// File: @openzeppelin/contracts/access/Ownable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)

pragma solidity ^0.8.0;

import "../utils/Context.sol";

/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor() {
        _transferOwnership(_msgSender());
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        _checkOwner();
        _;
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if the sender is not the owner.
     */
    function _checkOwner() internal view virtual {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions 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 {
        _transferOwnership(address(0));
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}

// File: @openzeppelin/contracts/token/ERC20/extensions/draft-IERC20Permit.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/draft-IERC20Permit.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
 * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
 *
 * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
 * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't
 * need to send a transaction, and thus is not required to hold Ether at all.
 */
interface IERC20Permit {
    /**
     * @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,
     * given ``owner``'s signed approval.
     *
     * IMPORTANT: The same issues {IERC20-approve} has related to transaction
     * ordering also apply here.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `deadline` must be a timestamp in the future.
     * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
     * over the EIP712-formatted function arguments.
     * - the signature must use ``owner``'s current nonce (see {nonces}).
     *
     * For more information on the signature format, see the
     * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
     * section].
     */
    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;

    /**
     * @dev Returns the current nonce for `owner`. This value must be
     * included whenever a signature is generated for {permit}.
     *
     * Every successful call to {permit} increases ``owner``'s nonce by one. This
     * prevents a signature from being used multiple times.
     */
    function nonces(address owner) external view returns (uint256);

    /**
     * @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.
     */
    // solhint-disable-next-line func-name-mixedcase
    function DOMAIN_SEPARATOR() external view returns (bytes32);
}

// File: @openzeppelin/contracts/token/ERC20/IERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);

    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `to`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address to, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `from` to `to` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) external returns (bool);
}

// File: @openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (token/ERC20/utils/SafeERC20.sol)

pragma solidity ^0.8.0;

import "../IERC20.sol";
import "../extensions/draft-IERC20Permit.sol";
import "../../../utils/Address.sol";

/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    using Address for address;

    function safeTransfer(
        IERC20 token,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    function safeTransferFrom(
        IERC20 token,
        address from,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }

    /**
     * @dev Deprecated. This function has issues similar to the ones found in
     * {IERC20-approve}, and its usage is discouraged.
     *
     * Whenever possible, use {safeIncreaseAllowance} and
     * {safeDecreaseAllowance} instead.
     */
    function safeApprove(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        require(
            (value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }

    function safeIncreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        uint256 newAllowance = token.allowance(address(this), spender) + value;
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    function safeDecreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        unchecked {
            uint256 oldAllowance = token.allowance(address(this), spender);
            require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
            uint256 newAllowance = oldAllowance - value;
            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
        }
    }

    function safePermit(
        IERC20Permit token,
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) internal {
        uint256 nonceBefore = token.nonces(owner);
        token.permit(owner, spender, value, deadline, v, r, s);
        uint256 nonceAfter = token.nonces(owner);
        require(nonceAfter == nonceBefore + 1, "SafeERC20: permit did not succeed");
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We use {Address-functionCall} to perform this call, which verifies that
        // the target address contains contract code and also asserts for success in the low-level call.

        bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
        if (returndata.length > 0) {
            // Return data is optional
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}

// File: @openzeppelin/contracts/utils/Address.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (utils/Address.sol)

pragma solidity ^0.8.1;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     *
     * [IMPORTANT]
     * ====
     * You shouldn't rely on `isContract` to protect against flash loan attacks!
     *
     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
     * constructor.
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize/address.code.length, which returns 0
        // for contracts in construction, since the code is only stored at the end
        // of the constructor execution.

        return account.code.length > 0;
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://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");

        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain `call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, "Address: low-level call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }

    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }

    /**
     * @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
     * the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
     *
     * _Available since v4.8._
     */
    function verifyCallResultFromTarget(
        address target,
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        if (success) {
            if (returndata.length == 0) {
                // only check isContract if the call was successful and the return data is empty
                // otherwise we already know that it was a contract
                require(isContract(target), "Address: call to non-contract");
            }
            return returndata;
        } else {
            _revert(returndata, errorMessage);
        }
    }

    /**
     * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason or using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            _revert(returndata, errorMessage);
        }
    }

    function _revert(bytes memory returndata, string memory errorMessage) private pure {
        // Look for revert reason and bubble it up if present
        if (returndata.length > 0) {
            // The easiest way to bubble the revert reason is using memory via assembly
            /// @solidity memory-safe-assembly
            assembly {
                let returndata_size := mload(returndata)
                revert(add(32, returndata), returndata_size)
            }
        } else {
            revert(errorMessage);
        }
    }
}

// File: @openzeppelin/contracts/utils/Context.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)

pragma solidity ^0.8.0;

/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}

// File: contracts/Farming.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.18;

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "./interfaces/IFarming.sol";

contract Farming is Ownable, IFarming {
  using SafeERC20 for IERC20;

  // Info of each user.
  struct UserInfo {
    uint256 amount;     // How many LP tokens the user has provided.
    uint256 rewardDebt; // Reward debt. See explanation below.
    //
    // We do some fancy math here. Basically, any point in time, the amount of ERC20s
    // entitled to a user but is pending to be distributed is:
    //
    //   pending reward = (user.amount * pool.accERC20PerShare) - user.rewardDebt
    //
    // Whenever a user deposits or withdraws LP tokens to a pool. Here's what happens:
    //   1. The pool's `accERC20PerShare` (and `lastRewardBlock`) gets updated.
    //   2. User receives the pending reward sent to his/her address.
    //   3. User's `amount` gets updated.
    //   4. User's `rewardDebt` gets updated.
  }

  // Info of each pool.
  struct PoolInfo {
    IERC20 lpToken;             // Address of LP token contract.
    uint256 allocPoint;         // How many allocation points assigned to this pool. ERC20s to distribute per block.
    uint256 lastRewardBlock;    // Last block number that ERC20s distribution occurs.
    uint256 accERC20PerShare;   // Accumulated ERC20s per share, times 1e36.
  }

  // Minimum number of blocks that needs to pass, from the deploy, in order to start distributing rewards
  // uint constant MINIMUM_BLOCKS_BEFORE_DISTRIBUTION = 216_000; // 30 days divided by 12 seconds (average Ethereum block time)
  uint constant MINIMUM_BLOCKS_BEFORE_DISTRIBUTION = 0; // Removed due to time constraints

  // Maximum number of blocks that needs to pass, from the deploy, in order to start distributing rewards
  uint constant MAXIMUM_BLOCKS_BEFORE_DISTRIBUTION = 1_296_000; // 180 days divided by 12 seconds (average Ethereum block time)

  // Address of the ERC20 Token contract.
  IERC20 public erc20;
  // The total amount of ERC20 that's paid out as reward.
  uint256 public paidOut;
  // ERC20 tokens rewarded per block.
  uint256 public rewardPerBlock;

  // Info of each pool.
  PoolInfo[] public poolInfo;
  // Info of each user that stakes LP tokens.
  mapping (uint256 => mapping (address => UserInfo)) public userInfo;
  // Total allocation points. Must be the sum of all allocation points in all pools.
  uint256 public totalAllocPoint;

  // The block number when farming starts.
  uint256 public startBlock;
  // The block number when farming ends.
  uint256 public endBlock;

  /**
    * @notice Constructor
    * @param _erc20 Address of the reward token
    * @param _rewardPerBlock Distributed rewards per block
    * @param _startBlock Block number from which users can farm
    */
  constructor(
    IERC20 _erc20, 
    uint256 _rewardPerBlock, 
    uint256 _startBlock
  ) {
    require(_startBlock >= block.number + MINIMUM_BLOCKS_BEFORE_DISTRIBUTION && 
      _startBlock <= block.number + MAXIMUM_BLOCKS_BEFORE_DISTRIBUTION, "constructor: invalid start block");

    erc20 = _erc20;
    rewardPerBlock = _rewardPerBlock;
    startBlock = _startBlock;
    endBlock = _startBlock;
  }

  /**
    * @notice Returns the number of farming pools
    * @return pools Number of farming pools
    */
  function poolLength() external view returns (uint256) {
    return poolInfo.length;
  }

  /**
    * @notice Fund the farming and extends the end block
    * @param _amount Amount of token to fund
    * @dev Caller must approve the transfer of token from its wallet
          to this contract before calling this function
    */
  function fund(
    uint256 _amount
  ) public {
    require(block.number < endBlock, "fund: too late, the farm is closed");
    require(_amount % rewardPerBlock == 0, "fund: invalid amount");

    erc20.safeTransferFrom(address(msg.sender), address(this), _amount);
    endBlock += _amount / rewardPerBlock;
  }

  /**
    * @notice Create a farming pool
    * @param _allocPoint Allocation points of the pool. This pool will receive
              _allocPoint / totalAllocPoint of the reward per block
    * @param _lpToken Address of the LP token
    * @param _withUpdate If true, updates other farmimg pools
    * @dev Owner should withdraw before endBlock in order to not lose rewards
    * @dev DO NOT add the same LP token more than once. Rewards will be messed
                up if you do.
    */
  function add(
    uint256 _allocPoint, 
    IERC20 _lpToken, 
    bool _withUpdate
  ) public onlyOwner {
    if (_withUpdate) {
      massUpdatePools();
    }
    uint256 lastRewardBlock = block.number > startBlock ? block.number : startBlock;
    totalAllocPoint = totalAllocPoint + _allocPoint;
    poolInfo.push(PoolInfo({
      lpToken: _lpToken,
      allocPoint: _allocPoint,
      lastRewardBlock: lastRewardBlock,
      accERC20PerShare: 0
    }));

    // Deposit 1 wei in order to not lose rewards 
    deposit(poolInfo.length - 1, 1 wei);
  }

  /**
    * @notice Update allocation points of a farming pool
    * @param _pid Pool id
    * @param _allocPoint Allocation points of the pool
    * @param _withUpdate If true, updates other farmimg pools
    */
  function set(
    uint256 _pid, 
    uint256 _allocPoint, 
    bool _withUpdate
  ) public onlyOwner {
    if (_withUpdate) {
      massUpdatePools();
    }
    totalAllocPoint = totalAllocPoint - poolInfo[_pid].allocPoint + _allocPoint;
    poolInfo[_pid].allocPoint = _allocPoint;
  }

  /**
    * @notice Returns the amount of deposited LPs for a user
    * @param _pid Pool id
    * @param _user Address of the user
    * @return deposited Deposited tokens of the user
    */
  function deposited(
    uint256 _pid, 
    address _user
  ) external view returns (uint256) {
    UserInfo storage user = userInfo[_pid][_user];
    return user.amount;
  }

  /**
    * @notice Returns the pending rewards for a user
    * @param _pid Pool id
    * @param _user Address of the user
    * @return rewards Rewards of the user in the farming pool
    */
  function pending(
    uint256 _pid, 
    address _user
  ) external view returns (uint256) {
    PoolInfo storage pool = poolInfo[_pid];
    UserInfo storage user = userInfo[_pid][_user];
    uint256 accERC20PerShare = pool.accERC20PerShare;
    uint256 lpSupply = pool.lpToken.balanceOf(address(this));
    uint256 lastBlock = block.number < endBlock ? block.number : endBlock;

    if (lastBlock > pool.lastRewardBlock && lpSupply != 0) {
      uint256 nrOfBlocks = lastBlock - pool.lastRewardBlock;
      uint256 erc20Reward = nrOfBlocks * rewardPerBlock * pool.allocPoint / totalAllocPoint;
      accERC20PerShare = accERC20PerShare + erc20Reward * 1e36 / lpSupply;
    }

    return user.amount * accERC20PerShare / 1e36 - user.rewardDebt;
  }

  /**
    * @notice Returns the total amount of pending rewards
    * @return totalRewards Total amount of pending rewards
    */
  function totalPending() external view returns (uint256) {
    if (block.number <= startBlock) {
      return 0;
    }

    uint256 lastBlock = block.number < endBlock ? block.number : endBlock;
    return rewardPerBlock * (lastBlock - startBlock) - paidOut;
  }

  /**
    * @notice Updates reward variables for every farming pool
    * @dev Can be really expensive in gas
    */
  function massUpdatePools() public {
    uint256 length = poolInfo.length;
    for (uint256 pid = 0; pid < length; ++pid) {
      updatePool(pid);
    }
  }

  /**
    * @notice Updates reward variables for a single farming pool
    * @param _pid Pool id
    */
  function updatePool(
    uint256 _pid
  ) public {
    PoolInfo storage pool = poolInfo[_pid];
    uint256 lastBlock = block.number < endBlock ? block.number : endBlock;

    if (lastBlock <= pool.lastRewardBlock) {
      return;
    }
    uint256 lpSupply = pool.lpToken.balanceOf(address(this));
    if (lpSupply == 0) {
      pool.lastRewardBlock = lastBlock;
      return;
    }

    uint256 nrOfBlocks = lastBlock - pool.lastRewardBlock;
    uint256 erc20Reward = nrOfBlocks * rewardPerBlock * pool.allocPoint / totalAllocPoint;

    pool.accERC20PerShare = pool.accERC20PerShare + erc20Reward * 1e36 / lpSupply;
    pool.lastRewardBlock = block.number;
  }

  /**
    * @notice Deposit LP tokens in a farming pool
    * @param _pid Pool id
    * @param _amount Amount of LP tokens to deposit
    */
  function deposit(
    uint256 _pid, 
    uint256 _amount
  ) public {
    require(block.number <= endBlock, "deposit: cannot deposit after end block");

    PoolInfo storage pool = poolInfo[_pid];
    UserInfo storage user = userInfo[_pid][msg.sender];
    updatePool(_pid);
    if (user.amount > 0) {
      uint256 pendingAmount = user.amount * pool.accERC20PerShare / 1e36 - user.rewardDebt;
      if (pendingAmount > 0) {
        erc20Transfer(msg.sender, pendingAmount);
      }
    }
    pool.lpToken.safeTransferFrom(address(msg.sender), address(this), _amount);
    user.amount = user.amount + _amount;
    user.rewardDebt = user.amount * pool.accERC20PerShare / 1e36;
    emit Deposit(msg.sender, _pid, _amount);
  }

  /**
    * @notice Withdraw tokens from a farming pool
    * @param _pid Pool id
    * @param _amount Amount of LP tokens to withdraw
    */
  function withdraw(
    uint256 _pid, 
    uint256 _amount
  ) public {
    PoolInfo storage pool = poolInfo[_pid];
    UserInfo storage user = userInfo[_pid][msg.sender];
    require(user.amount >= _amount, "withdraw: can't withdraw more than deposit");
    updatePool(_pid);

    uint256 pendingAmount = user.amount * pool.accERC20PerShare / 1e36 - user.rewardDebt;
    if (pendingAmount > 0) {
      erc20Transfer(msg.sender, pendingAmount);
    }
    
    user.amount = user.amount - _amount;
    user.rewardDebt = user.amount * pool.accERC20PerShare / 1e36;
    pool.lpToken.safeTransfer(address(msg.sender), _amount);
    emit Withdraw(msg.sender, _pid, _amount);
  }

  /**
    * @notice Withdraw LP tokens from a farming pool ignoring rewards
    * @param _pid Pool id
    * @dev Emergency only
    */
  function emergencyWithdraw(
    uint256 _pid
  ) public {
    PoolInfo storage pool = poolInfo[_pid];
    UserInfo storage user = userInfo[_pid][msg.sender];
    pool.lpToken.safeTransfer(address(msg.sender), user.amount);
    emit EmergencyWithdraw(msg.sender, _pid, user.amount);
    user.amount = 0;
    user.rewardDebt = 0;
  }

  // Transfer ERC20 and update the required ERC20 to payout all rewards
  function erc20Transfer(
    address _to, 
    uint256 _amount
  ) internal {
    SafeERC20.safeTransfer(erc20, _to, _amount);
    paidOut += _amount;
  }
}
// File: contracts/interfaces/IFarming.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.18;

interface IFarming {
    event Deposit(address indexed _user, uint256 indexed _pid, uint256 _amount);
    event Withdraw(address indexed _user, uint256 indexed _pid, uint256 _amount);
    event EmergencyWithdraw(address indexed _user, uint256 indexed _pid, uint256 _amount);
}