function getSharesForUnderlying(uint256 _amountUnderlying) public view returns (uint256){
uint256 _totalUnderlying = _getTotalUnderlying();
if (_totalUnderlying == 0){
return _amountUnderlying; // this will init at 1:1 _underlying:_shares
}
uint256 _totalShares = totalShares;
if (_totalShares == 0){
return _amountUnderlying; // this will init the first shares, expected contract underlying balance == 0, or there will be a bonus (doesn't belong to anyone so ok)
}
return _amountUnderlying.mul(_totalShares).div(_totalUnderlying);
}
// how many underlying for _amount of shares?
// if there are no shares, or no underlying yet, we are initing the contract or suffered a total loss
// either way, init this state at 1:1 shares:underlying
function getUnderlyingForShares(uint256 _amountShares) public view returns (uint256){
uint256 _totalShares = totalShares;
if (_totalShares == 0){
return _amountShares; // this will init at 1:1 _shares:_underlying
}
uint256 _totalUnderlying = _getTotalUnderlying();
if (_totalUnderlying == 0){
return _amountShares; // this will init at 1:1
}
return _amountShares.mul(_totalUnderlying).div(_totalShares);
}
function _sharesOf(address _account) internal view returns (uint256){
return shares[_account];
}
// function stub, this needs to be implemented in a contract which inherits this for a valid deployment
// sum the contract balance + working balance withdrawn from the contract and actively farming
// IMPLEMENT THIS
function _getTotalUnderlying() internal virtual view returns (uint256);
// in underlying
function _transfer(address _sender, address _recipient, uint256 _amount) internal {
uint256 _sharesToTransfer = getSharesForUnderlying(_amount);
_transferShares(_sender, _recipient, _sharesToTransfer);
emit Transfer(_sender, _recipient, _amount);
}
// in underlying
function _approve(address _owner, address _spender, uint256 _amount) internal {
require(_owner != address(0), "FARMTOKENV1: from == 0x0");
require(_spender != address(0), "FARMTOKENV1: to == 0x00");
allowances[_owner][_spender] = _amount;
emit Approval(_owner, _spender, _amount);
}
function _transferShares(address _sender, address _recipient, uint256 _amountShares) internal {
require(_sender != address(0), "FARMTOKENV1: from == 0x00");
require(_recipient != address(0), "FARMTOKENV1: to == 0x00");
uint256 _currentSenderShares = shares[_sender];
require(_amountShares <= _currentSenderShares, "FARMTOKENV1: transfer amount exceeds balance");
shares[_sender] = _currentSenderShares.sub(_amountShares);
shares[_recipient] = shares[_recipient].add(_amountShares);
}
function _mintShares(address _recipient, uint256 _amountShares) internal {
require(_recipient != address(0), "FARMTOKENV1: to == 0x00");
totalShares = totalShares.add(_amountShares);
shares[_recipient] = shares[_recipient].add(_amountShares);
// NOTE: we're not emitting a Transfer event from the zero address here
// If we mint shares with no underlying, we basically just diluted everyone
// It's not possible to send events from _everyone_ to reflect each balance dilution (ie: balance going down)
// Not compliant to ERC20 standard...
}
function _burnShares(address _account, uint256 _amountShares) internal {
require(_account != address(0), "FARMTOKENV1: burn from == 0x00");
uint256 _accountShares = shares[_account];
require(_amountShares <= _accountShares, "FARMTOKENV1: burn amount exceeds balance");
totalShares = totalShares.sub(_amountShares);
shares[_account] = _accountShares.sub(_amountShares);
// NOTE: we're not emitting a Transfer event to the zero address here
// If we burn shares without burning/withdrawing the underlying
// then it looks like a system wide credit to everyones balance
// It's not possible to send events to _everyone_ to reflect each balance credit (ie: balance going up)
// Not compliant to ERC20 standard...
}
}
contract FarmTreasuryV1 is ReentrancyGuard, FarmTokenV1 {
using SafeERC20 for IERC20;
using SafeMath for uint256;
using Address for address;
mapping(address => DepositInfo) public userDeposits;
mapping(address => bool) public noLockWhitelist;
struct DepositInfo {
uint256 amountUnderlyingLocked;
uint256 timestampDeposit;
uint256 timestampUnlocked;
}
uint256 internal constant LOOP_LIMIT = 200;
address payable public governance;
address payable public farmBoss;
bool public paused = false;
bool public pausedDeposits = false;
// fee schedule, can be changed by governance, in bips
// performance fee is on any gains, base fee is on AUM/yearly
uint256 public constant max = 10000;
uint256 public performanceToTreasury = 1000;
uint256 public performanceToFarmer = 1000;
uint256 public baseToTreasury = 100;
uint256 public baseToFarmer = 100;
// limits on rebalancing from the farmer, trying to negate errant rebalances
uint256 public rebalanceUpLimit = 100; // maximum of a 1% gain per rebalance
uint256 public rebalanceUpWaitTime = 23 hours;
uint256 public lastRebalanceUpTime;
// waiting period on withdraws from time of deposit
// locked amount linearly decreases until the time is up, so at waitPeriod/2 after deposit, you can withdraw depositAmt/2 funds.
uint256 public waitPeriod = 1 weeks;
// hot wallet holdings for instant withdraw, in bips
// if the hot wallet balance expires, the users will need to wait for the next rebalance period in order to withdraw
uint256 public hotWalletHoldings = 1000; // 10% initially
uint256 public ACTIVELY_FARMED;
event RebalanceHot(uint256 amountIn, uint256 amountToFarmer, uint256 timestamp);
event ProfitDeclared(bool profit, uint256 amount, uint256 timestamp, uint256 totalAmountInPool, uint256 totalSharesInPool, uint256 performanceFeeTotal, uint256 baseFeeTotal);
event Deposit(address depositor, uint256 amount, address referral);
event Withdraw(address withdrawer, uint256 amount);
constructor(string memory _nameUnderlying, uint8 _decimalsUnderlying, address _underlying) public FarmTokenV1(_nameUnderlying, _decimalsUnderlying, _underlying) {
governance = msg.sender;
lastRebalanceUpTime = block.timestamp;
}
function setGovernance(address payable _new) external {
require(msg.sender == governance, "FARMTREASURYV1: !governance");
governance = _new;
}
// the "farmBoss" is a trusted smart contract that functions kind of like an EOA.
// HOWEVER specific contract addresses need to be whitelisted in order for this contract to be allowed to interact w/ them
// the governance has full control over the farmBoss, and other addresses can have partial control for strategy rotation/rebalancing
function setFarmBoss(address payable _new) external {
require(msg.sender == governance, "FARMTREASURYV1: !governance");
farmBoss = _new;
}
function setNoLockWhitelist(address[] calldata _accounts, bool[] calldata _noLock) external {
require(msg.sender == governance, "FARMTREASURYV1: !governance");
require(_accounts.length == _noLock.length && _accounts.length <= LOOP_LIMIT, "FARMTREASURYV1: check array lengths");
for (uint256 i = 0; i < _accounts.length; i++){
noLockWhitelist[_accounts[i]] = _noLock[i];
}
}
function pause() external {
require(msg.sender == governance, "FARMTREASURYV1: !governance");
paused = true;
}
function unpause() external {
require(msg.sender == governance, "FARMTREASURYV1: !governance");
paused = false;
}
function pauseDeposits() external {
require(msg.sender == governance, "FARMTREASURYV1: !governance");
pausedDeposits = true;
}
function unpauseDeposits() external {
require(msg.sender == governance, "FARMTREASURYV1: !governance");
pausedDeposits = false;
}
function setFeeDistribution(uint256 _performanceToTreasury, uint256 _performanceToFarmer, uint256 _baseToTreasury, uint256 _baseToFarmer) external {
require(msg.sender == governance, "FARMTREASURYV1: !governance");
require(_performanceToTreasury.add(_performanceToFarmer) < max, "FARMTREASURYV1: too high performance");
require(_baseToTreasury.add(_baseToFarmer) <= 500, "FARMTREASURYV1: too high base");
performanceToTreasury = _performanceToTreasury;
performanceToFarmer = _performanceToFarmer;
baseToTreasury = _baseToTreasury;
baseToFarmer = _baseToFarmer;
}
function setWaitPeriod(uint256 _new) external {
require(msg.sender == governance, "FARMTREASURYV1: !governance");
require(_new <= 10 weeks, "FARMTREASURYV1: too long wait");
waitPeriod = _new;
}
function setHotWalletHoldings(uint256 _new) external {
require(msg.sender == governance, "FARMTREASURYV1: !governance");
require(_new <= max && _new >= 100, "FARMTREASURYV1: hot wallet values bad");
hotWalletHoldings = _new;
}
function setRebalanceUpLimit(uint256 _new) external {
require(msg.sender == governance, "FARMTREASURYV1: !governance");
require(_new < max, "FARMTREASURYV1: >= max");
rebalanceUpLimit = _new;
}
function setRebalanceUpWaitTime(uint256 _new) external {
require(msg.sender == governance, "FARMTREASURYV1: !governance");
require(_new <= 1 weeks, "FARMTREASURYV1: > 1 week");
rebalanceUpWaitTime = _new;
}
function deposit(uint256 _amountUnderlying, address _referral) external nonReentrant {
require(_amountUnderlying > 0, "FARMTREASURYV1: amount == 0");
require(!paused && !pausedDeposits, "FARMTREASURYV1: paused");
_deposit(_amountUnderlying, _referral);
IERC20 _underlying = IERC20(underlyingContract);
uint256 _before = _underlying.balanceOf(address(this));
_underlying.safeTransferFrom(msg.sender, address(this), _amountUnderlying);
uint256 _after = _underlying.balanceOf(address(this));
uint256 _total = _after.sub(_before);
require(_total >= _amountUnderlying, "FARMTREASURYV1: bad transfer");
}
function _deposit(uint256 _amountUnderlying, address _referral) internal {
// determine how many shares this will be
uint256 _sharesToMint = getSharesForUnderlying(_amountUnderlying);
_mintShares(msg.sender, _sharesToMint);
// store some important info for this deposit, that will be checked on withdraw/transfer of tokens
_storeDepositInfo(msg.sender, _amountUnderlying);
// emit deposit w/ referral event... can't refer yourself
if (_referral != msg.sender){
emit Deposit(msg.sender, _amountUnderlying, _referral);
}
else {
emit Deposit(msg.sender, _amountUnderlying, address(0));
}
emit Transfer(address(0), msg.sender, _amountUnderlying);
}
function _storeDepositInfo(address _account, uint256 _amountUnderlying) internal {
DepositInfo memory _existingInfo = userDeposits[_account];
// first deposit, make a new entry in the mapping, lock all funds for "waitPeriod"
if (_existingInfo.timestampDeposit == 0){
DepositInfo memory _info = DepositInfo(
{
amountUnderlyingLocked: _amountUnderlying,
timestampDeposit: block.timestamp,
timestampUnlocked: block.timestamp.add(waitPeriod)
}
);
userDeposits[_account] = _info;
}
// not the first deposit, if there are still funds locked, then average out the waits (ie: 1 BTC locked 10 days = 2 BTC locked 5 days)
else {
uint256 _lockedAmt = _getLockedAmount(_account, _existingInfo.amountUnderlyingLocked, _existingInfo.timestampDeposit, _existingInfo.timestampUnlocked);
// if there's no lock, disregard old info and make a new lock
if (_lockedAmt == 0){
DepositInfo memory _info = DepositInfo(
{
amountUnderlyingLocked: _amountUnderlying,
timestampDeposit: block.timestamp,
timestampUnlocked: block.timestamp.add(waitPeriod)
}
);
userDeposits[_account] = _info;
}
// funds are still locked from a past deposit, average out the waittime remaining with the waittime for this new deposit
/*
solve this equation:
newDepositAmt * waitPeriod + remainingAmt * existingWaitPeriod = (newDepositAmt + remainingAmt) * X waitPeriod
therefore:
(newDepositAmt * waitPeriod + remainingAmt * existingWaitPeriod)
X waitPeriod = ----------------------------------------------------------------
(newDepositAmt + remainingAmt)
Example: 7 BTC new deposit, with wait period of 2 weeks
1 BTC remaining, with remaining wait period of 1 week
...
(7 BTC * 2 weeks + 1 BTC * 1 week) / 8 BTC = 1.875 weeks
*/
else {
uint256 _lockedAmtTime = _lockedAmt.mul(_existingInfo.timestampUnlocked.sub(block.timestamp));
uint256 _newAmtTime = _amountUnderlying.mul(waitPeriod);
uint256 _total = _amountUnderlying.add(_lockedAmt);
uint256 _newLockedTime = (_lockedAmtTime.add(_newAmtTime)).div(_total);
DepositInfo memory _info = DepositInfo(
{
amountUnderlyingLocked: _total,
timestampDeposit: block.timestamp,
timestampUnlocked: block.timestamp.add(_newLockedTime)
}
);
userDeposits[_account] = _info;
}
}
}
function getLockedAmount(address _account) public view returns (uint256) {
DepositInfo memory _existingInfo = userDeposits[_account];
return _getLockedAmount(_account, _existingInfo.amountUnderlyingLocked, _existingInfo.timestampDeposit, _existingInfo.timestampUnlocked);
}
// the locked amount linearly decreases until the timestampUnlocked time, then it's zero
// Example: if 5 BTC contributed (2 week lock), then after 1 week there will be 2.5 BTC locked, the rest is free to transfer/withdraw
function _getLockedAmount(address _account, uint256 _amountLocked, uint256 _timestampDeposit, uint256 _timestampUnlocked) internal view returns (uint256) {
if (_timestampUnlocked <= block.timestamp || noLockWhitelist[_account]){
return 0;
}
else {
uint256 _remainingTime = _timestampUnlocked.sub(block.timestamp);
uint256 _totalTime = _timestampUnlocked.sub(_timestampDeposit);
return _amountLocked.mul(_remainingTime).div(_totalTime);
}
}
function withdraw(uint256 _amountUnderlying) external nonReentrant {
require(_amountUnderlying > 0, "FARMTREASURYV1: amount == 0");
require(!paused, "FARMTREASURYV1: paused");
_withdraw(_amountUnderlying);
IERC20(underlyingContract).safeTransfer(msg.sender, _amountUnderlying);
}
function _withdraw(uint256 _amountUnderlying) internal {
_verify(msg.sender, _amountUnderlying);
// try and catch the more obvious error of hot wallet being depleted, otherwise proceed
if (IERC20(underlyingContract).balanceOf(address(this)) < _amountUnderlying){
revert("FARMTREASURYV1: Hot wallet balance depleted. Please try smaller withdraw or wait for rebalancing.");
}
uint256 _sharesToBurn = getSharesForUnderlying(_amountUnderlying);
_burnShares(msg.sender, _sharesToBurn); // they must have >= _sharesToBurn, checked here
emit Transfer(msg.sender, address(0), _amountUnderlying);
emit Withdraw(msg.sender, _amountUnderlying);
}
// wait time verification
function _verify(address _account, uint256 _amountUnderlyingToSend) internal override {
DepositInfo memory _existingInfo = userDeposits[_account];
uint256 _lockedAmt = _getLockedAmount(_account, _existingInfo.amountUnderlyingLocked, _existingInfo.timestampDeposit, _existingInfo.timestampUnlocked);
uint256 _balance = balanceOf(_account);
// require that any funds locked are not leaving the account in question.
require(_balance.sub(_amountUnderlyingToSend) >= _lockedAmt, "FARMTREASURYV1: requested funds are temporarily locked");
}
// this means that we made a GAIN, due to standard farming gains
// operaratable by farmBoss, this is standard operating procedure, farmers can only report gains
function rebalanceUp(uint256 _amount, address _farmerRewards) external nonReentrant returns (bool, uint256) {
require(msg.sender == farmBoss, "FARMTREASURYV1: !farmBoss");
require(!paused, "FARMTREASURYV1: paused");
// fee logic & profit recording
// check farmer limits on rebalance wait time for earning reportings. if there is no _amount reported, we don't take any fees and skip these checks
// we should always allow pure hot wallet rebalances, however earnings needs some checks and restrictions
if (_amount > 0){
require(block.timestamp.sub(lastRebalanceUpTime) >= rebalanceUpWaitTime, "FARMTREASURYV1: <rebalanceUpWaitTime");
require(ACTIVELY_FARMED.mul(rebalanceUpLimit).div(max) >= _amount, "FARMTREASURYV1 _amount > rebalanceUpLimit");
// farmer incurred a gain of _amount, add this to the amount being farmed
ACTIVELY_FARMED = ACTIVELY_FARMED.add(_amount);
uint256 _totalPerformance = _performanceFee(_amount, _farmerRewards);
uint256 _totalAnnual = _annualFee(_farmerRewards);
// for farmer controls, and also for the annual fee time
// only update this if there is a reported gain, otherwise this is just a hot wallet rebalance, and we should always allow these
lastRebalanceUpTime = block.timestamp;
// for off-chain APY calculations, fees assessed
emit ProfitDeclared(true, _amount, block.timestamp, _getTotalUnderlying(), totalShares, _totalPerformance, _totalAnnual);
}
else {
// for off-chain APY calculations, no fees assessed
emit ProfitDeclared(true, _amount, block.timestamp, _getTotalUnderlying(), totalShares, 0, 0);
}
// end fee logic & profit recording
// funds are in the contract and gains are accounted for, now determine if we need to further rebalance the hot wallet up, or can take funds in order to farm
// start hot wallet and farmBoss rebalance logic
(bool _fundsNeeded, uint256 _amountChange) = _calcHotWallet();
_rebalanceHot(_fundsNeeded, _amountChange); // if the hot wallet rebalance fails, revert() the entire function
// end logic
return (_fundsNeeded, _amountChange); // in case we need them, FE simulations and such
}
// this means that the system took a loss, and it needs to be reflected in the next rebalance
// only operatable by governance, (large) losses should be extremely rare by good farming practices
// this would look like a farmed smart contract getting exploited/hacked, and us not having the necessary insurance for it
// possible that some more aggressive IL strategies could also need this function called
function rebalanceDown(uint256 _amount, bool _rebalanceHotWallet) external nonReentrant returns (bool, uint256) {
require(msg.sender == governance, "FARMTREASURYV1: !governance");
// require(!paused, "FARMTREASURYV1: paused"); <-- governance can only call this anyways, leave this commented out
ACTIVELY_FARMED = ACTIVELY_FARMED.sub(_amount);
if (_rebalanceHotWallet){
(bool _fundsNeeded, uint256 _amountChange) = _calcHotWallet();
_rebalanceHot(_fundsNeeded, _amountChange); // if the hot wallet rebalance fails, revert() the entire function
return (_fundsNeeded, _amountChange); // in case we need them, FE simulations and such
}
// for off-chain APY calculations, no fees assessed
emit ProfitDeclared(false, _amount, block.timestamp, _getTotalUnderlying(), totalShares, 0, 0);
return (false, 0);
}
function _performanceFee(uint256 _amount, address _farmerRewards) internal returns (uint256){
uint256 _existingShares = totalShares;
uint256 _balance = _getTotalUnderlying();
uint256 _performanceToFarmerUnderlying = _amount.mul(performanceToFarmer).div(max);
uint256 _performanceToTreasuryUnderlying = _amount.mul(performanceToTreasury).div(max);
uint256 _performanceTotalUnderlying = _performanceToFarmerUnderlying.add(_performanceToTreasuryUnderlying);
if (_performanceTotalUnderlying == 0){
return 0;
}
uint256 _sharesToMint = _underlyingFeeToShares(_performanceTotalUnderlying, _balance, _existingShares);
uint256 _sharesToFarmer = _sharesToMint.mul(_performanceToFarmerUnderlying).div(_performanceTotalUnderlying); // by the same ratio
uint256 _sharesToTreasury = _sharesToMint.sub(_sharesToFarmer);
_mintShares(_farmerRewards, _sharesToFarmer);
_mintShares(governance, _sharesToTreasury);
uint256 _underlyingFarmer = getUnderlyingForShares(_sharesToFarmer);
uint256 _underlyingTreasury = getUnderlyingForShares(_sharesToTreasury);
// do two mint events, in underlying, not shares
emit Transfer(address(0), _farmerRewards, _underlyingFarmer);
emit Transfer(address(0), governance, _underlyingTreasury);
return _underlyingFarmer.add(_underlyingTreasury);
}
// we are taking baseToTreasury + baseToFarmer each year, every time this is called, look when we took fee last, and linearize the fee to now();
function _annualFee(address _farmerRewards) internal returns (uint256) {
uint256 _lastAnnualFeeTime = lastRebalanceUpTime;
if (_lastAnnualFeeTime >= block.timestamp){
return 0;
}
uint256 _elapsedTime = block.timestamp.sub(_lastAnnualFeeTime);
uint256 _existingShares = totalShares;
uint256 _balance = _getTotalUnderlying();
uint256 _annualPossibleUnderlying = _balance.mul(_elapsedTime).div(365 days);
uint256 _annualToFarmerUnderlying = _annualPossibleUnderlying.mul(baseToFarmer).div(max);
uint256 _annualToTreasuryUnderlying = _annualPossibleUnderlying.mul(baseToFarmer).div(max);
uint256 _annualTotalUnderlying = _annualToFarmerUnderlying.add(_annualToTreasuryUnderlying);
if (_annualTotalUnderlying == 0){
return 0;
}
uint256 _sharesToMint = _underlyingFeeToShares(_annualTotalUnderlying, _balance, _existingShares);
uint256 _sharesToFarmer = _sharesToMint.mul(_annualToFarmerUnderlying).div(_annualTotalUnderlying); // by the same ratio
uint256 _sharesToTreasury = _sharesToMint.sub(_sharesToFarmer);
_mintShares(_farmerRewards, _sharesToFarmer);
_mintShares(governance, _sharesToTreasury);
uint256 _underlyingFarmer = getUnderlyingForShares(_sharesToFarmer);
uint256 _underlyingTreasury = getUnderlyingForShares(_sharesToTreasury);
// do two mint events, in underlying, not shares
emit Transfer(address(0), _farmerRewards, _underlyingFarmer);
emit Transfer(address(0), governance, _underlyingTreasury);
return _underlyingFarmer.add(_underlyingTreasury);
}
function _underlyingFeeToShares(uint256 _totalFeeUnderlying, uint256 _balance, uint256 _existingShares) pure internal returns (uint256 _sharesToMint){
// to mint the required amount of fee shares, solve:
/*
ratio:
currentShares newShares
-------------------------- : --------------------, where newShares = (currentShares + mintShares)
(totalUnderlying - feeAmt) totalUnderlying
solved:
---> (currentShares / (totalUnderlying - feeAmt) * totalUnderlying) - currentShares = mintShares, where newBalanceLessFee = (totalUnderlying - feeAmt)
*/
return _existingShares
.mul(_balance)
.div(_balance.sub(_totalFeeUnderlying))
.sub(_existingShares);
}
function _calcHotWallet() internal view returns (bool _fundsNeeded, uint256 _amountChange) {
uint256 _balanceHere = IERC20(underlyingContract).balanceOf(address(this));
uint256 _balanceFarmed = ACTIVELY_FARMED;
uint256 _totalAmount = _balanceHere.add(_balanceFarmed);
uint256 _hotAmount = _totalAmount.mul(hotWalletHoldings).div(max);
// we have too much in hot wallet, send to farmBoss
if (_balanceHere >= _hotAmount){
return (false, _balanceHere.sub(_hotAmount));
}
// we have too little in hot wallet, pull from farmBoss
if (_balanceHere < _hotAmount){
return (true, _hotAmount.sub(_balanceHere));
}
}
// usually paired with _calcHotWallet()
function _rebalanceHot(bool _fundsNeeded, uint256 _amountChange) internal {
if (_fundsNeeded){
uint256 _before = IERC20(underlyingContract).balanceOf(address(this));
IERC20(underlyingContract).safeTransferFrom(farmBoss, address(this), _amountChange);
uint256 _after = IERC20(underlyingContract).balanceOf(address(this));
uint256 _total = _after.sub(_before);
require(_total >= _amountChange, "FARMTREASURYV1: bad rebalance, hot wallet needs funds!");
// we took funds from the farmBoss to refill the hot wallet, reflect this in ACTIVELY_FARMED
ACTIVELY_FARMED = ACTIVELY_FARMED.sub(_amountChange);
emit RebalanceHot(_amountChange, 0, block.timestamp);
}
else {
require(farmBoss != address(0), "FARMTREASURYV1: !FarmBoss"); // don't burn funds
IERC20(underlyingContract).safeTransfer(farmBoss, _amountChange); // _calcHotWallet() guarantees we have funds here to send
// we sent more funds for the farmer to farm, reflect this
ACTIVELY_FARMED = ACTIVELY_FARMED.add(_amountChange);
emit RebalanceHot(0, _amountChange, block.timestamp);
}
}
function _getTotalUnderlying() internal override view returns (uint256) {
uint256 _balanceHere = IERC20(underlyingContract).balanceOf(address(this));
uint256 _balanceFarmed = ACTIVELY_FARMED;
return _balanceHere.add(_balanceFarmed);
}
function rescue(address _token, uint256 _amount) external nonReentrant {
require(msg.sender == governance, "FARMTREASURYV1: !governance");
if (_token != address(0)){
IERC20(_token).safeTransfer(governance, _amount);
}
else { // if _tokenContract is 0x0, then escape ETH
governance.transfer(_amount);
}
}
}