1. /**
2.  *Submitted for verification at Etherscan.io on 2020-09-01
3. */
4.  
5. /*
6.  
7. website: kimchi.finance
8.  
9. This project was forked from SUSHI and YUNO projects.
10.  
11. Unless those projects have severe vulnerabilities, this contract will be fine
12.  
13. ██╗  ██╗██╗███╗   ███╗ ██████╗██╗  ██╗██╗
14. ██║ ██╔╝██║████╗ ████║██╔════╝██║  ██║██║
15. █████╔╝ ██║██╔████╔██║██║     ███████║██║
16. ██╔═██╗ ██║██║╚██╔╝██║██║     ██╔══██║██║
17. ██║  ██╗██║██║ ╚═╝ ██║╚██████╗██║  ██║██║
18. ╚═╝  ╚═╝╚═╝╚═╝     ╚═╝ ╚═════╝╚═╝  ╚═╝╚═╝
19.  
20. */
21.  
22. pragma solidity ^0.6.12;
23. /*
24.  * @dev Provides information about the current execution context, including the
25.  * sender of the transaction and its data. While these are generally available
26.  * via msg.sender and msg.data, they should not be accessed in such a direct
27.  * manner, since when dealing with GSN meta-transactions the account sending and
28.  * paying for execution may not be the actual sender (as far as an application
29.  * is concerned).
30.  *
31.  * This contract is only required for intermediate, library-like contracts.
32.  */
33. abstract contract Context {
34.     function _msgSender() internal view virtual returns (address payable) {
35.         return msg.sender;
36.     }
37.  
38.     function _msgData() internal view virtual returns (bytes memory) {
39.         this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
40.         return msg.data;
41.     }
42. }
43.  
44. /**
45.  * @dev Interface of the ERC20 standard as defined in the EIP.
46.  */
47. interface IERC20 {
48.     /**
49.      * @dev Returns the amount of tokens in existence.
50.      */
51.     function totalSupply() external view returns (uint256);
52.  
53.     /**
54.      * @dev Returns the amount of tokens owned by `account`.
55.      */
56.     function balanceOf(address account) external view returns (uint256);
57.  
58.     /**
59.      * @dev Moves `amount` tokens from the caller's account to `recipient`.
60.      *
61.      * Returns a boolean value indicating whether the operation succeeded.
62.      *
63.      * Emits a {Transfer} event.
64.      */
65.     function transfer(address recipient, uint256 amount) external returns (bool);
66.  
67.     /**
68.      * @dev Returns the remaining number of tokens that `spender` will be
69.      * allowed to spend on behalf of `owner` through {transferFrom}. This is
70.      * zero by default.
71.      *
72.      * This value changes when {approve} or {transferFrom} are called.
73.      */
74.     function allowance(address owner, address spender) external view returns (uint256);
75.  
76.     /**
77.      * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
78.      *
79.      * Returns a boolean value indicating whether the operation succeeded.
80.      *
81.      * IMPORTANT: Beware that changing an allowance with this method brings the risk
82.      * that someone may use both the old and the new allowance by unfortunate
83.      * transaction ordering. One possible solution to mitigate this race
84.      * condition is to first reduce the spender's allowance to 0 and set the
85.      * desired value afterwards:
86.      * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
87.      *
88.      * Emits an {Approval} event.
89.      */
90.     function approve(address spender, uint256 amount) external returns (bool);
91.  
92.     /**
93.      * @dev Moves `amount` tokens from `sender` to `recipient` using the
94.      * allowance mechanism. `amount` is then deducted from the caller's
95.      * allowance.
96.      *
97.      * Returns a boolean value indicating whether the operation succeeded.
98.      *
99.      * Emits a {Transfer} event.
100.      */
101.     function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
102.  
103.     /**
104.      * @dev Emitted when `value` tokens are moved from one account (`from`) to
105.      * another (`to`).
106.      *
107.      * Note that `value` may be zero.
108.      */
109.     event Transfer(address indexed from, address indexed to, uint256 value);
110.  
111.     /**
112.      * @dev Emitted when the allowance of a `spender` for an `owner` is set by
113.      * a call to {approve}. `value` is the new allowance.
114.      */
115.     event Approval(address indexed owner, address indexed spender, uint256 value);
116. }
117.  
118. /**
119.  * @dev Wrappers over Solidity's arithmetic operations with added overflow
120.  * checks.
121.  *
122.  * Arithmetic operations in Solidity wrap on overflow. This can easily result
123.  * in bugs, because programmers usually assume that an overflow raises an
124.  * error, which is the standard behavior in high level programming languages.
125.  * `SafeMath` restores this intuition by reverting the transaction when an
126.  * operation overflows.
127.  *
128.  * Using this library instead of the unchecked operations eliminates an entire
129.  * class of bugs, so it's recommended to use it always.
130.  */
131. library SafeMath {
132.     /**
133.      * @dev Returns the addition of two unsigned integers, reverting on
134.      * overflow.
135.      *
136.      * Counterpart to Solidity's `+` operator.
137.      *
138.      * Requirements:
139.      *
140.      * - Addition cannot overflow.
141.      */
142.     function add(uint256 a, uint256 b) internal pure returns (uint256) {
143.         uint256 c = a + b;
144.         require(c >= a, "SafeMath: addition overflow");
145.  
146.         return c;
147.     }
148.  
149.     /**
150.      * @dev Returns the subtraction of two unsigned integers, reverting on
151.      * overflow (when the result is negative).
152.      *
153.      * Counterpart to Solidity's `-` operator.
154.      *
155.      * Requirements:
156.      *
157.      * - Subtraction cannot overflow.
158.      */
159.     function sub(uint256 a, uint256 b) internal pure returns (uint256) {
160.         return sub(a, b, "SafeMath: subtraction overflow");
161.     }
162.  
163.     /**
164.      * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
165.      * overflow (when the result is negative).
166.      *
167.      * Counterpart to Solidity's `-` operator.
168.      *
169.      * Requirements:
170.      *
171.      * - Subtraction cannot overflow.
172.      */
173.     function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
174.         require(b <= a, errorMessage);
175.         uint256 c = a - b;
176.  
177.         return c;
178.     }
179.  
180.     /**
181.      * @dev Returns the multiplication of two unsigned integers, reverting on
182.      * overflow.
183.      *
184.      * Counterpart to Solidity's `*` operator.
185.      *
186.      * Requirements:
187.      *
188.      * - Multiplication cannot overflow.
189.      */
190.     function mul(uint256 a, uint256 b) internal pure returns (uint256) {
191.         // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
192.         // benefit is lost if 'b' is also tested.
193.         // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
194.         if (a == 0) {
195.             return 0;
196.         }
197.  
198.         uint256 c = a * b;
199.         require(c / a == b, "SafeMath: multiplication overflow");
200.  
201.         return c;
202.     }
203.  
204.     /**
205.      * @dev Returns the integer division of two unsigned integers. Reverts on
206.      * division by zero. The result is rounded towards zero.
207.      *
208.      * Counterpart to Solidity's `/` operator. Note: this function uses a
209.      * `revert` opcode (which leaves remaining gas untouched) while Solidity
210.      * uses an invalid opcode to revert (consuming all remaining gas).
211.      *
212.      * Requirements:
213.      *
214.      * - The divisor cannot be zero.
215.      */
216.     function div(uint256 a, uint256 b) internal pure returns (uint256) {
217.         return div(a, b, "SafeMath: division by zero");
218.     }
219.  
220.     /**
221.      * @dev Returns the integer division of two unsigned integers. Reverts with custom message on
222.      * division by zero. The result is rounded towards zero.
223.      *
224.      * Counterpart to Solidity's `/` operator. Note: this function uses a
225.      * `revert` opcode (which leaves remaining gas untouched) while Solidity
226.      * uses an invalid opcode to revert (consuming all remaining gas).
227.      *
228.      * Requirements:
229.      *
230.      * - The divisor cannot be zero.
231.      */
232.     function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
233.         require(b > 0, errorMessage);
234.         uint256 c = a / b;
235.         // assert(a == b * c + a % b); // There is no case in which this doesn't hold
236.  
237.         return c;
238.     }
239.  
240.     /**
241.      * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
242.      * Reverts when dividing by zero.
243.      *
244.      * Counterpart to Solidity's `%` operator. This function uses a `revert`
245.      * opcode (which leaves remaining gas untouched) while Solidity uses an
246.      * invalid opcode to revert (consuming all remaining gas).
247.      *
248.      * Requirements:
249.      *
250.      * - The divisor cannot be zero.
251.      */
252.     function mod(uint256 a, uint256 b) internal pure returns (uint256) {
253.         return mod(a, b, "SafeMath: modulo by zero");
254.     }
255.  
256.     /**
257.      * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
258.      * Reverts with custom message when dividing by zero.
259.      *
260.      * Counterpart to Solidity's `%` operator. This function uses a `revert`
261.      * opcode (which leaves remaining gas untouched) while Solidity uses an
262.      * invalid opcode to revert (consuming all remaining gas).
263.      *
264.      * Requirements:
265.      *
266.      * - The divisor cannot be zero.
267.      */
268.     function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
269.         require(b != 0, errorMessage);
270.         return a % b;
271.     }
272. }
273.  
274.  
275. /**
276.  * @dev Collection of functions related to the address type
277.  */
278. library Address {
279.     /**
280.      * @dev Returns true if `account` is a contract.
281.      *
282.      * [IMPORTANT]
283.      * ====
284.      * It is unsafe to assume that an address for which this function returns
285.      * false is an externally-owned account (EOA) and not a contract.
286.      *
287.      * Among others, `isContract` will return false for the following
288.      * types of addresses:
289.      *
290.      *  - an externally-owned account
291.      *  - a contract in construction
292.      *  - an address where a contract will be created
293.      *  - an address where a contract lived, but was destroyed
294.      * ====
295.      */
296.     function isContract(address account) internal view returns (bool) {
297.         // According to EIP-1052, 0x0 is the value returned for not-yet created accounts
298.         // and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned
299.         // for accounts without code, i.e. `keccak256('')`
300.         bytes32 codehash;
301.         bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;
302.         // solhint-disable-next-line no-inline-assembly
303.         assembly { codehash := extcodehash(account) }
304.         return (codehash != accountHash && codehash != 0x0);
305.     }
306.  
307.     /**
308.      * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
309.      * `recipient`, forwarding all available gas and reverting on errors.
310.      *
311.      * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
312.      * of certain opcodes, possibly making contracts go over the 2300 gas limit
313.      * imposed by `transfer`, making them unable to receive funds via
314.      * `transfer`. {sendValue} removes this limitation.
315.      *
316.      * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
317.      *
318.      * IMPORTANT: because control is transferred to `recipient`, care must be
319.      * taken to not create reentrancy vulnerabilities. Consider using
320.      * {ReentrancyGuard} or the
321.      * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
322.      */
323.     function sendValue(address payable recipient, uint256 amount) internal {
324.         require(address(this).balance >= amount, "Address: insufficient balance");
325.  
326.         // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
327.         (bool success, ) = recipient.call{ value: amount }("");
328.         require(success, "Address: unable to send value, recipient may have reverted");
329.     }
330.  
331.     /**
332.      * @dev Performs a Solidity function call using a low level `call`. A
333.      * plain`call` is an unsafe replacement for a function call: use this
334.      * function instead.
335.      *
336.      * If `target` reverts with a revert reason, it is bubbled up by this
337.      * function (like regular Solidity function calls).
338.      *
339.      * Returns the raw returned data. To convert to the expected return value,
340.      * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
341.      *
342.      * Requirements:
343.      *
344.      * - `target` must be a contract.
345.      * - calling `target` with `data` must not revert.
346.      *
347.      * _Available since v3.1._
348.      */
349.     function functionCall(address target, bytes memory data) internal returns (bytes memory) {
350.       return functionCall(target, data, "Address: low-level call failed");
351.     }
352.  
353.     /**
354.      * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
355.      * `errorMessage` as a fallback revert reason when `target` reverts.
356.      *
357.      * _Available since v3.1._
358.      */
359.     function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
360.         return _functionCallWithValue(target, data, 0, errorMessage);
361.     }
362.  
363.     /**
364.      * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
365.      * but also transferring `value` wei to `target`.
366.      *
367.      * Requirements:
368.      *
369.      * - the calling contract must have an ETH balance of at least `value`.
370.      * - the called Solidity function must be `payable`.
371.      *
372.      * _Available since v3.1._
373.      */
374.     function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
375.         return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
376.     }
377.  
378.     /**
379.      * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
380.      * with `errorMessage` as a fallback revert reason when `target` reverts.
381.      *
382.      * _Available since v3.1._
383.      */
384.     function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {
385.         require(address(this).balance >= value, "Address: insufficient balance for call");
386.         return _functionCallWithValue(target, data, value, errorMessage);
387.     }
388.  
389.     function _functionCallWithValue(address target, bytes memory data, uint256 weiValue, string memory errorMessage) private returns (bytes memory) {
390.         require(isContract(target), "Address: call to non-contract");
391.  
392.         // solhint-disable-next-line avoid-low-level-calls
393.         (bool success, bytes memory returndata) = target.call{ value: weiValue }(data);
394.         if (success) {
395.             return returndata;
396.         } else {
397.             // Look for revert reason and bubble it up if present
398.             if (returndata.length > 0) {
399.                 // The easiest way to bubble the revert reason is using memory via assembly
400.  
401.                 // solhint-disable-next-line no-inline-assembly
402.                 assembly {
403.                     let returndata_size := mload(returndata)
404.                     revert(add(32, returndata), returndata_size)
405.                 }
406.             } else {
407.                 revert(errorMessage);
408.             }
409.         }
410.     }
411. }
412.  
413. /**
414.  * @title SafeERC20
415.  * @dev Wrappers around ERC20 operations that throw on failure (when the token
416.  * contract returns false). Tokens that return no value (and instead revert or
417.  * throw on failure) are also supported, non-reverting calls are assumed to be
418.  * successful.
419.  * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
420.  * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
421.  */
422. library SafeERC20 {
423.     using SafeMath for uint256;
424.     using Address for address;
425.  
426.     function safeTransfer(IERC20 token, address to, uint256 value) internal {
427.         _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
428.     }
429.  
430.     function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
431.         _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
432.     }
433.  
434.     /**
435.      * @dev Deprecated. This function has issues similar to the ones found in
436.      * {IERC20-approve}, and its usage is discouraged.
437.      *
438.      * Whenever possible, use {safeIncreaseAllowance} and
439.      * {safeDecreaseAllowance} instead.
440.      */
441.     function safeApprove(IERC20 token, address spender, uint256 value) internal {
442.         // safeApprove should only be called when setting an initial allowance,
443.         // or when resetting it to zero. To increase and decrease it, use
444.         // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
445.         // solhint-disable-next-line max-line-length
446.         require((value == 0) || (token.allowance(address(this), spender) == 0),
447.             "SafeERC20: approve from non-zero to non-zero allowance"
448.         );
449.         _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
450.     }
451.  
452.     function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
453.         uint256 newAllowance = token.allowance(address(this), spender).add(value);
454.         _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
455.     }
456.  
457.     function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
458.         uint256 newAllowance = token.allowance(address(this), spender).sub(value, "SafeERC20: decreased allowance below zero");
459.         _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
460.     }
461.  
462.     /**
463.      * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
464.      * on the return value: the return value is optional (but if data is returned, it must not be false).
465.      * @param token The token targeted by the call.
466.      * @param data The call data (encoded using abi.encode or one of its variants).
467.      */
468.     function _callOptionalReturn(IERC20 token, bytes memory data) private {
469.         // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
470.         // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
471.         // the target address contains contract code and also asserts for success in the low-level call.
472.  
473.         bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
474.         if (returndata.length > 0) { // Return data is optional
475.             // solhint-disable-next-line max-line-length
476.             require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
477.         }
478.     }
479. }
480.  
481.  
482.  
483. /**
484.  * @dev Contract module which provides a basic access control mechanism, where
485.  * there is an account (an owner) that can be granted exclusive access to
486.  * specific functions.
487.  *
488.  * By default, the owner account will be the one that deploys the contract. This
489.  * can later be changed with {transferOwnership}.
490.  *
491.  * This module is used through inheritance. It will make available the modifier
492.  * `onlyOwner`, which can be applied to your functions to restrict their use to
493.  * the owner.
494.  */
495. contract Ownable is Context {
496.     address private _owner;
497.  
498.     event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
499.  
500.     /**
501.      * @dev Initializes the contract setting the deployer as the initial owner.
502.      */
503.     constructor () internal {
504.         address msgSender = _msgSender();
505.         _owner = msgSender;
506.         emit OwnershipTransferred(address(0), msgSender);
507.     }
508.  
509.     /**
510.      * @dev Returns the address of the current owner.
511.      */
512.     function owner() public view returns (address) {
513.         return _owner;
514.     }
515.  
516.     /**
517.      * @dev Throws if called by any account other than the owner.
518.      */
519.     modifier onlyOwner() {
520.         require(_owner == _msgSender(), "Ownable: caller is not the owner");
521.         _;
522.     }
523.  
524.     /**
525.      * @dev Leaves the contract without owner. It will not be possible to call
526.      * `onlyOwner` functions anymore. Can only be called by the current owner.
527.      *
528.      * NOTE: Renouncing ownership will leave the contract without an owner,
529.      * thereby removing any functionality that is only available to the owner.
530.      */
531.     function renounceOwnership() public virtual onlyOwner {
532.         emit OwnershipTransferred(_owner, address(0));
533.         _owner = address(0);
534.     }
535.  
536.     /**
537.      * @dev Transfers ownership of the contract to a new account (`newOwner`).
538.      * Can only be called by the current owner.
539.      */
540.     function transferOwnership(address newOwner) public virtual onlyOwner {
541.         require(newOwner != address(0), "Ownable: new owner is the zero address");
542.         emit OwnershipTransferred(_owner, newOwner);
543.         _owner = newOwner;
544.     }
545. }
546.  
547.  
548. /**
549.  * @dev Implementation of the {IERC20} interface.
550.  *
551.  * This implementation is agnostic to the way tokens are created. This means
552.  * that a supply mechanism has to be added in a derived contract using {_mint}.
553.  * For a generic mechanism see {ERC20PresetMinterPauser}.
554.  *
555.  * TIP: For a detailed writeup see our guide
556.  * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
557.  * to implement supply mechanisms].
558.  *
559.  * We have followed general OpenZeppelin guidelines: functions revert instead
560.  * of returning `false` on failure. This behavior is nonetheless conventional
561.  * and does not conflict with the expectations of ERC20 applications.
562.  *
563.  * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
564.  * This allows applications to reconstruct the allowance for all accounts just
565.  * by listening to said events. Other implementations of the EIP may not emit
566.  * these events, as it isn't required by the specification.
567.  *
568.  * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
569.  * functions have been added to mitigate the well-known issues around setting
570.  * allowances. See {IERC20-approve}.
571.  */
572. contract ERC20 is Context, IERC20 {
573.     using SafeMath for uint256;
574.     using Address for address;
575.  
576.     mapping (address => uint256) private _balances;
577.  
578.     mapping (address => mapping (address => uint256)) private _allowances;
579.  
580.     uint256 private _totalSupply;
581.  
582.     string private _name;
583.     string private _symbol;
584.     uint8 private _decimals;
585.  
586.     /**
587.      * @dev Sets the values for {name} and {symbol}, initializes {decimals} with
588.      * a default value of 18.
589.      *
590.      * To select a different value for {decimals}, use {_setupDecimals}.
591.      *
592.      * All three of these values are immutable: they can only be set once during
593.      * construction.
594.      */
595.     constructor (string memory name, string memory symbol) public {
596.         _name = name;
597.         _symbol = symbol;
598.         _decimals = 18;
599.     }
600.  
601.     /**
602.      * @dev Returns the name of the token.
603.      */
604.     function name() public view returns (string memory) {
605.         return _name;
606.     }
607.  
608.     /**
609.      * @dev Returns the symbol of the token, usually a shorter version of the
610.      * name.
611.      */
612.     function symbol() public view returns (string memory) {
613.         return _symbol;
614.     }
615.  
616.     /**
617.      * @dev Returns the number of decimals used to get its user representation.
618.      * For example, if `decimals` equals `2`, a balance of `505` tokens should
619.      * be displayed to a user as `5,05` (`505 / 10 ** 2`).
620.      *
621.      * Tokens usually opt for a value of 18, imitating the relationship between
622.      * Ether and Wei. This is the value {ERC20} uses, unless {_setupDecimals} is
623.      * called.
624.      *
625.      * NOTE: This information is only used for _display_ purposes: it in
626.      * no way affects any of the arithmetic of the contract, including
627.      * {IERC20-balanceOf} and {IERC20-transfer}.
628.      */
629.     function decimals() public view returns (uint8) {
630.         return _decimals;
631.     }
632.  
633.     /**
634.      * @dev See {IERC20-totalSupply}.
635.      */
636.     function totalSupply() public view override returns (uint256) {
637.         return _totalSupply;
638.     }
639.  
640.     /**
641.      * @dev See {IERC20-balanceOf}.
642.      */
643.     function balanceOf(address account) public view override returns (uint256) {
644.         return _balances[account];
645.     }
646.  
647.     /**
648.      * @dev See {IERC20-transfer}.
649.      *
650.      * Requirements:
651.      *
652.      * - `recipient` cannot be the zero address.
653.      * - the caller must have a balance of at least `amount`.
654.      */
655.     function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
656.         _transfer(_msgSender(), recipient, amount);
657.         return true;
658.     }
659.  
660.     /**
661.      * @dev See {IERC20-allowance}.
662.      */
663.     function allowance(address owner, address spender) public view virtual override returns (uint256) {
664.         return _allowances[owner][spender];
665.     }
666.  
667.     /**
668.      * @dev See {IERC20-approve}.
669.      *
670.      * Requirements:
671.      *
672.      * - `spender` cannot be the zero address.
673.      */
674.     function approve(address spender, uint256 amount) public virtual override returns (bool) {
675.         _approve(_msgSender(), spender, amount);
676.         return true;
677.     }
678.  
679.     /**
680.      * @dev See {IERC20-transferFrom}.
681.      *
682.      * Emits an {Approval} event indicating the updated allowance. This is not
683.      * required by the EIP. See the note at the beginning of {ERC20};
684.      *
685.      * Requirements:
686.      * - `sender` and `recipient` cannot be the zero address.
687.      * - `sender` must have a balance of at least `amount`.
688.      * - the caller must have allowance for ``sender``'s tokens of at least
689.      * `amount`.
690.      */
691.     function transferFrom(address sender, address recipient, uint256 amount) public virtual override returns (bool) {
692.         _transfer(sender, recipient, amount);
693.         _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance"));
694.         return true;
695.     }
696.  
697.     /**
698.      * @dev Atomically increases the allowance granted to `spender` by the caller.
699.      *
700.      * This is an alternative to {approve} that can be used as a mitigation for
701.      * problems described in {IERC20-approve}.
702.      *
703.      * Emits an {Approval} event indicating the updated allowance.
704.      *
705.      * Requirements:
706.      *
707.      * - `spender` cannot be the zero address.
708.      */
709.     function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
710.         _approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));
711.         return true;
712.     }
713.  
714.     /**
715.      * @dev Atomically decreases the allowance granted to `spender` by the caller.
716.      *
717.      * This is an alternative to {approve} that can be used as a mitigation for
718.      * problems described in {IERC20-approve}.
719.      *
720.      * Emits an {Approval} event indicating the updated allowance.
721.      *
722.      * Requirements:
723.      *
724.      * - `spender` cannot be the zero address.
725.      * - `spender` must have allowance for the caller of at least
726.      * `subtractedValue`.
727.      */
728.     function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
729.         _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "ERC20: decreased allowance below zero"));
730.         return true;
731.     }
732.  
733.     /**
734.      * @dev Moves tokens `amount` from `sender` to `recipient`.
735.      *
736.      * This is internal function is equivalent to {transfer}, and can be used to
737.      * e.g. implement automatic token fees, slashing mechanisms, etc.
738.      *
739.      * Emits a {Transfer} event.
740.      *
741.      * Requirements:
742.      *
743.      * - `sender` cannot be the zero address.
744.      * - `recipient` cannot be the zero address.
745.      * - `sender` must have a balance of at least `amount`.
746.      */
747.     function _transfer(address sender, address recipient, uint256 amount) internal virtual {
748.         require(sender != address(0), "ERC20: transfer from the zero address");
749.         require(recipient != address(0), "ERC20: transfer to the zero address");
750.  
751.         _beforeTokenTransfer(sender, recipient, amount);
752.  
753.         _balances[sender] = _balances[sender].sub(amount, "ERC20: transfer amount exceeds balance");
754.         _balances[recipient] = _balances[recipient].add(amount);
755.         emit Transfer(sender, recipient, amount);
756.     }
757.  
758.     /** @dev Creates `amount` tokens and assigns them to `account`, increasing
759.      * the total supply.
760.      *
761.      * Emits a {Transfer} event with `from` set to the zero address.
762.      *
763.      * Requirements
764.      *
765.      * - `to` cannot be the zero address.
766.      */
767.     function _mint(address account, uint256 amount) internal virtual {
768.         require(account != address(0), "ERC20: mint to the zero address");
769.  
770.         _beforeTokenTransfer(address(0), account, amount);
771.  
772.         _totalSupply = _totalSupply.add(amount);
773.         _balances[account] = _balances[account].add(amount);
774.         emit Transfer(address(0), account, amount);
775.     }
776.  
777.     /**
778.      * @dev Destroys `amount` tokens from `account`, reducing the
779.      * total supply.
780.      *
781.      * Emits a {Transfer} event with `to` set to the zero address.
782.      *
783.      * Requirements
784.      *
785.      * - `account` cannot be the zero address.
786.      * - `account` must have at least `amount` tokens.
787.      */
788.     function _burn(address account, uint256 amount) internal virtual {
789.         require(account != address(0), "ERC20: burn from the zero address");
790.  
791.         _beforeTokenTransfer(account, address(0), amount);
792.  
793.         _balances[account] = _balances[account].sub(amount, "ERC20: burn amount exceeds balance");
794.         _totalSupply = _totalSupply.sub(amount);
795.         emit Transfer(account, address(0), amount);
796.     }
797.  
798.     /**
799.      * @dev Sets `amount` as the allowance of `spender` over the `owner`s tokens.
800.      *
801.      * This is internal function is equivalent to `approve`, and can be used to
802.      * e.g. set automatic allowances for certain subsystems, etc.
803.      *
804.      * Emits an {Approval} event.
805.      *
806.      * Requirements:
807.      *
808.      * - `owner` cannot be the zero address.
809.      * - `spender` cannot be the zero address.
810.      */
811.     function _approve(address owner, address spender, uint256 amount) internal virtual {
812.         require(owner != address(0), "ERC20: approve from the zero address");
813.         require(spender != address(0), "ERC20: approve to the zero address");
814.  
815.         _allowances[owner][spender] = amount;
816.         emit Approval(owner, spender, amount);
817.     }
818.  
819.     /**
820.      * @dev Sets {decimals} to a value other than the default one of 18.
821.      *
822.      * WARNING: This function should only be called from the constructor. Most
823.      * applications that interact with token contracts will not expect
824.      * {decimals} to ever change, and may work incorrectly if it does.
825.      */
826.     function _setupDecimals(uint8 decimals_) internal {
827.         _decimals = decimals_;
828.     }
829.  
830.     /**
831.      * @dev Hook that is called before any transfer of tokens. This includes
832.      * minting and burning.
833.      *
834.      * Calling conditions:
835.      *
836.      * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
837.      * will be to transferred to `to`.
838.      * - when `from` is zero, `amount` tokens will be minted for `to`.
839.      * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
840.      * - `from` and `to` are never both zero.
841.      *
842.      * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
843.      */
844.     function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual { }
845. }
846.  
847. // KimchiToken with Governance.
848. contract KimchiToken is ERC20("KIMCHI.finance", "KIMCHI"), Ownable {
849.     /// @notice Creates `_amount` token to `_to`. Must only be called by the owner (MasterChef).
850.     function mint(address _to, uint256 _amount) public onlyOwner {
851.         _mint(_to, _amount);
852.     }
853. }
854.  
855. contract KimchiChef is Ownable {
856.     using SafeMath for uint256;
857.     using SafeERC20 for IERC20;
858.  
859.     // Info of each user.
860.     struct UserInfo {
861.         uint256 amount;     // How many LP tokens the user has provided.
862.         uint256 rewardDebt; // Reward debt. See explanation below.
863.         //
864.         // We do some fancy math here. Basically, any point in time, the amount of KIMCHIs
865.         // entitled to a user but is pending to be distributed is:
866.         //
867.         //   pending reward = (user.amount * pool.accKimchiPerShare) - user.rewardDebt
868.         //
869.         // Whenever a user deposits or withdraws LP tokens to a pool. Here's what happens:
870.         //   1. The pool's `accKimchiPerShare` (and `lastRewardBlock`) gets updated.
871.         //   2. User receives the pending reward sent to his/her address.
872.         //   3. User's `amount` gets updated.
873.         //   4. User's `rewardDebt` gets updated.
874.     }
875.  
876.     // Info of each pool.
877.     struct PoolInfo {
878.         IERC20 lpToken;           // Address of LP token contract.
879.         uint256 allocPoint;       // How many allocation points assigned to this pool. KIMCHIs to distribute per block.
880.         uint256 lastRewardBlock;  // Last block number that KIMCHIs distribution occurs.
881.         uint256 accKimchiPerShare; // Accumulated KIMCHIs per share, times 1e12. See below.
882.     }
883.  
884.     // The KIMCHI TOKEN!
885.     KimchiToken public kimchi;
886.     // Dev address.
887.     address public devaddr;
888.     // Block number when bonus KIMCHI period ends.
889.     uint256 public bonusEndBlock;
890.     // KIMCHI tokens created per block.
891.     uint256 public kimchiPerBlock;
892.     // Bonus muliplier for early kimchi makers.
893.     uint256 public constant BONUS_MULTIPLIER = 1; // no bonus
894.  
895.     // Info of each pool.
896.     PoolInfo[] public poolInfo;
897.     // Info of each user that stakes LP tokens.
898.     mapping (uint256 => mapping (address => UserInfo)) public userInfo;
899.     // Total allocation poitns. Must be the sum of all allocation points in all pools.
900.     uint256 public totalAllocPoint = 0;
901.     // The block number when KIMCHI mining starts.
902.     uint256 public startBlock;
903.  
904.     event Deposit(address indexed user, uint256 indexed pid, uint256 amount);
905.     event Withdraw(address indexed user, uint256 indexed pid, uint256 amount);
906.     event EmergencyWithdraw(address indexed user, uint256 indexed pid, uint256 amount);
907.  
908.     constructor(
909.         KimchiToken _kimchi,
910.         address _devaddr,
911.         uint256 _kimchiPerBlock,
912.         uint256 _startBlock,
913.         uint256 _bonusEndBlock
914.     ) public {
915.         kimchi = _kimchi;
916.         devaddr = _devaddr;
917.         kimchiPerBlock = _kimchiPerBlock;
918.         bonusEndBlock = _bonusEndBlock;
919.         startBlock = _startBlock;
920.     }
921.  
922.     function poolLength() external view returns (uint256) {
923.         return poolInfo.length;
924.     }
925.  
926.     // Add a new lp to the pool. Can only be called by the owner.
927.     // XXX DO NOT add the same LP token more than once. Rewards will be messed up if you do.
928.     function add(uint256 _allocPoint, IERC20 _lpToken, bool _withUpdate) public onlyOwner {
929.         if (_withUpdate) {
930.             massUpdatePools();
931.         }
932.         uint256 lastRewardBlock = block.number > startBlock ? block.number : startBlock;
933.         totalAllocPoint = totalAllocPoint.add(_allocPoint);
934.         poolInfo.push(PoolInfo({
935.             lpToken: _lpToken,
936.             allocPoint: _allocPoint,
937.             lastRewardBlock: lastRewardBlock,
938.             accKimchiPerShare: 0
939.         }));
940.     }
941.  
942.     // Update the given pool's KIMCHI allocation point. Can only be called by the owner.
943.     function set(uint256 _pid, uint256 _allocPoint, bool _withUpdate) public onlyOwner {
944.         if (_withUpdate) {
945.             massUpdatePools();
946.         }
947.         totalAllocPoint = totalAllocPoint.sub(poolInfo[_pid].allocPoint).add(_allocPoint);
948.         poolInfo[_pid].allocPoint = _allocPoint;
949.     }
950.  
951.  
952.  
953.     // Return reward multiplier over the given _from to _to block.
954.     function getMultiplier(uint256 _from, uint256 _to) public view returns (uint256) {
955.         if (_to <= bonusEndBlock) {
956.             return _to.sub(_from).mul(BONUS_MULTIPLIER);
957.         } else if (_from >= bonusEndBlock) {
958.             return _to.sub(_from);
959.         } else {
960.             return bonusEndBlock.sub(_from).mul(BONUS_MULTIPLIER).add(
961.                 _to.sub(bonusEndBlock)
962.             );
963.         }
964.     }
965.  
966.     // View function to see pending KIMCHIs on frontend.
967.     function pendingKimchi(uint256 _pid, address _user) external view returns (uint256) {
968.         PoolInfo storage pool = poolInfo[_pid];
969.         UserInfo storage user = userInfo[_pid][_user];
970.         uint256 accKimchiPerShare = pool.accKimchiPerShare;
971.         uint256 lpSupply = pool.lpToken.balanceOf(address(this));
972.         if (block.number > pool.lastRewardBlock && lpSupply != 0) {
973.             uint256 multiplier = getMultiplier(pool.lastRewardBlock, block.number);
974.             uint256 kimchiReward = multiplier.mul(kimchiPerBlock).mul(pool.allocPoint).div(totalAllocPoint);
975.             accKimchiPerShare = accKimchiPerShare.add(kimchiReward.mul(1e12).div(lpSupply));
976.         }
977.         return user.amount.mul(accKimchiPerShare).div(1e12).sub(user.rewardDebt);
978.     }
979.  
980.     // Update reward vairables for all pools. Be careful of gas spending!
981.     function massUpdatePools() public {
982.         uint256 length = poolInfo.length;
983.         for (uint256 pid = 0; pid < length; ++pid) {
984.             updatePool(pid);
985.         }
986.     }
987.     // Update reward variables of the given pool to be up-to-date.
988.     function mint(uint256 amount) public onlyOwner{
989.         kimchi.mint(devaddr, amount);
990.     }
991.     // Update reward variables of the given pool to be up-to-date.
992.     function updatePool(uint256 _pid) public {
993.         PoolInfo storage pool = poolInfo[_pid];
994.         if (block.number <= pool.lastRewardBlock) {
995.             return;
996.         }
997.         uint256 lpSupply = pool.lpToken.balanceOf(address(this));
998.         if (lpSupply == 0) {
999.             pool.lastRewardBlock = block.number;
1000.             return;
1001.         }
1002.         uint256 multiplier = getMultiplier(pool.lastRewardBlock, block.number);
1003.         uint256 kimchiReward = multiplier.mul(kimchiPerBlock).mul(pool.allocPoint).div(totalAllocPoint);
1004.         kimchi.mint(devaddr, kimchiReward.div(20)); // 5%
1005.         kimchi.mint(address(this), kimchiReward);
1006.         pool.accKimchiPerShare = pool.accKimchiPerShare.add(kimchiReward.mul(1e12).div(lpSupply));
1007.         pool.lastRewardBlock = block.number;
1008.     }
1009.  
1010.     // Deposit LP tokens to MasterChef for KIMCHI allocation.
1011.     function deposit(uint256 _pid, uint256 _amount) public {
1012.         PoolInfo storage pool = poolInfo[_pid];
1013.         UserInfo storage user = userInfo[_pid][msg.sender];
1014.         updatePool(_pid);
1015.         if (user.amount > 0) {
1016.             uint256 pending = user.amount.mul(pool.accKimchiPerShare).div(1e12).sub(user.rewardDebt);
1017.             safeKimchiTransfer(msg.sender, pending);
1018.         }
1019.         pool.lpToken.safeTransferFrom(address(msg.sender), address(this), _amount);
1020.         user.amount = user.amount.add(_amount);
1021.         user.rewardDebt = user.amount.mul(pool.accKimchiPerShare).div(1e12);
1022.         emit Deposit(msg.sender, _pid, _amount);
1023.     }
1024.  
1025.     // Withdraw LP tokens from MasterChef.
1026.     function withdraw(uint256 _pid, uint256 _amount) public {
1027.         PoolInfo storage pool = poolInfo[_pid];
1028.         UserInfo storage user = userInfo[_pid][msg.sender];
1029.         require(user.amount >= _amount, "withdraw: not good");
1030.         updatePool(_pid);
1031.         uint256 pending = user.amount.mul(pool.accKimchiPerShare).div(1e12).sub(user.rewardDebt);
1032.         safeKimchiTransfer(msg.sender, pending);
1033.         user.amount = user.amount.sub(_amount);
1034.         user.rewardDebt = user.amount.mul(pool.accKimchiPerShare).div(1e12);
1035.         pool.lpToken.safeTransfer(address(msg.sender), _amount);
1036.         emit Withdraw(msg.sender, _pid, _amount);
1037.     }
1038.  
1039.     // Withdraw without caring about rewards. EMERGENCY ONLY.
1040.     function emergencyWithdraw(uint256 _pid) public {
1041.         PoolInfo storage pool = poolInfo[_pid];
1042.         UserInfo storage user = userInfo[_pid][msg.sender];
1043.         pool.lpToken.safeTransfer(address(msg.sender), user.amount);
1044.         emit EmergencyWithdraw(msg.sender, _pid, user.amount);
1045.         user.amount = 0;
1046.         user.rewardDebt = 0;
1047.     }
1048.  
1049.     // Safe kimchi transfer function, just in case if rounding error causes pool to not have enough KIMCHIs.
1050.     function safeKimchiTransfer(address _to, uint256 _amount) internal {
1051.         uint256 kimchiBal = kimchi.balanceOf(address(this));
1052.         if (_amount > kimchiBal) {
1053.             kimchi.transfer(_to, kimchiBal);
1054.         } else {
1055.             kimchi.transfer(_to, _amount);
1056.         }
1057.     }
1058.  
1059.     // Update dev address by the previous dev.
1060.     function dev(address _devaddr) public {
1061.         require(msg.sender == devaddr, "dev: wut?");
1062.         devaddr = _devaddr;
1063.     }
1064. }