Ape.Cash Token & Staking - Smart Contract Audit Report

Summary

Ape.Cash Audit Report The Ape.Cash is a DeFi experiment that combines traditional deflationary tokens and staking incentives with charity. The token has a transfer fee which is split among burning tokens, rewarding developers, and giving to charity.

THIS IS A DRAFT; CONTRACTS ARE BEING UPDATED - current results are NOT VALID.

Ape.Cash's contracts have been deployed to the mainnet at the following addresses:
  • ApeToken - #
  • ApeStakingPool - #
  • Click here to download the source code as a .sol file.

    
    
    
    pragma solidity ^0.6.0;
    
    /*
     * @dev Provides information about the current execution context, including the
     * sender of the transaction and its data. While these are generally available
     * via msg.sender and msg.data, they should not be accessed in such a direct
     * manner, since when dealing with 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;
        }
    }
    
    pragma solidity >=0.6.2;
    
    interface IUniswapV2Router01 {
        function factory() external pure returns (address);
        function WETH() external pure returns (address);
    
        function addLiquidity(
            address tokenA,
            address tokenB,
            uint amountADesired,
            uint amountBDesired,
            uint amountAMin,
            uint amountBMin,
            address to,
            uint deadline
        ) external returns (uint amountA, uint amountB, uint liquidity);
        function addLiquidityETH(
            address token,
            uint amountTokenDesired,
            uint amountTokenMin,
            uint amountETHMin,
            address to,
            uint deadline
        ) external payable returns (uint amountToken, uint amountETH, uint liquidity);
        function removeLiquidity(
            address tokenA,
            address tokenB,
            uint liquidity,
            uint amountAMin,
            uint amountBMin,
            address to,
            uint deadline
        ) external returns (uint amountA, uint amountB);
        function removeLiquidityETH(
            address token,
            uint liquidity,
            uint amountTokenMin,
            uint amountETHMin,
            address to,
            uint deadline
        ) external returns (uint amountToken, uint amountETH);
        function removeLiquidityWithPermit(
            address tokenA,
            address tokenB,
            uint liquidity,
            uint amountAMin,
            uint amountBMin,
            address to,
            uint deadline,
            bool approveMax, uint8 v, bytes32 r, bytes32 s
        ) external returns (uint amountA, uint amountB);
        function removeLiquidityETHWithPermit(
            address token,
            uint liquidity,
            uint amountTokenMin,
            uint amountETHMin,
            address to,
            uint deadline,
            bool approveMax, uint8 v, bytes32 r, bytes32 s
        ) external returns (uint amountToken, uint amountETH);
        function swapExactTokensForTokens(
            uint amountIn,
            uint amountOutMin,
            address[] calldata path,
            address to,
            uint deadline
        ) external returns (uint[] memory amounts);
        function swapTokensForExactTokens(
            uint amountOut,
            uint amountInMax,
            address[] calldata path,
            address to,
            uint deadline
        ) external returns (uint[] memory amounts);
        function swapExactETHForTokens(uint amountOutMin, address[] calldata path, address to, uint deadline)
            external
            payable
            returns (uint[] memory amounts);
        function swapTokensForExactETH(uint amountOut, uint amountInMax, address[] calldata path, address to, uint deadline)
            external
            returns (uint[] memory amounts);
        function swapExactTokensForETH(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline)
            external
            returns (uint[] memory amounts);
        function swapETHForExactTokens(uint amountOut, address[] calldata path, address to, uint deadline)
            external
            payable
            returns (uint[] memory amounts);
    
        function quote(uint amountA, uint reserveA, uint reserveB) external pure returns (uint amountB);
        function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut) external pure returns (uint amountOut);
        function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut) external pure returns (uint amountIn);
        function getAmountsOut(uint amountIn, address[] calldata path) external view returns (uint[] memory amounts);
        function getAmountsIn(uint amountOut, address[] calldata path) external view returns (uint[] memory amounts);
    }
    
    pragma solidity >=0.6.2;
    
    interface IUniswapV2Router02 is IUniswapV2Router01 {
        function removeLiquidityETHSupportingFeeOnTransferTokens(
            address token,
            uint liquidity,
            uint amountTokenMin,
            uint amountETHMin,
            address to,
            uint deadline
        ) external returns (uint amountETH);
        function removeLiquidityETHWithPermitSupportingFeeOnTransferTokens(
            address token,
            uint liquidity,
            uint amountTokenMin,
            uint amountETHMin,
            address to,
            uint deadline,
            bool approveMax, uint8 v, bytes32 r, bytes32 s
        ) external returns (uint amountETH);
    
        function swapExactTokensForTokensSupportingFeeOnTransferTokens(
            uint amountIn,
            uint amountOutMin,
            address[] calldata path,
            address to,
            uint deadline
        ) external;
        function swapExactETHForTokensSupportingFeeOnTransferTokens(
            uint amountOutMin,
            address[] calldata path,
            address to,
            uint deadline
        ) external payable;
        function swapExactTokensForETHSupportingFeeOnTransferTokens(
            uint amountIn,
            uint amountOutMin,
            address[] calldata path,
            address to,
            uint deadline
        ) external;
    }
    
    pragma solidity >=0.5.0;
    
    interface IUniswapV2Pair {
        event Approval(address indexed owner, address indexed spender, uint value);
        event Transfer(address indexed from, address indexed to, uint value);
    
        function name() external pure returns (string memory);
        function symbol() external pure returns (string memory);
        function decimals() external pure returns (uint8);
        function totalSupply() external view returns (uint);
        function balanceOf(address owner) external view returns (uint);
        function allowance(address owner, address spender) external view returns (uint);
    
        function approve(address spender, uint value) external returns (bool);
        function transfer(address to, uint value) external returns (bool);
        function transferFrom(address from, address to, uint value) external returns (bool);
    
        function DOMAIN_SEPARATOR() external view returns (bytes32);
        function PERMIT_TYPEHASH() external pure returns (bytes32);
        function nonces(address owner) external view returns (uint);
    
        function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;
    
        event Mint(address indexed sender, uint amount0, uint amount1);
        event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
        event Swap(
            address indexed sender,
            uint amount0In,
            uint amount1In,
            uint amount0Out,
            uint amount1Out,
            address indexed to
        );
        event Sync(uint112 reserve0, uint112 reserve1);
    
        function MINIMUM_LIQUIDITY() external pure returns (uint);
        function factory() external view returns (address);
        function token0() external view returns (address);
        function token1() external view returns (address);
        function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast);
        function price0CumulativeLast() external view returns (uint);
        function price1CumulativeLast() external view returns (uint);
        function kLast() external view returns (uint);
    
        function mint(address to) external returns (uint liquidity);
        function burn(address to) external returns (uint amount0, uint amount1);
        function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external;
        function skim(address to) external;
        function sync() external;
    
        function initialize(address, address) external;
    }
    pragma solidity ^0.6.0;
    
    /**
     * @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].
     */
    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;
        }
    }
    pragma solidity ^0.6.0;
    
    /**
     * @dev Library for managing
     * https://en.wikipedia.org/wiki/Set_(abstract_data_type)[sets] of primitive
     * types.
     *
     * Sets have the following properties:
     *
     * - Elements are added, removed, and checked for existence in constant time
     * (O(1)).
     * - Elements are enumerated in O(n). No guarantees are made on the ordering.
     *
     * ```
     * contract Example {
     *     // Add the library methods
     *     using EnumerableSet for EnumerableSet.AddressSet;
     *
     *     // Declare a set state variable
     *     EnumerableSet.AddressSet private mySet;
     * }
     * ```
     *
     * As of v3.0.0, only sets of type `address` (`AddressSet`) and `uint256`
     * (`UintSet`) are supported.
     */
    library EnumerableSet {
        // To implement this library for multiple types with as little code
        // repetition as possible, we write it in terms of a generic Set type with
        // bytes32 values.
        // The Set implementation uses private functions, and user-facing
        // implementations (such as AddressSet) are just wrappers around the
        // underlying Set.
        // This means that we can only create new EnumerableSets for types that fit
        // in bytes32.
    
        struct Set {
            // Storage of set values
            bytes32[] _values;
    
            // Position of the value in the `values` array, plus 1 because index 0
            // means a value is not in the set.
            mapping (bytes32 => uint256) _indexes;
        }
    
        /**
         * @dev Add a value to a set. O(1).
         *
         * Returns true if the value was added to the set, that is if it was not
         * already present.
         */
        function _add(Set storage set, bytes32 value) private returns (bool) {
            if (!_contains(set, value)) {
                set._values.push(value);
                // The value is stored at length-1, but we add 1 to all indexes
                // and use 0 as a sentinel value
                set._indexes[value] = set._values.length;
                return true;
            } else {
                return false;
            }
        }
    
        /**
         * @dev Removes a value from a set. O(1).
         *
         * Returns true if the value was removed from the set, that is if it was
         * present.
         */
        function _remove(Set storage set, bytes32 value) private returns (bool) {
            // We read and store the value's index to prevent multiple reads from the same storage slot
            uint256 valueIndex = set._indexes[value];
    
            if (valueIndex != 0) { // Equivalent to contains(set, value)
                // To delete an element from the _values array in O(1), we swap the element to delete with the last one in
                // the array, and then remove the last element (sometimes called as 'swap and pop').
                // This modifies the order of the array, as noted in {at}.
    
                uint256 toDeleteIndex = valueIndex - 1;
                uint256 lastIndex = set._values.length - 1;
    
                // When the value to delete is the last one, the swap operation is unnecessary. However, since this occurs
                // so rarely, we still do the swap anyway to avoid the gas cost of adding an 'if' statement.
    
                bytes32 lastvalue = set._values[lastIndex];
    
                // Move the last value to the index where the value to delete is
                set._values[toDeleteIndex] = lastvalue;
                // Update the index for the moved value
                set._indexes[lastvalue] = toDeleteIndex + 1; // All indexes are 1-based
    
                // Delete the slot where the moved value was stored
                set._values.pop();
    
                // Delete the index for the deleted slot
                delete set._indexes[value];
    
                return true;
            } else {
                return false;
            }
        }
    
        /**
         * @dev Returns true if the value is in the set. O(1).
         */
        function _contains(Set storage set, bytes32 value) private view returns (bool) {
            return set._indexes[value] != 0;
        }
    
        /**
         * @dev Returns the number of values on the set. O(1).
         */
        function _length(Set storage set) private view returns (uint256) {
            return set._values.length;
        }
    
       /**
        * @dev Returns the value stored at position `index` in the set. O(1).
        *
        * Note that there are no guarantees on the ordering of values inside the
        * array, and it may change when more values are added or removed.
        *
        * Requirements:
        *
        * - `index` must be strictly less than {length}.
        */
        function _at(Set storage set, uint256 index) private view returns (bytes32) {
            require(set._values.length > index, "EnumerableSet: index out of bounds");
            return set._values[index];
        }
    
        // AddressSet
    
        struct AddressSet {
            Set _inner;
        }
    
        /**
         * @dev Add a value to a set. O(1).
         *
         * Returns true if the value was added to the set, that is if it was not
         * already present.
         */
        function add(AddressSet storage set, address value) internal returns (bool) {
            return _add(set._inner, bytes32(uint256(value)));
        }
    
        /**
         * @dev Removes a value from a set. O(1).
         *
         * Returns true if the value was removed from the set, that is if it was
         * present.
         */
        function remove(AddressSet storage set, address value) internal returns (bool) {
            return _remove(set._inner, bytes32(uint256(value)));
        }
    
        /**
         * @dev Returns true if the value is in the set. O(1).
         */
        function contains(AddressSet storage set, address value) internal view returns (bool) {
            return _contains(set._inner, bytes32(uint256(value)));
        }
    
        /**
         * @dev Returns the number of values in the set. O(1).
         */
        function length(AddressSet storage set) internal view returns (uint256) {
            return _length(set._inner);
        }
    
       /**
        * @dev Returns the value stored at position `index` in the set. O(1).
        *
        * Note that there are no guarantees on the ordering of values inside the
        * array, and it may change when more values are added or removed.
        *
        * Requirements:
        *
        * - `index` must be strictly less than {length}.
        */
        function at(AddressSet storage set, uint256 index) internal view returns (address) {
            return address(uint256(_at(set._inner, index)));
        }
    
    
        // UintSet
    
        struct UintSet {
            Set _inner;
        }
    
        /**
         * @dev Add a value to a set. O(1).
         *
         * Returns true if the value was added to the set, that is if it was not
         * already present.
         */
        function add(UintSet storage set, uint256 value) internal returns (bool) {
            return _add(set._inner, bytes32(value));
        }
    
        /**
         * @dev Removes a value from a set. O(1).
         *
         * Returns true if the value was removed from the set, that is if it was
         * present.
         */
        function remove(UintSet storage set, uint256 value) internal returns (bool) {
            return _remove(set._inner, bytes32(value));
        }
    
        /**
         * @dev Returns true if the value is in the set. O(1).
         */
        function contains(UintSet storage set, uint256 value) internal view returns (bool) {
            return _contains(set._inner, bytes32(value));
        }
    
        /**
         * @dev Returns the number of values on the set. O(1).
         */
        function length(UintSet storage set) internal view returns (uint256) {
            return _length(set._inner);
        }
    
       /**
        * @dev Returns the value stored at position `index` in the set. O(1).
        *
        * Note that there are no guarantees on the ordering of values inside the
        * array, and it may change when more values are added or removed.
        *
        * Requirements:
        *
        * - `index` must be strictly less than {length}.
        */
        function at(UintSet storage set, uint256 index) internal view returns (uint256) {
            return uint256(_at(set._inner, index));
        }
    }
    pragma solidity ^0.6.2;
    
    /**
     * @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 in 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");
            return _functionCallWithValue(target, data, value, errorMessage);
        }
    
        function _functionCallWithValue(address target, bytes memory data, uint256 weiValue, string memory errorMessage) private returns (bytes memory) {
            require(isContract(target), "Address: call to non-contract");
    
            // solhint-disable-next-line avoid-low-level-calls
            (bool success, bytes memory returndata) = target.call{ value: weiValue }(data);
            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);
                }
            }
        }
    }
    
    pragma solidity ^0.6.0;
    
    /**
     * @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);
    }
    
    pragma solidity ^0.6.0;
    
    /**
     * @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, 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) {
            return sub(a, b, "SafeMath: subtraction overflow");
        }
    
        /**
         * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
         * overflow (when the result is negative).
         *
         * 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);
            uint256 c = a - b;
    
            return c;
        }
    
        /**
         * @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) {
            // 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 0;
            }
    
            uint256 c = a * b;
            require(c / a == b, "SafeMath: multiplication overflow");
    
            return c;
        }
    
        /**
         * @dev Returns the integer division of two unsigned integers. Reverts 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) {
            return div(a, b, "SafeMath: division by zero");
        }
    
        /**
         * @dev Returns the integer division of two unsigned integers. Reverts with custom message 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, string memory errorMessage) internal pure returns (uint256) {
            require(b > 0, errorMessage);
            uint256 c = a / b;
            // assert(a == b * c + a % b); // There is no case in which this doesn't hold
    
            return c;
        }
    
        /**
         * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
         * Reverts 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) {
            return mod(a, b, "SafeMath: modulo by zero");
        }
    
        /**
         * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
         * Reverts with custom message 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, string memory errorMessage) internal pure returns (uint256) {
            require(b != 0, errorMessage);
            return a % b;
        }
    }
    
    
    pragma solidity ^0.6.0;
    
    
    /**
     * @dev Implementation of the {IERC20} interface.
     *
     * This implementation is agnostic to the way tokens are created. This means
     * that a supply mechanism has to be added in a derived contract using {_mint}.
     * For a generic mechanism see {ERC20PresetMinterPauser}.
     *
     * TIP: For a detailed writeup see our guide
     * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
     * to implement supply mechanisms].
     *
     * We have followed general OpenZeppelin guidelines: functions revert instead
     * of returning `false` on failure. This behavior is nonetheless conventional
     * and does not conflict with the expectations of ERC20 applications.
     *
     * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
     * This allows applications to reconstruct the allowance for all accounts just
     * by listening to said events. Other implementations of the EIP may not emit
     * these events, as it isn't required by the specification.
     *
     * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
     * functions have been added to mitigate the well-known issues around setting
     * allowances. See {IERC20-approve}.
     */
    contract ERC20 is Context, IERC20 {
        using SafeMath for uint256;
        using Address for address;
    
        mapping (address => uint256) private _balances;
    
        mapping (address => mapping (address => uint256)) private _allowances;
    
        uint256 private _totalSupply;
    
        string private _name;
        string private _symbol;
        uint8 private _decimals;
    
        /**
         * @dev Sets the values for {name} and {symbol}, initializes {decimals} with
         * a default value of 18.
         *
         * To select a different value for {decimals}, use {_setupDecimals}.
         *
         * All three of these values are immutable: they can only be set once during
         * construction.
         */
        constructor (string memory name, string memory symbol) public {
            _name = name;
            _symbol = symbol;
            _decimals = 18;
        }
    
        /**
         * @dev Returns the name of the token.
         */
        function name() public view returns (string memory) {
            return _name;
        }
    
        /**
         * @dev Returns the symbol of the token, usually a shorter version of the
         * name.
         */
        function symbol() public view returns (string memory) {
            return _symbol;
        }
    
        /**
         * @dev Returns the number of decimals used to get its user representation.
         * For example, if `decimals` equals `2`, a balance of `505` tokens should
         * be displayed to a user as `5,05` (`505 / 10 ** 2`).
         *
         * Tokens usually opt for a value of 18, imitating the relationship between
         * Ether and Wei. This is the value {ERC20} uses, unless {_setupDecimals} is
         * called.
         *
         * NOTE: This information is only used for _display_ purposes: it in
         * no way affects any of the arithmetic of the contract, including
         * {IERC20-balanceOf} and {IERC20-transfer}.
         */
        function decimals() public view returns (uint8) {
            return _decimals;
        }
    
        /**
         * @dev See {IERC20-totalSupply}.
         */
        function totalSupply() public view override returns (uint256) {
            return _totalSupply;
        }
    
        /**
         * @dev See {IERC20-balanceOf}.
         */
        function balanceOf(address account) public view override returns (uint256) {
            return _balances[account];
        }
    
        /**
         * @dev See {IERC20-transfer}.
         *
         * Requirements:
         *
         * - `recipient` cannot be the zero address.
         * - the caller must have a balance of at least `amount`.
         */
        function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
            _transfer(_msgSender(), recipient, amount);
            return true;
        }
    
        /**
         * @dev See {IERC20-allowance}.
         */
        function allowance(address owner, address spender) public view virtual override returns (uint256) {
            return _allowances[owner][spender];
        }
    
        /**
         * @dev See {IERC20-approve}.
         *
         * Requirements:
         *
         * - `spender` cannot be the zero address.
         */
        function approve(address spender, uint256 amount) public virtual override returns (bool) {
            _approve(_msgSender(), spender, amount);
            return true;
        }
    
        /**
         * @dev See {IERC20-transferFrom}.
         *
         * Emits an {Approval} event indicating the updated allowance. This is not
         * required by the EIP. See the note at the beginning of {ERC20};
         *
         * Requirements:
         * - `sender` and `recipient` cannot be the zero address.
         * - `sender` must have a balance of at least `amount`.
         * - the caller must have allowance for ``sender``'s tokens of at least
         * `amount`.
         */
        function transferFrom(address sender, address recipient, uint256 amount) public virtual override returns (bool) {
            _transfer(sender, recipient, amount);
            _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance"));
            return true;
        }
    
        /**
         * @dev Atomically increases the allowance granted to `spender` by the caller.
         *
         * This is an alternative to {approve} that can be used as a mitigation for
         * problems described in {IERC20-approve}.
         *
         * Emits an {Approval} event indicating the updated allowance.
         *
         * Requirements:
         *
         * - `spender` cannot be the zero address.
         */
        function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
            _approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));
            return true;
        }
    
        /**
         * @dev Atomically decreases the allowance granted to `spender` by the caller.
         *
         * This is an alternative to {approve} that can be used as a mitigation for
         * problems described in {IERC20-approve}.
         *
         * Emits an {Approval} event indicating the updated allowance.
         *
         * Requirements:
         *
         * - `spender` cannot be the zero address.
         * - `spender` must have allowance for the caller of at least
         * `subtractedValue`.
         */
        function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
            _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "ERC20: decreased allowance below zero"));
            return true;
        }
    
        /**
         * @dev Moves tokens `amount` from `sender` to `recipient`.
         *
         * This is internal function is equivalent to {transfer}, and can be used to
         * e.g. implement automatic token fees, slashing mechanisms, etc.
         *
         * Emits a {Transfer} event.
         *
         * Requirements:
         *
         * - `sender` cannot be the zero address.
         * - `recipient` cannot be the zero address.
         * - `sender` must have a balance of at least `amount`.
         */
        function _transfer(address sender, address recipient, uint256 amount) internal virtual {
            require(sender != address(0), "ERC20: transfer from the zero address");
            require(recipient != address(0), "ERC20: transfer to the zero address");
    
            _beforeTokenTransfer(sender, recipient, amount);
    
            _balances[sender] = _balances[sender].sub(amount, "ERC20: transfer amount exceeds balance");
            _balances[recipient] = _balances[recipient].add(amount);
            emit Transfer(sender, recipient, amount);
        }
    
        /** @dev Creates `amount` tokens and assigns them to `account`, increasing
         * the total supply.
         *
         * Emits a {Transfer} event with `from` set to the zero address.
         *
         * Requirements
         *
         * - `to` cannot be the zero address.
         */
        function _mint(address account, uint256 amount) internal virtual {
            require(account != address(0), "ERC20: mint to the zero address");
    
            _beforeTokenTransfer(address(0), account, amount);
    
            _totalSupply = _totalSupply.add(amount);
            _balances[account] = _balances[account].add(amount);
            emit Transfer(address(0), account, amount);
        }
    
        /**
         * @dev Destroys `amount` tokens from `account`, reducing the
         * total supply.
         *
         * Emits a {Transfer} event with `to` set to the zero address.
         *
         * Requirements
         *
         * - `account` cannot be the zero address.
         * - `account` must have at least `amount` tokens.
         */
        function _burn(address account, uint256 amount) internal virtual {
            require(account != address(0), "ERC20: burn from the zero address");
    
            _beforeTokenTransfer(account, address(0), amount);
    
            _balances[account] = _balances[account].sub(amount, "ERC20: burn amount exceeds balance");
            _totalSupply = _totalSupply.sub(amount);
            emit Transfer(account, address(0), amount);
        }
    
        /**
         * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
         *
         * This internal function is equivalent to `approve`, and can be used to
         * e.g. set automatic allowances for certain subsystems, etc.
         *
         * Emits an {Approval} event.
         *
         * Requirements:
         *
         * - `owner` cannot be the zero address.
         * - `spender` cannot be the zero address.
         */
        function _approve(address owner, address spender, uint256 amount) internal virtual {
            require(owner != address(0), "ERC20: approve from the zero address");
            require(spender != address(0), "ERC20: approve to the zero address");
    
            _allowances[owner][spender] = amount;
            emit Approval(owner, spender, amount);
        }
    
        /**
         * @dev Sets {decimals} to a value other than the default one of 18.
         *
         * WARNING: This function should only be called from the constructor. Most
         * applications that interact with token contracts will not expect
         * {decimals} to ever change, and may work incorrectly if it does.
         */
        function _setupDecimals(uint8 decimals_) internal {
            _decimals = decimals_;
        }
    
        /**
         * @dev Hook that is called before any transfer of tokens. This includes
         * minting and burning.
         *
         * Calling conditions:
         *
         * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
         * will be to transferred to `to`.
         * - when `from` is zero, `amount` tokens will be minted for `to`.
         * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
         * - `from` and `to` are never both zero.
         *
         * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
         */
        function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual { }
    }
    
    pragma solidity ^0.6.0;
    
    /**
     * @dev Contract module which provides a basic access control mechanism, where
     * there is an account (an owner) that can be granted exclusive access to
     * specific functions.
     *
     * By default, the owner account will be the one that deploys the contract. This
     * can later be changed with {transferOwnership}.
     *
     * This module is used through inheritance. It will make available the modifier
     * `onlyOwner`, which can be applied to your functions to restrict their use to
     * the owner.
     */
    contract Ownable is Context {
        address private _owner;
    
        event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
    
        /**
         * @dev Initializes the contract setting the deployer as the initial owner.
         */
        constructor () internal {
            address msgSender = _msgSender();
            _owner = msgSender;
            emit OwnershipTransferred(address(0), msgSender);
        }
    
        /**
         * @dev Returns the address of the current owner.
         */
        function owner() public view returns (address) {
            return _owner;
        }
    
        /**
         * @dev Throws if called by any account other than the owner.
         */
        modifier onlyOwner() {
            require(_owner == _msgSender(), "Ownable: caller is not the owner");
            _;
        }
    
        /**
         * @dev Leaves the contract without owner. It will not be possible to call
         * `onlyOwner` functions anymore. Can only be called by the current owner.
         *
         * NOTE: Renouncing ownership will leave the contract without an owner,
         * thereby removing any functionality that is only available to the owner.
         */
        function renounceOwnership() public virtual onlyOwner {
            emit OwnershipTransferred(_owner, address(0));
            _owner = address(0);
        }
    
        /**
         * @dev Transfers ownership of the contract to a new account (`newOwner`).
         * Can only be called by the current owner.
         */
        function transferOwnership(address newOwner) public virtual onlyOwner {
            require(newOwner != address(0), "Ownable: new owner is the zero address");
            emit OwnershipTransferred(_owner, newOwner);
            _owner = newOwner;
        }
    }
    
    pragma solidity ^0.6.0;
    
    /**
     * @dev Contract module that allows children to implement role-based access
     * control mechanisms.
     *
     * Roles are referred to by their `bytes32` identifier. These should be exposed
     * in the external API and be unique. The best way to achieve this is by
     * using `public constant` hash digests:
     *
     * ```
     * bytes32 public constant MY_ROLE = keccak256("MY_ROLE");
     * ```
     *
     * Roles can be used to represent a set of permissions. To restrict access to a
     * function call, use {hasRole}:
     *
     * ```
     * function foo() public {
     *     require(hasRole(MY_ROLE, msg.sender));
     *     ...
     * }
     * ```
     *
     * Roles can be granted and revoked dynamically via the {grantRole} and
     * {revokeRole} functions. Each role has an associated admin role, and only
     * accounts that have a role's admin role can call {grantRole} and {revokeRole}.
     *
     * By default, the admin role for all roles is `DEFAULT_ADMIN_ROLE`, which means
     * that only accounts with this role will be able to grant or revoke other
     * roles. More complex role relationships can be created by using
     * {_setRoleAdmin}.
     *
     * WARNING: The `DEFAULT_ADMIN_ROLE` is also its own admin: it has permission to
     * grant and revoke this role. Extra precautions should be taken to secure
     * accounts that have been granted it.
     */
    abstract contract AccessControl is Context {
        using EnumerableSet for EnumerableSet.AddressSet;
        using Address for address;
    
        struct RoleData {
            EnumerableSet.AddressSet members;
            bytes32 adminRole;
        }
    
        mapping (bytes32 => RoleData) private _roles;
    
        bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00;
    
        /**
         * @dev Emitted when `newAdminRole` is set as ``role``'s admin role, replacing `previousAdminRole`
         *
         * `DEFAULT_ADMIN_ROLE` is the starting admin for all roles, despite
         * {RoleAdminChanged} not being emitted signaling this.
         *
         * _Available since v3.1._
         */
        event RoleAdminChanged(bytes32 indexed role, bytes32 indexed previousAdminRole, bytes32 indexed newAdminRole);
    
        /**
         * @dev Emitted when `account` is granted `role`.
         *
         * `sender` is the account that originated the contract call, an admin role
         * bearer except when using {_setupRole}.
         */
        event RoleGranted(bytes32 indexed role, address indexed account, address indexed sender);
    
        /**
         * @dev Emitted when `account` is revoked `role`.
         *
         * `sender` is the account that originated the contract call:
         *   - if using `revokeRole`, it is the admin role bearer
         *   - if using `renounceRole`, it is the role bearer (i.e. `account`)
         */
        event RoleRevoked(bytes32 indexed role, address indexed account, address indexed sender);
    
        /**
         * @dev Returns `true` if `account` has been granted `role`.
         */
        function hasRole(bytes32 role, address account) public view returns (bool) {
            return _roles[role].members.contains(account);
        }
    
        /**
         * @dev Returns the number of accounts that have `role`. Can be used
         * together with {getRoleMember} to enumerate all bearers of a role.
         */
        function getRoleMemberCount(bytes32 role) public view returns (uint256) {
            return _roles[role].members.length();
        }
    
        /**
         * @dev Returns one of the accounts that have `role`. `index` must be a
         * value between 0 and {getRoleMemberCount}, non-inclusive.
         *
         * Role bearers are not sorted in any particular way, and their ordering may
         * change at any point.
         *
         * WARNING: When using {getRoleMember} and {getRoleMemberCount}, make sure
         * you perform all queries on the same block. See the following
         * https://forum.openzeppelin.com/t/iterating-over-elements-on-enumerableset-in-openzeppelin-contracts/2296[forum post]
         * for more information.
         */
        function getRoleMember(bytes32 role, uint256 index) public view returns (address) {
            return _roles[role].members.at(index);
        }
    
        /**
         * @dev Returns the admin role that controls `role`. See {grantRole} and
         * {revokeRole}.
         *
         * To change a role's admin, use {_setRoleAdmin}.
         */
        function getRoleAdmin(bytes32 role) public view returns (bytes32) {
            return _roles[role].adminRole;
        }
    
        /**
         * @dev Grants `role` to `account`.
         *
         * If `account` had not been already granted `role`, emits a {RoleGranted}
         * event.
         *
         * Requirements:
         *
         * - the caller must have ``role``'s admin role.
         */
        function grantRole(bytes32 role, address account) public virtual {
            require(hasRole(_roles[role].adminRole, _msgSender()), "AccessControl: sender must be an admin to grant");
    
            _grantRole(role, account);
        }
    
        /**
         * @dev Revokes `role` from `account`.
         *
         * If `account` had been granted `role`, emits a {RoleRevoked} event.
         *
         * Requirements:
         *
         * - the caller must have ``role``'s admin role.
         */
        function revokeRole(bytes32 role, address account) public virtual {
            require(hasRole(_roles[role].adminRole, _msgSender()), "AccessControl: sender must be an admin to revoke");
    
            _revokeRole(role, account);
        }
    
        /**
         * @dev Revokes `role` from the calling account.
         *
         * Roles are often managed via {grantRole} and {revokeRole}: this function's
         * purpose is to provide a mechanism for accounts to lose their privileges
         * if they are compromised (such as when a trusted device is misplaced).
         *
         * If the calling account had been granted `role`, emits a {RoleRevoked}
         * event.
         *
         * Requirements:
         *
         * - the caller must be `account`.
         */
        function renounceRole(bytes32 role, address account) public virtual {
            require(account == _msgSender(), "AccessControl: can only renounce roles for self");
    
            _revokeRole(role, account);
        }
    
        /**
         * @dev Grants `role` to `account`.
         *
         * If `account` had not been already granted `role`, emits a {RoleGranted}
         * event. Note that unlike {grantRole}, this function doesn't perform any
         * checks on the calling account.
         *
         * [WARNING]
         * ====
         * This function should only be called from the constructor when setting
         * up the initial roles for the system.
         *
         * Using this function in any other way is effectively circumventing the admin
         * system imposed by {AccessControl}.
         * ====
         */
        function _setupRole(bytes32 role, address account) internal virtual {
            _grantRole(role, account);
        }
    
        /**
         * @dev Sets `adminRole` as ``role``'s admin role.
         *
         * Emits a {RoleAdminChanged} event.
         */
        function _setRoleAdmin(bytes32 role, bytes32 adminRole) internal virtual {
            emit RoleAdminChanged(role, _roles[role].adminRole, adminRole);
            _roles[role].adminRole = adminRole;
        }
    
        function _grantRole(bytes32 role, address account) private {
            if (_roles[role].members.add(account)) {
                emit RoleGranted(role, account, _msgSender());
            }
        }
    
        function _revokeRole(bytes32 role, address account) private {
            if (_roles[role].members.remove(account)) {
                emit RoleRevoked(role, account, _msgSender());
            }
        }
    }
    
    pragma solidity ^0.6.12;
    
    
    contract UniswapAware {
        address public uniswapEthPair;
        IUniswapV2Pair public uniswapPairImpl;
    
        function isContract(address _addr) internal view returns (bool) {
            uint32 size;
            assembly {
                size := extcodesize(_addr)
            }
            return (size > 0);
        }
    
        constructor() public {
            uniswapEthPair = pairFor(
                0x5C69bEe701ef814a2B6a3EDD4B1652CB9cc5aA6f,
                0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2,
                address(this)
            );
        }
    
        function pairFor(
            address factory,
            address tokenA,
            address tokenB
        ) public pure returns (address pair) {
            (address token0, address token1) =
                tokenA < tokenB ? (tokenA, tokenB) : (tokenB, tokenA);
            pair = address(
                uint256(
                    keccak256(
                        abi.encodePacked(
                            hex"ff",
                            factory,
                            keccak256(abi.encodePacked(token0, token1)),
                            hex"96e8ac4277198ff8b6f785478aa9a39f403cb768dd02cbee326c3e7da348845f"
                        )
                    )
                )
            );
        }
    
        modifier onlyAfterUniswap() {
            require(
                isContract(uniswapEthPair),
                "You can't perform this action until the Uniswap listing"
            );
            _;
        }
    
        modifier onlyBeforeUniswap() {
            require(
                !isContract(uniswapEthPair),
                "You can't perform this action after the Uniswap listing"
            );
            _;
        }
    }
    
    pragma solidity ^0.6.12;
    
    
    contract RoleAware is AccessControl, UniswapAware {
        bytes32 public constant STAKING_POOL_ROLE = keccak256("STAKING_POOL_ROLE");
        bytes32 public constant WHITELIST_ROLE = keccak256("WHITELIST_ROLE");
        bytes32 public constant WHITELIST_TO_ROLE = keccak256("WHITELIST_TO_ROLE");
        bytes32 public constant WHITELIST_FROM_ROLE =
            keccak256("WHITELIST_FROM_ROLE");
        bytes32 public constant DEVELOPER_ROLE = keccak256("DEVELOPER_ROLE");
        address payable public _developer;
    
        constructor(address payable developer, address[] memory stakingPools)
            public
        {
            _developer = developer;
    
            _setupRole(DEVELOPER_ROLE, _developer);
            _setupRole(DEFAULT_ADMIN_ROLE, _developer);
    
            grantRole(WHITELIST_ROLE, address(this));
            // O(n) iteration allowed as stakingPools will contain very few items
            for (uint256 i = 0; i < stakingPools.length; i++) {
                grantRole(STAKING_POOL_ROLE, stakingPools[i]);
                grantRole(WHITELIST_ROLE, stakingPools[i]);
            }
        }
    
        modifier onlyDeveloper() {
            require(hasRole(DEVELOPER_ROLE, msg.sender), "Caller is not developer");
            _;
        }
    
        // distinct from external staking pools, Ape staking pools can mint rewards for users
        modifier onlyStakingPool() {
            require(
                hasRole(STAKING_POOL_ROLE, msg.sender),
                "Caller is not a staking pool"
            );
            _;
        }
    
        // needed to add new external liquidity pools - pools should not be burned by default
        function addWhitelist(address grantee) public onlyDeveloper {
            grantRole(WHITELIST_ROLE, grantee);
        }
    
        function addWhitelistTo(address grantee) public onlyDeveloper {
            grantRole(WHITELIST_TO_ROLE, grantee);
        }
    
        function addWhitelistFrom(address grantee) public onlyDeveloper {
            grantRole(WHITELIST_FROM_ROLE, grantee);
        }
    
        function anyWhitelisted(address sender, address recipient)
            internal
            view
            returns (bool)
        {
            return (hasRole(WHITELIST_ROLE, sender) ||
                hasRole(WHITELIST_ROLE, recipient) ||
                hasRole(WHITELIST_ROLE, msg.sender) ||
                hasRole(WHITELIST_TO_ROLE, recipient) ||
                hasRole(WHITELIST_FROM_ROLE, sender));
        }
    }
    
    
    pragma solidity ^0.6.12;
    
    abstract contract ERC20Vestable is RoleAware, ERC20 {
        uint256 public vestingTime = 4 days;
    
        function setVestingTime(uint256 newTime) public onlyDeveloper {
            vestingTime = newTime;
        }
    
        // tokens vest 10% every n days. `claimFunds` can be called once every n days
        struct VestingAllowance {
            uint256 frequency;
            uint256 allowance;
            uint256 claimAmount;
            uint256 lastClaimed;
        }
    
        mapping(address => VestingAllowance) public vestingAllowances;
    
        function _grantFunds(address beneficiary) internal {
            
            VestingAllowance memory userAllowance = vestingAllowances[beneficiary];
            require(
                userAllowance.allowance > 0 &&
                    userAllowance.allowance >= userAllowance.claimAmount,
                "Entire allowance already claimed, or no initial allowance"
            );
            userAllowance.allowance = userAllowance.allowance.sub(userAllowance.claimAmount);
            vestingAllowances[beneficiary] = userAllowance;
            _mint(beneficiary, userAllowance.claimAmount.mul(10**uint256(decimals())));
        }
    
        // internal function only ever called from constructor
        function _addBeneficiary(
            address beneficiary,
            uint256 amount,
            uint256 claimFrequency,
            bool grant
        ) internal onlyBeforeUniswap {
            vestingAllowances[beneficiary] = VestingAllowance(
                claimFrequency,
                amount,
                amount.div(10),
                now
            );
            // beneficiary gets 10% of funds immediately
            if (grant) {
                _grantFunds(beneficiary);
            }
        }
    
        function claimFunds() public {
            VestingAllowance memory allowance = vestingAllowances[msg.sender];
            require(
                allowance.lastClaimed != 0 &&
                    (now >= allowance.lastClaimed.add(allowance.frequency) || now >= allowance.lastClaimed.add(vestingTime)),
                "Allowance already claimed for this time period"
            );
            allowance.lastClaimed = now;
            vestingAllowances[msg.sender] = allowance;
            _grantFunds(msg.sender);
        }
    
    
        // function callable before uinswap listing to allow v1 holders to be compensated
        function addV1Beneficiary(address[] memory addresses, uint256[] memory amounts)
            public
            onlyDeveloper
            onlyBeforeUniswap
        {
            for (uint256 index = 0; index < addresses.length; index++) {
                _addBeneficiary(addresses[index], amounts[index], 4 days, false);
            }
        }
    }
    
    pragma solidity ^0.6.12;
    
    abstract contract ERC20Presaleable is RoleAware, ReentrancyGuard, ERC20 {
        bool public isPresale = false;
    
        uint256 public presaleApePerEther = 2500;
        uint256 public uniswapApePerEth = 1800;
        uint256 public presaleEtherReceived = 0 ether;
        uint256 public maxPresaleEtherValue;
    
        uint256 internal _minTokenPurchaseAmount = .1 ether;
        uint256 internal _maxTokenPurchaseAmount = 1.5 ether;
    
        mapping(address => bool) private _whitelisted;
        mapping(address => uint256) public presaleContributions;
    
        event PresalePurchased(address buyer, uint256 entitlement, uint256 weiContributed);
    
        constructor(uint256 maxPresaleValue) public {
            maxPresaleEtherValue = maxPresaleValue.mul(1 ether);
        }
    
        modifier onlyDuringPresale() {
            require(isPresale == true || _whitelisted[msg.sender], "The presale is not active");
            _;
        }
    
        modifier onlyBeforePresale() {
            require(isPresale == false);
            _;
        }
    
        function stopPresale() public onlyDeveloper onlyDuringPresale {
            isPresale = false;
        }
    
        function startPresale() public onlyBeforeUniswap onlyDeveloper {
            isPresale = true;
        }
    
        function addPresaleWhitelist(address buyer) public onlyBeforeUniswap onlyDeveloper {
            _whitelisted[buyer] = true;
        }
    
        function presale()
            public
            payable
            onlyDuringPresale
            nonReentrant
            returns (bool)
        {
            require(
                msg.value >= _minTokenPurchaseAmount,
                "Minimum purchase amount not met"
            );
            require(
                presaleEtherReceived.add(msg.value) <= maxPresaleEtherValue || _whitelisted[msg.sender],
                "Presale maximum already achieved"
            );
            require(
                presaleContributions[msg.sender].add(msg.value.mul(presaleApePerEther)) <=
                    _maxTokenPurchaseAmount.mul(presaleApePerEther),
                "Amount of ether sent too high"
            );
    
            presaleContributions[msg.sender] = presaleContributions[msg.sender].add(msg.value.mul(presaleApePerEther));
    
    
            if (!_whitelisted[msg.sender]) {
                presaleEtherReceived = presaleEtherReceived.add(msg.value);
            }
    
            emit PresalePurchased(msg.sender, presaleContributions[msg.sender], msg.value);
    
            _developer.transfer(msg.value.mul(2).div(10));
        }
    
        function _getPresaleEntitlement() internal returns (uint256) {
            require(
                presaleContributions[msg.sender] >= 0,
                "No presale contribution or already redeemed"
            );
            uint256 value = presaleContributions[msg.sender];
            presaleContributions[msg.sender] = 0;
            return value;
        }
    
        // presale funds only claimable after uniswap pair created to prevent malicious 3rd-party listing
        function claimPresale()
            public
            onlyAfterUniswap
            nonReentrant
            returns (bool)
        {
            uint256 result = _getPresaleEntitlement();
            if (result > 0) {
                _mint(msg.sender, result);
            }
        }
    
    }
    
    pragma solidity ^0.6.12;
    
    abstract contract ERC20Burnable is RoleAware, ERC20 {
        uint256 public minimumSupply = 20000 * (10**18);
        uint256 public maximumSupply = 5000000 * (10**18);
        uint256 private constant roughDay = 60 * 60 * 24;
        uint256 public timeListed = 0;
    
        // address of giveth, an on-chain charity
        address
            public constant GIVETH_ADDRESS = 0x8f951903C9360345B4e1b536c7F5ae8f88A64e79;
    
        function _partialBurn(
            uint256 amount,
            address recipient,
            address sender
        ) internal returns (uint256) {
            if (anyWhitelisted(sender, recipient)) {
                return amount;
            }
            uint256 burnAmount = calculateBurnAmount(amount, recipient, sender);
            if (burnAmount > 0) {
                _burn(sender, burnAmount);
                _mint(GIVETH_ADDRESS, burnAmount.div(25));
                _mint(_developer, burnAmount.div(25));
            }
    
            return amount.sub(burnAmount);
        }
    
        function calculateBurnAmount(
            uint256 amount,
            address recipient,
            address sender
        ) public view returns (uint256) {
            uint256 burnAmount = 0;
            uint256 burnPercentage = 0;
    
            if (timeListed != 0) {
                uint256 sinceLaunch = now.add(1).sub(timeListed.add(1));
                uint256 daysSinceLaunch = sinceLaunch.div(roughDay);
                if (daysSinceLaunch > 10) {
                    burnPercentage = 5;
                } else {
                    burnPercentage = uint256(15).sub(daysSinceLaunch);
                }
            }
    
            if (totalSupply() > minimumSupply) {
                burnAmount = amount.mul(burnPercentage).div(100);
                uint256 availableBurn = totalSupply().sub(minimumSupply);
                if (burnAmount > availableBurn) {
                    burnAmount = availableBurn;
                }
            }
    
            return burnAmount;
        }
    
        function transfer(address recipient, uint256 amount)
            public
            virtual
            override
            returns (bool)
        {
            return
                super.transfer(
                    recipient,
                    _partialBurn(amount, recipient, msg.sender)
                );
        }
    
        function transferFrom(
            address sender,
            address recipient,
            uint256 amount
        ) public virtual override returns (bool) {
            return
                super.transferFrom(
                    sender,
                    recipient,
                    _partialBurn(amount, recipient, sender)
                );
        }
    
    }
    
    pragma solidity ^0.6.12;
    
    
    contract ApeToken is ERC20Burnable, ERC20Vestable, ERC20Presaleable {
        IUniswapV2Router02 private router;
        uint256 public constant MAX_INT = uint256(-1);
        uint256 public stakingPoolDateAdd;
        address public stakingPoolPending;
    
        address
            public constant UNISWAP_ROUTER_ADDRESS = 0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D;
    
        event LiquidityAdded(
            uint256 amountToken,
            uint256 amountEth,
            uint256 liquidity
        );
    
        event DeveloperAddedPendingPool(address pendingPool);
        event DeveloperAddedPool(address pool);
    
        constructor(
            address payable secondDeveloper,
            address[] memory stakingPools,
            address marketing,
            uint256 presaleCap,
            address[] memory supporters,
            uint256[] memory supporterRewards
        )
            public
            ERC20("Ape.cash V2", "APEv2")
            RoleAware(msg.sender, stakingPools)
            ERC20Presaleable(presaleCap)
        {
            
            // number of tokens is vested over 3 months, see ERC20Vestable
            _addBeneficiary(msg.sender, 105000, 10 days, true);
            _addBeneficiary(secondDeveloper, 45000, 10 days, true);
            _addBeneficiary(marketing, 50000, 10 days, true);
            
            addWhitelist(UNISWAP_ROUTER_ADDRESS);
            router = IUniswapV2Router02(UNISWAP_ROUTER_ADDRESS);
    
            for (uint256 index = 0; index < supporters.length; index++) {
                _mint(supporters[index], supporterRewards[index]);
            }
        }
    
        // developer can add staking pools. as these can mint, function is timelocked for 24 hours
        function addStakingPoolConfirm() public onlyDeveloper {
            require(now >= stakingPoolDateAdd.add(24 hours));
            grantRole(STAKING_POOL_ROLE, stakingPoolPending);
            grantRole(WHITELIST_ROLE, stakingPoolPending);
            emit DeveloperAddedPool(stakingPoolPending);
        }
    
        function addStakingPoolInitial(address stakingPool) public onlyDeveloper {
            stakingPoolDateAdd = now;
            stakingPoolPending = stakingPool;
            emit DeveloperAddedPendingPool(stakingPool);
        }
    
        // allow contracts with role ape staking pool to mint rewards for users
        function mint(address to, uint256 amount)
            public
            onlyStakingPool
            nonReentrant
        {
            if (totalSupply() <= maximumSupply) {
                _mint(to, amount);
            }
        }
    
        function listOnUniswap() public onlyDeveloper onlyBeforeUniswap {
            // mint 1800 APE per held ETH to list on Uniswap
            timeListed = now;
    
            addWhitelist(uniswapEthPair);
            uint256 ethBalance = address(this).balance;
            uint256 apeBalance = ethBalance.mul(uniswapApePerEth);
    
            _mint(address(this), apeBalance);
    
            _approve(address(this), address(router), apeBalance);
    
            (uint256 amountToken, uint256 amountEth, uint256 liquidity) = router
                .addLiquidityETH{value: ethBalance}(
                address(this),
                apeBalance,
                apeBalance,
                ethBalance,
                address(0),
                block.timestamp + uint256(5).mul(1 minutes)
            );
    
            revokeRole(WHITELIST_ROLE, uniswapEthPair);
            revokeRole(WHITELIST_ROLE, UNISWAP_ROUTER_ADDRESS);
    
            addWhitelistFrom(uniswapEthPair);
            stopPresale();
    
            uniswapPairImpl = IUniswapV2Pair(uniswapEthPair);
            emit LiquidityAdded(amountToken, amountEth, liquidity);
        }
    
        function transfer(address recipient, uint256 amount)
            public
            override(ERC20Burnable, ERC20)
            returns (bool)
        {
            return ERC20Burnable.transfer(recipient, amount);
        }
    
        function transferFrom(
            address sender,
            address recipient,
            uint256 amount
        ) public override(ERC20Burnable, ERC20) returns (bool) {
            return ERC20Burnable.transferFrom(sender, recipient, amount);
        }
    
    }
    
    
    pragma solidity ^0.6.12;
    
    
    
    contract ApeStakingPool is ReentrancyGuard, Ownable {
        using SafeMath for uint256;
    
        uint256 private constant UINT256_MAX = ~uint256(0);
        uint256 private constant MONTH = 30 days;
    
        ApeToken private _apeTokenInstnace;
        address private _apeTokenAddress;
    
        uint256 private _deployedAt;
    
        uint256 public _totalStaked;
        mapping(address => uint256) private _staked;
        mapping(address => uint256) private _lastClaim;
        address private _developerFund;
    
        event StakeIncreased(address indexed staker, uint256 amount);
        event StakeDecreased(address indexed staker, uint256 amount);
        event Rewards(
            address indexed staker,
            uint256 mintage,
            uint256 developerFund
        );
    
        constructor() public {
            _developerFund = msg.sender;
            _deployedAt = block.timestamp;
        }
    
        function setApeToken(address apeTokenAddress) external onlyOwner {
            require(_apeTokenAddress == address(0));
            _apeTokenAddress = apeTokenAddress;
            _apeTokenInstnace = ApeToken(apeTokenAddress);
        }
    
        function upgradeDevelopmentFund(address fund) external onlyOwner {
            _developerFund = fund;
        }
    
        function ape() external view returns (address) {
            return address(_apeTokenInstnace);
        }
    
        function totalStaked() external view returns (uint256) {
            return _totalStaked;
        }
    
        function staked(address staker) external view returns (uint256) {
            return _staked[staker];
        }
    
        function lastClaim(address staker) external view returns (uint256) {
            return _lastClaim[staker];
        }
    
        function increaseStake(uint256 amount) external {
    
            require(_apeTokenInstnace.transferFrom(msg.sender, address(this), amount));
            _totalStaked = _totalStaked.add(amount);
            _lastClaim[msg.sender] = block.timestamp;
            _staked[msg.sender] = _staked[msg.sender].add(amount);
            emit StakeIncreased(msg.sender, amount);
        }
    
        function decreaseStake(uint256 amount) external {
            _staked[msg.sender] = _staked[msg.sender].sub(amount);
            _totalStaked = _totalStaked.sub(amount);
            require(_apeTokenInstnace.transfer(address(msg.sender), amount));
            emit StakeDecreased(msg.sender, amount);
        }
    
        function _calculateMintage(address staker) private view returns (uint256) {
            uint256 stakedAmount = _staked[staker];
    
            uint256 timeElapsed = block.timestamp.sub(_lastClaim[staker]);
            uint256 mintage = 0;
    
            if (timeElapsed > 60) {
                uint256 minutesElapsed = timeElapsed.div(60);
                mintage = stakedAmount.mul(minutesElapsed).mul(20).div(15).div(30*24*60);
            }
            return mintage;
        }
    
        function calculateRewards(address staker) public view returns (uint256) {
            return _calculateMintage(staker).div(20).mul(19);
        }
    
        function claimRewards() external nonReentrant {
    
            uint256 mintage = _calculateMintage(msg.sender);
            uint256 mintagePiece = mintage.div(20);
            require(mintagePiece > 0, "You are not entitled to any rewards!");
    
            _lastClaim[msg.sender] = block.timestamp;
            _apeTokenInstnace.mint(msg.sender, mintage.sub(mintagePiece));
            _apeTokenInstnace.mint(_developerFund, mintagePiece);
    
            emit Rewards(msg.sender, mintage, mintagePiece);
        }
    }