// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

/**
 * @dev This abstract contract provides a fallback function that delegates all calls to another contract using the EVM
 * instruction `delegatecall`. We refer to the second contract as the _implementation_ behind the proxy, and it has to
 * be specified by overriding the virtual {_implementation} function.
 *
 * Additionally, delegation to the implementation can be triggered manually through the {_fallback} function, or to a
 * different contract through the {_delegate} function.
 *
 * The success and return data of the delegated call will be returned back to the caller of the proxy.
 */
abstract contract Proxy {
    /**
     * @dev Delegates the current call to `implementation`.
     *
     * This function does not return to its internall call site, it will return directly to the external caller.
     */
    function _delegate(address implementation) internal virtual {
        // solhint-disable-next-line no-inline-assembly
        assembly {
        // Copy msg.data. We take full control of memory in this inline assembly
        // block because it will not return to Solidity code. We overwrite the
        // Solidity scratch pad at memory position 0.
            calldatacopy(0, 0, calldatasize())

        // Call the implementation.
        // out and outsize are 0 because we don't know the size yet.
            let result := delegatecall(gas(), implementation, 0, calldatasize(), 0, 0)

        // Copy the returned data.
            returndatacopy(0, 0, returndatasize())

            switch result
            // delegatecall returns 0 on error.
            case 0 { revert(0, returndatasize()) }
            default { return(0, returndatasize()) }
        }
    }

    /**
     * @dev This is a virtual function that should be overriden so it returns the address to which the fallback function
     * and {_fallback} should delegate.
     */
    function _implementation() internal view virtual returns (address);

    /**
     * @dev Delegates the current call to the address returned by `_implementation()`.
     *
     * This function does not return to its internall call site, it will return directly to the external caller.
     */
    function _fallback() internal virtual {
        _beforeFallback();
        _delegate(_implementation());
    }

    /**
     * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if no other
     * function in the contract matches the call data.
     */
    fallback () external payable virtual {
        _fallback();
    }

    /**
     * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if call data
     * is empty.
     */
    receive () external payable virtual {
        _fallback();
    }

    /**
     * @dev Hook that is called before falling back to the implementation. Can happen as part of a manual `_fallback`
     * call, or as part of the Solidity `fallback` or `receive` functions.
     *
     * If overriden should call `super._beforeFallback()`.
     */
    function _beforeFallback() internal virtual {
    }
}


/**
 * @dev This abstract contract provides getters and event emitting update functions for
 * https://eips.ethereum.org/EIPS/eip-1967[EIP1967] slots.
 *
 * _Available since v4.1._
 *
 */
abstract contract ERC1967Upgrade {
    // This is the keccak-256 hash of "eip1967.proxy.rollback" subtracted by 1
    bytes32 private constant _ROLLBACK_SLOT = 0x4910fdfa16fed3260ed0e7147f7cc6da11a60208b5b9406d12a635614ffd9143;

    /**
     * @dev Storage slot with the address of the current implementation.
     * This is the keccak-256 hash of "eip1967.proxy.implementation" subtracted by 1, and is
     * validated in the constructor.
     */
    bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;

    /**
     * @dev Emitted when the implementation is upgraded.
     */
    event Upgraded(address indexed implementation);

    /**
     * @dev Returns the current implementation address.
     */
    function _getImplementation() internal view returns (address) {
        return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
    }

    /**
     * @dev Stores a new address in the EIP1967 implementation slot.
     */
    function _setImplementation(address newImplementation) private {
        require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
        StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
    }

    /**
     * @dev Perform implementation upgrade
     *
     * Emits an {Upgraded} event.
     */
    function _upgradeTo(address newImplementation) internal {
        _setImplementation(newImplementation);
        emit Upgraded(newImplementation);
    }

    /**
     * @dev Perform implementation upgrade with additional setup call.
     *
     * Emits an {Upgraded} event.
     */
    function _upgradeToAndCall(address newImplementation, bytes memory data, bool forceCall) internal {
        _setImplementation(newImplementation);
        emit Upgraded(newImplementation);
        if (data.length > 0 || forceCall) {
            Address.functionDelegateCall(newImplementation, data);
        }
    }

    /**
     * @dev Perform implementation upgrade with security checks for UUPS proxies, and additional setup call.
     *
     * Emits an {Upgraded} event.
     */
    function _upgradeToAndCallSecure(address newImplementation, bytes memory data, bool forceCall) internal {
        address oldImplementation = _getImplementation();

        // Initial upgrade and setup call
        _setImplementation(newImplementation);
        if (data.length > 0 || forceCall) {
            Address.functionDelegateCall(newImplementation, data);
        }

        // Perform rollback test if not already in progress
        StorageSlot.BooleanSlot storage rollbackTesting = StorageSlot.getBooleanSlot(_ROLLBACK_SLOT);
        if (!rollbackTesting.value) {
            // Trigger rollback using upgradeTo from the new implementation
            rollbackTesting.value = true;
            Address.functionDelegateCall(
                newImplementation,
                abi.encodeWithSignature(
                    "upgradeTo(address)",
                    oldImplementation
                )
            );
            rollbackTesting.value = false;
            // Check rollback was effective
            require(oldImplementation == _getImplementation(), "ERC1967Upgrade: upgrade breaks further upgrades");
            // Finally reset to the new implementation and log the upgrade
            _setImplementation(newImplementation);
            emit Upgraded(newImplementation);
        }
    }

    /**
     * @dev Perform beacon upgrade with additional setup call. Note: This upgrades the address of the beacon, it does
     * not upgrade the implementation contained in the beacon (see {UpgradeableBeacon-_setImplementation} for that).
     *
     * Emits a {BeaconUpgraded} event.
     */
    function _upgradeBeaconToAndCall(address newBeacon, bytes memory data, bool forceCall) internal {
        _setBeacon(newBeacon);
        emit BeaconUpgraded(newBeacon);
        if (data.length > 0 || forceCall) {
            Address.functionDelegateCall(IBeacon(newBeacon).implementation(), data);
        }
    }

    /**
     * @dev Storage slot with the admin of the contract.
     * This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is
     * validated in the constructor.
     */
    bytes32 internal constant _ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;

    /**
     * @dev Emitted when the admin account has changed.
     */
    event AdminChanged(address previousAdmin, address newAdmin);

    /**
     * @dev Returns the current admin.
     */
    function _getAdmin() internal view returns (address) {
        return StorageSlot.getAddressSlot(_ADMIN_SLOT).value;
    }

    /**
     * @dev Stores a new address in the EIP1967 admin slot.
     */
    function _setAdmin(address newAdmin) private {
        require(newAdmin != address(0), "ERC1967: new admin is the zero address");
        StorageSlot.getAddressSlot(_ADMIN_SLOT).value = newAdmin;
    }

    /**
     * @dev Changes the admin of the proxy.
     *
     * Emits an {AdminChanged} event.
     */
    function _changeAdmin(address newAdmin) internal {
        emit AdminChanged(_getAdmin(), newAdmin);
        _setAdmin(newAdmin);
    }

    /**
     * @dev The storage slot of the UpgradeableBeacon contract which defines the implementation for this proxy.
     * This is bytes32(uint256(keccak256('eip1967.proxy.beacon')) - 1)) and is validated in the constructor.
     */
    bytes32 internal constant _BEACON_SLOT = 0xa3f0ad74e5423aebfd80d3ef4346578335a9a72aeaee59ff6cb3582b35133d50;

    /**
     * @dev Emitted when the beacon is upgraded.
     */
    event BeaconUpgraded(address indexed beacon);

    /**
     * @dev Returns the current beacon.
     */
    function _getBeacon() internal view returns (address) {
        return StorageSlot.getAddressSlot(_BEACON_SLOT).value;
    }

    /**
     * @dev Stores a new beacon in the EIP1967 beacon slot.
     */
    function _setBeacon(address newBeacon) private {
        require(
            Address.isContract(newBeacon),
            "ERC1967: new beacon is not a contract"
        );
        require(
            Address.isContract(IBeacon(newBeacon).implementation()),
            "ERC1967: beacon implementation is not a contract"
        );
        StorageSlot.getAddressSlot(_BEACON_SLOT).value = newBeacon;
    }
}

/**
 * @dev This is the interface that {BeaconProxy} expects of its beacon.
 */
interface IBeacon {
    /**
     * @dev Must return an address that can be used as a delegate call target.
     *
     * {BeaconProxy} will check that this address is a contract.
     */
    function implementation() external view returns (address);
}

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize, which returns 0 for contracts in
        // construction, since the code is only stored at the end of the
        // constructor execution.

        uint256 size;
        // solhint-disable-next-line no-inline-assembly
        assembly { size := extcodesize(account) }
        return size > 0;
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
        (bool success, ) = recipient.call{ value: amount }("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

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

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

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

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

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.call{ value: value }(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

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

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data, string memory errorMessage) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.staticcall(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

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

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
        require(isContract(target), "Address: delegate call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

    function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns(bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly

                // solhint-disable-next-line no-inline-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

/**
 * @dev Library for reading and writing primitive types to specific storage slots.
 *
 * Storage slots are often used to avoid storage conflict when dealing with upgradeable contracts.
 * This library helps with reading and writing to such slots without the need for inline assembly.
 *
 * The functions in this library return Slot structs that contain a `value` member that can be used to read or write.
 *
 * Example usage to set ERC1967 implementation slot:
 * ```
 * contract ERC1967 {
 *     bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
 *
 *     function _getImplementation() internal view returns (address) {
 *         return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
 *     }
 *
 *     function _setImplementation(address newImplementation) internal {
 *         require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
 *         StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
 *     }
 * }
 * ```
 *
 * _Available since v4.1 for `address`, `bool`, `bytes32`, and `uint256`._
 */
library StorageSlot {
    struct AddressSlot {
        address value;
    }

    struct BooleanSlot {
        bool value;
    }

    struct Bytes32Slot {
        bytes32 value;
    }

    struct Uint256Slot {
        uint256 value;
    }

    /**
     * @dev Returns an `AddressSlot` with member `value` located at `slot`.
     */
    function getAddressSlot(bytes32 slot) internal pure returns (AddressSlot storage r) {
        assembly {
            r.slot := slot
        }
    }

    /**
     * @dev Returns an `BooleanSlot` with member `value` located at `slot`.
     */
    function getBooleanSlot(bytes32 slot) internal pure returns (BooleanSlot storage r) {
        assembly {
            r.slot := slot
        }
    }

    /**
     * @dev Returns an `Bytes32Slot` with member `value` located at `slot`.
     */
    function getBytes32Slot(bytes32 slot) internal pure returns (Bytes32Slot storage r) {
        assembly {
            r.slot := slot
        }
    }

    /**
     * @dev Returns an `Uint256Slot` with member `value` located at `slot`.
     */
    function getUint256Slot(bytes32 slot) internal pure returns (Uint256Slot storage r) {
        assembly {
            r.slot := slot
        }
    }
}

/*
 * @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) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}

/**
 * @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 () {
        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), msgSender);
    }

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

/**
 * @dev This is an auxiliary contract meant to be assigned as the admin of a {TransparentUpgradeableProxy}. For an
 * explanation of why you would want to use this see the documentation for {TransparentUpgradeableProxy}.
 */
contract ProxyAdmin is Ownable {

    /**
     * @dev Returns the current implementation of `proxy`.
     *
     * Requirements:
     *
     * - This contract must be the admin of `proxy`.
     */
    function getProxyImplementation(TransparentUpgradeableProxy proxy) public view virtual returns (address) {
        // We need to manually run the static call since the getter cannot be flagged as view
        // bytes4(keccak256("implementation()")) == 0x5c60da1b
        (bool success, bytes memory returndata) = address(proxy).staticcall(hex"5c60da1b");
        require(success);
        return abi.decode(returndata, (address));
    }

    /**
     * @dev Returns the current admin of `proxy`.
     *
     * Requirements:
     *
     * - This contract must be the admin of `proxy`.
     */
    function getProxyAdmin(TransparentUpgradeableProxy proxy) public view virtual returns (address) {
        // We need to manually run the static call since the getter cannot be flagged as view
        // bytes4(keccak256("admin()")) == 0xf851a440
        (bool success, bytes memory returndata) = address(proxy).staticcall(hex"f851a440");
        require(success);
        return abi.decode(returndata, (address));
    }

    /**
     * @dev Changes the admin of `proxy` to `newAdmin`.
     *
     * Requirements:
     *
     * - This contract must be the current admin of `proxy`.
     */
    function changeProxyAdmin(TransparentUpgradeableProxy proxy, address newAdmin) public virtual onlyOwner {
        proxy.changeAdmin(newAdmin);
    }

    /**
     * @dev Upgrades `proxy` to `implementation`. See {TransparentUpgradeableProxy-upgradeTo}.
     *
     * Requirements:
     *
     * - This contract must be the admin of `proxy`.
     */
    function upgrade(TransparentUpgradeableProxy proxy, address implementation) public virtual onlyOwner {
        proxy.upgradeTo(implementation);
    }

    /**
     * @dev Upgrades `proxy` to `implementation` and calls a function on the new implementation. See
     * {TransparentUpgradeableProxy-upgradeToAndCall}.
     *
     * Requirements:
     *
     * - This contract must be the admin of `proxy`.
     */
    function upgradeAndCall(TransparentUpgradeableProxy proxy, address implementation, bytes memory data) public payable virtual onlyOwner {
        proxy.upgradeToAndCall{value: msg.value}(implementation, data);
    }
}


/**
 * @dev Base contract for building openzeppelin-upgrades compatible implementations for the {ERC1967Proxy}. It includes
 * publicly available upgrade functions that are called by the plugin and by the secure upgrade mechanism to verify
 * continuation of the upgradability.
 *
 * The {_authorizeUpgrade} function MUST be overridden to include access restriction to the upgrade mechanism.
 *
 * _Available since v4.1._
 */
abstract contract UUPSUpgradeable is ERC1967Upgrade {
    function upgradeTo(address newImplementation) external virtual {
        _authorizeUpgrade(newImplementation);
        _upgradeToAndCallSecure(newImplementation, bytes(""), false);
    }

    function upgradeToAndCall(address newImplementation, bytes memory data) external payable virtual {
        _authorizeUpgrade(newImplementation);
        _upgradeToAndCallSecure(newImplementation, data, true);
    }

    function _authorizeUpgrade(address newImplementation) internal virtual;
}


abstract contract Proxiable is UUPSUpgradeable {
    function _authorizeUpgrade(address newImplementation) internal override {
        _beforeUpgrade(newImplementation);
    }

    function _beforeUpgrade(address newImplementation) internal virtual;
}

contract ChildOfProxiable is Proxiable {
    function _beforeUpgrade(address newImplementation) internal virtual override {}
}


/**
 * @dev This contract implements an upgradeable proxy. It is upgradeable because calls are delegated to an
 * implementation address that can be changed. This address is stored in storage in the location specified by
 * https://eips.ethereum.org/EIPS/eip-1967[EIP1967], so that it doesn't conflict with the storage layout of the
 * implementation behind the proxy.
 */
contract ERC1967Proxy is Proxy, ERC1967Upgrade {
    /**
     * @dev Initializes the upgradeable proxy with an initial implementation specified by `_logic`.
     *
     * If `_data` is nonempty, it's used as data in a delegate call to `_logic`. This will typically be an encoded
     * function call, and allows initializating the storage of the proxy like a Solidity constructor.
     */
    constructor(address _logic, bytes memory _data) payable {
        assert(_IMPLEMENTATION_SLOT == bytes32(uint256(keccak256("eip1967.proxy.implementation")) - 1));
        _upgradeToAndCall(_logic, _data, false);
    }

    /**
     * @dev Returns the current implementation address.
     */
    function _implementation() internal view virtual override returns (address impl) {
        return ERC1967Upgrade._getImplementation();
    }
}

/**
 * @dev This contract implements a proxy that is upgradeable by an admin.
 *
 * To avoid https://medium.com/nomic-labs-blog/malicious-backdoors-in-ethereum-proxies-62629adf3357[proxy selector
 * clashing], which can potentially be used in an attack, this contract uses the
 * https://blog.openzeppelin.com/the-transparent-proxy-pattern/[transparent proxy pattern]. This pattern implies two
 * things that go hand in hand:
 *
 * 1. If any account other than the admin calls the proxy, the call will be forwarded to the implementation, even if
 * that call matches one of the admin functions exposed by the proxy itself.
 * 2. If the admin calls the proxy, it can access the admin functions, but its calls will never be forwarded to the
 * implementation. If the admin tries to call a function on the implementation it will fail with an error that says
 * "admin cannot fallback to proxy target".
 *
 * These properties mean that the admin account can only be used for admin actions like upgrading the proxy or changing
 * the admin, so it's best if it's a dedicated account that is not used for anything else. This will avoid headaches due
 * to sudden errors when trying to call a function from the proxy implementation.
 *
 * Our recommendation is for the dedicated account to be an instance of the {ProxyAdmin} contract. If set up this way,
 * you should think of the `ProxyAdmin` instance as the real administrative interface of your proxy.
 */
contract TransparentUpgradeableProxy is ERC1967Proxy {
    /**
     * @dev Initializes an upgradeable proxy managed by `_admin`, backed by the implementation at `_logic`, and
     * optionally initialized with `_data` as explained in {ERC1967Proxy-constructor}.
     */
    constructor(address _logic, address admin_, bytes memory _data) payable ERC1967Proxy(_logic, _data) {
        assert(_ADMIN_SLOT == bytes32(uint256(keccak256("eip1967.proxy.admin")) - 1));
        _changeAdmin(admin_);
    }

    /**
     * @dev Modifier used internally that will delegate the call to the implementation unless the sender is the admin.
     */
    modifier ifAdmin() {
        if (msg.sender == _getAdmin()) {
            _;
        } else {
            _fallback();
        }
    }

    /**
     * @dev Returns the current admin.
     *
     * NOTE: Only the admin can call this function. See {ProxyAdmin-getProxyAdmin}.
     *
     * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
     * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
     * `0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103`
     */
    function admin() external ifAdmin returns (address admin_) {
        admin_ = _getAdmin();
    }

    /**
     * @dev Returns the current implementation.
     *
     * NOTE: Only the admin can call this function. See {ProxyAdmin-getProxyImplementation}.
     *
     * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
     * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
     * `0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc`
     */
    function implementation() external ifAdmin returns (address implementation_) {
        implementation_ = _implementation();
    }

    /**
     * @dev Changes the admin of the proxy.
     *
     * Emits an {AdminChanged} event.
     *
     * NOTE: Only the admin can call this function. See {ProxyAdmin-changeProxyAdmin}.
     */
    function changeAdmin(address newAdmin) external virtual ifAdmin {
        _changeAdmin(newAdmin);
    }

    /**
     * @dev Upgrade the implementation of the proxy.
     *
     * NOTE: Only the admin can call this function. See {ProxyAdmin-upgrade}.
     */
    function upgradeTo(address newImplementation) external ifAdmin {
        _upgradeToAndCall(newImplementation, bytes(""), false);
    }

    /**
     * @dev Upgrade the implementation of the proxy, and then call a function from the new implementation as specified
     * by `data`, which should be an encoded function call. This is useful to initialize new storage variables in the
     * proxied contract.
     *
     * NOTE: Only the admin can call this function. See {ProxyAdmin-upgradeAndCall}.
     */
    function upgradeToAndCall(address newImplementation, bytes calldata data) external payable ifAdmin {
        _upgradeToAndCall(newImplementation, data, true);
    }

    /**
     * @dev Returns the current admin.
     */
    function _admin() internal view virtual returns (address) {
        return _getAdmin();
    }

    /**
     * @dev Makes sure the admin cannot access the fallback function. See {Proxy-_beforeFallback}.
     */
    function _beforeFallback() internal virtual override {
        require(msg.sender != _getAdmin(), "TransparentUpgradeableProxy: admin cannot fallback to proxy target");
        super._beforeFallback();
    }
}


// Kept for backwards compatibility with older versions of Hardhat and Truffle plugins.
contract AdminUpgradeabilityProxy is TransparentUpgradeableProxy {
    constructor(address logic, address admin, bytes memory data) payable TransparentUpgradeableProxy(logic, admin, data) {}
}

// SPDX-License-Identifier: MIT
pragma solidity 0.8.4;
import { Initializable } from "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
import { IERC20Upgradeable } from "@openzeppelin/contracts-upgradeable/token/ERC20/IERC20Upgradeable.sol";
import { SafeERC20Upgradeable } from "@openzeppelin/contracts-upgradeable/token/ERC20/utils/SafeERC20Upgradeable.sol";
import { SafeCast } from "./libraries/SafeCast.sol";
import { BitMaps } from "@openzeppelin/contracts/utils/structs/BitMaps.sol";
import { MerkleProof } from "@openzeppelin/contracts/utils/cryptography/MerkleProof.sol";
import { V2Migrator } from "./base/V2Migrator.sol";
import { CorePool } from "./base/CorePool.sol";
import { ErrorHandler } from "./libraries/ErrorHandler.sol";
import { Stake } from "./libraries/Stake.sol";
import { IFactory } from "./interfaces/IFactory.sol";
import { ICorePool } from "./interfaces/ICorePool.sol";
import { ICorePoolV1 } from "./interfaces/ICorePoolV1.sol";
import { SushiLPPool } from "./SushiLPPool.sol";
/**
 * @title ILV Pool
 *
 * @dev ILV Pool contract to be deployed, with all base contracts inherited.
 * @dev Extends functionality working as a router to SushiLP Pool and deployed flash pools.
 *      through functions like `claimYieldRewardsMultiple()` and `claimVaultRewardsMultiple()`,
 *      ILV Pool is trusted by other pools and verified by the factory to aggregate functions
 *      and add quality of life features for stakers.
 */
contract ILVPool is Initializable, V2Migrator {
    using ErrorHandler for bytes4;
    using Stake for uint256;
    using SafeERC20Upgradeable for IERC20Upgradeable;
    using SafeCast for uint256;
    using BitMaps for BitMaps.BitMap;
    /// @dev stores merkle root related to users yield weight in v1.
    bytes32 public merkleRoot;
    /// @dev bitmap mapping merkle tree user indexes to a bit that tells
    ///      whether a user has already migrated yield or not.
    BitMaps.BitMap internal _usersMigrated;
    /// @dev maps `keccak256(userAddress,stakeId)` to a bool value that tells
    ///      if a v1 yield has already been minted by v2 contract.
    mapping(address => mapping(uint256 => bool)) public v1YieldMinted;
    /// @dev Used to calculate vault (revenue distribution) rewards, keeps track
    ///      of the correct ILV balance in the v1 core pool.
    uint256 public v1PoolTokenReserve;
    /**
     * @dev logs `_migratePendingRewards()`
     *
     * @param from user address
     * @param pendingRewardsMigrated value of pending rewards migrated
     * @param useSILV whether user claimed v1 pending rewards as ILV or sILV
     */
    event LogMigratePendingRewards(address indexed from, uint256 pendingRewardsMigrated, bool useSILV);
    /**
     * @dev logs `_migrateYieldWeights()`
     *
     * @param from user address
     * @param yieldWeightMigrated total amount of weight coming from yield in v1
     *
     */
    event LogMigrateYieldWeight(address indexed from, uint256 yieldWeightMigrated);
    /**
     * @dev logs `mintV1YieldMultiple()`.
     *
     * @param from user address
     * @param value number of ILV tokens minted
     *
     */
    event LogV1YieldMintedMultiple(address indexed from, uint256 value);
    /// @dev Calls `__V2Migrator_init()`.
    function initialize(
        address ilv_,
        address silv_,
        address _poolToken,
        address factory_,
        uint64 _initTime,
        uint32 _weight,
        address _corePoolV1,
        uint256 v1StakeMaxPeriod_
    ) external initializer {
        // calls internal v2 migrator initializer
        __V2Migrator_init(ilv_, silv_, _poolToken, _corePoolV1, factory_, _initTime, _weight, v1StakeMaxPeriod_);
    }
    /**
     * @dev Updates value that keeps track of v1 global locked tokens weight.
     *
     * @param _v1PoolTokenReserve new value to be stored
     */
    function setV1PoolTokenReserve(uint256 _v1PoolTokenReserve) external virtual {
        // only factory controller can update the _v1GlobalWeight
        _requireIsFactoryController();
        // update v1PoolTokenReserve state variable
        v1PoolTokenReserve = _v1PoolTokenReserve;
    }
    /// @inheritdoc CorePool
    function getTotalReserves() external view virtual override returns (uint256 totalReserves) {
        totalReserves = poolTokenReserve + v1PoolTokenReserve;
    }
    /**
     * @dev Sets the yield weight tree root.
     * @notice Can only be called by the eDAO.
     *
     * @param _merkleRoot 32 bytes tree root.
     */
    function setMerkleRoot(bytes32 _merkleRoot) external virtual {
        // checks if function is being called by PoolFactory.owner()
        _requireIsFactoryController();
        // stores the merkle root
        merkleRoot = _merkleRoot;
    }
    /**
     * @dev Returns whether an user of a given _index in the bitmap has already
     *      migrated v1 yield weight stored in the merkle tree or not.
     *
     * @param _index user index in the bitmap, can be checked in the off-chain
     *               merkle tree
     * @return whether user has already migrated yield weights or not
     */
    function hasMigratedYield(uint256 _index) public view returns (bool) {
        // checks if the merkle tree index linked to a user address has a bit of
        // value 0 or 1
        return _usersMigrated.get(_index);
    }
    /**
     * @dev Executed by other core pools and flash pools
     *      as part of yield rewards processing logic (`_claimYieldRewards()` function).
     * @dev Executed when _useSILV is false and pool is not an ILV pool -
     *      see `CorePool._processRewards()`.
     *
     * @param _staker an address which stakes (the yield reward)
     * @param _value amount to be staked (yield reward amount)
     */
    function stakeAsPool(address _staker, uint256 _value) external nonReentrant {
        // checks if contract is paused
        _requireNotPaused();
        // expects caller to be a valid contract registered by the pool factory
        this.stakeAsPool.selector.verifyAccess(_factory.poolExists(msg.sender));
        // gets storage pointer to user
        User storage user = users[_staker];
        // uses v1 weight values for rewards calculations
        uint256 v1WeightToAdd = _useV1Weight(_staker);
        // update user state
        _updateReward(_staker, v1WeightToAdd);
        // calculates take weight based on how much yield has been generated
        // (by checking _value) and multiplies by the 2e6 constant, since
        // yield is always locked for a year.
        uint256 stakeWeight = _value * Stake.YIELD_STAKE_WEIGHT_MULTIPLIER;
        // initialize new yield stake being created in memory
        Stake.Data memory newStake = Stake.Data({
            value: (_value).toUint120(),
            lockedFrom: (_now256()).toUint64(),
            lockedUntil: (_now256() + Stake.MAX_STAKE_PERIOD).toUint64(),
            isYield: true
        });
        // sum new yield stake weight to user's total weight
        user.totalWeight += (stakeWeight).toUint248();
        // add the new yield stake to storage
        user.stakes.push(newStake);
        // update global weight and global pool token count
        globalWeight += stakeWeight;
        poolTokenReserve += _value;
        // emits an event
        emit LogStake(
            msg.sender,
            _staker,
            (user.stakes.length - 1),
            _value,
            (_now256() + Stake.MAX_STAKE_PERIOD).toUint64()
        );
    }
    /**
     * @dev Calls internal `_migrateLockedStakes`,  `_migrateYieldWeights`
     *      and `_migratePendingRewards` functions for a complete migration
     *      of a v1 user to v2.
     * @dev See `_migrateLockedStakes` and _`migrateYieldWeights`.
     */
    function executeMigration(
        bytes32[] calldata _proof,
        uint256 _index,
        uint248 _yieldWeight,
        uint256 _pendingV1Rewards,
        bool _useSILV,
        uint256[] calldata _stakeIds
    ) external virtual {
        // verifies that user isn't a v1 blacklisted user
        _requireNotBlacklisted(msg.sender);
        // checks if contract is paused
        _requireNotPaused();
        // uses v1 weight values for rewards calculations
        uint256 v1WeightToAdd = _useV1Weight(msg.sender);
        // update user state
        _updateReward(msg.sender, v1WeightToAdd);
        // call internal migrate locked stake function
        // which does the loop to store each v1 stake
        // reference in v2 and all required data
        _migrateLockedStakes(_stakeIds);
        // checks if user is also migrating the v1 yield accumulated weight
        if (_yieldWeight > 0) {
            // if that's the case, passes the merkle proof with the user index
            // in the merkle tree, and the yield weight being migrated
            // which will be verified, and then update user state values by the
            // internal function
            _migrateYieldWeights(_proof, _index, _yieldWeight, _pendingV1Rewards, _useSILV);
        }
    }
    /**
     * @dev Calls multiple pools claimYieldRewardsFromRouter() in order to claim yield
     * in 1 transaction.
     *
     * @notice ILV pool works as a router for claiming multiple pools registered
     *         in the factory.
     *
     * @param _pools array of pool addresses
     * @param _useSILV array of bool values telling if the pool should claim reward
     *                 as ILV or sILV
     */
    function claimYieldRewardsMultiple(address[] calldata _pools, bool[] calldata _useSILV) external virtual {
        // checks if contract is paused
        _requireNotPaused();
        // we're using selector to simplify input and access validation
        bytes4 fnSelector = this.claimYieldRewardsMultiple.selector;
        // checks if user passed the correct number of inputs
        fnSelector.verifyInput(_pools.length == _useSILV.length, 0);
        // loops over each pool passed to execute the necessary checks, and call
        // the functions according to the pool
        for (uint256 i = 0; i < _pools.length; i++) {
            // gets current pool in the loop
            address pool = _pools[i];
            // verifies that the given pool is a valid pool registered by the pool
            // factory contract
            fnSelector.verifyAccess(IFactory(_factory).poolExists(pool));
            // if the pool passed is the ILV pool (i.e this contract),
            // just calls an internal function
            if (ICorePool(pool).poolToken() == _ilv) {
                // call internal _claimYieldRewards
                _claimYieldRewards(msg.sender, _useSILV[i]);
            } else {
                // if not, executes a calls to the other core pool which will handle
                // the other pool reward claim
                SushiLPPool(pool).claimYieldRewardsFromRouter(msg.sender, _useSILV[i]);
            }
        }
    }
    /**
     * @dev Calls multiple pools claimVaultRewardsFromRouter() in order to claim yield
     * in 1 transaction.
     *
     * @notice ILV pool works as a router for claiming multiple pools registered
     *         in the factory
     *
     * @param _pools array of pool addresses
     */
    function claimVaultRewardsMultiple(address[] calldata _pools) external virtual {
        // checks if contract is paused
        _requireNotPaused();
        // loops over each pool passed to execute the necessary checks, and call
        // the functions according to the pool
        for (uint256 i = 0; i < _pools.length; i++) {
            // gets current pool in the loop
            address pool = _pools[i];
            // we're using selector to simplify input and state validation
            // checks if the given pool is a valid one registred by the pool
            // factory contract
            this.claimVaultRewardsMultiple.selector.verifyAccess(IFactory(_factory).poolExists(pool));
            // if the pool passed is the ILV pool (i.e this contract),
            // just calls an internal function
            if (ICorePool(pool).poolToken() == _ilv) {
                // call internal _claimVaultRewards
                _claimVaultRewards(msg.sender);
            } else {
                // if not, executes a calls to the other core pool which will handle
                // the other pool reward claim
                SushiLPPool(pool).claimVaultRewardsFromRouter(msg.sender);
            }
        }
    }
    /**
     * @dev Aggregates in one single mint call multiple yield stakeIds from v1.
     * @dev reads v1 ILV pool to execute checks, if everything is correct, it stores
     *      in memory total amount of yield to be minted and calls the PoolFactory to mint
     *      it to msg.sender.
     *
     * @notice V1 won't be able to mint ILV yield anymore. This mean only this function
     *         in the V2 contract is able to mint previously accumulated V1 yield.
     *
     * @param _stakeIds array of yield ids in v1 from msg.sender user
     */
    function mintV1YieldMultiple(uint256[] calldata _stakeIds) external virtual {
        // we're using function selector to simplify validation
        bytes4 fnSelector = this.mintV1YieldMultiple.selector;
        // verifies that user isn't a v1 blacklisted user
        _requireNotBlacklisted(msg.sender);
        // checks if contract is paused
        _requireNotPaused();
        // gets storage pointer to the user
        User storage user = users[msg.sender];
        // initialize variables that will be used inside the loop
        // to store how much yield needs to be minted and how much
        // weight needs to be removed from the user
        uint256 amountToMint;
        uint256 weightToRemove;
        // initializes variable that will store how much v1 weight the user has
        uint256 v1WeightToAdd;
        // avoids stack too deep error
        {
            // uses v1 weight values for rewards calculations
            uint256 _v1WeightToAdd = _useV1Weight(msg.sender);
            // update user state
            _updateReward(msg.sender, _v1WeightToAdd);
            v1WeightToAdd = _v1WeightToAdd;
        }
        // loops over each stake id, doing the necessary checks and
        // updating the mapping that keep tracks of v1 yield mints.
        for (uint256 i = 0; i < _stakeIds.length; i++) {
            // gets current stake id in the loop
            uint256 _stakeId = _stakeIds[i];
            // call v1 core pool to get all required data associated with
            // the passed v1 stake id
            (uint256 tokenAmount, uint256 _weight, uint64 lockedFrom, uint64 lockedUntil, bool isYield) = ICorePoolV1(
                corePoolV1
            ).getDeposit(msg.sender, _stakeId);
            // checks if the obtained v1 stake (through getDeposit)
            // is indeed yield
            fnSelector.verifyState(isYield, i * 3);
            // expects the yield v1 stake to be unlocked
            fnSelector.verifyState(_now256() > lockedUntil, i * 4 + 1);
            // expects that the v1 stake hasn't been minted yet
            fnSelector.verifyState(!v1YieldMinted[msg.sender][_stakeId], i * 5 + 2);
            // verifies if the yield has been created before v2 launches
            fnSelector.verifyState(lockedFrom < _v1StakeMaxPeriod, i * 6 + 3);
            // marks v1 yield as minted
            v1YieldMinted[msg.sender][_stakeId] = true;
            // updates variables that will be used for minting yield and updating
            // user struct later
            amountToMint += tokenAmount;
            weightToRemove += _weight;
        }
        // subtracts value accumulated during the loop
        user.totalWeight -= (weightToRemove).toUint248();
        // subtracts weight and token value from global variables
        globalWeight -= weightToRemove;
        // gets token value by dividing by yield weight multiplier
        poolTokenReserve -= (weightToRemove) / Stake.YIELD_STAKE_WEIGHT_MULTIPLIER;
        // expects the factory to mint ILV yield to the msg.sender user
        // after all checks and calculations have been successfully
        // executed
        _factory.mintYieldTo(msg.sender, amountToMint, false);
        // emits an event
        emit LogV1YieldMintedMultiple(msg.sender, amountToMint);
    }
    /**
     * @dev Verifies a proof from the yield weights merkle, and if it's valid,
     *      adds the v1 user yield weight to the v2 `user.totalWeight`.
     * @dev The yield weights merkle tree will be published after the initial contracts
     *      deployment, and then the merkle root is added through `setMerkleRoot` function.
     *
     * @param _proof bytes32 array with the proof generated off-chain
     * @param _index user index in the merkle tree
     * @param _yieldWeight user yield weight in v1 stored by the merkle tree
     * @param _pendingV1Rewards user pending rewards in v1 stored by the merkle tree
     * @param _useSILV whether the user wants rewards in sILV token or in a v2 ILV yield stake
     */
    function _migrateYieldWeights(
        bytes32[] calldata _proof,
        uint256 _index,
        uint256 _yieldWeight,
        uint256 _pendingV1Rewards,
        bool _useSILV
    ) internal virtual {
        // gets storage pointer to the user
        User storage user = users[msg.sender];
        // bytes4(keccak256("_migrateYieldWeights(bytes32[],uint256,uint256)")))
        bytes4 fnSelector = 0x660e5908;
        // requires that the user hasn't migrated the yield yet
        fnSelector.verifyAccess(!hasMigratedYield(_index));
        // compute leaf and verify merkle proof
        bytes32 leaf = keccak256(abi.encodePacked(_index, msg.sender, _yieldWeight, _pendingV1Rewards));
        // verifies the merkle proof and requires the return value to be true
        fnSelector.verifyInput(MerkleProof.verify(_proof, merkleRoot, leaf), 0);
        // gets the value compounded into v2 as ILV yield to be added into v2 user.totalWeight
        uint256 pendingRewardsCompounded = _migratePendingRewards(_pendingV1Rewards, _useSILV);
        uint256 weightCompounded = pendingRewardsCompounded * Stake.YIELD_STAKE_WEIGHT_MULTIPLIER;
        uint256 ilvYieldMigrated = _yieldWeight / Stake.YIELD_STAKE_WEIGHT_MULTIPLIER;
        // add v1 yield weight to the v2 user
        user.totalWeight += (_yieldWeight + weightCompounded).toUint248();
        // adds v1 pending yield compounded + v1 total yield to global weight
        // and poolTokenReserve in the v2 contract.
        globalWeight += (weightCompounded + _yieldWeight);
        poolTokenReserve += (pendingRewardsCompounded + ilvYieldMigrated);
        // set user as claimed in bitmap
        _usersMigrated.set(_index);
        // emits an event
        emit LogMigrateYieldWeight(msg.sender, _yieldWeight);
    }
    /**
     * @dev Gets pending rewards in the v1 ilv pool and v1 lp pool stored in the merkle tree,
     *      and allows the v1 users of those pools to claim them as ILV compounded in the v2 pool or
     *      sILV minted to their wallet.
     * @dev Eligible users are filtered and stored in the merkle tree.
     *
     * @param _pendingV1Rewards user pending rewards in v1 stored by the merkle tree
     * @param _useSILV whether the user wants rewards in sILV token or in a v2 ILV yield stake
     *
     * @return pendingRewardsCompounded returns the value compounded into the v2 pool (if the user selects ILV)
     */
    function _migratePendingRewards(uint256 _pendingV1Rewards, bool _useSILV)
        internal
        virtual
        returns (uint256 pendingRewardsCompounded)
    {
        // gets pointer to user
        User storage user = users[msg.sender];
        // if the user (msg.sender) wants to mint pending rewards as sILV, simply mint
        if (_useSILV) {
            // calls the factory to mint sILV
            _factory.mintYieldTo(msg.sender, _pendingV1Rewards, _useSILV);
        } else {
            // otherwise we create a new v2 yield stake (ILV)
            Stake.Data memory stake = Stake.Data({
                value: (_pendingV1Rewards).toUint120(),
                lockedFrom: (_now256()).toUint64(),
                lockedUntil: (_now256() + Stake.MAX_STAKE_PERIOD).toUint64(),
                isYield: true
            });
            // adds new ILV yield stake to user array
            // notice that further values will be updated later in execution
            // (user.totalWeight, user.subYieldRewards, user.subVaultRewards, ...)
            user.stakes.push(stake);
            // updates function's return value
            pendingRewardsCompounded = _pendingV1Rewards;
        }
        // emits an event
        emit LogMigratePendingRewards(msg.sender, _pendingV1Rewards, _useSILV);
    }
    /**
     * @inheritdoc CorePool
     * @dev In the ILV Pool we verify that the user isn't coming from v1.
     * @dev If user has weight in v1, we can't allow them to call this
     *      function, otherwise it would throw an error in the new address when calling
     *      mintV1YieldMultiple if the user migrates.
     */
    function moveFundsFromWallet(address _to) public virtual override {
        // we're using function selector to simplify validation
        bytes4 fnSelector = this.moveFundsFromWallet.selector;
        // we query v1 ilv pool contract
        (, uint256 totalWeight, , ) = ICorePoolV1(corePoolV1).users(msg.sender);
        // we check that the v1 total weight is 0 i.e the user can't have any yield
        fnSelector.verifyState(totalWeight == 0, 0);
        // call parent moveFundsFromWalet which contains further checks and the actual
        // execution
        super.moveFundsFromWallet(_to);
    }
    /**
     * @dev Empty reserved space in storage. The size of the __gap array is calculated so that
     *      the amount of storage used by a contract always adds up to the 50.
     *      See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[46] private __gap;
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
 * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
 * behind a proxy. Since a proxied contract can't have a constructor, it's common to move constructor logic to an
 * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
 * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
 *
 * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
 * possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}.
 *
 * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
 * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
 */
abstract contract Initializable {
    /**
     * @dev Indicates that the contract has been initialized.
     */
    bool private _initialized;
    /**
     * @dev Indicates that the contract is in the process of being initialized.
     */
    bool private _initializing;
    /**
     * @dev Modifier to protect an initializer function from being invoked twice.
     */
    modifier initializer() {
        require(_initializing || !_initialized, "Initializable: contract is already initialized");
        bool isTopLevelCall = !_initializing;
        if (isTopLevelCall) {
            _initializing = true;
            _initialized = true;
        }
        _;
        if (isTopLevelCall) {
            _initializing = false;
        }
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20Upgradeable {
    /**
     * @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);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "../IERC20Upgradeable.sol";
import "../../../utils/AddressUpgradeable.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 SafeERC20Upgradeable {
    using AddressUpgradeable for address;
    function safeTransfer(
        IERC20Upgradeable token,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }
    function safeTransferFrom(
        IERC20Upgradeable 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(
        IERC20Upgradeable 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(
        IERC20Upgradeable 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(
        IERC20Upgradeable 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));
        }
    }
    /**
     * @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(IERC20Upgradeable 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");
        }
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/math/SafeCast.sol)
pragma solidity 0.8.4;
import { ErrorHandler } from "./ErrorHandler.sol";
/**
 * @notice Copied from OpenZeppelin's SafeCast.sol, adapted to use just in the required
 * uint sizes.
 * @dev Wrappers over Solidity's uintXX/intXX casting operators with added overflow
 * checks.
 *
 * Downcasting from uint256/int256 in Solidity does not revert on overflow. This can
 * easily result in undesired exploitation or bugs, since developers usually
 * assume that overflows raise errors. `SafeCast` restores this intuition by
 * reverting the transaction when such 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.
 *
 * Can be combined with {SafeMath} and {SignedSafeMath} to extend it to smaller types, by performing
 * all math on `uint256` and `int256` and then downcasting.
 */
library SafeCast {
    using ErrorHandler for bytes4;
    /**
     * @dev Returns the downcasted uint248 from uint256, reverting on
     * overflow (when the input is greater than largest uint248).
     *
     * Counterpart to Solidity's `uint248` operator.
     *
     * Requirements:
     *
     * - input must fit into 248 bits
     */
    function toUint248(uint256 _value) internal pure returns (uint248) {
        // we're using selector to simplify input and state validation
        // internal function simulated selector is `bytes4(keccak256("toUint248(uint256))"))`
        bytes4 fnSelector = 0x3fd72672;
        fnSelector.verifyInput(_value <= type(uint248).max, 0);
        return uint248(_value);
    }
    /**
     * @dev Returns the downcasted uint128 from uint256, reverting on
     * overflow (when the input is greater than largest uint128).
     *
     * Counterpart to Solidity's `uint128` operator.
     *
     * Requirements:
     *
     * - input must fit into 128 bits
     */
    function toUint128(uint256 _value) internal pure returns (uint128) {
        // we're using selector to simplify input and state validation
        // internal function simulated selector is `bytes4(keccak256("toUint128(uint256))"))`
        bytes4 fnSelector = 0x809fdd33;
        fnSelector.verifyInput(_value <= type(uint128).max, 0);
        return uint128(_value);
    }
    /**
     * @dev Returns the downcasted uint120 from uint256, reverting on
     * overflow (when the input is greater than largest uint120).
     *
     * Counterpart to Solidity's `uint120` operator.
     *
     * Requirements:
     *
     * - input must fit into 120 bits
     */
    function toUint120(uint256 _value) internal pure returns (uint120) {
        // we're using selector to simplify input and state validation
        // internal function simulated selector is `bytes4(keccak256("toUint120(uint256))"))`
        bytes4 fnSelector = 0x1e4e4bad;
        fnSelector.verifyInput(_value <= type(uint120).max, 0);
        return uint120(_value);
    }
    /**
     * @dev Returns the downcasted uint64 from uint256, reverting on
     * overflow (when the input is greater than largest uint64).
     *
     * Counterpart to Solidity's `uint64` operator.
     *
     * Requirements:
     *
     * - input must fit into 64 bits
     */
    function toUint64(uint256 _value) internal pure returns (uint64) {
        // we're using selector to simplify input and state validation
        // internal function simulated selector is `bytes4(keccak256("toUint64(uint256))"))`
        bytes4 fnSelector = 0x2665fad0;
        fnSelector.verifyInput(_value <= type(uint64).max, 0);
        return uint64(_value);
    }
    /**
     * @dev Returns the downcasted uint32 from uint256, reverting on
     * overflow (when the input is greater than largest uint32).
     *
     * Counterpart to Solidity's `uint32` operator.
     *
     * Requirements:
     *
     * - input must fit into 32 bits
     */
    function toUint32(uint256 _value) internal pure returns (uint32) {
        // we're using selector to simplify input and state validation
        // internal function simulated selector is `bytes4(keccak256("toUint32(uint256))"))`
        bytes4 fnSelector = 0xc8193255;
        fnSelector.verifyInput(_value <= type(uint32).max, 0);
        return uint32(_value);
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
 * @dev Library for managing uint256 to bool mapping in a compact and efficient way, providing the keys are sequential.
 * Largelly inspired by Uniswap's https://github.com/Uniswap/merkle-distributor/blob/master/contracts/MerkleDistributor.sol[merkle-distributor].
 */
library BitMaps {
    struct BitMap {
        mapping(uint256 => uint256) _data;
    }
    /**
     * @dev Returns whether the bit at `index` is set.
     */
    function get(BitMap storage bitmap, uint256 index) internal view returns (bool) {
        uint256 bucket = index >> 8;
        uint256 mask = 1 << (index & 0xff);
        return bitmap._data[bucket] & mask != 0;
    }
    /**
     * @dev Sets the bit at `index` to the boolean `value`.
     */
    function setTo(
        BitMap storage bitmap,
        uint256 index,
        bool value
    ) internal {
        if (value) {
            set(bitmap, index);
        } else {
            unset(bitmap, index);
        }
    }
    /**
     * @dev Sets the bit at `index`.
     */
    function set(BitMap storage bitmap, uint256 index) internal {
        uint256 bucket = index >> 8;
        uint256 mask = 1 << (index & 0xff);
        bitmap._data[bucket] |= mask;
    }
    /**
     * @dev Unsets the bit at `index`.
     */
    function unset(BitMap storage bitmap, uint256 index) internal {
        uint256 bucket = index >> 8;
        uint256 mask = 1 << (index & 0xff);
        bitmap._data[bucket] &= ~mask;
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
 * @dev These functions deal with verification of Merkle Trees proofs.
 *
 * The proofs can be generated using the JavaScript library
 * https://github.com/miguelmota/merkletreejs[merkletreejs].
 * Note: the hashing algorithm should be keccak256 and pair sorting should be enabled.
 *
 * See `test/utils/cryptography/MerkleProof.test.js` for some examples.
 */
library MerkleProof {
    /**
     * @dev Returns true if a `leaf` can be proved to be a part of a Merkle tree
     * defined by `root`. For this, a `proof` must be provided, containing
     * sibling hashes on the branch from the leaf to the root of the tree. Each
     * pair of leaves and each pair of pre-images are assumed to be sorted.
     */
    function verify(
        bytes32[] memory proof,
        bytes32 root,
        bytes32 leaf
    ) internal pure returns (bool) {
        bytes32 computedHash = leaf;
        for (uint256 i = 0; i < proof.length; i++) {
            bytes32 proofElement = proof[i];
            if (computedHash <= proofElement) {
                // Hash(current computed hash + current element of the proof)
                computedHash = keccak256(abi.encodePacked(computedHash, proofElement));
            } else {
                // Hash(current element of the proof + current computed hash)
                computedHash = keccak256(abi.encodePacked(proofElement, computedHash));
            }
        }
        // Check if the computed hash (root) is equal to the provided root
        return computedHash == root;
    }
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.4;
import { Initializable } from "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
import { ICorePoolV1 } from "../interfaces/ICorePoolV1.sol";
import { ErrorHandler } from "../libraries/ErrorHandler.sol";
import { Stake } from "../libraries/Stake.sol";
import { CorePool } from "./CorePool.sol";
/**
 * @title V2Migrator
 *
 * @dev V2Migrator inherits all CorePool base contract functionaltiy, and adds
 *      v1 to v2 migration related functions. This is a core smart contract of
 *      Sushi LP and ILV pools, and manages users locked and yield weights coming
 *      from v1.
 * @dev Parameters need to be reviewed carefully before deployment for the migration process.
 * @dev Users will migrate their locked stakes, which are stored in the contract,
 *      and v1 total yield weights by data stored in a merkle tree using merkle proofs.
 */
abstract contract V2Migrator is Initializable, CorePool {
    using ErrorHandler for bytes4;
    using Stake for uint256;
    /// @dev Maps v1 addresses that are black listed for v2 migration.
    mapping(address => bool) public isBlacklisted;
    /// @dev Stores maximum timestamp of a v1 stake (yield) accepted in v2.
    uint256 internal _v1StakeMaxPeriod;
    /// @dev Stores maximum timestamp of a v1 stake (deposit) accepted in v2.
    uint256 internal constant _v1DepositMaxPeriod = 1648150500;
    /**
     * @dev logs `_migrateLockedStakes()`
     *
     * @param from user address
     * @param totalV1WeightAdded total amount of weight coming from locked stakes in v1
     *
     */
    event LogMigrateLockedStakes(address indexed from, uint256 totalV1WeightAdded);
    /**
     * @dev V2Migrator initializer function.
     *
     * @param v1StakeMaxPeriod_ max timestamp that we accept _lockedFrom values
     *                         in v1 stakes
     */
    function __V2Migrator_init(
        address ilv_,
        address silv_,
        address _poolToken,
        address _corePoolV1,
        address factory_,
        uint64 _initTime,
        uint32 _weight,
        uint256 v1StakeMaxPeriod_
    ) internal initializer {
        // call internal core pool intializar
        __CorePool_init(ilv_, silv_, _poolToken, _corePoolV1, factory_, _initTime, _weight);
        // sets max period for upgrading to V2 contracts i.e migrating
        _v1StakeMaxPeriod = v1StakeMaxPeriod_;
    }
    /**
     * @notice Blacklists a list of v1 user addresses by setting the
     *         _isBlacklisted flag to true.
     *
     * @dev The intention is to prevent addresses that exploited v1 to be able to move
     *      stake ids to the v2 contracts and to be able to mint any yield from a v1
     *      stake id with the isYield flag set to true.
     *
     * @param _users v1 users address array
     */
    function blacklistUsers(address[] calldata _users) external virtual {
        // only the factory controller can blacklist users
        _requireIsFactoryController();
        // we're using selector to simplify validation
        bytes4 fnSelector = this.blacklistUsers.selector;
        // gets each user in the array to be blacklisted
        for (uint256 i = 0; i < _users.length; i++) {
            // makes sure user passed isn't the address 0
            fnSelector.verifyInput(_users[i] != address(0), 0);
            // updates mapping
            isBlacklisted[_users[i]] = true;
        }
    }
    /**
     * @dev External migrateLockedStakes call, used in the Sushi LP pool contract.
     * @dev The function is used by users that want to migrate locked stakes in v1,
     *      but have no yield in the pool. This happens in two scenarios:
     *
     *      1 - The user pool is the Sushi LP pool, which only has stakes;
     *      2 - The user joined ILV pool recently, doesn't have much yield and
     *          doesn't want to migrate their yield weight in the pool;
     * @notice Most of the times this function will be used in the inherited Sushi
     *         LP pool contract (called by the v1 user coming from sushi pool),
     *         but it's possible that a v1 user coming from the ILV pool decides
     *         to use this function instead of `executeMigration()` defined in
     *         the ILV pool contract.
     *
     * @param _stakeIds array of v1 stake ids
     */
    function migrateLockedStakes(uint256[] calldata _stakeIds) external virtual {
        // verifies that user isn't a v1 blacklisted user
        _requireNotBlacklisted(msg.sender);
        // checks if contract is paused
        _requireNotPaused();
        // uses v1 weight values for rewards calculations
        uint256 v1WeightToAdd = _useV1Weight(msg.sender);
        // update user state
        _updateReward(msg.sender, v1WeightToAdd);
        // call internal migrate locked stake function
        // which does the loop to store each v1 stake
        // reference in v2 and all required data
        _migrateLockedStakes(_stakeIds);
    }
    /**
     * @dev Reads v1 core pool locked stakes data (by looping through the `_stakeIds` array),
     *      checks if it's a valid v1 stake to migrate and save the id to v2 user struct.
     *
     * @dev Only `msg.sender` can migrate v1 stakes to v2.
     *
     * @param _stakeIds array of v1 stake ids
     */
    function _migrateLockedStakes(uint256[] calldata _stakeIds) internal virtual {
        User storage user = users[msg.sender];
        // we're using selector to simplify input and state validation
        // internal function simulated selector is `bytes4(keccak256("_migrateLockedStakes(uint256[])"))`
        bytes4 fnSelector = 0x80812525;
        // initializes variable which will tell how much
        // weight in v1 the user is bringing to v2
        uint256 totalV1WeightAdded;
        // loops over each v1 stake id passed to do the necessary validity checks
        // and store the values required in v2 to keep track of v1 weight in order
        // to include it in v2 rewards (yield and revenue distribution) calculations
        for (uint256 i = 0; i < _stakeIds.length; i++) {
            // reads the v1 stake by calling the v1 core pool getDeposit and separates
            // all required data in the struct to be used
            (, uint256 _weight, uint64 lockedFrom, , bool isYield) = ICorePoolV1(corePoolV1).getDeposit(
                msg.sender,
                _stakeIds[i]
            );
            // checks if the v1 stake is in the valid period for migration
            fnSelector.verifyState(lockedFrom <= _v1DepositMaxPeriod, i * 3);
            // checks if the v1 stake has been locked originally and isn't a yield
            // stake, which are the requirements for moving to v2 through this function
            fnSelector.verifyState(lockedFrom > 0 && !isYield, i * 3 + 1);
            // checks if the user has already brought those v1 stakes to v2
            fnSelector.verifyState(v1StakesWeights[msg.sender][_stakeIds[i]] == 0, i * 3 + 2);
            // adds v1 weight to the dynamic mapping which will be used in calculations
            v1StakesWeights[msg.sender][_stakeIds[i]] = _weight;
            // updates the variable keeping track of the total weight migrated
            totalV1WeightAdded += _weight;
            // update value keeping track of v1 stakes ids mapping length
            user.v1IdsLength++;
            // adds stake id to mapping keeping track of each v1 stake id
            user.v1StakesIds[user.v1IdsLength - 1] = _stakeIds[i];
        }
        // emits an event
        emit LogMigrateLockedStakes(msg.sender, totalV1WeightAdded);
    }
    /**
     * @dev Utility used by functions that can't allow blacklisted users to call.
     * @dev Blocks user addresses stored in the _isBlacklisted mapping to call actions like
     *      minting v1 yield stake ids and migrating locked stakes.
     */
    function _requireNotBlacklisted(address _user) internal view virtual {
        // we're using selector to simplify input and access validation
        bytes4 fnSelector = this.migrateLockedStakes.selector;
        // makes sure that msg.sender isn't a blacklisted address
        fnSelector.verifyAccess(!isBlacklisted[_user]);
    }
    /**
     * @dev Empty reserved space in storage. The size of the __gap array is calculated so that
     *      the amount of storage used by a contract always adds up to the 50.
     *      See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[48] private __gap;
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.4;
import { Initializable } from "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
import { IERC20Upgradeable } from "@openzeppelin/contracts-upgradeable/token/ERC20/IERC20Upgradeable.sol";
import { SafeERC20Upgradeable } from "@openzeppelin/contracts-upgradeable/token/ERC20/utils/SafeERC20Upgradeable.sol";
import { SafeCast } from "../libraries/SafeCast.sol";
import { UUPSUpgradeable } from "@openzeppelin/contracts-upgradeable/proxy/utils/UUPSUpgradeable.sol";
import { ReentrancyGuardUpgradeable } from "@openzeppelin/contracts-upgradeable/security/ReentrancyGuardUpgradeable.sol";
import { PausableUpgradeable } from "@openzeppelin/contracts-upgradeable/security/PausableUpgradeable.sol";
import { Timestamp } from "./Timestamp.sol";
import { VaultRecipient } from "./VaultRecipient.sol";
import { ErrorHandler } from "../libraries/ErrorHandler.sol";
import { Stake } from "../libraries/Stake.sol";
import { IILVPool } from "../interfaces/IILVPool.sol";
import { IFactory } from "../interfaces/IFactory.sol";
import { ICorePool } from "../interfaces/ICorePool.sol";
import { ICorePoolV1 } from "../interfaces/ICorePoolV1.sol";
/**
 * @title Core Pool
 *
 * @notice An abstract contract containing common logic for ILV and ILV/ETH SLP pools.
 *
 * @dev Base smart contract for ILV and LP pool. Stores each pool user by mapping
 *      its address to the user struct. User struct stores v2 stakes, which fit
 *      in 1 storage slot each (by using the Stake lib), total weights, pending
 *      yield and revenue distributions, and v1 stake ids. ILV and LP stakes can
 *      be made through flexible stake mode, which only increments the flexible
 *      balance of a given user, or through locked staking. Locked staking creates
 *      a new Stake element fitting 1 storage slot with its value and lock duration.
 *      When calculating pending rewards, CorePool checks v1 locked stakes weights
 *      to increment in the calculations and stores pending yield and pending revenue
 *      distributions. Every time a stake or unstake related function is called,
 *      it updates pending values, but don't require instant claimings. Rewards
 *      claiming are executed in separate functions, and in the case of yield,
 *      it also requires the user checking whether ILV or sILV is wanted as the yield reward.
 *
 * @dev Deployment and initialization.
 *      After proxy is deployed and attached to the implementation, it should be
 *      registered by the PoolFactory contract
 *      Additionally, 3 token instance addresses must be defined on deployment:
 *          - ILV token address
 *          - sILV token address, used to mint sILV rewards
 *          - pool token address, it can be ILV token address, ILV/ETH pair address, and others
 *
 * @dev Pool weight defines the fraction of the yield current pool receives among the other pools,
 *      pool factory is responsible for the weight synchronization between the pools.
 * @dev The weight is logically 20% for ILV pool and 80% for ILV/ETH pool initially.
 *      It can be changed through ICCPs and new flash pools added in the protocol.
 *      Since Solidity doesn't support fractions the weight is defined by the division of
 *      pool weight by total pools weight (sum of all registered pools within the factory).
 * @dev For ILV Pool we use 200 as weight and for ILV/ETH SLP pool - 800.
 *
 */
abstract contract CorePool is
    Initializable,
    UUPSUpgradeable,
    VaultRecipient,
    ReentrancyGuardUpgradeable,
    PausableUpgradeable,
    Timestamp
{
    using SafeERC20Upgradeable for IERC20Upgradeable;
    using SafeCast for uint256;
    using Stake for Stake.Data;
    using ErrorHandler for bytes4;
    using Stake for uint256;
    /// @dev Data structure representing token holder using a pool.
    struct User {
        /// @dev pending yield rewards to be claimed
        uint128 pendingYield;
        /// @dev pending revenue distribution to be claimed
        uint128 pendingRevDis;
        /// @dev Total weight
        uint248 totalWeight;
        /// @dev number of v1StakesIds
        uint8 v1IdsLength;
        /// @dev Checkpoint variable for yield calculation
        uint256 yieldRewardsPerWeightPaid;
        /// @dev Checkpoint variable for vault rewards calculation
        uint256 vaultRewardsPerWeightPaid;
        /// @dev An array of holder's stakes
        Stake.Data[] stakes;
        /// @dev A mapping of holder's stakes ids in V1
        mapping(uint256 => uint256) v1StakesIds;
    }
    /// @dev Data structure used in `unstakeLockedMultiple()` function.
    struct UnstakeParameter {
        uint256 stakeId;
        uint256 value;
    }
    /// @dev Token holder storage, maps token holder address to their data record.
    mapping(address => User) public users;
    /// @dev Maps `keccak256(userAddress,stakeId)` to a uint256 value that tells
    ///      a v1 locked stake weight that has already been migrated to v2
    ///      and is updated through _useV1Weight.
    mapping(address => mapping(uint256 => uint256)) public v1StakesWeights;
    /// @dev Link to sILV ERC20 Token instance.
    address internal _silv;
    /// @dev Link to ILV ERC20 Token instance.
    address internal _ilv;
    /// @dev Address of v1 core pool with same poolToken.
    address internal corePoolV1;
    /// @dev Link to the pool token instance, for example ILV or ILV/ETH pair.
    address public poolToken;
    /// @dev Pool weight, initial values are 200 for ILV pool and 800 for ILV/ETH.
    uint32 public weight;
    /// @dev Timestamp of the last yield distribution event.
    uint64 public lastYieldDistribution;
    /// @dev Used to calculate yield rewards.
    /// @dev This value is different from "reward per token" used in flash pool.
    /// @dev Note: stakes are different in duration and "weight" reflects that.
    uint256 public yieldRewardsPerWeight;
    /// @dev Used to calculate rewards, keeps track of the tokens weight locked in staking.
    uint256 public globalWeight;
    /// @dev Used to calculate rewards, keeps track of the correct token weight in the v1
    ///      core pool.
    uint256 public v1GlobalWeight;
    /// @dev Pool tokens value available in the pool;
    ///      pool token examples are ILV (ILV core pool) or ILV/ETH pair (LP core pool).
    /// @dev For LP core pool this value doesnt' count for ILV tokens received as Vault rewards
    ///      while for ILV core pool it does count for such tokens as well.
    uint256 public poolTokenReserve;
    /// @dev Flag indicating pool type, false means "core pool".
    bool public constant isFlashPool = false;
    /**
     * @dev Fired in _stake() and stakeAsPool() in ILVPool contract.
     * @param by address that executed the stake function (user or pool)
     * @param from token holder address, the tokens will be returned to that address
     * @param stakeId id of the new stake created
     * @param value value of tokens staked
     * @param lockUntil timestamp indicating when tokens should unlock (max 2 years)
     */
    event LogStake(address indexed by, address indexed from, uint256 stakeId, uint256 value, uint64 lockUntil);
    /**
     * @dev Fired in `unstakeLocked()`.
     *
     * @param to address receiving the tokens (user)
     * @param stakeId id value of the stake
     * @param value number of tokens unstaked
     * @param isYield whether stake struct unstaked was coming from yield or not
     */
    event LogUnstakeLocked(address indexed to, uint256 stakeId, uint256 value, bool isYield);
    /**
     * @dev Fired in `unstakeLockedMultiple()`.
     *
     * @param to address receiving the tokens (user)
     * @param totalValue total number of tokens unstaked
     * @param unstakingYield whether unstaked tokens had isYield flag true or false
     */
    event LogUnstakeLockedMultiple(address indexed to, uint256 totalValue, bool unstakingYield);
    /**
     * @dev Fired in `_sync()`, `sync()` and dependent functions (stake, unstake, etc.).
     *
     * @param by an address which performed an operation
     * @param yieldRewardsPerWeight updated yield rewards per weight value
     * @param lastYieldDistribution usually, current timestamp
     */
    event LogSync(address indexed by, uint256 yieldRewardsPerWeight, uint64 lastYieldDistribution);
    /**
     * @dev Fired in `_claimYieldRewards()`.
     *
     * @param by an address which claimed the rewards (staker or ilv pool contract
     *            in case of a multiple claim call)
     * @param from an address which received the yield
     * @param sILV flag indicating if reward was paid (minted) in sILV
     * @param value value of yield paid
     */
    event LogClaimYieldRewards(address indexed by, address indexed from, bool sILV, uint256 value);
    /**
     * @dev Fired in `_claimVaultRewards()`.
     *
     * @param by an address which claimed the rewards (staker or ilv pool contract
     *            in case of a multiple claim call)
     * @param from an address which received the yield
     * @param value value of yield paid
     */
    event LogClaimVaultRewards(address indexed by, address indexed from, uint256 value);
    /**
     * @dev Fired in `_updateRewards()`.
     *
     * @param by an address which processed the rewards (staker or ilv pool contract
     *            in case of a multiple claim call)
     * @param from an address which received the yield
     * @param yieldValue value of yield processed
     * @param revDisValue value of revenue distribution processed
     */
    event LogUpdateRewards(address indexed by, address indexed from, uint256 yieldValue, uint256 revDisValue);
    /**
     * @dev fired in `moveFundsFromWallet()`.
     *
     * @param from user asking migration
     * @param to new user address
     * @param previousTotalWeight total weight of `from` before moving to a new address
     * @param newTotalWeight total weight of `to` after moving to a new address
     * @param previousYield pending yield of `from` before moving to a new address
     * @param newYield pending yield of `to` after moving to a new address
     * @param previousRevDis pending revenue distribution of `from` before moving to a new address
     * @param newRevDis pending revenue distribution of `to` after moving to a new address
     */
    event LogMoveFundsFromWallet(
        address indexed from,
        address indexed to,
        uint248 previousTotalWeight,
        uint248 newTotalWeight,
        uint128 previousYield,
        uint128 newYield,
        uint128 previousRevDis,
        uint128 newRevDis
    );
    /**
     * @dev Fired in `receiveVaultRewards()`.
     *
     * @param by an address that sent the rewards, always a vault
     * @param value amount of tokens received
     */
    event LogReceiveVaultRewards(address indexed by, uint256 value);
    /**
     * @dev Used in child contracts to initialize the pool.
     *
     * @param ilv_ ILV ERC20 Token address
     * @param silv_ sILV ERC20 Token address
     * @param _poolToken token the pool operates on, for example ILV or ILV/ETH pair
     * @param _corePoolV1 v1 core pool address
     * @param factory_ PoolFactory contract address
     * @param _initTime initial timestamp used to calculate the rewards
     *      note: _initTime is set to the future effectively meaning _sync() calls will do nothing
     *           before _initTime
     * @param _weight number representing the pool's weight, which in _sync calls
     *        is used by checking the total pools weight in the PoolFactory contract
     */
    function __CorePool_init(
        address ilv_,
        address silv_,
        address _poolToken,
        address _corePoolV1,
        address factory_,
        uint64 _initTime,
        uint32 _weight
    ) internal initializer {
        // we're using selector to simplify input and state validation
        // internal function simulated selector is
        // `bytes4(keccak256("__CorePool_init(address,address,address,address,address,uint64,uint32)"))`
        bytes4 fnSelector = 0x1512be06;
        // verify the inputs
        fnSelector.verifyNonZeroInput(uint160(_poolToken), 2);
        fnSelector.verifyNonZeroInput(uint160(_corePoolV1), 3);
        fnSelector.verifyNonZeroInput(_initTime, 5);
        fnSelector.verifyNonZeroInput(_weight, 6);
        __FactoryControlled_init(factory_);
        __ReentrancyGuard_init();
        __Pausable_init();
        // save the inputs into internal state variables
        _ilv = ilv_;
        _silv = silv_;
        poolToken = _poolToken;
        corePoolV1 = _corePoolV1;
        weight = _weight;
        // init the dependent internal state variables
        lastYieldDistribution = _initTime;
    }
    /**
     * @notice Calculates current yield rewards value available for address specified.
     *
     * @dev See `_pendingRewards()` for further details.
     *
     * @dev External `pendingRewards()` returns pendingYield and pendingRevDis
     *         accumulated with already stored user.pendingYield and user.pendingRevDis.
     *
     * @param _staker an address to calculate yield rewards value for
     */
    function pendingRewards(address _staker)
        external
        view
        virtual
        returns (uint256 pendingYield, uint256 pendingRevDis)
    {
        this.pendingRewards.selector.verifyNonZeroInput(uint160(_staker), 0);
        // `newYieldRewardsPerWeight` will be the stored or recalculated value for `yieldRewardsPerWeight`
        uint256 newYieldRewardsPerWeight;
        // gas savings
        uint256 _lastYieldDistribution = lastYieldDistribution;
        // based on the rewards per weight value, calculate pending rewards;
        User storage user = users[_staker];
        // initializes both variables from one storage slot
        (uint256 v1StakesLength, uint256 userWeight) = (uint256(user.v1IdsLength), uint256(user.totalWeight));
        // total user v1 weight to be used
        uint256 totalV1Weight;
        if (v1StakesLength > 0) {
            // loops through v1StakesIds and adds v1 weight
            for (uint256 i = 0; i < v1StakesLength; i++) {
                uint256 stakeId = user.v1StakesIds[i];
                (, uint256 _weight, , , ) = ICorePoolV1(corePoolV1).getDeposit(_staker, stakeId);
                uint256 storedWeight = v1StakesWeights[_staker][stakeId];
                totalV1Weight += _weight <= storedWeight ? _weight : storedWeight;
            }
        }
        // if smart contract state was not updated recently, `yieldRewardsPerWeight` value
        // is outdated and we need to recalculate it in order to calculate pending rewards correctly
        if (_now256() > _lastYieldDistribution && globalWeight != 0) {
            uint256 endTime = _factory.endTime();
            uint256 multiplier = _now256() > endTime
                ? endTime - _lastYieldDistribution
                : _now256() - _lastYieldDistribution;
            uint256 ilvRewards = (multiplier * weight * _factory.ilvPerSecond()) / _factory.totalWeight();
            // recalculated value for `yieldRewardsPerWeight`
            newYieldRewardsPerWeight =
                ilvRewards.getRewardPerWeight((globalWeight + v1GlobalWeight)) +
                yieldRewardsPerWeight;
        } else {
            // if smart contract state is up to date, we don't recalculate
            newYieldRewardsPerWeight = yieldRewardsPerWeight;
        }
        pendingYield =
            (userWeight + totalV1Weight).earned(newYieldRewardsPerWeight, user.yieldRewardsPerWeightPaid) +
            user.pendingYield;
        pendingRevDis =
            (userWeight + totalV1Weight).earned(vaultRewardsPerWeight, user.vaultRewardsPerWeightPaid) +
            user.pendingRevDis;
    }
    /**
     * @notice Returns total staked token balance for the given address.
     * @dev Loops through stakes and returns total balance.
     * @notice Expected to be called externally through `eth_call`. Gas shouldn't
     *         be an issue here.
     *
     * @param _user an address to query balance for
     * @return balance total staked token balance
     */
    function balanceOf(address _user) external view virtual returns (uint256 balance) {
        // gets storage pointer to _user
        User storage user = users[_user];
        // loops over each user stake and adds to the total balance.
        for (uint256 i = 0; i < user.stakes.length; i++) {
            balance += user.stakes[i].value;
        }
    }
    /**
     * @dev Returns the sum of poolTokenReserve with the deposit reserves in v1.
     * @dev In ILV Pool contract the eDAO stores the v1 reserve value, and
     *      in the SLP pool we're able to query it from the v1 lp pool contract.
     */
    function getTotalReserves() external view virtual returns (uint256 totalReserves);
    /**
     * @notice Returns information on the given stake for the given address.
     *
     * @dev See getStakesLength.
     *
     * @param _user an address to query stake for
     * @param _stakeId zero-indexed stake ID for the address specified
     * @return stake info as Stake structure
     */
    function getStake(address _user, uint256 _stakeId) external view virtual returns (Stake.Data memory) {
        // read stake at specified index and return
        return users[_user].stakes[_stakeId];
    }
    /**
     * @notice Returns a v1 stake id in the `user.v1StakesIds` array.
     *
     * @dev Get v1 stake id position through `getV1StakePosition()`.
     *
     * @param _user an address to query stake for
     * @param _position position index in the array
     * @return stakeId value
     */
    function getV1StakeId(address _user, uint256 _position) external view virtual returns (uint256) {
        // returns the v1 stake id indicated at _position value
        return users[_user].v1StakesIds[_position];
    }
    /**
     * @notice Returns a v1 stake position in the `user.v1StakesIds` array.
     *
     * @dev Helper function to call `getV1StakeId()`.
     * @dev Reverts if stakeId isn't found.
     *
     * @param _user an address to query stake for
     * @param _desiredId desired stakeId position in the array to find
     * @return position stake info as Stake structure
     */
    function getV1StakePosition(address _user, uint256 _desiredId) external view virtual returns (uint256 position) {
        // gets storage pointer to user
        User storage user = users[_user];
        // loops over each v1 stake id and checks if it's the one
        // that the caller is looking for
        for (uint256 i = 0; i < user.v1IdsLength; i++) {
            if (user.v1StakesIds[i] == _desiredId) {
                // if it's the desired stake id, return the array index (i.e position)
                return i;
            }
        }
        revert();
    }
    /**
     * @notice Returns number of stakes for the given address. Allows iteration over stakes.
     *
     * @dev See `getStake()`.
     *
     * @param _user an address to query stake length for
     * @return number of stakes for the given address
     */
    function getStakesLength(address _user) external view virtual returns (uint256) {
        // read stakes array length and return
        return users[_user].stakes.length;
    }
    /**
     * @dev Set paused/unpaused state in the pool contract.
     *
     * @param _shouldPause whether the contract should be paused/unpausd
     */
    function pause(bool _shouldPause) external {
        // checks if caller is authorized to pause
        _requireIsFactoryController();
        // checks bool input and pause/unpause the contract depending on
        // msg.sender's request
        if (_shouldPause) {
            _pause();
        } else {
            _unpause();
        }
    }
    /**
     * @notice Stakes specified value of tokens for the specified value of time,
     *      and pays pending yield rewards if any.
     *
     * @dev Requires value to stake and lock duration to be greater than zero.
     *
     * @param _value value of tokens to stake
     * @param _lockDuration stake duration as unix timestamp
     */
    function stake(uint256 _value, uint64 _lockDuration) external virtual nonReentrant {
        // checks if the contract is in a paused state
        _requireNotPaused();
        // we're using selector to simplify input and state validation
        bytes4 fnSelector = this.stake.selector;
        // validate the inputs
        fnSelector.verifyNonZeroInput(_value, 1);
        fnSelector.verifyInput(_lockDuration >= Stake.MIN_STAKE_PERIOD && _lockDuration <= Stake.MAX_STAKE_PERIOD, 2);
        // get a link to user data struct, we will write to it later
        User storage user = users[msg.sender];
        // uses v1 weight values for rewards calculations
        uint256 v1WeightToAdd = _useV1Weight(msg.sender);
        // update user state
        _updateReward(msg.sender, v1WeightToAdd);
        // calculates until when a stake is going to be locked
        uint64 lockUntil = (_now256()).toUint64() + _lockDuration;
        // stake weight formula rewards for locking
        uint256 stakeWeight = (((lockUntil - _now256()) * Stake.WEIGHT_MULTIPLIER) /
            Stake.MAX_STAKE_PERIOD +
            Stake.BASE_WEIGHT) * _value;
        // makes sure stakeWeight is valid
        assert(stakeWeight > 0);
        // create and save the stake (append it to stakes array)
        Stake.Data memory userStake = Stake.Data({
            value: (_value).toUint120(),
            lockedFrom: (_now256()).toUint64(),
            lockedUntil: lockUntil,
            isYield: false
        });
        // pushes new stake to `stakes` array
        user.stakes.push(userStake);
        // update user weight
        user.totalWeight += (stakeWeight).toUint248();
        // update global weight value and global pool token count
        globalWeight += stakeWeight;
        poolTokenReserve += _value;
        // transfer `_value`
        IERC20Upgradeable(poolToken).safeTransferFrom(address(msg.sender), address(this), _value);
        // emit an event
        emit LogStake(msg.sender, msg.sender, (user.stakes.length - 1), _value, lockUntil);
    }
    /**
     * @dev Moves msg.sender stake data to a new address.
     * @dev V1 stakes are never migrated to the new address. We process all rewards,
     *      clean the previous user (msg.sender), add the previous user data to
     *      the desired address and update subYieldRewards/subVaultRewards values
     *      in order to make sure both addresses will have rewards cleaned.
     *
     * @param _to new user address, needs to be a fresh address with no stakes
     */
    function moveFundsFromWallet(address _to) public virtual {
        // checks if the contract is in a paused state
        _requireNotPaused();
        // gets storage pointer to msg.sender user struct
        User storage previousUser = users[msg.sender];
        // gets storage pointer to desired address user struct
        User storage newUser = users[_to];
        // uses v1 weight values for rewards calculations
        uint256 v1WeightToAdd = _useV1Weight(msg.sender);
        // We process update global and user's rewards
        // before moving the user funds to a new wallet.
        // This way we can ensure that all v1 ids weight have been used before the v2
        // stakes to a new address.
        _updateReward(msg.sender, v1WeightToAdd);
        // we're using selector to simplify input and state validation
        bytes4 fnSelector = this.moveFundsFromWallet.selector;
        // validate input is set
        fnSelector.verifyNonZeroInput(uint160(_to), 0);
        // verify new user records are empty
        fnSelector.verifyState(
            newUser.totalWeight == 0 &&
                newUser.v1IdsLength == 0 &&
                newUser.stakes.length == 0 &&
                newUser.yieldRewardsPerWeightPaid == 0 &&
                newUser.vaultRewardsPerWeightPaid == 0,
            0
        );
        // saves previous user total weight
        uint248 previousTotalWeight = previousUser.totalWeight;
        // saves previous user pending yield
        uint128 previousYield = previousUser.pendingYield;
        // saves previous user pending rev dis
        uint128 previousRevDis = previousUser.pendingRevDis;
        // It's expected to have all previous user values
        // migrated to the new user address (_to).
        // We recalculate yield and vault rewards values
        // to make sure new user pending yield and pending rev dis to be stored
        // at newUser.pendingYield and newUser.pendingRevDis is 0, since we just processed
        // all pending rewards calling _updateReward.
        newUser.totalWeight = previousTotalWeight;
        newUser.pendingYield = previousYield;
        newUser.pendingRevDis = previousRevDis;
        newUser.yieldRewardsPerWeightPaid = yieldRewardsPerWeight;
        newUser.vaultRewardsPerWeightPaid = vaultRewardsPerWeight;
        newUser.stakes = previousUser.stakes;
        delete previousUser.totalWeight;
        delete previousUser.pendingYield;
        delete previousUser.pendingRevDis;
        delete previousUser.stakes;
        // emits an event
        emit LogMoveFundsFromWallet(
            msg.sender,
            _to,
            previousTotalWeight,
            newUser.totalWeight,
            previousYield,
            newUser.pendingYield,
            previousRevDis,
            newUser.pendingRevDis
        );
    }
    /**
     * @notice Service function to synchronize pool state with current time.
     *
     * @dev Can be executed by anyone at any time, but has an effect only when
     *      at least one second passes between synchronizations.
     * @dev Executed internally when staking, unstaking, processing rewards in order
     *      for calculations to be correct and to reflect state progress of the contract.
     * @dev When timing conditions are not met (executed too frequently, or after factory
     *      end time), function doesn't throw and exits silently.
     */
    function sync() external virtual {
        _requireNotPaused();
        // calls internal function
        _sync();
    }
    /**
     * @dev Calls internal `_claimYieldRewards()` passing `msg.sender` as `_staker`.
     *
     * @notice Pool state is updated before calling the internal function.
     */
    function claimYieldRewards(bool _useSILV) external virtual {
        // checks if the contract is in a paused state
        _requireNotPaused();
        // calls internal function
        _claimYieldRewards(msg.sender, _useSILV);
    }
    /**
     * @dev Calls internal `_claimVaultRewards()` passing `msg.sender` as `_staker`.
     *
     * @notice Pool state is updated before calling the internal function.
     */
    function claimVaultRewards() external virtual {
        // checks if the contract is in a paused state
        _requireNotPaused();
        // calls internal function
        _claimVaultRewards(msg.sender);
    }
    /**
     * @dev Claims both revenue distribution and yield rewards in one call.
     *
     */
    function claimAllRewards(bool _useSILV) external virtual {
        // checks if the contract is in a paused state
        _requireNotPaused();
        // calls internal yield and vault rewards functions
        _claimVaultRewards(msg.sender);
        _claimYieldRewards(msg.sender, _useSILV);
    }
    /**
     * @dev Executed by the vault to transfer vault rewards ILV from the vault
     *      into the pool.
     *
     * @dev This function is executed only for ILV core pools.
     *
     * @param _value amount of ILV rewards to transfer into the pool
     */
    function receiveVaultRewards(uint256 _value) external virtual {
        // always sync the pool state vars before moving forward
        _sync();
        // checks if the contract is in a paused state
        _requireNotPaused();
        // checks if msg.sender is the vault contract
        _requireIsVault();
        // we're using selector to simplify input and state validation
        bytes4 fnSelector = this.receiveVaultRewards.selector;
        // return silently if there is no reward to receive
        if (_value == 0) {
            return;
        }
        // verify weight is not zero
        fnSelector.verifyState(globalWeight > 0 || v1GlobalWeight > 0, 0);
        // we update vaultRewardsPerWeight value using v1 and v2 global weight,
        // expecting to distribute revenue distribution correctly to all users
        // coming from v1 and new v2 users.
        vaultRewardsPerWeight += _value.getRewardPerWeight(globalWeight + v1GlobalWeight);
        // transfers ILV from the Vault contract to the pool
        IERC20Upgradeable(_ilv).safeTransferFrom(msg.sender, address(this), _value);
        // emits an event
        emit LogReceiveVaultRewards(msg.sender, _value);
    }
    /**
     * @dev Updates value that keeps track of v1 global locked tokens weight.
     *
     * @param _v1GlobalWeight new value to be stored
     */
    function setV1GlobalWeight(uint256 _v1GlobalWeight) external virtual {
        // only factory controller can update the _v1GlobalWeight
        _requireIsFactoryController();
        // update v1GlobalWeight state variable
        v1GlobalWeight = _v1GlobalWeight;
    }
    /**
     * @dev Executed by the factory to modify pool weight; the factory is expected
     *      to keep track of the total pools weight when updating.
     *
     * @dev Set weight to zero to disable the pool.
     *
     * @param _weight new weight to set for the pool
     */
    function setWeight(uint32 _weight) external virtual {
        // update pool state using current weight value
        _sync();
        // verify function is executed by the factory
        this.setWeight.selector.verifyAccess(msg.sender == address(_factory));
        // set the new weight value
        weight = _weight;
    }
    /**
     * @dev Unstakes a stake that has been previously locked, and is now in an unlocked
     *      state. If the stake has the isYield flag set to true, then the contract
     *      requests ILV to be minted by the PoolFactory. Otherwise it transfers ILV or LP
     *      from the contract balance.
     *
     * @param _stakeId stake ID to unstake from, zero-indexed
     * @param _value value of tokens to unstake
     */
    function unstake(uint256 _stakeId, uint256 _value) external virtual {
        // checks if the contract is in a paused state
        _requireNotPaused();
        // we're using selector to simplify input and state validation
        bytes4 fnSelector = this.unstake.selector;
        // verify a value is set
        fnSelector.verifyNonZeroInput(_value, 0);
        // get a link to user data struct, we will write to it later
        User storage user = users[msg.sender];
        // get a link to the corresponding stake, we may write to it later
        Stake.Data storage userStake = user.stakes[_stakeId];
        // checks if stake is unlocked already
        fnSelector.verifyState(_now256() > userStake.lockedUntil, 0);
        // stake structure may get deleted, so we save isYield flag to be able to use it
        // we also save stakeValue for gasSavings
        (uint120 stakeValue, bool isYield) = (userStake.value, userStake.isYield);
        // verify available balance
        fnSelector.verifyInput(stakeValue >= _value, 1);
        // uses v1 weight values for rewards calculations
        uint256 v1WeightToAdd = _useV1Weight(msg.sender);
        // and process current pending rewards if any
        _updateReward(msg.sender, v1WeightToAdd);
        // store stake weight
        uint256 previousWeight = userStake.weight();
        // value used to save new weight after updates in storage
        uint256 newWeight;
        // update the stake, or delete it if its depleted
        if (stakeValue - _value == 0) {
            // deletes stake struct, no need to save new weight because it stays 0
            delete user.stakes[_stakeId];
        } else {
            userStake.value -= (_value).toUint120();
            // saves new weight to memory
            newWeight = userStake.weight();
        }
        // update user record
        user.totalWeight = uint248(user.totalWeight - previousWeight + newWeight);
        // update global weight variable
        globalWeight = globalWeight - previousWeight + newWeight;
        // update global pool token count
        poolTokenReserve -= _value;
        // if the stake was created by the pool itself as a yield reward
        if (isYield) {
            // mint the yield via the factory
            _factory.mintYieldTo(msg.sender, _value, false);
        } else {
            // otherwise just return tokens back to holder
            IERC20Upgradeable(poolToken).safeTransfer(msg.sender, _value);
        }
        // emits an event
        emit LogUnstakeLocked(msg.sender, _stakeId, _value, isYield);
    }
    /**
     * @dev Executes unstake on multiple stakeIds. See `unstakeLocked()`.
     * @dev Optimizes gas by requiring all unstakes to be made either in yield stakes
     *      or in non yield stakes. That way we can transfer or mint tokens in one call.
     *
     * @notice User is required to either mint ILV or unstake pool tokens in the function call.
     *         There's no way to do both operations in one call.
     *
     * @param _stakes array of stakeIds and values to be unstaked in each stake from
     *                the msg.sender
     * @param _unstakingYield whether all stakeIds have isYield flag set to true or false,
     *                        i.e if we're minting ILV or transferring pool tokens
     */
    function unstakeMultiple(UnstakeParameter[] calldata _stakes, bool _unstakingYield) external virtual {
        // checks if the contract is in a paused state
        _requireNotPaused();
        // we're using selector to simplify input and state validation
        bytes4 fnSelector = this.unstakeMultiple.selector;
        // verifies if user has passed any value to be unstaked
        fnSelector.verifyNonZeroInput(_stakes.length, 0);
        // gets storage pointer to the user
        User storage user = users[msg.sender];
        // uses v1 weight values for rewards calculations
        uint256 v1WeightToAdd = _useV1Weight(msg.sender);
        _updateReward(msg.sender, v1WeightToAdd);
        // initialize variables that expect to receive the total
        // weight to be removed from the user and the value to be
        // unstaked from the pool.
        uint256 weightToRemove;
        uint256 valueToUnstake;
        for (uint256 i = 0; i < _stakes.length; i++) {
            // destructure calldata parameters
            (uint256 _stakeId, uint256 _value) = (_stakes[i].stakeId, _stakes[i].value);
            Stake.Data storage userStake = user.stakes[_stakeId];
            // checks if stake is unlocked already
            fnSelector.verifyState(_now256() > userStake.lockedUntil, i * 3);
            // checks if unstaking value is valid
            fnSelector.verifyNonZeroInput(_value, 1);
            // stake structure may get deleted, so we save isYield flag to be able to use it
            // we also save stakeValue for gas savings
            (uint120 stakeValue, bool isYield) = (userStake.value, userStake.isYield);
            // verifies if the selected stake is yield (i.e ILV to be minted)
            // or not, the function needs to either mint yield or transfer tokens
            // and can't do both operations at the same time.
            fnSelector.verifyState(isYield == _unstakingYield, i * 3 + 1);
            // checks if there's enough tokens to unstake
            fnSelector.verifyState(stakeValue >= _value, i * 3 + 2);
            // store stake weight
            uint256 previousWeight = userStake.weight();
            // value used to save new weight after updates in storage
            uint256 newWeight;
            // update the stake, or delete it if its depleted
            if (stakeValue - _value == 0) {
                // deletes stake struct, no need to save new weight because it stays 0
                delete user.stakes[_stakeId];
            } else {
                // removes _value from the stake with safe cast
                userStake.value -= (_value).toUint120();
                // saves new weight to memory
                newWeight = userStake.weight();
            }
            // updates the values initialized earlier with the amounts that
            // need to be subtracted (weight) and transferred (value to unstake)
            weightToRemove += previousWeight - newWeight;
            valueToUnstake += _value;
        }
        // subtracts weight
        user.totalWeight -= (weightToRemove).toUint248();
        // update global variable
        globalWeight -= weightToRemove;
        // update pool token count
        poolTokenReserve -= valueToUnstake;
        // if the stake was created by the pool itself as a yield reward
        if (_unstakingYield) {
            // mint the yield via the factory
            _factory.mintYieldTo(msg.sender, valueToUnstake, false);
        } else {
            // otherwise just return tokens back to holder
            IERC20Upgradeable(poolToken).safeTransfer(msg.sender, valueToUnstake);
        }
        // emits an event
        emit LogUnstakeLockedMultiple(msg.sender, valueToUnstake, _unstakingYield);
    }
    /**
     * @dev Used internally, mostly by children implementations, see `sync()`.
     *
     * @dev Updates smart contract state (`yieldRewardsPerWeight`, `lastYieldDistribution`),
     *      updates factory state via `updateILVPerSecond`
     */
    function _sync() internal virtual {
        // gas savings
        IFactory factory_ = _factory;
        // update ILV per second value in factory if required
        if (factory_.shouldUpdateRatio()) {
            factory_.updateILVPerSecond();
        }
        // check bound conditions and if these are not met -
        // exit silently, without emitting an event
        uint256 endTime = factory_.endTime();
        if (lastYieldDistribution >= endTime) {
            return;
        }
        if (_now256() <= lastYieldDistribution) {
            return;
        }
        // if locking weight is zero - update only `lastYieldDistribution` and exit
        if (globalWeight == 0 && v1GlobalWeight == 0) {
            lastYieldDistribution = (_now256()).toUint64();
            return;
        }
        // to calculate the reward we need to know how many seconds passed, and reward per second
        uint256 currentTimestamp = _now256() > endTime ? endTime : _now256();
        uint256 secondsPassed = currentTimestamp - lastYieldDistribution;
        uint256 ilvPerSecond = factory_.ilvPerSecond();
        // calculate the reward
        uint256 ilvReward = (secondsPassed * ilvPerSecond * weight) / factory_.totalWeight();
        // update rewards per weight and `lastYieldDistribution`
        yieldRewardsPerWeight += ilvReward.getRewardPerWeight((globalWeight + v1GlobalWeight));
        lastYieldDistribution = (currentTimestamp).toUint64();
        // emit an event
        emit LogSync(msg.sender, yieldRewardsPerWeight, lastYieldDistribution);
    }
    /**
     * @dev claims all pendingYield from _staker using ILV or sILV.
     *
     * @notice sILV is minted straight away to _staker wallet, ILV is created as
     *         a new stake and locked for Stake.MAX_STAKE_PERIOD.
     *
     * @param _staker user address
     * @param _useSILV whether the user wants to claim ILV or sILV
     */
    function _claimYieldRewards(address _staker, bool _useSILV) internal virtual {
        // get link to a user data structure, we will write into it later
        User storage user = users[_staker];
        // uses v1 weight values for rewards calculations
        uint256 v1WeightToAdd = _useV1Weight(_staker);
        // update user state
        _updateReward(_staker, v1WeightToAdd);
        // check pending yield rewards to claim and save to memory
        uint256 pendingYieldToClaim = uint256(user.pendingYield);
        // if pending yield is zero - just return silently
        if (pendingYieldToClaim == 0) return;
        // clears user pending yield
        user.pendingYield = 0;
        // if sILV is requested
        if (_useSILV) {
            // - mint sILV
            _factory.mintYieldTo(_staker, pendingYieldToClaim, true);
        } else if (poolToken == _ilv) {
            // calculate pending yield weight,
            // 2e6 is the bonus weight when staking for 1 year
            uint256 stakeWeight = pendingYieldToClaim * Stake.YIELD_STAKE_WEIGHT_MULTIPLIER;
            // if the pool is ILV Pool - create new ILV stake
            // and save it - push it into stakes array
            Stake.Data memory newStake = Stake.Data({
                value: (pendingYieldToClaim).toUint120(),
                lockedFrom: (_now256()).toUint64(),
                lockedUntil: (_now256() + Stake.MAX_STAKE_PERIOD).toUint64(), // staking yield for 1 year
                isYield: true
            });
            // add memory stake to storage
            user.stakes.push(newStake);
            // updates total user weight with the newly created stake's weight
            user.totalWeight += (stakeWeight).toUint248();
            // update global variable
            globalWeight += stakeWeight;
            // update reserve count
            poolTokenReserve += pendingYieldToClaim;
        } else {
            // for other pools - stake as pool
            address ilvPool = _factory.getPoolAddress(_ilv);
            IILVPool(ilvPool).stakeAsPool(_staker, pendingYieldToClaim);
        }
        // emits an event
        emit LogClaimYieldRewards(msg.sender, _staker, _useSILV, pendingYieldToClaim);
    }
    /**
     * @dev Claims all pendingRevDis from _staker using ILV.
     * @dev ILV is sent straight away to _staker address.
     *
     * @param _staker user address
     */
    function _claimVaultRewards(address _staker) internal virtual {
        // get link to a user data structure, we will write into it later
        User storage user = users[_staker];
        // uses v1 weight values for rewards calculations
        uint256 v1WeightToAdd = _useV1Weight(_staker);
        // update user state
        _updateReward(_staker, v1WeightToAdd);
        // check pending yield rewards to claim and save to memory
        uint256 pendingRevDis = uint256(user.pendingRevDis);
        // if pending yield is zero - just return silently
        if (pendingRevDis == 0) return;
        // clears user pending revenue distribution
        user.pendingRevDis = 0;
        IERC20Upgradeable(_ilv).safeTransfer(_staker, pendingRevDis);
        // emits an event
        emit LogClaimVaultRewards(msg.sender, _staker, pendingRevDis);
    }
    /**
     * @dev Calls CorePoolV1 contract, gets v1 stake ids weight and returns.
     * @dev Used by `_pendingRewards()` to calculate yield and revenue distribution
     *      rewards taking v1 weights into account.
     *
     * @notice If v1 weights have changed since last call, we use latest v1 weight for
     *         yield and revenue distribution rewards calculations, and recalculate
     *         user sub rewards values in order to have correct rewards estimations.
     *
     * @param _staker user address passed
     *
     * @return totalV1Weight uint256 value of v1StakesIds weights
     */
    function _useV1Weight(address _staker) internal virtual returns (uint256 totalV1Weight) {
        // gets user storage pointer
        User storage user = users[_staker];
        // gas savings
        uint256 v1StakesLength = user.v1IdsLength;
        // checks if user has any migrated stake from v1
        if (v1StakesLength > 0) {
            // loops through v1StakesIds and adds v1 weight
            for (uint256 i = 0; i < v1StakesLength; i++) {
                // saves v1 stake id to memory
                uint256 stakeId = user.v1StakesIds[i];
                (, uint256 _weight, , , ) = ICorePoolV1(corePoolV1).getDeposit(_staker, stakeId);
                // gets weight stored initially in the v1StakesWeights mapping
                // through V2Migrator contract
                uint256 storedWeight = v1StakesWeights[_staker][stakeId];
                // only stores the current v1 weight that is going to be used for calculations
                // if current v1 weight is equal to or less than the stored weight.
                // This way we make sure that v1 weight never increases for any reason
                // (e.g increasing a v1 stake lock through v1 contract) and messes up calculations.
                totalV1Weight += _weight <= storedWeight ? _weight : storedWeight;
                // if _weight has updated in v1 to a lower value, we also update
                // stored weight in v2 for next calculations
                if (storedWeight > _weight) {
                    // if deposit has been completely unstaked in v1, set stake id weight to 1
                    // so we can keep track that it has been already migrated.
                    // otherwise just update value to _weight
                    v1StakesWeights[_staker][stakeId] = _weight == 0 ? 1 : _weight;
                }
            }
        }
    }
    /**
     * @dev Checks if pool is paused.
     * @dev We use this internal function instead of the modifier coming from
     *      Pausable contract in order to decrease contract's bytecode size.
     */
    function _requireNotPaused() internal view virtual {
        // we're using selector to simplify input and state validation
        // internal function simulated selector is `bytes4(keccak256("_requireNotPaused()"))`
        bytes4 fnSelector = 0xabb87a6f;
        // checks paused variable value from Pausable Open Zeppelin
        fnSelector.verifyState(!paused(), 0);
    }
    /**
     * @dev Must be called every time user.totalWeight is changed.
     * @dev Syncs the global pool state, processes the user pending rewards (if any),
     *      and updates check points values stored in the user struct.
     * @dev If user is coming from v1 pool, it expects to receive this v1 user weight
     *      to include in rewards calculations.
     *
     * @param _staker user address
     * @param _v1WeightToAdd v1 weight to be added to calculations
     */
    function _updateReward(address _staker, uint256 _v1WeightToAdd) internal virtual {
        // update pool state
        _sync();
        // gets storage reference to the user
        User storage user = users[_staker];
        // gas savings
        uint256 userTotalWeight = uint256(user.totalWeight) + _v1WeightToAdd;
        // calculates pending yield to be added
        uint256 pendingYield = userTotalWeight.earned(yieldRewardsPerWeight, user.yieldRewardsPerWeightPaid);
        // calculates pending reenue distribution to be added
        uint256 pendingRevDis = userTotalWeight.earned(vaultRewardsPerWeight, user.vaultRewardsPerWeightPaid);
        // increases stored user.pendingYield with value returned
        user.pendingYield += pendingYield.toUint128();
        // increases stored user.pendingRevDis with value returned
        user.pendingRevDis += pendingRevDis.toUint128();
        // updates user checkpoint values for future calculations
        user.yieldRewardsPerWeightPaid = yieldRewardsPerWeight;
        user.vaultRewardsPerWeightPaid = vaultRewardsPerWeight;
        // emit an event
        emit LogUpdateRewards(msg.sender, _staker, pendingYield, pendingRevDis);
    }
    /**
     * @dev See UUPSUpgradeable `_authorizeUpgrade()`.
     * @dev Just checks if `msg.sender` == `factory.owner()` i.e eDAO multisig address.
     * @dev eDAO multisig is responsible by handling upgrades and executing other
     *      admin actions approved by the Council.
     */
    function _authorizeUpgrade(address) internal view virtual override {
        // checks caller is factory.owner()
        _requireIsFactoryController();
    }
    /**
     * @dev Empty reserved space in storage. The size of the __gap array is calculated so that
     *      the amount of storage used by a contract always adds up to the 50.
     *      See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[39] private __gap;
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.4;
/**
 * @title Errors Library.
 *
 * @notice Introduces some very common input and state validation for smart contracts,
 *      such as non-zero input validation, general boolean expression validation, access validation.
 *
 * @notice Throws pre-defined errors instead of string error messages to reduce gas costs.
 *
 * @notice Since the library handles only very common errors, concrete smart contracts may
 *      also introduce their own error types and handling.
 *
 * @author Basil Gorin
 */
library ErrorHandler {
    /**
     * @notice Thrown on zero input at index specified in a function specified.
     *
     * @param fnSelector function selector, defines a function where error was thrown
     * @param paramIndex function parameter index which caused an error thrown
     */
    error ZeroInput(bytes4 fnSelector, uint8 paramIndex);
    /**
     * @notice Thrown on invalid input at index specified in a function specified.
     *
     * @param fnSelector function selector, defines a function where error was thrown
     * @param paramIndex function parameter index which caused an error thrown
     */
    error InvalidInput(bytes4 fnSelector, uint8 paramIndex);
    /**
     * @notice Thrown on invalid state in a function specified.
     *
     * @param fnSelector function selector, defines a function where error was thrown
     * @param errorCode unique error code determining the exact place in code where error was thrown
     */
    error InvalidState(bytes4 fnSelector, uint256 errorCode);
    /**
     * @notice Thrown on invalid access to a function specified.
     *
     * @param fnSelector function selector, defines a function where error was thrown
     * @param addr an address which access was denied, usually transaction sender
     */
    error AccessDenied(bytes4 fnSelector, address addr);
    /**
     * @notice Verifies an input is set (non-zero).
     *
     * @param fnSelector function selector, defines a function which called the verification
     * @param value a value to check if it's set (non-zero)
     * @param paramIndex function parameter index which is verified
     */
    function verifyNonZeroInput(
        bytes4 fnSelector,
        uint256 value,
        uint8 paramIndex
    ) internal pure {
        if (value == 0) {
            revert ZeroInput(fnSelector, paramIndex);
        }
    }
    /**
     * @notice Verifies an input is correct.
     *
     * @param fnSelector function selector, defines a function which called the verification
     * @param expr a boolean expression used to verify the input
     * @param paramIndex function parameter index which is verified
     */
    function verifyInput(
        bytes4 fnSelector,
        bool expr,
        uint8 paramIndex
    ) internal pure {
        if (!expr) {
            revert InvalidInput(fnSelector, paramIndex);
        }
    }
    /**
     * @notice Verifies smart contract state is correct.
     *
     * @param fnSelector function selector, defines a function which called the verification
     * @param expr a boolean expression used to verify the contract state
     * @param errorCode unique error code determining the exact place in code which is verified
     */
    function verifyState(
        bytes4 fnSelector,
        bool expr,
        uint256 errorCode
    ) internal pure {
        if (!expr) {
            revert InvalidState(fnSelector, errorCode);
        }
    }
    /**
     * @notice Verifies an access to the function.
     *
     * @param fnSelector function selector, defines a function which called the verification
     * @param expr a boolean expression used to verify the access
     */
    function verifyAccess(bytes4 fnSelector, bool expr) internal view {
        if (!expr) {
            revert AccessDenied(fnSelector, msg.sender);
        }
    }
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.4;
/**
 * @dev Stake library used by ILV pool and Sushi LP Pool.
 *
 * @dev Responsible to manage weight calculation and store important constants
 *      related to stake period, base weight and multipliers utilized.
 */
library Stake {
    struct Data {
        /// @dev token amount staked
        uint120 value;
        /// @dev locking period - from
        uint64 lockedFrom;
        /// @dev locking period - until
        uint64 lockedUntil;
        /// @dev indicates if the stake was created as a yield reward
        bool isYield;
    }
    /**
     * @dev Stake weight is proportional to stake value and time locked, precisely
     *      "stake value wei multiplied by (fraction of the year locked plus one)".
     * @dev To avoid significant precision loss due to multiplication by "fraction of the year" [0, 1],
     *      weight is stored multiplied by 1e6 constant, as an integer.
     * @dev Corner case 1: if time locked is zero, weight is stake value multiplied by 1e6 + base weight
     * @dev Corner case 2: if time locked is two years, division of
            (lockedUntil - lockedFrom) / MAX_STAKE_PERIOD is 1e6, and
     *      weight is a stake value multiplied by 2 * 1e6.
     */
    uint256 internal constant WEIGHT_MULTIPLIER = 1e6;
    /**
     * @dev Minimum weight value, if result of multiplication using WEIGHT_MULTIPLIER
     *      is 0 (e.g stake flexible), then BASE_WEIGHT is used.
     */
    uint256 internal constant BASE_WEIGHT = 1e6;
    /**
     * @dev Minimum period that someone can lock a stake for.
     */
    uint256 internal constant MIN_STAKE_PERIOD = 30 days;
    /**
     * @dev Maximum period that someone can lock a stake for.
     */
    uint256 internal constant MAX_STAKE_PERIOD = 365 days;
    /**
     * @dev Rewards per weight are stored multiplied by 1e20 as uint.
     */
    uint256 internal constant REWARD_PER_WEIGHT_MULTIPLIER = 1e20;
    /**
     * @dev When we know beforehand that staking is done for yield instead of
     *      executing `weight()` function we use the following constant.
     */
    uint256 internal constant YIELD_STAKE_WEIGHT_MULTIPLIER = 2 * 1e6;
    function weight(Data storage _self) internal view returns (uint256) {
        return
            uint256(
                (((_self.lockedUntil - _self.lockedFrom) * WEIGHT_MULTIPLIER) / MAX_STAKE_PERIOD + BASE_WEIGHT) *
                    _self.value
            );
    }
    /**
     * @dev Converts stake weight (not to be mixed with the pool weight) to
     *      ILV reward value, applying the 10^12 division on weight
     *
     * @param _weight stake weight
     * @param _rewardPerWeight ILV reward per weight
     * @param _rewardPerWeightPaid last reward per weight value used for user earnings
     * @return reward value normalized to 10^12
     */
    function earned(
        uint256 _weight,
        uint256 _rewardPerWeight,
        uint256 _rewardPerWeightPaid
    ) internal pure returns (uint256) {
        // apply the formula and return
        return (_weight * (_rewardPerWeight - _rewardPerWeightPaid)) / REWARD_PER_WEIGHT_MULTIPLIER;
    }
    /**
     * @dev Converts reward ILV value to stake weight (not to be mixed with the pool weight),
     *      applying the 10^12 multiplication on the reward.
     *      - OR -
     * @dev Converts reward ILV value to reward/weight if stake weight is supplied as second
     *      function parameter instead of reward/weight.
     *
     * @param _reward yield reward
     * @param _globalWeight total weight in the pool
     * @return reward per weight value
     */
    function getRewardPerWeight(uint256 _reward, uint256 _globalWeight) internal pure returns (uint256) {
        // apply the reverse formula and return
        return (_reward * REWARD_PER_WEIGHT_MULTIPLIER) / _globalWeight;
    }
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.4;
import { ICorePool } from "./ICorePool.sol";
interface IFactory {
    function owner() external view returns (address);
    function ilvPerSecond() external view returns (uint192);
    function totalWeight() external view returns (uint32);
    function secondsPerUpdate() external view returns (uint32);
    function endTime() external view returns (uint32);
    function lastRatioUpdate() external view returns (uint32);
    function pools(address _poolToken) external view returns (ICorePool);
    function poolExists(address _poolAddress) external view returns (bool);
    function getPoolAddress(address poolToken) external view returns (address);
    function getPoolData(address _poolToken)
        external
        view
        returns (
            address,
            address,
            uint32,
            bool
        );
    function shouldUpdateRatio() external view returns (bool);
    function registerPool(ICorePool pool) external;
    function updateILVPerSecond() external;
    function mintYieldTo(
        address _to,
        uint256 _value,
        bool _useSILV
    ) external;
    function changePoolWeight(address pool, uint32 weight) external;
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.4;
import { Stake } from "../libraries/Stake.sol";
interface ICorePool {
    function users(address _user)
        external
        view
        returns (
            uint128,
            uint128,
            uint128,
            uint248,
            uint8,
            uint256,
            uint256
        );
    function poolToken() external view returns (address);
    function isFlashPool() external view returns (bool);
    function weight() external view returns (uint32);
    function lastYieldDistribution() external view returns (uint64);
    function yieldRewardsPerWeight() external view returns (uint256);
    function globalWeight() external view returns (uint256);
    function pendingRewards(address _user) external view returns (uint256, uint256);
    function poolTokenReserve() external view returns (uint256);
    function balanceOf(address _user) external view returns (uint256);
    function getTotalReserves() external view returns (uint256);
    function getStake(address _user, uint256 _stakeId) external view returns (Stake.Data memory);
    function getStakesLength(address _user) external view returns (uint256);
    function sync() external;
    function setWeight(uint32 _weight) external;
    function receiveVaultRewards(uint256 value) external;
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.4;
interface ICorePoolV1 {
    struct V1Stake {
        // @dev token amount staked
        uint256 tokenAmount;
        // @dev stake weight
        uint256 weight;
        // @dev locking period - from
        uint64 lockedFrom;
        // @dev locking period - until
        uint64 lockedUntil;
        // @dev indicates if the stake was created as a yield reward
        bool isYield;
    }
    struct V1User {
        // @dev Total staked amount
        uint256 tokenAmount;
        // @dev Total weight
        uint256 totalWeight;
        // @dev Auxiliary variable for yield calculation
        uint256 subYieldRewards;
        // @dev Auxiliary variable for vault rewards calculation
        uint256 subVaultRewards;
        // @dev An array of holder's deposits
        V1Stake[] deposits;
    }
    function users(address _who)
        external
        view
        returns (
            uint256,
            uint256,
            uint256,
            uint256
        );
    function getDeposit(address _from, uint256 _stakeId)
        external
        view
        returns (
            uint256,
            uint256,
            uint64,
            uint64,
            bool
        );
    function poolToken() external view returns (address);
    function usersLockingWeight() external view returns (uint256);
    function poolTokenReserve() external view returns (uint256);
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.4;
import { Initializable } from "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
import { V2Migrator } from "./base/V2Migrator.sol";
import { CorePool } from "./base/CorePool.sol";
import { ErrorHandler } from "./libraries/ErrorHandler.sol";
import { ICorePoolV1 } from "./interfaces/ICorePoolV1.sol";
/**
 * @title The Sushi LP Pool.
 *
 * @dev Extends all functionality from V2Migrator contract, there isn't a lot of
 *      additions compared to ILV pool. Sushi LP pool basically needs to be able
 *      to be called by ILV pool in batch calls where we claim rewards from multiple
 *      pools.
 */
contract SushiLPPool is Initializable, V2Migrator {
    using ErrorHandler for bytes4;
    /// @dev Calls __V2Migrator_init().
    function initialize(
        address ilv_,
        address silv_,
        address _poolToken,
        address _factory,
        uint64 _initTime,
        uint32 _weight,
        address _corePoolV1,
        uint256 v1StakeMaxPeriod_
    ) external initializer {
        __V2Migrator_init(ilv_, silv_, _poolToken, _corePoolV1, _factory, _initTime, _weight, v1StakeMaxPeriod_);
    }
    /// @inheritdoc CorePool
    function getTotalReserves() external view virtual override returns (uint256 totalReserves) {
        totalReserves = poolTokenReserve + ICorePoolV1(corePoolV1).poolTokenReserve();
    }
    /**
     * @notice This function can be called only by ILV core pool.
     *
     * @dev Uses ILV pool as a router by receiving the _staker address and executing
     *      the internal `_claimYieldRewards()`.
     * @dev Its usage allows claiming multiple pool contracts in one transaction.
     *
     * @param _staker user address
     * @param _useSILV whether it should claim pendingYield as ILV or sILV
     */
    function claimYieldRewardsFromRouter(address _staker, bool _useSILV) external virtual {
        // checks if contract is paused
        _requireNotPaused();
        // checks if caller is the ILV pool
        _requirePoolIsValid();
        // calls internal _claimYieldRewards function (in CorePool.sol)
        _claimYieldRewards(_staker, _useSILV);
    }
    /**
     * @notice This function can be called only by ILV core pool.
     *
     * @dev Uses ILV pool as a router by receiving the _staker address and executing
     *      the internal `_claimVaultRewards()`.
     * @dev Its usage allows claiming multiple pool contracts in one transaction.
     *
     * @param _staker user address
     */
    function claimVaultRewardsFromRouter(address _staker) external virtual {
        // checks if contract is paused
        _requireNotPaused();
        // checks if caller is the ILV pool
        _requirePoolIsValid();
        // calls internal _claimVaultRewards function (in CorePool.sol)
        _claimVaultRewards(_staker);
    }
    /**
     * @dev Checks if caller is ILV pool.
     * @dev We are using an internal function instead of a modifier in order to
     *      reduce the contract's bytecode size.
     */
    function _requirePoolIsValid() internal view virtual {
        // we're using selector to simplify input and state validation
        // internal function simulated selector is `bytes4(keccak256("_requirePoolIsValid()"))`
        bytes4 fnSelector = 0x250f303f;
        // checks if pool is the ILV pool
        bool poolIsValid = address(_factory.pools(_ilv)) == msg.sender;
        fnSelector.verifyState(poolIsValid, 0);
    }
    /**
     * @dev Empty reserved space in storage. The size of the __gap array is calculated so that
     *      the amount of storage used by a contract always adds up to the 50.
     *      See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[50] private __gap;
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
 * @dev Collection of functions related to the address type
 */
library AddressUpgradeable {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize, which returns 0 for contracts in
        // construction, since the code is only stored at the end of the
        // constructor execution.
        uint256 size;
        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");
        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }
    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain `call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCall(target, data, "Address: low-level call failed");
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }
    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        require(isContract(target), "Address: call to non-contract");
        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResult(success, returndata, errorMessage);
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");
        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }
    /**
     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason 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 {
            // 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
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "../ERC1967/ERC1967UpgradeUpgradeable.sol";
import "./Initializable.sol";
/**
 * @dev An upgradeability mechanism designed for UUPS proxies. The functions included here can perform an upgrade of an
 * {ERC1967Proxy}, when this contract is set as the implementation behind such a proxy.
 *
 * A security mechanism ensures that an upgrade does not turn off upgradeability accidentally, although this risk is
 * reinstated if the upgrade retains upgradeability but removes the security mechanism, e.g. by replacing
 * `UUPSUpgradeable` with a custom implementation of upgrades.
 *
 * The {_authorizeUpgrade} function must be overridden to include access restriction to the upgrade mechanism.
 *
 * _Available since v4.1._
 */
abstract contract UUPSUpgradeable is Initializable, ERC1967UpgradeUpgradeable {
    function __UUPSUpgradeable_init() internal initializer {
        __ERC1967Upgrade_init_unchained();
        __UUPSUpgradeable_init_unchained();
    }
    function __UUPSUpgradeable_init_unchained() internal initializer {
    }
    /// @custom:oz-upgrades-unsafe-allow state-variable-immutable state-variable-assignment
    address private immutable __self = address(this);
    /**
     * @dev Check that the execution is being performed through a delegatecall call and that the execution context is
     * a proxy contract with an implementation (as defined in ERC1967) pointing to self. This should only be the case
     * for UUPS and transparent proxies that are using the current contract as their implementation. Execution of a
     * function through ERC1167 minimal proxies (clones) would not normally pass this test, but is not guaranteed to
     * fail.
     */
    modifier onlyProxy() {
        require(address(this) != __self, "Function must be called through delegatecall");
        require(_getImplementation() == __self, "Function must be called through active proxy");
        _;
    }
    /**
     * @dev Upgrade the implementation of the proxy to `newImplementation`.
     *
     * Calls {_authorizeUpgrade}.
     *
     * Emits an {Upgraded} event.
     */
    function upgradeTo(address newImplementation) external virtual onlyProxy {
        _authorizeUpgrade(newImplementation);
        _upgradeToAndCallSecure(newImplementation, new bytes(0), false);
    }
    /**
     * @dev Upgrade the implementation of the proxy to `newImplementation`, and subsequently execute the function call
     * encoded in `data`.
     *
     * Calls {_authorizeUpgrade}.
     *
     * Emits an {Upgraded} event.
     */
    function upgradeToAndCall(address newImplementation, bytes memory data) external payable virtual onlyProxy {
        _authorizeUpgrade(newImplementation);
        _upgradeToAndCallSecure(newImplementation, data, true);
    }
    /**
     * @dev Function that should revert when `msg.sender` is not authorized to upgrade the contract. Called by
     * {upgradeTo} and {upgradeToAndCall}.
     *
     * Normally, this function will use an xref:access.adoc[access control] modifier such as {Ownable-onlyOwner}.
     *
     * ```solidity
     * function _authorizeUpgrade(address) internal override onlyOwner {}
     * ```
     */
    function _authorizeUpgrade(address newImplementation) internal virtual;
    uint256[50] private __gap;
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "../proxy/utils/Initializable.sol";
/**
 * @dev Contract module that helps prevent reentrant calls to a function.
 *
 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
 * available, which can be applied to functions to make sure there are no nested
 * (reentrant) calls to them.
 *
 * Note that because there is a single `nonReentrant` guard, functions marked as
 * `nonReentrant` may not call one another. This can be worked around by making
 * those functions `private`, and then adding `external` `nonReentrant` entry
 * points to them.
 *
 * TIP: If you would like to learn more about reentrancy and alternative ways
 * to protect against it, check out our blog post
 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
 */
abstract contract ReentrancyGuardUpgradeable is Initializable {
    // 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;
    function __ReentrancyGuard_init() internal initializer {
        __ReentrancyGuard_init_unchained();
    }
    function __ReentrancyGuard_init_unchained() internal initializer {
        _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;
    }
    uint256[49] private __gap;
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "../utils/ContextUpgradeable.sol";
import "../proxy/utils/Initializable.sol";
/**
 * @dev Contract module which allows children to implement an emergency stop
 * mechanism that can be triggered by an authorized account.
 *
 * This module is used through inheritance. It will make available the
 * modifiers `whenNotPaused` and `whenPaused`, which can be applied to
 * the functions of your contract. Note that they will not be pausable by
 * simply including this module, only once the modifiers are put in place.
 */
abstract contract PausableUpgradeable is Initializable, ContextUpgradeable {
    /**
     * @dev Emitted when the pause is triggered by `account`.
     */
    event Paused(address account);
    /**
     * @dev Emitted when the pause is lifted by `account`.
     */
    event Unpaused(address account);
    bool private _paused;
    /**
     * @dev Initializes the contract in unpaused state.
     */
    function __Pausable_init() internal initializer {
        __Context_init_unchained();
        __Pausable_init_unchained();
    }
    function __Pausable_init_unchained() internal initializer {
        _paused = false;
    }
    /**
     * @dev Returns true if the contract is paused, and false otherwise.
     */
    function paused() public view virtual returns (bool) {
        return _paused;
    }
    /**
     * @dev Modifier to make a function callable only when the contract is not paused.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    modifier whenNotPaused() {
        require(!paused(), "Pausable: paused");
        _;
    }
    /**
     * @dev Modifier to make a function callable only when the contract is paused.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    modifier whenPaused() {
        require(paused(), "Pausable: not paused");
        _;
    }
    /**
     * @dev Triggers stopped state.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    function _pause() internal virtual whenNotPaused {
        _paused = true;
        emit Paused(_msgSender());
    }
    /**
     * @dev Returns to normal state.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    function _unpause() internal virtual whenPaused {
        _paused = false;
        emit Unpaused(_msgSender());
    }
    uint256[49] private __gap;
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.4;
/// @title Function for getting block timestamp.
/// @dev Base contract that is overridden for tests.
abstract contract Timestamp {
    /**
     * @dev Testing time-dependent functionality is difficult and the best way of
     *      doing it is to override time in helper test smart contracts.
     *
     * @return `block.timestamp` in mainnet, custom values in testnets (if overridden).
     */
    function _now256() internal view virtual returns (uint256) {
        // return current block timestamp
        return block.timestamp;
    }
    /**
     * @dev Empty reserved space in storage. The size of the __gap array is calculated so that
     *      the amount of storage used by a contract always adds up to the 50.
     *      See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[50] private __gap;
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.4;
import { Initializable } from "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
import { FactoryControlled } from "./FactoryControlled.sol";
import { ErrorHandler } from "../libraries/ErrorHandler.sol";
abstract contract VaultRecipient is Initializable, FactoryControlled {
    using ErrorHandler for bytes4;
    /// @dev Link to deployed IlluviumVault instance.
    address internal _vault;
    /// @dev Used to calculate vault rewards.
    /// @dev This value is different from "reward per token" used in locked pool.
    /// @dev Note: stakes are different in duration and "weight" reflects that,
    uint256 public vaultRewardsPerWeight;
    /**
     * @dev Fired in `setVault()`.
     *
     * @param by an address which executed the function, always a factory owner
     * @param previousVault previous vault contract address
     * @param newVault new vault address
     */
    event LogSetVault(address indexed by, address previousVault, address newVault);
    /**
     * @dev Executed only by the factory owner to Set the vault.
     *
     * @param vault_ an address of deployed IlluviumVault instance
     */
    function setVault(address vault_) external virtual {
        // we're using selector to simplify input and state validation
        bytes4 fnSelector = this.setVault.selector;
        // verify function is executed by the factory owner
        fnSelector.verifyState(_factory.owner() == msg.sender, 0);
        // verify input is set
        fnSelector.verifyInput(vault_ != address(0), 0);
        // saves current vault to memory
        address previousVault = vault_;
        // update vault address
        _vault = vault_;
        // emit an event
        emit LogSetVault(msg.sender, previousVault, _vault);
    }
    /// @dev Utility function to check if caller is the Vault contract
    function _requireIsVault() internal view virtual {
        // we're using selector to simplify input and state validation
        // internal function simulated selector is `bytes4(keccak256("_requireIsVault()"))`
        bytes4 fnSelector = 0xeeea774b;
        // checks if caller is the same stored vault address
        fnSelector.verifyAccess(msg.sender == _vault);
    }
    /**
     * @dev Empty reserved space in storage. The size of the __gap array is calculated so that
     *      the amount of storage used by a contract always adds up to the 50.
     *      See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[48] private __gap;
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.4;
import { ICorePool } from "./ICorePool.sol";
interface IILVPool is ICorePool {
    function stakeAsPool(address _staker, uint256 _value) external;
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.2;
import "../beacon/IBeaconUpgradeable.sol";
import "../../utils/AddressUpgradeable.sol";
import "../../utils/StorageSlotUpgradeable.sol";
import "../utils/Initializable.sol";
/**
 * @dev This abstract contract provides getters and event emitting update functions for
 * https://eips.ethereum.org/EIPS/eip-1967[EIP1967] slots.
 *
 * _Available since v4.1._
 *
 * @custom:oz-upgrades-unsafe-allow delegatecall
 */
abstract contract ERC1967UpgradeUpgradeable is Initializable {
    function __ERC1967Upgrade_init() internal initializer {
        __ERC1967Upgrade_init_unchained();
    }
    function __ERC1967Upgrade_init_unchained() internal initializer {
    }
    // This is the keccak-256 hash of "eip1967.proxy.rollback" subtracted by 1
    bytes32 private constant _ROLLBACK_SLOT = 0x4910fdfa16fed3260ed0e7147f7cc6da11a60208b5b9406d12a635614ffd9143;
    /**
     * @dev Storage slot with the address of the current implementation.
     * This is the keccak-256 hash of "eip1967.proxy.implementation" subtracted by 1, and is
     * validated in the constructor.
     */
    bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
    /**
     * @dev Emitted when the implementation is upgraded.
     */
    event Upgraded(address indexed implementation);
    /**
     * @dev Returns the current implementation address.
     */
    function _getImplementation() internal view returns (address) {
        return StorageSlotUpgradeable.getAddressSlot(_IMPLEMENTATION_SLOT).value;
    }
    /**
     * @dev Stores a new address in the EIP1967 implementation slot.
     */
    function _setImplementation(address newImplementation) private {
        require(AddressUpgradeable.isContract(newImplementation), "ERC1967: new implementation is not a contract");
        StorageSlotUpgradeable.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
    }
    /**
     * @dev Perform implementation upgrade
     *
     * Emits an {Upgraded} event.
     */
    function _upgradeTo(address newImplementation) internal {
        _setImplementation(newImplementation);
        emit Upgraded(newImplementation);
    }
    /**
     * @dev Perform implementation upgrade with additional setup call.
     *
     * Emits an {Upgraded} event.
     */
    function _upgradeToAndCall(
        address newImplementation,
        bytes memory data,
        bool forceCall
    ) internal {
        _upgradeTo(newImplementation);
        if (data.length > 0 || forceCall) {
            _functionDelegateCall(newImplementation, data);
        }
    }
    /**
     * @dev Perform implementation upgrade with security checks for UUPS proxies, and additional setup call.
     *
     * Emits an {Upgraded} event.
     */
    function _upgradeToAndCallSecure(
        address newImplementation,
        bytes memory data,
        bool forceCall
    ) internal {
        address oldImplementation = _getImplementation();
        // Initial upgrade and setup call
        _setImplementation(newImplementation);
        if (data.length > 0 || forceCall) {
            _functionDelegateCall(newImplementation, data);
        }
        // Perform rollback test if not already in progress
        StorageSlotUpgradeable.BooleanSlot storage rollbackTesting = StorageSlotUpgradeable.getBooleanSlot(_ROLLBACK_SLOT);
        if (!rollbackTesting.value) {
            // Trigger rollback using upgradeTo from the new implementation
            rollbackTesting.value = true;
            _functionDelegateCall(
                newImplementation,
                abi.encodeWithSignature("upgradeTo(address)", oldImplementation)
            );
            rollbackTesting.value = false;
            // Check rollback was effective
            require(oldImplementation == _getImplementation(), "ERC1967Upgrade: upgrade breaks further upgrades");
            // Finally reset to the new implementation and log the upgrade
            _upgradeTo(newImplementation);
        }
    }
    /**
     * @dev Storage slot with the admin of the contract.
     * This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is
     * validated in the constructor.
     */
    bytes32 internal constant _ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;
    /**
     * @dev Emitted when the admin account has changed.
     */
    event AdminChanged(address previousAdmin, address newAdmin);
    /**
     * @dev Returns the current admin.
     */
    function _getAdmin() internal view returns (address) {
        return StorageSlotUpgradeable.getAddressSlot(_ADMIN_SLOT).value;
    }
    /**
     * @dev Stores a new address in the EIP1967 admin slot.
     */
    function _setAdmin(address newAdmin) private {
        require(newAdmin != address(0), "ERC1967: new admin is the zero address");
        StorageSlotUpgradeable.getAddressSlot(_ADMIN_SLOT).value = newAdmin;
    }
    /**
     * @dev Changes the admin of the proxy.
     *
     * Emits an {AdminChanged} event.
     */
    function _changeAdmin(address newAdmin) internal {
        emit AdminChanged(_getAdmin(), newAdmin);
        _setAdmin(newAdmin);
    }
    /**
     * @dev The storage slot of the UpgradeableBeacon contract which defines the implementation for this proxy.
     * This is bytes32(uint256(keccak256('eip1967.proxy.beacon')) - 1)) and is validated in the constructor.
     */
    bytes32 internal constant _BEACON_SLOT = 0xa3f0ad74e5423aebfd80d3ef4346578335a9a72aeaee59ff6cb3582b35133d50;
    /**
     * @dev Emitted when the beacon is upgraded.
     */
    event BeaconUpgraded(address indexed beacon);
    /**
     * @dev Returns the current beacon.
     */
    function _getBeacon() internal view returns (address) {
        return StorageSlotUpgradeable.getAddressSlot(_BEACON_SLOT).value;
    }
    /**
     * @dev Stores a new beacon in the EIP1967 beacon slot.
     */
    function _setBeacon(address newBeacon) private {
        require(AddressUpgradeable.isContract(newBeacon), "ERC1967: new beacon is not a contract");
        require(
            AddressUpgradeable.isContract(IBeaconUpgradeable(newBeacon).implementation()),
            "ERC1967: beacon implementation is not a contract"
        );
        StorageSlotUpgradeable.getAddressSlot(_BEACON_SLOT).value = newBeacon;
    }
    /**
     * @dev Perform beacon upgrade with additional setup call. Note: This upgrades the address of the beacon, it does
     * not upgrade the implementation contained in the beacon (see {UpgradeableBeacon-_setImplementation} for that).
     *
     * Emits a {BeaconUpgraded} event.
     */
    function _upgradeBeaconToAndCall(
        address newBeacon,
        bytes memory data,
        bool forceCall
    ) internal {
        _setBeacon(newBeacon);
        emit BeaconUpgraded(newBeacon);
        if (data.length > 0 || forceCall) {
            _functionDelegateCall(IBeaconUpgradeable(newBeacon).implementation(), data);
        }
    }
    /**
     * @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) private returns (bytes memory) {
        require(AddressUpgradeable.isContract(target), "Address: delegate call to non-contract");
        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return AddressUpgradeable.verifyCallResult(success, returndata, "Address: low-level delegate call failed");
    }
    uint256[50] private __gap;
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
 * @dev This is the interface that {BeaconProxy} expects of its beacon.
 */
interface IBeaconUpgradeable {
    /**
     * @dev Must return an address that can be used as a delegate call target.
     *
     * {BeaconProxy} will check that this address is a contract.
     */
    function implementation() external view returns (address);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
 * @dev Library for reading and writing primitive types to specific storage slots.
 *
 * Storage slots are often used to avoid storage conflict when dealing with upgradeable contracts.
 * This library helps with reading and writing to such slots without the need for inline assembly.
 *
 * The functions in this library return Slot structs that contain a `value` member that can be used to read or write.
 *
 * Example usage to set ERC1967 implementation slot:
 * ```
 * contract ERC1967 {
 *     bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
 *
 *     function _getImplementation() internal view returns (address) {
 *         return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
 *     }
 *
 *     function _setImplementation(address newImplementation) internal {
 *         require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
 *         StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
 *     }
 * }
 * ```
 *
 * _Available since v4.1 for `address`, `bool`, `bytes32`, and `uint256`._
 */
library StorageSlotUpgradeable {
    struct AddressSlot {
        address value;
    }
    struct BooleanSlot {
        bool value;
    }
    struct Bytes32Slot {
        bytes32 value;
    }
    struct Uint256Slot {
        uint256 value;
    }
    /**
     * @dev Returns an `AddressSlot` with member `value` located at `slot`.
     */
    function getAddressSlot(bytes32 slot) internal pure returns (AddressSlot storage r) {
        assembly {
            r.slot := slot
        }
    }
    /**
     * @dev Returns an `BooleanSlot` with member `value` located at `slot`.
     */
    function getBooleanSlot(bytes32 slot) internal pure returns (BooleanSlot storage r) {
        assembly {
            r.slot := slot
        }
    }
    /**
     * @dev Returns an `Bytes32Slot` with member `value` located at `slot`.
     */
    function getBytes32Slot(bytes32 slot) internal pure returns (Bytes32Slot storage r) {
        assembly {
            r.slot := slot
        }
    }
    /**
     * @dev Returns an `Uint256Slot` with member `value` located at `slot`.
     */
    function getUint256Slot(bytes32 slot) internal pure returns (Uint256Slot storage r) {
        assembly {
            r.slot := slot
        }
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "../proxy/utils/Initializable.sol";
/**
 * @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 ContextUpgradeable is Initializable {
    function __Context_init() internal initializer {
        __Context_init_unchained();
    }
    function __Context_init_unchained() internal initializer {
    }
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }
    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
    uint256[50] private __gap;
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.4;
import { Initializable } from "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
import { IFactory } from "../interfaces/IFactory.sol";
import { ErrorHandler } from "../libraries/ErrorHandler.sol";
/**
 * @title FactoryControlled
 *
 * @dev Abstract smart contract responsible to hold IFactory factory address.
 * @dev Stores PoolFactory address on initialization.
 *
 */
abstract contract FactoryControlled is Initializable {
    using ErrorHandler for bytes4;
    /// @dev Link to the pool factory IlluviumPoolFactory instance.
    IFactory internal _factory;
    /// @dev Attachs PoolFactory address to the FactoryControlled contract.
    function __FactoryControlled_init(address factory_) internal initializer {
        // we're using selector to simplify input and state validation
        // internal function simulated selector is `bytes4(keccak256("__FactoryControlled_init(address)"))`
        bytes4 fnSelector = 0xbb6c0dbf;
        fnSelector.verifyNonZeroInput(uint160(factory_), 0);
        _factory = IFactory(factory_);
    }
    /// @dev checks if caller is factory admin (eDAO multisig address).
    function _requireIsFactoryController() internal view virtual {
        // we're using selector to simplify input and state validation
        // internal function simulated selector is `bytes4(keccak256("_requireIsFactoryController()"))`
        bytes4 fnSelector = 0x39e71deb;
        fnSelector.verifyAccess(msg.sender == _factory.owner());
    }
    /**
     * @dev Empty reserved space in storage. The size of the __gap array is calculated so that
     *      the amount of storage used by a contract always adds up to the 50.
     *      See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[49] private __gap;
}

// SPDX-License-Identifier: MIT
pragma solidity 0.8.1;
import "./IlluviumPoolBase.sol";
/**
 * @title Illuvium Core Pool
 *
 * @notice Core pools represent permanent pools like ILV or ILV/ETH Pair pool,
 *      core pools allow staking for arbitrary periods of time up to 1 year
 *
 * @dev See IlluviumPoolBase for more details
 *
 * @author Pedro Bergamini, reviewed by Basil Gorin
 */
contract IlluviumCorePool is IlluviumPoolBase {
    /// @dev Flag indicating pool type, false means "core pool"
    bool public constant override isFlashPool = false;
    /// @dev Link to deployed IlluviumVault instance
    address public vault;
    /// @dev Used to calculate vault rewards
    /// @dev This value is different from "reward per token" used in locked pool
    /// @dev Note: stakes are different in duration and "weight" reflects that
    uint256 public vaultRewardsPerWeight;
    /// @dev Pool tokens value available in the pool;
    ///      pool token examples are ILV (ILV core pool) or ILV/ETH pair (LP core pool)
    /// @dev For LP core pool this value doesnt' count for ILV tokens received as Vault rewards
    ///      while for ILV core pool it does count for such tokens as well
    uint256 public poolTokenReserve;
    /**
     * @dev Fired in receiveVaultRewards()
     *
     * @param _by an address that sent the rewards, always a vault
     * @param amount amount of tokens received
     */
    event VaultRewardsReceived(address indexed _by, uint256 amount);
    /**
     * @dev Fired in _processVaultRewards() and dependent functions, like processRewards()
     *
     * @param _by an address which executed the function
     * @param _to an address which received a reward
     * @param amount amount of reward received
     */
    event VaultRewardsClaimed(address indexed _by, address indexed _to, uint256 amount);
    /**
     * @dev Fired in setVault()
     *
     * @param _by an address which executed the function, always a factory owner
     */
    event VaultUpdated(address indexed _by, address _fromVal, address _toVal);
    /**
     * @dev Creates/deploys an instance of the core pool
     *
     * @param _ilv ILV ERC20 Token IlluviumERC20 address
     * @param _silv sILV ERC20 Token EscrowedIlluviumERC20 address
     * @param _factory Pool factory IlluviumPoolFactory instance/address
     * @param _poolToken token the pool operates on, for example ILV or ILV/ETH pair
     * @param _initBlock initial block used to calculate the rewards
     * @param _weight number representing a weight of the pool, actual weight fraction
     *      is calculated as that number divided by the total pools weight and doesn't exceed one
     */
    constructor(
        address _ilv,
        address _silv,
        IlluviumPoolFactory _factory,
        address _poolToken,
        uint64 _initBlock,
        uint32 _weight
    ) IlluviumPoolBase(_ilv, _silv, _factory, _poolToken, _initBlock, _weight) {}
    /**
     * @notice Calculates current vault rewards value available for address specified
     *
     * @dev Performs calculations based on current smart contract state only,
     *      not taking into account any additional time/blocks which might have passed
     *
     * @param _staker an address to calculate vault rewards value for
     * @return pending calculated vault reward value for the given address
     */
    function pendingVaultRewards(address _staker) public view returns (uint256 pending) {
        User memory user = users[_staker];
        return weightToReward(user.totalWeight, vaultRewardsPerWeight) - user.subVaultRewards;
    }
    /**
     * @dev Executed only by the factory owner to Set the vault
     *
     * @param _vault an address of deployed IlluviumVault instance
     */
    function setVault(address _vault) external {
        // verify function is executed by the factory owner
        require(factory.owner() == msg.sender, "access denied");
        // verify input is set
        require(_vault != address(0), "zero input");
        // emit an event
        emit VaultUpdated(msg.sender, vault, _vault);
        // update vault address
        vault = _vault;
    }
    /**
     * @dev Executed by the vault to transfer vault rewards ILV from the vault
     *      into the pool
     *
     * @dev This function is executed only for ILV core pools
     *
     * @param _rewardsAmount amount of ILV rewards to transfer into the pool
     */
    function receiveVaultRewards(uint256 _rewardsAmount) external {
        require(msg.sender == vault, "access denied");
        // return silently if there is no reward to receive
        if (_rewardsAmount == 0) {
            return;
        }
        require(usersLockingWeight > 0, "zero locking weight");
        transferIlvFrom(msg.sender, address(this), _rewardsAmount);
        vaultRewardsPerWeight += rewardToWeight(_rewardsAmount, usersLockingWeight);
        // update `poolTokenReserve` only if this is a ILV Core Pool
        if (poolToken == ilv) {
            poolTokenReserve += _rewardsAmount;
        }
        emit VaultRewardsReceived(msg.sender, _rewardsAmount);
    }
    /**
     * @notice Service function to calculate and pay pending vault and yield rewards to the sender
     *
     * @dev Internally executes similar function `_processRewards` from the parent smart contract
     *      to calculate and pay yield rewards; adds vault rewards processing
     *
     * @dev Can be executed by anyone at any time, but has an effect only when
     *      executed by deposit holder and when at least one block passes from the
     *      previous reward processing
     * @dev Executed internally when "staking as a pool" (`stakeAsPool`)
     * @dev When timing conditions are not met (executed too frequently, or after factory
     *      end block), function doesn't throw and exits silently
     *
     * @dev _useSILV flag has a context of yield rewards only
     *
     * @param _useSILV flag indicating whether to mint sILV token as a reward or not;
     *      when set to true - sILV reward is minted immediately and sent to sender,
     *      when set to false - new ILV reward deposit gets created if pool is an ILV pool
     *      (poolToken is ILV token), or new pool deposit gets created together with sILV minted
     *      when pool is not an ILV pool (poolToken is not an ILV token)
     */
    function processRewards(bool _useSILV) external override {
        _processRewards(msg.sender, _useSILV, true);
    }
    /**
     * @dev Executed internally by the pool itself (from the parent `IlluviumPoolBase` smart contract)
     *      as part of yield rewards processing logic (`IlluviumPoolBase._processRewards` function)
     * @dev Executed when _useSILV is false and pool is not an ILV pool - see `IlluviumPoolBase._processRewards`
     *
     * @param _staker an address which stakes (the yield reward)
     * @param _amount amount to be staked (yield reward amount)
     */
    function stakeAsPool(address _staker, uint256 _amount) external {
        require(factory.poolExists(msg.sender), "access denied");
        _sync();
        User storage user = users[_staker];
        if (user.tokenAmount > 0) {
            _processRewards(_staker, true, false);
        }
        uint256 depositWeight = _amount * YEAR_STAKE_WEIGHT_MULTIPLIER;
        Deposit memory newDeposit =
            Deposit({
                tokenAmount: _amount,
                lockedFrom: uint64(now256()),
                lockedUntil: uint64(now256() + 365 days),
                weight: depositWeight,
                isYield: true
            });
        user.tokenAmount += _amount;
        user.totalWeight += depositWeight;
        user.deposits.push(newDeposit);
        usersLockingWeight += depositWeight;
        user.subYieldRewards = weightToReward(user.totalWeight, yieldRewardsPerWeight);
        user.subVaultRewards = weightToReward(user.totalWeight, vaultRewardsPerWeight);
        // update `poolTokenReserve` only if this is a LP Core Pool (stakeAsPool can be executed only for LP pool)
        poolTokenReserve += _amount;
    }
    /**
     * @inheritdoc IlluviumPoolBase
     *
     * @dev Additionally to the parent smart contract, updates vault rewards of the holder,
     *      and updates (increases) pool token reserve (pool tokens value available in the pool)
     */
    function _stake(
        address _staker,
        uint256 _amount,
        uint64 _lockedUntil,
        bool _useSILV,
        bool _isYield
    ) internal override {
        super._stake(_staker, _amount, _lockedUntil, _useSILV, _isYield);
        User storage user = users[_staker];
        user.subVaultRewards = weightToReward(user.totalWeight, vaultRewardsPerWeight);
        poolTokenReserve += _amount;
    }
    /**
     * @inheritdoc IlluviumPoolBase
     *
     * @dev Additionally to the parent smart contract, updates vault rewards of the holder,
     *      and updates (decreases) pool token reserve (pool tokens value available in the pool)
     */
    function _unstake(
        address _staker,
        uint256 _depositId,
        uint256 _amount,
        bool _useSILV
    ) internal override {
        User storage user = users[_staker];
        Deposit memory stakeDeposit = user.deposits[_depositId];
        require(stakeDeposit.lockedFrom == 0 || now256() > stakeDeposit.lockedUntil, "deposit not yet unlocked");
        poolTokenReserve -= _amount;
        super._unstake(_staker, _depositId, _amount, _useSILV);
        user.subVaultRewards = weightToReward(user.totalWeight, vaultRewardsPerWeight);
    }
    /**
     * @inheritdoc IlluviumPoolBase
     *
     * @dev Additionally to the parent smart contract, processes vault rewards of the holder,
     *      and for ILV pool updates (increases) pool token reserve (pool tokens value available in the pool)
     */
    function _processRewards(
        address _staker,
        bool _useSILV,
        bool _withUpdate
    ) internal override returns (uint256 pendingYield) {
        _processVaultRewards(_staker);
        pendingYield = super._processRewards(_staker, _useSILV, _withUpdate);
        // update `poolTokenReserve` only if this is a ILV Core Pool
        if (poolToken == ilv && !_useSILV) {
            poolTokenReserve += pendingYield;
        }
    }
    /**
     * @dev Used internally to process vault rewards for the staker
     *
     * @param _staker address of the user (staker) to process rewards for
     */
    function _processVaultRewards(address _staker) private {
        User storage user = users[_staker];
        uint256 pendingVaultClaim = pendingVaultRewards(_staker);
        if (pendingVaultClaim == 0) return;
        // read ILV token balance of the pool via standard ERC20 interface
        uint256 ilvBalance = IERC20(ilv).balanceOf(address(this));
        require(ilvBalance >= pendingVaultClaim, "contract ILV balance too low");
        // update `poolTokenReserve` only if this is a ILV Core Pool
        if (poolToken == ilv) {
            // protects against rounding errors
            poolTokenReserve -= pendingVaultClaim > poolTokenReserve ? poolTokenReserve : pendingVaultClaim;
        }
        user.subVaultRewards = weightToReward(user.totalWeight, vaultRewardsPerWeight);
        // transfer fails if pool ILV balance is not enough - which is a desired behavior
        transferIlv(_staker, pendingVaultClaim);
        emit VaultRewardsClaimed(msg.sender, _staker, pendingVaultClaim);
    }
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.1;
import "../interfaces/IPool.sol";
import "../interfaces/ICorePool.sol";
import "./ReentrancyGuard.sol";
import "./IlluviumPoolFactory.sol";
import "../utils/SafeERC20.sol";
import "../token/EscrowedIlluviumERC20.sol";
/**
 * @title Illuvium Pool Base
 *
 * @notice An abstract contract containing common logic for any pool,
 *      be it a flash pool (temporary pool like SNX) or a core pool (permanent pool like ILV/ETH or ILV pool)
 *
 * @dev Deployment and initialization.
 *      Any pool deployed must be bound to the deployed pool factory (IlluviumPoolFactory)
 *      Additionally, 3 token instance addresses must be defined on deployment:
 *          - ILV token address
 *          - sILV token address, used to mint sILV rewards
 *          - pool token address, it can be ILV token address, ILV/ETH pair address, and others
 *
 * @dev Pool weight defines the fraction of the yield current pool receives among the other pools,
 *      pool factory is responsible for the weight synchronization between the pools.
 * @dev The weight is logically 10% for ILV pool and 90% for ILV/ETH pool.
 *      Since Solidity doesn't support fractions the weight is defined by the division of
 *      pool weight by total pools weight (sum of all registered pools within the factory)
 * @dev For ILV Pool we use 100 as weight and for ILV/ETH pool - 900.
 *
 * @author Pedro Bergamini, reviewed by Basil Gorin
 */
abstract contract IlluviumPoolBase is IPool, IlluviumAware, ReentrancyGuard {
    /// @dev Data structure representing token holder using a pool
    struct User {
        // @dev Total staked amount
        uint256 tokenAmount;
        // @dev Total weight
        uint256 totalWeight;
        // @dev Auxiliary variable for yield calculation
        uint256 subYieldRewards;
        // @dev Auxiliary variable for vault rewards calculation
        uint256 subVaultRewards;
        // @dev An array of holder's deposits
        Deposit[] deposits;
    }
    /// @dev Token holder storage, maps token holder address to their data record
    mapping(address => User) public users;
    /// @dev Link to sILV ERC20 Token EscrowedIlluviumERC20 instance
    address public immutable override silv;
    /// @dev Link to the pool factory IlluviumPoolFactory instance
    IlluviumPoolFactory public immutable factory;
    /// @dev Link to the pool token instance, for example ILV or ILV/ETH pair
    address public immutable override poolToken;
    /// @dev Pool weight, 100 for ILV pool or 900 for ILV/ETH
    uint32 public override weight;
    /// @dev Block number of the last yield distribution event
    uint64 public override lastYieldDistribution;
    /// @dev Used to calculate yield rewards
    /// @dev This value is different from "reward per token" used in locked pool
    /// @dev Note: stakes are different in duration and "weight" reflects that
    uint256 public override yieldRewardsPerWeight;
    /// @dev Used to calculate yield rewards, keeps track of the tokens weight locked in staking
    uint256 public override usersLockingWeight;
    /**
     * @dev Stake weight is proportional to deposit amount and time locked, precisely
     *      "deposit amount wei multiplied by (fraction of the year locked plus one)"
     * @dev To avoid significant precision loss due to multiplication by "fraction of the year" [0, 1],
     *      weight is stored multiplied by 1e6 constant, as an integer
     * @dev Corner case 1: if time locked is zero, weight is deposit amount multiplied by 1e6
     * @dev Corner case 2: if time locked is one year, fraction of the year locked is one, and
     *      weight is a deposit amount multiplied by 2 * 1e6
     */
    uint256 internal constant WEIGHT_MULTIPLIER = 1e6;
    /**
     * @dev When we know beforehand that staking is done for a year, and fraction of the year locked is one,
     *      we use simplified calculation and use the following constant instead previos one
     */
    uint256 internal constant YEAR_STAKE_WEIGHT_MULTIPLIER = 2 * WEIGHT_MULTIPLIER;
    /**
     * @dev Rewards per weight are stored multiplied by 1e12, as integers.
     */
    uint256 internal constant REWARD_PER_WEIGHT_MULTIPLIER = 1e12;
    /**
     * @dev Fired in _stake() and stake()
     *
     * @param _by an address which performed an operation, usually token holder
     * @param _from token holder address, the tokens will be returned to that address
     * @param amount amount of tokens staked
     */
    event Staked(address indexed _by, address indexed _from, uint256 amount);
    /**
     * @dev Fired in _updateStakeLock() and updateStakeLock()
     *
     * @param _by an address which performed an operation
     * @param depositId updated deposit ID
     * @param lockedFrom deposit locked from value
     * @param lockedUntil updated deposit locked until value
     */
    event StakeLockUpdated(address indexed _by, uint256 depositId, uint64 lockedFrom, uint64 lockedUntil);
    /**
     * @dev Fired in _unstake() and unstake()
     *
     * @param _by an address which performed an operation, usually token holder
     * @param _to an address which received the unstaked tokens, usually token holder
     * @param amount amount of tokens unstaked
     */
    event Unstaked(address indexed _by, address indexed _to, uint256 amount);
    /**
     * @dev Fired in _sync(), sync() and dependent functions (stake, unstake, etc.)
     *
     * @param _by an address which performed an operation
     * @param yieldRewardsPerWeight updated yield rewards per weight value
     * @param lastYieldDistribution usually, current block number
     */
    event Synchronized(address indexed _by, uint256 yieldRewardsPerWeight, uint64 lastYieldDistribution);
    /**
     * @dev Fired in _processRewards(), processRewards() and dependent functions (stake, unstake, etc.)
     *
     * @param _by an address which performed an operation
     * @param _to an address which claimed the yield reward
     * @param sIlv flag indicating if reward was paid (minted) in sILV
     * @param amount amount of yield paid
     */
    event YieldClaimed(address indexed _by, address indexed _to, bool sIlv, uint256 amount);
    /**
     * @dev Fired in setWeight()
     *
     * @param _by an address which performed an operation, always a factory
     * @param _fromVal old pool weight value
     * @param _toVal new pool weight value
     */
    event PoolWeightUpdated(address indexed _by, uint32 _fromVal, uint32 _toVal);
    /**
     * @dev Overridden in sub-contracts to construct the pool
     *
     * @param _ilv ILV ERC20 Token IlluviumERC20 address
     * @param _silv sILV ERC20 Token EscrowedIlluviumERC20 address
     * @param _factory Pool factory IlluviumPoolFactory instance/address
     * @param _poolToken token the pool operates on, for example ILV or ILV/ETH pair
     * @param _initBlock initial block used to calculate the rewards
     *      note: _initBlock can be set to the future effectively meaning _sync() calls will do nothing
     * @param _weight number representing a weight of the pool, actual weight fraction
     *      is calculated as that number divided by the total pools weight and doesn't exceed one
     */
    constructor(
        address _ilv,
        address _silv,
        IlluviumPoolFactory _factory,
        address _poolToken,
        uint64 _initBlock,
        uint32 _weight
    ) IlluviumAware(_ilv) {
        // verify the inputs are set
        require(_silv != address(0), "sILV address not set");
        require(address(_factory) != address(0), "ILV Pool fct address not set");
        require(_poolToken != address(0), "pool token address not set");
        require(_initBlock > 0, "init block not set");
        require(_weight > 0, "pool weight not set");
        // verify sILV instance supplied
        require(
            EscrowedIlluviumERC20(_silv).TOKEN_UID() ==
                0xac3051b8d4f50966afb632468a4f61483ae6a953b74e387a01ef94316d6b7d62,
            "unexpected sILV TOKEN_UID"
        );
        // verify IlluviumPoolFactory instance supplied
        require(
            _factory.FACTORY_UID() == 0xc5cfd88c6e4d7e5c8a03c255f03af23c0918d8e82cac196f57466af3fd4a5ec7,
            "unexpected FACTORY_UID"
        );
        // save the inputs into internal state variables
        silv = _silv;
        factory = _factory;
        poolToken = _poolToken;
        weight = _weight;
        // init the dependent internal state variables
        lastYieldDistribution = _initBlock;
    }
    /**
     * @notice Calculates current yield rewards value available for address specified
     *
     * @param _staker an address to calculate yield rewards value for
     * @return calculated yield reward value for the given address
     */
    function pendingYieldRewards(address _staker) external view override returns (uint256) {
        // `newYieldRewardsPerWeight` will store stored or recalculated value for `yieldRewardsPerWeight`
        uint256 newYieldRewardsPerWeight;
        // if smart contract state was not updated recently, `yieldRewardsPerWeight` value
        // is outdated and we need to recalculate it in order to calculate pending rewards correctly
        if (blockNumber() > lastYieldDistribution && usersLockingWeight != 0) {
            uint256 endBlock = factory.endBlock();
            uint256 multiplier =
                blockNumber() > endBlock ? endBlock - lastYieldDistribution : blockNumber() - lastYieldDistribution;
            uint256 ilvRewards = (multiplier * weight * factory.ilvPerBlock()) / factory.totalWeight();
            // recalculated value for `yieldRewardsPerWeight`
            newYieldRewardsPerWeight = rewardToWeight(ilvRewards, usersLockingWeight) + yieldRewardsPerWeight;
        } else {
            // if smart contract state is up to date, we don't recalculate
            newYieldRewardsPerWeight = yieldRewardsPerWeight;
        }
        // based on the rewards per weight value, calculate pending rewards;
        User memory user = users[_staker];
        uint256 pending = weightToReward(user.totalWeight, newYieldRewardsPerWeight) - user.subYieldRewards;
        return pending;
    }
    /**
     * @notice Returns total staked token balance for the given address
     *
     * @param _user an address to query balance for
     * @return total staked token balance
     */
    function balanceOf(address _user) external view override returns (uint256) {
        // read specified user token amount and return
        return users[_user].tokenAmount;
    }
    /**
     * @notice Returns information on the given deposit for the given address
     *
     * @dev See getDepositsLength
     *
     * @param _user an address to query deposit for
     * @param _depositId zero-indexed deposit ID for the address specified
     * @return deposit info as Deposit structure
     */
    function getDeposit(address _user, uint256 _depositId) external view override returns (Deposit memory) {
        // read deposit at specified index and return
        return users[_user].deposits[_depositId];
    }
    /**
     * @notice Returns number of deposits for the given address. Allows iteration over deposits.
     *
     * @dev See getDeposit
     *
     * @param _user an address to query deposit length for
     * @return number of deposits for the given address
     */
    function getDepositsLength(address _user) external view override returns (uint256) {
        // read deposits array length and return
        return users[_user].deposits.length;
    }
    /**
     * @notice Stakes specified amount of tokens for the specified amount of time,
     *      and pays pending yield rewards if any
     *
     * @dev Requires amount to stake to be greater than zero
     *
     * @param _amount amount of tokens to stake
     * @param _lockUntil stake period as unix timestamp; zero means no locking
     * @param _useSILV a flag indicating if previous reward to be paid as sILV
     */
    function stake(
        uint256 _amount,
        uint64 _lockUntil,
        bool _useSILV
    ) external override {
        // delegate call to an internal function
        _stake(msg.sender, _amount, _lockUntil, _useSILV, false);
    }
    /**
     * @notice Unstakes specified amount of tokens, and pays pending yield rewards if any
     *
     * @dev Requires amount to unstake to be greater than zero
     *
     * @param _depositId deposit ID to unstake from, zero-indexed
     * @param _amount amount of tokens to unstake
     * @param _useSILV a flag indicating if reward to be paid as sILV
     */
    function unstake(
        uint256 _depositId,
        uint256 _amount,
        bool _useSILV
    ) external override {
        // delegate call to an internal function
        _unstake(msg.sender, _depositId, _amount, _useSILV);
    }
    /**
     * @notice Extends locking period for a given deposit
     *
     * @dev Requires new lockedUntil value to be:
     *      higher than the current one, and
     *      in the future, but
     *      no more than 1 year in the future
     *
     * @param depositId updated deposit ID
     * @param lockedUntil updated deposit locked until value
     * @param useSILV used for _processRewards check if it should use ILV or sILV
     */
    function updateStakeLock(
        uint256 depositId,
        uint64 lockedUntil,
        bool useSILV
    ) external {
        // sync and call processRewards
        _sync();
        _processRewards(msg.sender, useSILV, false);
        // delegate call to an internal function
        _updateStakeLock(msg.sender, depositId, lockedUntil);
    }
    /**
     * @notice Service function to synchronize pool state with current time
     *
     * @dev Can be executed by anyone at any time, but has an effect only when
     *      at least one block passes between synchronizations
     * @dev Executed internally when staking, unstaking, processing rewards in order
     *      for calculations to be correct and to reflect state progress of the contract
     * @dev When timing conditions are not met (executed too frequently, or after factory
     *      end block), function doesn't throw and exits silently
     */
    function sync() external override {
        // delegate call to an internal function
        _sync();
    }
    /**
     * @notice Service function to calculate and pay pending yield rewards to the sender
     *
     * @dev Can be executed by anyone at any time, but has an effect only when
     *      executed by deposit holder and when at least one block passes from the
     *      previous reward processing
     * @dev Executed internally when staking and unstaking, executes sync() under the hood
     *      before making further calculations and payouts
     * @dev When timing conditions are not met (executed too frequently, or after factory
     *      end block), function doesn't throw and exits silently
     *
     * @param _useSILV flag indicating whether to mint sILV token as a reward or not;
     *      when set to true - sILV reward is minted immediately and sent to sender,
     *      when set to false - new ILV reward deposit gets created if pool is an ILV pool
     *      (poolToken is ILV token), or new pool deposit gets created together with sILV minted
     *      when pool is not an ILV pool (poolToken is not an ILV token)
     */
    function processRewards(bool _useSILV) external virtual override {
        // delegate call to an internal function
        _processRewards(msg.sender, _useSILV, true);
    }
    /**
     * @dev Executed by the factory to modify pool weight; the factory is expected
     *      to keep track of the total pools weight when updating
     *
     * @dev Set weight to zero to disable the pool
     *
     * @param _weight new weight to set for the pool
     */
    function setWeight(uint32 _weight) external override {
        // verify function is executed by the factory
        require(msg.sender == address(factory), "access denied");
        // emit an event logging old and new weight values
        emit PoolWeightUpdated(msg.sender, weight, _weight);
        // set the new weight value
        weight = _weight;
    }
    /**
     * @dev Similar to public pendingYieldRewards, but performs calculations based on
     *      current smart contract state only, not taking into account any additional
     *      time/blocks which might have passed
     *
     * @param _staker an address to calculate yield rewards value for
     * @return pending calculated yield reward value for the given address
     */
    function _pendingYieldRewards(address _staker) internal view returns (uint256 pending) {
        // read user data structure into memory
        User memory user = users[_staker];
        // and perform the calculation using the values read
        return weightToReward(user.totalWeight, yieldRewardsPerWeight) - user.subYieldRewards;
    }
    /**
     * @dev Used internally, mostly by children implementations, see stake()
     *
     * @param _staker an address which stakes tokens and which will receive them back
     * @param _amount amount of tokens to stake
     * @param _lockUntil stake period as unix timestamp; zero means no locking
     * @param _useSILV a flag indicating if previous reward to be paid as sILV
     * @param _isYield a flag indicating if that stake is created to store yield reward
     *      from the previously unstaked stake
     */
    function _stake(
        address _staker,
        uint256 _amount,
        uint64 _lockUntil,
        bool _useSILV,
        bool _isYield
    ) internal virtual {
        // validate the inputs
        require(_amount > 0, "zero amount");
        require(
            _lockUntil == 0 || (_lockUntil > now256() && _lockUntil - now256() <= 365 days),
            "invalid lock interval"
        );
        // update smart contract state
        _sync();
        // get a link to user data struct, we will write to it later
        User storage user = users[_staker];
        // process current pending rewards if any
        if (user.tokenAmount > 0) {
            _processRewards(_staker, _useSILV, false);
        }
        // in most of the cases added amount `addedAmount` is simply `_amount`
        // however for deflationary tokens this can be different
        // read the current balance
        uint256 previousBalance = IERC20(poolToken).balanceOf(address(this));
        // transfer `_amount`; note: some tokens may get burnt here
        transferPoolTokenFrom(address(msg.sender), address(this), _amount);
        // read new balance, usually this is just the difference `previousBalance - _amount`
        uint256 newBalance = IERC20(poolToken).balanceOf(address(this));
        // calculate real amount taking into account deflation
        uint256 addedAmount = newBalance - previousBalance;
        // set the `lockFrom` and `lockUntil` taking into account that
        // zero value for `_lockUntil` means "no locking" and leads to zero values
        // for both `lockFrom` and `lockUntil`
        uint64 lockFrom = _lockUntil > 0 ? uint64(now256()) : 0;
        uint64 lockUntil = _lockUntil;
        // stake weight formula rewards for locking
        uint256 stakeWeight =
            (((lockUntil - lockFrom) * WEIGHT_MULTIPLIER) / 365 days + WEIGHT_MULTIPLIER) * addedAmount;
        // makes sure stakeWeight is valid
        assert(stakeWeight > 0);
        // create and save the deposit (append it to deposits array)
        Deposit memory deposit =
            Deposit({
                tokenAmount: addedAmount,
                weight: stakeWeight,
                lockedFrom: lockFrom,
                lockedUntil: lockUntil,
                isYield: _isYield
            });
        // deposit ID is an index of the deposit in `deposits` array
        user.deposits.push(deposit);
        // update user record
        user.tokenAmount += addedAmount;
        user.totalWeight += stakeWeight;
        user.subYieldRewards = weightToReward(user.totalWeight, yieldRewardsPerWeight);
        // update global variable
        usersLockingWeight += stakeWeight;
        // emit an event
        emit Staked(msg.sender, _staker, _amount);
    }
    /**
     * @dev Used internally, mostly by children implementations, see unstake()
     *
     * @param _staker an address which unstakes tokens (which previously staked them)
     * @param _depositId deposit ID to unstake from, zero-indexed
     * @param _amount amount of tokens to unstake
     * @param _useSILV a flag indicating if reward to be paid as sILV
     */
    function _unstake(
        address _staker,
        uint256 _depositId,
        uint256 _amount,
        bool _useSILV
    ) internal virtual {
        // verify an amount is set
        require(_amount > 0, "zero amount");
        // get a link to user data struct, we will write to it later
        User storage user = users[_staker];
        // get a link to the corresponding deposit, we may write to it later
        Deposit storage stakeDeposit = user.deposits[_depositId];
        // deposit structure may get deleted, so we save isYield flag to be able to use it
        bool isYield = stakeDeposit.isYield;
        // verify available balance
        // if staker address ot deposit doesn't exist this check will fail as well
        require(stakeDeposit.tokenAmount >= _amount, "amount exceeds stake");
        // update smart contract state
        _sync();
        // and process current pending rewards if any
        _processRewards(_staker, _useSILV, false);
        // recalculate deposit weight
        uint256 previousWeight = stakeDeposit.weight;
        uint256 newWeight =
            (((stakeDeposit.lockedUntil - stakeDeposit.lockedFrom) * WEIGHT_MULTIPLIER) /
                365 days +
                WEIGHT_MULTIPLIER) * (stakeDeposit.tokenAmount - _amount);
        // update the deposit, or delete it if its depleted
        if (stakeDeposit.tokenAmount - _amount == 0) {
            delete user.deposits[_depositId];
        } else {
            stakeDeposit.tokenAmount -= _amount;
            stakeDeposit.weight = newWeight;
        }
        // update user record
        user.tokenAmount -= _amount;
        user.totalWeight = user.totalWeight - previousWeight + newWeight;
        user.subYieldRewards = weightToReward(user.totalWeight, yieldRewardsPerWeight);
        // update global variable
        usersLockingWeight = usersLockingWeight - previousWeight + newWeight;
        // if the deposit was created by the pool itself as a yield reward
        if (isYield) {
            // mint the yield via the factory
            factory.mintYieldTo(msg.sender, _amount);
        } else {
            // otherwise just return tokens back to holder
            transferPoolToken(msg.sender, _amount);
        }
        // emit an event
        emit Unstaked(msg.sender, _staker, _amount);
    }
    /**
     * @dev Used internally, mostly by children implementations, see sync()
     *
     * @dev Updates smart contract state (`yieldRewardsPerWeight`, `lastYieldDistribution`),
     *      updates factory state via `updateILVPerBlock`
     */
    function _sync() internal virtual {
        // update ILV per block value in factory if required
        if (factory.shouldUpdateRatio()) {
            factory.updateILVPerBlock();
        }
        // check bound conditions and if these are not met -
        // exit silently, without emitting an event
        uint256 endBlock = factory.endBlock();
        if (lastYieldDistribution >= endBlock) {
            return;
        }
        if (blockNumber() <= lastYieldDistribution) {
            return;
        }
        // if locking weight is zero - update only `lastYieldDistribution` and exit
        if (usersLockingWeight == 0) {
            lastYieldDistribution = uint64(blockNumber());
            return;
        }
        // to calculate the reward we need to know how many blocks passed, and reward per block
        uint256 currentBlock = blockNumber() > endBlock ? endBlock : blockNumber();
        uint256 blocksPassed = currentBlock - lastYieldDistribution;
        uint256 ilvPerBlock = factory.ilvPerBlock();
        // calculate the reward
        uint256 ilvReward = (blocksPassed * ilvPerBlock * weight) / factory.totalWeight();
        // update rewards per weight and `lastYieldDistribution`
        yieldRewardsPerWeight += rewardToWeight(ilvReward, usersLockingWeight);
        lastYieldDistribution = uint64(currentBlock);
        // emit an event
        emit Synchronized(msg.sender, yieldRewardsPerWeight, lastYieldDistribution);
    }
    /**
     * @dev Used internally, mostly by children implementations, see processRewards()
     *
     * @param _staker an address which receives the reward (which has staked some tokens earlier)
     * @param _useSILV flag indicating whether to mint sILV token as a reward or not, see processRewards()
     * @param _withUpdate flag allowing to disable synchronization (see sync()) if set to false
     * @return pendingYield the rewards calculated and optionally re-staked
     */
    function _processRewards(
        address _staker,
        bool _useSILV,
        bool _withUpdate
    ) internal virtual returns (uint256 pendingYield) {
        // update smart contract state if required
        if (_withUpdate) {
            _sync();
        }
        // calculate pending yield rewards, this value will be returned
        pendingYield = _pendingYieldRewards(_staker);
        // if pending yield is zero - just return silently
        if (pendingYield == 0) return 0;
        // get link to a user data structure, we will write into it later
        User storage user = users[_staker];
        // if sILV is requested
        if (_useSILV) {
            // - mint sILV
            mintSIlv(_staker, pendingYield);
        } else if (poolToken == ilv) {
            // calculate pending yield weight,
            // 2e6 is the bonus weight when staking for 1 year
            uint256 depositWeight = pendingYield * YEAR_STAKE_WEIGHT_MULTIPLIER;
            // if the pool is ILV Pool - create new ILV deposit
            // and save it - push it into deposits array
            Deposit memory newDeposit =
                Deposit({
                    tokenAmount: pendingYield,
                    lockedFrom: uint64(now256()),
                    lockedUntil: uint64(now256() + 365 days), // staking yield for 1 year
                    weight: depositWeight,
                    isYield: true
                });
            user.deposits.push(newDeposit);
            // update user record
            user.tokenAmount += pendingYield;
            user.totalWeight += depositWeight;
            // update global variable
            usersLockingWeight += depositWeight;
        } else {
            // for other pools - stake as pool
            address ilvPool = factory.getPoolAddress(ilv);
            ICorePool(ilvPool).stakeAsPool(_staker, pendingYield);
        }
        // update users's record for `subYieldRewards` if requested
        if (_withUpdate) {
            user.subYieldRewards = weightToReward(user.totalWeight, yieldRewardsPerWeight);
        }
        // emit an event
        emit YieldClaimed(msg.sender, _staker, _useSILV, pendingYield);
    }
    /**
     * @dev See updateStakeLock()
     *
     * @param _staker an address to update stake lock
     * @param _depositId updated deposit ID
     * @param _lockedUntil updated deposit locked until value
     */
    function _updateStakeLock(
        address _staker,
        uint256 _depositId,
        uint64 _lockedUntil
    ) internal {
        // validate the input time
        require(_lockedUntil > now256(), "lock should be in the future");
        // get a link to user data struct, we will write to it later
        User storage user = users[_staker];
        // get a link to the corresponding deposit, we may write to it later
        Deposit storage stakeDeposit = user.deposits[_depositId];
        // validate the input against deposit structure
        require(_lockedUntil > stakeDeposit.lockedUntil, "invalid new lock");
        // verify locked from and locked until values
        if (stakeDeposit.lockedFrom == 0) {
            require(_lockedUntil - now256() <= 365 days, "max lock period is 365 days");
            stakeDeposit.lockedFrom = uint64(now256());
        } else {
            require(_lockedUntil - stakeDeposit.lockedFrom <= 365 days, "max lock period is 365 days");
        }
        // update locked until value, calculate new weight
        stakeDeposit.lockedUntil = _lockedUntil;
        uint256 newWeight =
            (((stakeDeposit.lockedUntil - stakeDeposit.lockedFrom) * WEIGHT_MULTIPLIER) /
                365 days +
                WEIGHT_MULTIPLIER) * stakeDeposit.tokenAmount;
        // save previous weight
        uint256 previousWeight = stakeDeposit.weight;
        // update weight
        stakeDeposit.weight = newWeight;
        // update user total weight and global locking weight
        user.totalWeight = user.totalWeight - previousWeight + newWeight;
        usersLockingWeight = usersLockingWeight - previousWeight + newWeight;
        // emit an event
        emit StakeLockUpdated(_staker, _depositId, stakeDeposit.lockedFrom, _lockedUntil);
    }
    /**
     * @dev Converts stake weight (not to be mixed with the pool weight) to
     *      ILV reward value, applying the 10^12 division on weight
     *
     * @param _weight stake weight
     * @param rewardPerWeight ILV reward per weight
     * @return reward value normalized to 10^12
     */
    function weightToReward(uint256 _weight, uint256 rewardPerWeight) public pure returns (uint256) {
        // apply the formula and return
        return (_weight * rewardPerWeight) / REWARD_PER_WEIGHT_MULTIPLIER;
    }
    /**
     * @dev Converts reward ILV value to stake weight (not to be mixed with the pool weight),
     *      applying the 10^12 multiplication on the reward
     *      - OR -
     * @dev Converts reward ILV value to reward/weight if stake weight is supplied as second
     *      function parameter instead of reward/weight
     *
     * @param reward yield reward
     * @param rewardPerWeight reward/weight (or stake weight)
     * @return stake weight (or reward/weight)
     */
    function rewardToWeight(uint256 reward, uint256 rewardPerWeight) public pure returns (uint256) {
        // apply the reverse formula and return
        return (reward * REWARD_PER_WEIGHT_MULTIPLIER) / rewardPerWeight;
    }
    /**
     * @dev Testing time-dependent functionality is difficult and the best way of
     *      doing it is to override block number in helper test smart contracts
     *
     * @return `block.number` in mainnet, custom values in testnets (if overridden)
     */
    function blockNumber() public view virtual returns (uint256) {
        // return current block number
        return block.number;
    }
    /**
     * @dev Testing time-dependent functionality is difficult and the best way of
     *      doing it is to override time in helper test smart contracts
     *
     * @return `block.timestamp` in mainnet, custom values in testnets (if overridden)
     */
    function now256() public view virtual returns (uint256) {
        // return current block timestamp
        return block.timestamp;
    }
    /**
     * @dev Executes EscrowedIlluviumERC20.mint(_to, _values)
     *      on the bound EscrowedIlluviumERC20 instance
     *
     * @dev Reentrancy safe due to the EscrowedIlluviumERC20 design
     */
    function mintSIlv(address _to, uint256 _value) private {
        // just delegate call to the target
        EscrowedIlluviumERC20(silv).mint(_to, _value);
    }
    /**
     * @dev Executes SafeERC20.safeTransfer on a pool token
     *
     * @dev Reentrancy safety enforced via `ReentrancyGuard.nonReentrant`
     */
    function transferPoolToken(address _to, uint256 _value) internal nonReentrant {
        // just delegate call to the target
        SafeERC20.safeTransfer(IERC20(poolToken), _to, _value);
    }
    /**
     * @dev Executes SafeERC20.safeTransferFrom on a pool token
     *
     * @dev Reentrancy safety enforced via `ReentrancyGuard.nonReentrant`
     */
    function transferPoolTokenFrom(
        address _from,
        address _to,
        uint256 _value
    ) internal nonReentrant {
        // just delegate call to the target
        SafeERC20.safeTransferFrom(IERC20(poolToken), _from, _to, _value);
    }
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.1;
import "./ILinkedToILV.sol";
/**
 * @title Illuvium Pool
 *
 * @notice An abstraction representing a pool, see IlluviumPoolBase for details
 *
 * @author Pedro Bergamini, reviewed by Basil Gorin
 */
interface IPool is ILinkedToILV {
    /**
     * @dev Deposit is a key data structure used in staking,
     *      it represents a unit of stake with its amount, weight and term (time interval)
     */
    struct Deposit {
        // @dev token amount staked
        uint256 tokenAmount;
        // @dev stake weight
        uint256 weight;
        // @dev locking period - from
        uint64 lockedFrom;
        // @dev locking period - until
        uint64 lockedUntil;
        // @dev indicates if the stake was created as a yield reward
        bool isYield;
    }
    // for the rest of the functions see Soldoc in IlluviumPoolBase
    function silv() external view returns (address);
    function poolToken() external view returns (address);
    function isFlashPool() external view returns (bool);
    function weight() external view returns (uint32);
    function lastYieldDistribution() external view returns (uint64);
    function yieldRewardsPerWeight() external view returns (uint256);
    function usersLockingWeight() external view returns (uint256);
    function pendingYieldRewards(address _user) external view returns (uint256);
    function balanceOf(address _user) external view returns (uint256);
    function getDeposit(address _user, uint256 _depositId) external view returns (Deposit memory);
    function getDepositsLength(address _user) external view returns (uint256);
    function stake(
        uint256 _amount,
        uint64 _lockedUntil,
        bool useSILV
    ) external;
    function unstake(
        uint256 _depositId,
        uint256 _amount,
        bool useSILV
    ) external;
    function sync() external;
    function processRewards(bool useSILV) external;
    function setWeight(uint32 _weight) external;
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.1;
import "./IPool.sol";
interface ICorePool is IPool {
    function vaultRewardsPerToken() external view returns (uint256);
    function poolTokenReserve() external view returns (uint256);
    function stakeAsPool(address _staker, uint256 _amount) external;
    function receiveVaultRewards(uint256 _amount) external;
}
// https://raw.githubusercontent.com/OpenZeppelin/openzeppelin-contracts/master/contracts/security/ReentrancyGuard.sol
// #24a0bc23cfe3fbc76f8f2510b78af1e948ae6651
// SPDX-License-Identifier: MIT
pragma solidity 0.8.1;
/**
 * @dev Contract module that helps prevent reentrant calls to a function.
 *
 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
 * available, which can be applied to functions to make sure there are no nested
 * (reentrant) calls to them.
 *
 * Note that because there is a single `nonReentrant` guard, functions marked as
 * `nonReentrant` may not call one another. This can be worked around by making
 * those functions `private`, and then adding `external` `nonReentrant` entry
 * points to them.
 *
 * TIP: If you would like to learn more about reentrancy and alternative ways
 * to protect against it, check out our blog post
 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
 */
abstract contract ReentrancyGuard {
  // Booleans are more expensive than uint256 or any type that takes up a full
  // word because each write operation emits an extra SLOAD to first read the
  // slot's contents, replace the bits taken up by the boolean, and then write
  // back. This is the compiler's defense against contract upgrades and
  // pointer aliasing, and it cannot be disabled.
  // The values being non-zero value makes deployment a bit more expensive,
  // but in exchange the refund on every call to nonReentrant will be lower in
  // amount. Since refunds are capped to a percentage of the total
  // transaction's gas, it is best to keep them low in cases like this one, to
  // increase the likelihood of the full refund coming into effect.
  uint256 private constant _NOT_ENTERED = 1;
  uint256 private constant _ENTERED = 2;
  uint256 private _status;
  constructor () {
    _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;
  }
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.1;
import "../interfaces/IPool.sol";
import "./IlluviumAware.sol";
import "./IlluviumCorePool.sol";
import "../token/EscrowedIlluviumERC20.sol";
import "../utils/Ownable.sol";
/**
 * @title Illuvium Pool Factory
 *
 * @notice ILV Pool Factory manages Illuvium Yield farming pools, provides a single
 *      public interface to access the pools, provides an interface for the pools
 *      to mint yield rewards, access pool-related info, update weights, etc.
 *
 * @notice The factory is authorized (via its owner) to register new pools, change weights
 *      of the existing pools, removing the pools (by changing their weights to zero)
 *
 * @dev The factory requires ROLE_TOKEN_CREATOR permission on the ILV token to mint yield
 *      (see `mintYieldTo` function)
 *
 * @author Pedro Bergamini, reviewed by Basil Gorin
 */
contract IlluviumPoolFactory is Ownable, IlluviumAware {
    /**
     * @dev Smart contract unique identifier, a random number
     * @dev Should be regenerated each time smart contact source code is changed
     *      and changes smart contract itself is to be redeployed
     * @dev Generated using https://www.random.org/bytes/
     */
    uint256 public constant FACTORY_UID = 0xc5cfd88c6e4d7e5c8a03c255f03af23c0918d8e82cac196f57466af3fd4a5ec7;
    /// @dev Auxiliary data structure used only in getPoolData() view function
    struct PoolData {
        // @dev pool token address (like ILV)
        address poolToken;
        // @dev pool address (like deployed core pool instance)
        address poolAddress;
        // @dev pool weight (200 for ILV pools, 800 for ILV/ETH pools - set during deployment)
        uint32 weight;
        // @dev flash pool flag
        bool isFlashPool;
    }
    /**
     * @dev ILV/block determines yield farming reward base
     *      used by the yield pools controlled by the factory
     */
    uint192 public ilvPerBlock;
    /**
     * @dev The yield is distributed proportionally to pool weights;
     *      total weight is here to help in determining the proportion
     */
    uint32 public totalWeight;
    /**
     * @dev ILV/block decreases by 3% every blocks/update (set to 91252 blocks during deployment);
     *      an update is triggered by executing `updateILVPerBlock` public function
     */
    uint32 public immutable blocksPerUpdate;
    /**
     * @dev End block is the last block when ILV/block can be decreased;
     *      it is implied that yield farming stops after that block
     */
    uint32 public endBlock;
    /**
     * @dev Each time the ILV/block ratio gets updated, the block number
     *      when the operation has occurred gets recorded into `lastRatioUpdate`
     * @dev This block number is then used to check if blocks/update `blocksPerUpdate`
     *      has passed when decreasing yield reward by 3%
     */
    uint32 public lastRatioUpdate;
    /// @dev sILV token address is used to create ILV core pool(s)
    address public immutable silv;
    /// @dev Maps pool token address (like ILV) -> pool address (like core pool instance)
    mapping(address => address) public pools;
    /// @dev Keeps track of registered pool addresses, maps pool address -> exists flag
    mapping(address => bool) public poolExists;
    /**
     * @dev Fired in createPool() and registerPool()
     *
     * @param _by an address which executed an action
     * @param poolToken pool token address (like ILV)
     * @param poolAddress deployed pool instance address
     * @param weight pool weight
     * @param isFlashPool flag indicating if pool is a flash pool
     */
    event PoolRegistered(
        address indexed _by,
        address indexed poolToken,
        address indexed poolAddress,
        uint64 weight,
        bool isFlashPool
    );
    /**
     * @dev Fired in changePoolWeight()
     *
     * @param _by an address which executed an action
     * @param poolAddress deployed pool instance address
     * @param weight new pool weight
     */
    event WeightUpdated(address indexed _by, address indexed poolAddress, uint32 weight);
    /**
     * @dev Fired in updateILVPerBlock()
     *
     * @param _by an address which executed an action
     * @param newIlvPerBlock new ILV/block value
     */
    event IlvRatioUpdated(address indexed _by, uint256 newIlvPerBlock);
    /**
     * @dev Creates/deploys a factory instance
     *
     * @param _ilv ILV ERC20 token address
     * @param _silv sILV ERC20 token address
     * @param _ilvPerBlock initial ILV/block value for rewards
     * @param _blocksPerUpdate how frequently the rewards gets updated (decreased by 3%), blocks
     * @param _initBlock block number to measure _blocksPerUpdate from
     * @param _endBlock block number when farming stops and rewards cannot be updated anymore
     */
    constructor(
        address _ilv,
        address _silv,
        uint192 _ilvPerBlock,
        uint32 _blocksPerUpdate,
        uint32 _initBlock,
        uint32 _endBlock
    ) IlluviumAware(_ilv) {
        // verify the inputs are set
        require(_silv != address(0), "sILV address not set");
        require(_ilvPerBlock > 0, "ILV/block not set");
        require(_blocksPerUpdate > 0, "blocks/update not set");
        require(_initBlock > 0, "init block not set");
        require(_endBlock > _initBlock, "invalid end block: must be greater than init block");
        // verify sILV instance supplied
        require(
            EscrowedIlluviumERC20(_silv).TOKEN_UID() ==
                0xac3051b8d4f50966afb632468a4f61483ae6a953b74e387a01ef94316d6b7d62,
            "unexpected sILV TOKEN_UID"
        );
        // save the inputs into internal state variables
        silv = _silv;
        ilvPerBlock = _ilvPerBlock;
        blocksPerUpdate = _blocksPerUpdate;
        lastRatioUpdate = _initBlock;
        endBlock = _endBlock;
    }
    /**
     * @notice Given a pool token retrieves corresponding pool address
     *
     * @dev A shortcut for `pools` mapping
     *
     * @param poolToken pool token address (like ILV) to query pool address for
     * @return pool address for the token specified
     */
    function getPoolAddress(address poolToken) external view returns (address) {
        // read the mapping and return
        return pools[poolToken];
    }
    /**
     * @notice Reads pool information for the pool defined by its pool token address,
     *      designed to simplify integration with the front ends
     *
     * @param _poolToken pool token address to query pool information for
     * @return pool information packed in a PoolData struct
     */
    function getPoolData(address _poolToken) public view returns (PoolData memory) {
        // get the pool address from the mapping
        address poolAddr = pools[_poolToken];
        // throw if there is no pool registered for the token specified
        require(poolAddr != address(0), "pool not found");
        // read pool information from the pool smart contract
        // via the pool interface (IPool)
        address poolToken = IPool(poolAddr).poolToken();
        bool isFlashPool = IPool(poolAddr).isFlashPool();
        uint32 weight = IPool(poolAddr).weight();
        // create the in-memory structure and return it
        return PoolData({ poolToken: poolToken, poolAddress: poolAddr, weight: weight, isFlashPool: isFlashPool });
    }
    /**
     * @dev Verifies if `blocksPerUpdate` has passed since last ILV/block
     *      ratio update and if ILV/block reward can be decreased by 3%
     *
     * @return true if enough time has passed and `updateILVPerBlock` can be executed
     */
    function shouldUpdateRatio() public view returns (bool) {
        // if yield farming period has ended
        if (blockNumber() > endBlock) {
            // ILV/block reward cannot be updated anymore
            return false;
        }
        // check if blocks/update (91252 blocks) have passed since last update
        return blockNumber() >= lastRatioUpdate + blocksPerUpdate;
    }
    /**
     * @dev Creates a core pool (IlluviumCorePool) and registers it within the factory
     *
     * @dev Can be executed by the pool factory owner only
     *
     * @param poolToken pool token address (like ILV, or ILV/ETH pair)
     * @param initBlock init block to be used for the pool created
     * @param weight weight of the pool to be created
     */
    function createPool(
        address poolToken,
        uint64 initBlock,
        uint32 weight
    ) external virtual onlyOwner {
        // create/deploy new core pool instance
        IPool pool = new IlluviumCorePool(ilv, silv, this, poolToken, initBlock, weight);
        // register it within a factory
        registerPool(address(pool));
    }
    /**
     * @dev Registers an already deployed pool instance within the factory
     *
     * @dev Can be executed by the pool factory owner only
     *
     * @param poolAddr address of the already deployed pool instance
     */
    function registerPool(address poolAddr) public onlyOwner {
        // read pool information from the pool smart contract
        // via the pool interface (IPool)
        address poolToken = IPool(poolAddr).poolToken();
        bool isFlashPool = IPool(poolAddr).isFlashPool();
        uint32 weight = IPool(poolAddr).weight();
        // ensure that the pool is not already registered within the factory
        require(pools[poolToken] == address(0), "this pool is already registered");
        // create pool structure, register it within the factory
        pools[poolToken] = poolAddr;
        poolExists[poolAddr] = true;
        // update total pool weight of the factory
        totalWeight += weight;
        // emit an event
        emit PoolRegistered(msg.sender, poolToken, poolAddr, weight, isFlashPool);
    }
    /**
     * @notice Decreases ILV/block reward by 3%, can be executed
     *      no more than once per `blocksPerUpdate` blocks
     */
    function updateILVPerBlock() external {
        // checks if ratio can be updated i.e. if blocks/update (91252 blocks) have passed
        require(shouldUpdateRatio(), "too frequent");
        // decreases ILV/block reward by 3%
        ilvPerBlock = (ilvPerBlock * 97) / 100;
        // set current block as the last ratio update block
        lastRatioUpdate = uint32(blockNumber());
        // emit an event
        emit IlvRatioUpdated(msg.sender, ilvPerBlock);
    }
    /**
     * @dev Mints ILV tokens; executed by ILV Pool only
     *
     * @dev Requires factory to have ROLE_TOKEN_CREATOR permission
     *      on the ILV ERC20 token instance
     *
     * @param _to an address to mint tokens to
     * @param _amount amount of ILV tokens to mint
     */
    function mintYieldTo(address _to, uint256 _amount) external {
        // verify that sender is a pool registered withing the factory
        require(poolExists[msg.sender], "access denied");
        // mint ILV tokens as required
        mintIlv(_to, _amount);
    }
    /**
     * @dev Changes the weight of the pool;
     *      executed by the pool itself or by the factory owner
     *
     * @param poolAddr address of the pool to change weight for
     * @param weight new weight value to set to
     */
    function changePoolWeight(address poolAddr, uint32 weight) external {
        // verify function is executed either by factory owner or by the pool itself
        require(msg.sender == owner() || poolExists[msg.sender]);
        // recalculate total weight
        totalWeight = totalWeight + weight - IPool(poolAddr).weight();
        // set the new pool weight
        IPool(poolAddr).setWeight(weight);
        // emit an event
        emit WeightUpdated(msg.sender, poolAddr, weight);
    }
    /**
     * @dev Testing time-dependent functionality is difficult and the best way of
     *      doing it is to override block number in helper test smart contracts
     *
     * @return `block.number` in mainnet, custom values in testnets (if overridden)
     */
    function blockNumber() public view virtual returns (uint256) {
        // return current block number
        return block.number;
    }
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.1;
import "../interfaces/IERC20.sol";
import "./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'
        // solhint-disable-next-line max-line-length
        require(
            (value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }
    function safeIncreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        uint256 newAllowance = token.allowance(address(this), spender) + value;
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }
    function safeDecreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        uint256 newAllowance = token.allowance(address(this), spender) - value;
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }
    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
        // the target address contains contract code and also asserts for success in the low-level call.
        bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
        if (returndata.length > 0) {
            // Return data is optional
            // solhint-disable-next-line max-line-length
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.1;
import "../utils/ERC20.sol";
import "../utils/AccessControl.sol";
contract EscrowedIlluviumERC20 is ERC20("Escrowed Illuvium", "sILV"), AccessControl {
  /**
   * @dev Smart contract unique identifier, a random number
   * @dev Should be regenerated each time smart contact source code is changed
   *      and changes smart contract itself is to be redeployed
   * @dev Generated using https://www.random.org/bytes/
   */
  uint256 public constant TOKEN_UID = 0xac3051b8d4f50966afb632468a4f61483ae6a953b74e387a01ef94316d6b7d62;
  /**
   * @notice Must be called by ROLE_TOKEN_CREATOR addresses.
   *
   * @param recipient address to receive the tokens.
   * @param amount number of tokens to be minted.
   */
  function mint(address recipient, uint256 amount) external {
    require(isSenderInRole(ROLE_TOKEN_CREATOR), "insufficient privileges (ROLE_TOKEN_CREATOR required)");
    _mint(recipient, amount);
  }
  /**
   * @param amount number of tokens to be burned.
   */
  function burn(uint256 amount) external {
    _burn(msg.sender, amount);
  }
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.1;
/**
 * @title Linked to ILV Marker Interface
 *
 * @notice Marks smart contracts which are linked to IlluviumERC20 token instance upon construction,
 *      all these smart contracts share a common ilv() address getter
 *
 * @notice Implementing smart contracts MUST verify that they get linked to real IlluviumERC20 instance
 *      and that ilv() getter returns this very same instance address
 *
 * @author Basil Gorin
 */
interface ILinkedToILV {
  /**
   * @notice Getter for a verified IlluviumERC20 instance address
   *
   * @return IlluviumERC20 token instance address smart contract is linked to
   */
  function ilv() external view returns (address);
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.1;
import "../token/IlluviumERC20.sol";
import "../interfaces/ILinkedToILV.sol";
/**
 * @title Illuvium Aware
 *
 * @notice Helper smart contract to be inherited by other smart contracts requiring to
 *      be linked to verified IlluviumERC20 instance and performing some basic tasks on it
 *
 * @author Basil Gorin
 */
abstract contract IlluviumAware is ILinkedToILV {
  /// @dev Link to ILV ERC20 Token IlluviumERC20 instance
  address public immutable override ilv;
  /**
   * @dev Creates IlluviumAware instance, requiring to supply deployed IlluviumERC20 instance address
   *
   * @param _ilv deployed IlluviumERC20 instance address
   */
  constructor(address _ilv) {
    // verify ILV address is set and is correct
    require(_ilv != address(0), "ILV address not set");
    require(IlluviumERC20(_ilv).TOKEN_UID() == 0x83ecb176af7c4f35a45ff0018282e3a05a1018065da866182df12285866f5a2c, "unexpected TOKEN_UID");
    // write ILV address
    ilv = _ilv;
  }
  /**
   * @dev Executes IlluviumERC20.safeTransferFrom(address(this), _to, _value, "")
   *      on the bound IlluviumERC20 instance
   *
   * @dev Reentrancy safe due to the IlluviumERC20 design
   */
  function transferIlv(address _to, uint256 _value) internal {
    // just delegate call to the target
    transferIlvFrom(address(this), _to, _value);
  }
  /**
   * @dev Executes IlluviumERC20.transferFrom(_from, _to, _value)
   *      on the bound IlluviumERC20 instance
   *
   * @dev Reentrancy safe due to the IlluviumERC20 design
   */
  function transferIlvFrom(address _from, address _to, uint256 _value) internal {
    // just delegate call to the target
    IlluviumERC20(ilv).transferFrom(_from, _to, _value);
  }
  /**
   * @dev Executes IlluviumERC20.mint(_to, _values)
   *      on the bound IlluviumERC20 instance
   *
   * @dev Reentrancy safe due to the IlluviumERC20 design
   */
  function mintIlv(address _to, uint256 _value) internal {
    // just delegate call to the target
    IlluviumERC20(ilv).mint(_to, _value);
  }
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.1;
/**
 * @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 {
    address private _owner;
    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor() {
        address msgSender = msg.sender;
        _owner = msgSender;
        emit OwnershipTransferred(address(0), msgSender);
    }
    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }
    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(owner() == msg.sender, "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;
    }
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.1;
import "../utils/AddressUtils.sol";
import "../utils/AccessControl.sol";
import "./ERC20Receiver.sol";
/**
 * @title Illuvium (ILV) ERC20 token
 *
 * @notice Illuvium is a core ERC20 token powering the game.
 *      It serves as an in-game currency, is tradable on exchanges,
 *      it powers up the governance protocol (Illuvium DAO) and participates in Yield Farming.
 *
 * @dev Token Summary:
 *      - Symbol: ILV
 *      - Name: Illuvium
 *      - Decimals: 18
 *      - Initial token supply: 7,000,000 ILV
 *      - Maximum final token supply: 10,000,000 ILV
 *          - Up to 3,000,000 ILV may get minted in 3 years period via yield farming
 *      - Mintable: total supply may increase
 *      - Burnable: total supply may decrease
 *
 * @dev Token balances and total supply are effectively 192 bits long, meaning that maximum
 *      possible total supply smart contract is able to track is 2^192 (close to 10^40 tokens)
 *
 * @dev Smart contract doesn't use safe math. All arithmetic operations are overflow/underflow safe.
 *      Additionally, Solidity 0.8.1 enforces overflow/underflow safety.
 *
 * @dev ERC20: reviewed according to https://eips.ethereum.org/EIPS/eip-20
 *
 * @dev ERC20: contract has passed OpenZeppelin ERC20 tests,
 *      see https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/test/token/ERC20/ERC20.behavior.js
 *      see https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/test/token/ERC20/ERC20.test.js
 *      see adopted copies of these tests in the `test` folder
 *
 * @dev ERC223/ERC777: not supported;
 *      send tokens via `safeTransferFrom` and implement `ERC20Receiver.onERC20Received` on the receiver instead
 *
 * @dev Multiple Withdrawal Attack on ERC20 Tokens (ISBN:978-1-7281-3027-9) - resolved
 *      Related events and functions are marked with "ISBN:978-1-7281-3027-9" tag:
 *        - event Transferred(address indexed _by, address indexed _from, address indexed _to, uint256 _value)
 *        - event Approved(address indexed _owner, address indexed _spender, uint256 _oldValue, uint256 _value)
 *        - function increaseAllowance(address _spender, uint256 _value) public returns (bool)
 *        - function decreaseAllowance(address _spender, uint256 _value) public returns (bool)
 *      See: https://ieeexplore.ieee.org/document/8802438
 *      See: https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
 *
 * @author Basil Gorin
 */
contract IlluviumERC20 is AccessControl {
  /**
   * @dev Smart contract unique identifier, a random number
   * @dev Should be regenerated each time smart contact source code is changed
   *      and changes smart contract itself is to be redeployed
   * @dev Generated using https://www.random.org/bytes/
   */
  uint256 public constant TOKEN_UID = 0x83ecb176af7c4f35a45ff0018282e3a05a1018065da866182df12285866f5a2c;
  /**
   * @notice Name of the token: Illuvium
   *
   * @notice ERC20 name of the token (long name)
   *
   * @dev ERC20 `function name() public view returns (string)`
   *
   * @dev Field is declared public: getter name() is created when compiled,
   *      it returns the name of the token.
   */
  string public constant name = "Illuvium";
  /**
   * @notice Symbol of the token: ILV
   *
   * @notice ERC20 symbol of that token (short name)
   *
   * @dev ERC20 `function symbol() public view returns (string)`
   *
   * @dev Field is declared public: getter symbol() is created when compiled,
   *      it returns the symbol of the token
   */
  string public constant symbol = "ILV";
  /**
   * @notice Decimals of the token: 18
   *
   * @dev ERC20 `function decimals() public view returns (uint8)`
   *
   * @dev Field is declared public: getter decimals() is created when compiled,
   *      it returns the number of decimals used to get its user representation.
   *      For example, if `decimals` equals `6`, a balance of `1,500,000` tokens should
   *      be displayed to a user as `1,5` (`1,500,000 / 10 ** 6`).
   *
   * @dev NOTE: This information is only used for _display_ purposes: it in
   *      no way affects any of the arithmetic of the contract, including balanceOf() and transfer().
   */
  uint8 public constant decimals = 18;
  /**
   * @notice Total supply of the token: initially 7,000,000,
   *      with the potential to grow up to 10,000,000 during yield farming period (3 years)
   *
   * @dev ERC20 `function totalSupply() public view returns (uint256)`
   *
   * @dev Field is declared public: getter totalSupply() is created when compiled,
   *      it returns the amount of tokens in existence.
   */
  uint256 public totalSupply; // is set to 7 million * 10^18 in the constructor
  /**
   * @dev A record of all the token balances
   * @dev This mapping keeps record of all token owners:
   *      owner => balance
   */
  mapping(address => uint256) public tokenBalances;
  /**
   * @notice A record of each account's voting delegate
   *
   * @dev Auxiliary data structure used to sum up an account's voting power
   *
   * @dev This mapping keeps record of all voting power delegations:
   *      voting delegator (token owner) => voting delegate
   */
  mapping(address => address) public votingDelegates;
  /**
   * @notice A voting power record binds voting power of a delegate to a particular
   *      block when the voting power delegation change happened
   */
  struct VotingPowerRecord {
    /*
     * @dev block.number when delegation has changed; starting from
     *      that block voting power value is in effect
     */
    uint64 blockNumber;
    /*
     * @dev cumulative voting power a delegate has obtained starting
     *      from the block stored in blockNumber
     */
    uint192 votingPower;
  }
  /**
   * @notice A record of each account's voting power
   *
   * @dev Primarily data structure to store voting power for each account.
   *      Voting power sums up from the account's token balance and delegated
   *      balances.
   *
   * @dev Stores current value and entire history of its changes.
   *      The changes are stored as an array of checkpoints.
   *      Checkpoint is an auxiliary data structure containing voting
   *      power (number of votes) and block number when the checkpoint is saved
   *
   * @dev Maps voting delegate => voting power record
   */
  mapping(address => VotingPowerRecord[]) public votingPowerHistory;
  /**
   * @dev A record of nonces for signing/validating signatures in `delegateWithSig`
   *      for every delegate, increases after successful validation
   *
   * @dev Maps delegate address => delegate nonce
   */
  mapping(address => uint256) public nonces;
  /**
   * @notice A record of all the allowances to spend tokens on behalf
   * @dev Maps token owner address to an address approved to spend
   *      some tokens on behalf, maps approved address to that amount
   * @dev owner => spender => value
   */
  mapping(address => mapping(address => uint256)) public transferAllowances;
  /**
   * @notice Enables ERC20 transfers of the tokens
   *      (transfer by the token owner himself)
   * @dev Feature FEATURE_TRANSFERS must be enabled in order for
   *      `transfer()` function to succeed
   */
  uint32 public constant FEATURE_TRANSFERS = 0x0000_0001;
  /**
   * @notice Enables ERC20 transfers on behalf
   *      (transfer by someone else on behalf of token owner)
   * @dev Feature FEATURE_TRANSFERS_ON_BEHALF must be enabled in order for
   *      `transferFrom()` function to succeed
   * @dev Token owner must call `approve()` first to authorize
   *      the transfer on behalf
   */
  uint32 public constant FEATURE_TRANSFERS_ON_BEHALF = 0x0000_0002;
  /**
   * @dev Defines if the default behavior of `transfer` and `transferFrom`
   *      checks if the receiver smart contract supports ERC20 tokens
   * @dev When feature FEATURE_UNSAFE_TRANSFERS is enabled the transfers do not
   *      check if the receiver smart contract supports ERC20 tokens,
   *      i.e. `transfer` and `transferFrom` behave like `unsafeTransferFrom`
   * @dev When feature FEATURE_UNSAFE_TRANSFERS is disabled (default) the transfers
   *      check if the receiver smart contract supports ERC20 tokens,
   *      i.e. `transfer` and `transferFrom` behave like `safeTransferFrom`
   */
  uint32 public constant FEATURE_UNSAFE_TRANSFERS = 0x0000_0004;
  /**
   * @notice Enables token owners to burn their own tokens,
   *      including locked tokens which are burnt first
   * @dev Feature FEATURE_OWN_BURNS must be enabled in order for
   *      `burn()` function to succeed when called by token owner
   */
  uint32 public constant FEATURE_OWN_BURNS = 0x0000_0008;
  /**
   * @notice Enables approved operators to burn tokens on behalf of their owners,
   *      including locked tokens which are burnt first
   * @dev Feature FEATURE_OWN_BURNS must be enabled in order for
   *      `burn()` function to succeed when called by approved operator
   */
  uint32 public constant FEATURE_BURNS_ON_BEHALF = 0x0000_0010;
  /**
   * @notice Enables delegators to elect delegates
   * @dev Feature FEATURE_DELEGATIONS must be enabled in order for
   *      `delegate()` function to succeed
   */
  uint32 public constant FEATURE_DELEGATIONS = 0x0000_0020;
  /**
   * @notice Enables delegators to elect delegates on behalf
   *      (via an EIP712 signature)
   * @dev Feature FEATURE_DELEGATIONS must be enabled in order for
   *      `delegateWithSig()` function to succeed
   */
  uint32 public constant FEATURE_DELEGATIONS_ON_BEHALF = 0x0000_0040;
  /**
   * @notice Token creator is responsible for creating (minting)
   *      tokens to an arbitrary address
   * @dev Role ROLE_TOKEN_CREATOR allows minting tokens
   *      (calling `mint` function)
   */
  uint32 public constant ROLE_TOKEN_CREATOR = 0x0001_0000;
  /**
   * @notice Token destroyer is responsible for destroying (burning)
   *      tokens owned by an arbitrary address
   * @dev Role ROLE_TOKEN_DESTROYER allows burning tokens
   *      (calling `burn` function)
   */
  uint32 public constant ROLE_TOKEN_DESTROYER = 0x0002_0000;
  /**
   * @notice ERC20 receivers are allowed to receive tokens without ERC20 safety checks,
   *      which may be useful to simplify tokens transfers into "legacy" smart contracts
   * @dev When `FEATURE_UNSAFE_TRANSFERS` is not enabled addresses having
   *      `ROLE_ERC20_RECEIVER` permission are allowed to receive tokens
   *      via `transfer` and `transferFrom` functions in the same way they
   *      would via `unsafeTransferFrom` function
   * @dev When `FEATURE_UNSAFE_TRANSFERS` is enabled `ROLE_ERC20_RECEIVER` permission
   *      doesn't affect the transfer behaviour since
   *      `transfer` and `transferFrom` behave like `unsafeTransferFrom` for any receiver
   * @dev ROLE_ERC20_RECEIVER is a shortening for ROLE_UNSAFE_ERC20_RECEIVER
   */
  uint32 public constant ROLE_ERC20_RECEIVER = 0x0004_0000;
  /**
   * @notice ERC20 senders are allowed to send tokens without ERC20 safety checks,
   *      which may be useful to simplify tokens transfers into "legacy" smart contracts
   * @dev When `FEATURE_UNSAFE_TRANSFERS` is not enabled senders having
   *      `ROLE_ERC20_SENDER` permission are allowed to send tokens
   *      via `transfer` and `transferFrom` functions in the same way they
   *      would via `unsafeTransferFrom` function
   * @dev When `FEATURE_UNSAFE_TRANSFERS` is enabled `ROLE_ERC20_SENDER` permission
   *      doesn't affect the transfer behaviour since
   *      `transfer` and `transferFrom` behave like `unsafeTransferFrom` for any receiver
   * @dev ROLE_ERC20_SENDER is a shortening for ROLE_UNSAFE_ERC20_SENDER
   */
  uint32 public constant ROLE_ERC20_SENDER = 0x0008_0000;
  /**
   * @dev Magic value to be returned by ERC20Receiver upon successful reception of token(s)
   * @dev Equal to `bytes4(keccak256("onERC20Received(address,address,uint256,bytes)"))`,
   *      which can be also obtained as `ERC20Receiver(address(0)).onERC20Received.selector`
   */
  bytes4 private constant ERC20_RECEIVED = 0x4fc35859;
  /**
   * @notice EIP-712 contract's domain typeHash, see https://eips.ethereum.org/EIPS/eip-712#rationale-for-typehash
   */
  bytes32 public constant DOMAIN_TYPEHASH = keccak256("EIP712Domain(string name,uint256 chainId,address verifyingContract)");
  /**
   * @notice EIP-712 delegation struct typeHash, see https://eips.ethereum.org/EIPS/eip-712#rationale-for-typehash
   */
  bytes32 public constant DELEGATION_TYPEHASH = keccak256("Delegation(address delegate,uint256 nonce,uint256 expiry)");
  /**
   * @dev Fired in transfer(), transferFrom() and some other (non-ERC20) functions
   *
   * @dev ERC20 `event Transfer(address indexed _from, address indexed _to, uint256 _value)`
   *
   * @param _from an address tokens were consumed from
   * @param _to an address tokens were sent to
   * @param _value number of tokens transferred
   */
  event Transfer(address indexed _from, address indexed _to, uint256 _value);
  /**
   * @dev Fired in approve() and approveAtomic() functions
   *
   * @dev ERC20 `event Approval(address indexed _owner, address indexed _spender, uint256 _value)`
   *
   * @param _owner an address which granted a permission to transfer
   *      tokens on its behalf
   * @param _spender an address which received a permission to transfer
   *      tokens on behalf of the owner `_owner`
   * @param _value amount of tokens granted to transfer on behalf
   */
  event Approval(address indexed _owner, address indexed _spender, uint256 _value);
  /**
   * @dev Fired in mint() function
   *
   * @param _by an address which minted some tokens (transaction sender)
   * @param _to an address the tokens were minted to
   * @param _value an amount of tokens minted
   */
  event Minted(address indexed _by, address indexed _to, uint256 _value);
  /**
   * @dev Fired in burn() function
   *
   * @param _by an address which burned some tokens (transaction sender)
   * @param _from an address the tokens were burnt from
   * @param _value an amount of tokens burnt
   */
  event Burnt(address indexed _by, address indexed _from, uint256 _value);
  /**
   * @dev Resolution for the Multiple Withdrawal Attack on ERC20 Tokens (ISBN:978-1-7281-3027-9)
   *
   * @dev Similar to ERC20 Transfer event, but also logs an address which executed transfer
   *
   * @dev Fired in transfer(), transferFrom() and some other (non-ERC20) functions
   *
   * @param _by an address which performed the transfer
   * @param _from an address tokens were consumed from
   * @param _to an address tokens were sent to
   * @param _value number of tokens transferred
   */
  event Transferred(address indexed _by, address indexed _from, address indexed _to, uint256 _value);
  /**
   * @dev Resolution for the Multiple Withdrawal Attack on ERC20 Tokens (ISBN:978-1-7281-3027-9)
   *
   * @dev Similar to ERC20 Approve event, but also logs old approval value
   *
   * @dev Fired in approve() and approveAtomic() functions
   *
   * @param _owner an address which granted a permission to transfer
   *      tokens on its behalf
   * @param _spender an address which received a permission to transfer
   *      tokens on behalf of the owner `_owner`
   * @param _oldValue previously granted amount of tokens to transfer on behalf
   * @param _value new granted amount of tokens to transfer on behalf
   */
  event Approved(address indexed _owner, address indexed _spender, uint256 _oldValue, uint256 _value);
  /**
   * @dev Notifies that a key-value pair in `votingDelegates` mapping has changed,
   *      i.e. a delegator address has changed its delegate address
   *
   * @param _of delegator address, a token owner
   * @param _from old delegate, an address which delegate right is revoked
   * @param _to new delegate, an address which received the voting power
   */
  event DelegateChanged(address indexed _of, address indexed _from, address indexed _to);
  /**
   * @dev Notifies that a key-value pair in `votingPowerHistory` mapping has changed,
   *      i.e. a delegate's voting power has changed.
   *
   * @param _of delegate whose voting power has changed
   * @param _fromVal previous number of votes delegate had
   * @param _toVal new number of votes delegate has
   */
  event VotingPowerChanged(address indexed _of, uint256 _fromVal, uint256 _toVal);
  /**
   * @dev Deploys the token smart contract,
   *      assigns initial token supply to the address specified
   *
   * @param _initialHolder owner of the initial token supply
   */
  constructor(address _initialHolder) {
    // verify initial holder address non-zero (is set)
    require(_initialHolder != address(0), "_initialHolder not set (zero address)");
    // mint initial supply
    mint(_initialHolder, 7_000_000e18);
  }
  // ===== Start: ERC20/ERC223/ERC777 functions =====
  /**
   * @notice Gets the balance of a particular address
   *
   * @dev ERC20 `function balanceOf(address _owner) public view returns (uint256 balance)`
   *
   * @param _owner the address to query the the balance for
   * @return balance an amount of tokens owned by the address specified
   */
  function balanceOf(address _owner) public view returns (uint256 balance) {
    // read the balance and return
    return tokenBalances[_owner];
  }
  /**
   * @notice Transfers some tokens to an external address or a smart contract
   *
   * @dev ERC20 `function transfer(address _to, uint256 _value) public returns (bool success)`
   *
   * @dev Called by token owner (an address which has a
   *      positive token balance tracked by this smart contract)
   * @dev Throws on any error like
   *      * insufficient token balance or
   *      * incorrect `_to` address:
   *          * zero address or
   *          * self address or
   *          * smart contract which doesn't support ERC20
   *
   * @param _to an address to transfer tokens to,
   *      must be either an external address or a smart contract,
   *      compliant with the ERC20 standard
   * @param _value amount of tokens to be transferred, must
   *      be greater than zero
   * @return success true on success, throws otherwise
   */
  function transfer(address _to, uint256 _value) public returns (bool success) {
    // just delegate call to `transferFrom`,
    // `FEATURE_TRANSFERS` is verified inside it
    return transferFrom(msg.sender, _to, _value);
  }
  /**
   * @notice Transfers some tokens on behalf of address `_from' (token owner)
   *      to some other address `_to`
   *
   * @dev ERC20 `function transferFrom(address _from, address _to, uint256 _value) public returns (bool success)`
   *
   * @dev Called by token owner on his own or approved address,
   *      an address approved earlier by token owner to
   *      transfer some amount of tokens on its behalf
   * @dev Throws on any error like
   *      * insufficient token balance or
   *      * incorrect `_to` address:
   *          * zero address or
   *          * same as `_from` address (self transfer)
   *          * smart contract which doesn't support ERC20
   *
   * @param _from token owner which approved caller (transaction sender)
   *      to transfer `_value` of tokens on its behalf
   * @param _to an address to transfer tokens to,
   *      must be either an external address or a smart contract,
   *      compliant with the ERC20 standard
   * @param _value amount of tokens to be transferred, must
   *      be greater than zero
   * @return success true on success, throws otherwise
   */
  function transferFrom(address _from, address _to, uint256 _value) public returns (bool success) {
    // depending on `FEATURE_UNSAFE_TRANSFERS` we execute either safe (default)
    // or unsafe transfer
    // if `FEATURE_UNSAFE_TRANSFERS` is enabled
    // or receiver has `ROLE_ERC20_RECEIVER` permission
    // or sender has `ROLE_ERC20_SENDER` permission
    if(isFeatureEnabled(FEATURE_UNSAFE_TRANSFERS)
      || isOperatorInRole(_to, ROLE_ERC20_RECEIVER)
      || isSenderInRole(ROLE_ERC20_SENDER)) {
      // we execute unsafe transfer - delegate call to `unsafeTransferFrom`,
      // `FEATURE_TRANSFERS` is verified inside it
      unsafeTransferFrom(_from, _to, _value);
    }
    // otherwise - if `FEATURE_UNSAFE_TRANSFERS` is disabled
    // and receiver doesn't have `ROLE_ERC20_RECEIVER` permission
    else {
      // we execute safe transfer - delegate call to `safeTransferFrom`, passing empty `_data`,
      // `FEATURE_TRANSFERS` is verified inside it
      safeTransferFrom(_from, _to, _value, "");
    }
    // both `unsafeTransferFrom` and `safeTransferFrom` throw on any error, so
    // if we're here - it means operation successful,
    // just return true
    return true;
  }
  /**
   * @notice Transfers some tokens on behalf of address `_from' (token owner)
   *      to some other address `_to`
   *
   * @dev Inspired by ERC721 safeTransferFrom, this function allows to
   *      send arbitrary data to the receiver on successful token transfer
   * @dev Called by token owner on his own or approved address,
   *      an address approved earlier by token owner to
   *      transfer some amount of tokens on its behalf
   * @dev Throws on any error like
   *      * insufficient token balance or
   *      * incorrect `_to` address:
   *          * zero address or
   *          * same as `_from` address (self transfer)
   *          * smart contract which doesn't support ERC20Receiver interface
   * @dev Returns silently on success, throws otherwise
   *
   * @param _from token owner which approved caller (transaction sender)
   *      to transfer `_value` of tokens on its behalf
   * @param _to an address to transfer tokens to,
   *      must be either an external address or a smart contract,
   *      compliant with the ERC20 standard
   * @param _value amount of tokens to be transferred, must
   *      be greater than zero
   * @param _data [optional] additional data with no specified format,
   *      sent in onERC20Received call to `_to` in case if its a smart contract
   */
  function safeTransferFrom(address _from, address _to, uint256 _value, bytes memory _data) public {
    // first delegate call to `unsafeTransferFrom`
    // to perform the unsafe token(s) transfer
    unsafeTransferFrom(_from, _to, _value);
    // after the successful transfer - check if receiver supports
    // ERC20Receiver and execute a callback handler `onERC20Received`,
    // reverting whole transaction on any error:
    // check if receiver `_to` supports ERC20Receiver interface
    if(AddressUtils.isContract(_to)) {
      // if `_to` is a contract - execute onERC20Received
      bytes4 response = ERC20Receiver(_to).onERC20Received(msg.sender, _from, _value, _data);
      // expected response is ERC20_RECEIVED
      require(response == ERC20_RECEIVED, "invalid onERC20Received response");
    }
  }
  /**
   * @notice Transfers some tokens on behalf of address `_from' (token owner)
   *      to some other address `_to`
   *
   * @dev In contrast to `safeTransferFrom` doesn't check recipient
   *      smart contract to support ERC20 tokens (ERC20Receiver)
   * @dev Designed to be used by developers when the receiver is known
   *      to support ERC20 tokens but doesn't implement ERC20Receiver interface
   * @dev Called by token owner on his own or approved address,
   *      an address approved earlier by token owner to
   *      transfer some amount of tokens on its behalf
   * @dev Throws on any error like
   *      * insufficient token balance or
   *      * incorrect `_to` address:
   *          * zero address or
   *          * same as `_from` address (self transfer)
   * @dev Returns silently on success, throws otherwise
   *
   * @param _from token owner which approved caller (transaction sender)
   *      to transfer `_value` of tokens on its behalf
   * @param _to an address to transfer tokens to,
   *      must be either an external address or a smart contract,
   *      compliant with the ERC20 standard
   * @param _value amount of tokens to be transferred, must
   *      be greater than zero
   */
  function unsafeTransferFrom(address _from, address _to, uint256 _value) public {
    // if `_from` is equal to sender, require transfers feature to be enabled
    // otherwise require transfers on behalf feature to be enabled
    require(_from == msg.sender && isFeatureEnabled(FEATURE_TRANSFERS)
         || _from != msg.sender && isFeatureEnabled(FEATURE_TRANSFERS_ON_BEHALF),
            _from == msg.sender? "transfers are disabled": "transfers on behalf are disabled");
    // non-zero source address check - Zeppelin
    // obviously, zero source address is a client mistake
    // it's not part of ERC20 standard but it's reasonable to fail fast
    // since for zero value transfer transaction succeeds otherwise
    require(_from != address(0), "ERC20: transfer from the zero address"); // Zeppelin msg
    // non-zero recipient address check
    require(_to != address(0), "ERC20: transfer to the zero address"); // Zeppelin msg
    // sender and recipient cannot be the same
    require(_from != _to, "sender and recipient are the same (_from = _to)");
    // sending tokens to the token smart contract itself is a client mistake
    require(_to != address(this), "invalid recipient (transfer to the token smart contract itself)");
    // according to ERC-20 Token Standard, https://eips.ethereum.org/EIPS/eip-20
    // "Transfers of 0 values MUST be treated as normal transfers and fire the Transfer event."
    if(_value == 0) {
      // emit an ERC20 transfer event
      emit Transfer(_from, _to, _value);
      // don't forget to return - we're done
      return;
    }
    // no need to make arithmetic overflow check on the _value - by design of mint()
    // in case of transfer on behalf
    if(_from != msg.sender) {
      // read allowance value - the amount of tokens allowed to transfer - into the stack
      uint256 _allowance = transferAllowances[_from][msg.sender];
      // verify sender has an allowance to transfer amount of tokens requested
      require(_allowance >= _value, "ERC20: transfer amount exceeds allowance"); // Zeppelin msg
      // update allowance value on the stack
      _allowance -= _value;
      // update the allowance value in storage
      transferAllowances[_from][msg.sender] = _allowance;
      // emit an improved atomic approve event
      emit Approved(_from, msg.sender, _allowance + _value, _allowance);
      // emit an ERC20 approval event to reflect the decrease
      emit Approval(_from, msg.sender, _allowance);
    }
    // verify sender has enough tokens to transfer on behalf
    require(tokenBalances[_from] >= _value, "ERC20: transfer amount exceeds balance"); // Zeppelin msg
    // perform the transfer:
    // decrease token owner (sender) balance
    tokenBalances[_from] -= _value;
    // increase `_to` address (receiver) balance
    tokenBalances[_to] += _value;
    // move voting power associated with the tokens transferred
    __moveVotingPower(votingDelegates[_from], votingDelegates[_to], _value);
    // emit an improved transfer event
    emit Transferred(msg.sender, _from, _to, _value);
    // emit an ERC20 transfer event
    emit Transfer(_from, _to, _value);
  }
  /**
   * @notice Approves address called `_spender` to transfer some amount
   *      of tokens on behalf of the owner
   *
   * @dev ERC20 `function approve(address _spender, uint256 _value) public returns (bool success)`
   *
   * @dev Caller must not necessarily own any tokens to grant the permission
   *
   * @param _spender an address approved by the caller (token owner)
   *      to spend some tokens on its behalf
   * @param _value an amount of tokens spender `_spender` is allowed to
   *      transfer on behalf of the token owner
   * @return success true on success, throws otherwise
   */
  function approve(address _spender, uint256 _value) public returns (bool success) {
    // non-zero spender address check - Zeppelin
    // obviously, zero spender address is a client mistake
    // it's not part of ERC20 standard but it's reasonable to fail fast
    require(_spender != address(0), "ERC20: approve to the zero address"); // Zeppelin msg
    // read old approval value to emmit an improved event (ISBN:978-1-7281-3027-9)
    uint256 _oldValue = transferAllowances[msg.sender][_spender];
    // perform an operation: write value requested into the storage
    transferAllowances[msg.sender][_spender] = _value;
    // emit an improved atomic approve event (ISBN:978-1-7281-3027-9)
    emit Approved(msg.sender, _spender, _oldValue, _value);
    // emit an ERC20 approval event
    emit Approval(msg.sender, _spender, _value);
    // operation successful, return true
    return true;
  }
  /**
   * @notice Returns the amount which _spender is still allowed to withdraw from _owner.
   *
   * @dev ERC20 `function allowance(address _owner, address _spender) public view returns (uint256 remaining)`
   *
   * @dev A function to check an amount of tokens owner approved
   *      to transfer on its behalf by some other address called "spender"
   *
   * @param _owner an address which approves transferring some tokens on its behalf
   * @param _spender an address approved to transfer some tokens on behalf
   * @return remaining an amount of tokens approved address `_spender` can transfer on behalf
   *      of token owner `_owner`
   */
  function allowance(address _owner, address _spender) public view returns (uint256 remaining) {
    // read the value from storage and return
    return transferAllowances[_owner][_spender];
  }
  // ===== End: ERC20/ERC223/ERC777 functions =====
  // ===== Start: Resolution for the Multiple Withdrawal Attack on ERC20 Tokens (ISBN:978-1-7281-3027-9) =====
  /**
   * @notice Increases the allowance granted to `spender` by the transaction sender
   *
   * @dev Resolution for the Multiple Withdrawal Attack on ERC20 Tokens (ISBN:978-1-7281-3027-9)
   *
   * @dev Throws if value to increase by is zero or too big and causes arithmetic overflow
   *
   * @param _spender an address approved by the caller (token owner)
   *      to spend some tokens on its behalf
   * @param _value an amount of tokens to increase by
   * @return success true on success, throws otherwise
   */
  function increaseAllowance(address _spender, uint256 _value) public virtual returns (bool) {
    // read current allowance value
    uint256 currentVal = transferAllowances[msg.sender][_spender];
    // non-zero _value and arithmetic overflow check on the allowance
    require(currentVal + _value > currentVal, "zero value approval increase or arithmetic overflow");
    // delegate call to `approve` with the new value
    return approve(_spender, currentVal + _value);
  }
  /**
   * @notice Decreases the allowance granted to `spender` by the caller.
   *
   * @dev Resolution for the Multiple Withdrawal Attack on ERC20 Tokens (ISBN:978-1-7281-3027-9)
   *
   * @dev Throws if value to decrease by is zero or is bigger than currently allowed value
   *
   * @param _spender an address approved by the caller (token owner)
   *      to spend some tokens on its behalf
   * @param _value an amount of tokens to decrease by
   * @return success true on success, throws otherwise
   */
  function decreaseAllowance(address _spender, uint256 _value) public virtual returns (bool) {
    // read current allowance value
    uint256 currentVal = transferAllowances[msg.sender][_spender];
    // non-zero _value check on the allowance
    require(_value > 0, "zero value approval decrease");
    // verify allowance decrease doesn't underflow
    require(currentVal >= _value, "ERC20: decreased allowance below zero");
    // delegate call to `approve` with the new value
    return approve(_spender, currentVal - _value);
  }
  // ===== End: Resolution for the Multiple Withdrawal Attack on ERC20 Tokens (ISBN:978-1-7281-3027-9) =====
  // ===== Start: Minting/burning extension =====
  /**
   * @dev Mints (creates) some tokens to address specified
   * @dev The value specified is treated as is without taking
   *      into account what `decimals` value is
   * @dev Behaves effectively as `mintTo` function, allowing
   *      to specify an address to mint tokens to
   * @dev Requires sender to have `ROLE_TOKEN_CREATOR` permission
   *
   * @dev Throws on overflow, if totalSupply + _value doesn't fit into uint256
   *
   * @param _to an address to mint tokens to
   * @param _value an amount of tokens to mint (create)
   */
  function mint(address _to, uint256 _value) public {
    // check if caller has sufficient permissions to mint tokens
    require(isSenderInRole(ROLE_TOKEN_CREATOR), "insufficient privileges (ROLE_TOKEN_CREATOR required)");
    // non-zero recipient address check
    require(_to != address(0), "ERC20: mint to the zero address"); // Zeppelin msg
    // non-zero _value and arithmetic overflow check on the total supply
    // this check automatically secures arithmetic overflow on the individual balance
    require(totalSupply + _value > totalSupply, "zero value mint or arithmetic overflow");
    // uint192 overflow check (required by voting delegation)
    require(totalSupply + _value <= type(uint192).max, "total supply overflow (uint192)");
    // perform mint:
    // increase total amount of tokens value
    totalSupply += _value;
    // increase `_to` address balance
    tokenBalances[_to] += _value;
    // create voting power associated with the tokens minted
    __moveVotingPower(address(0), votingDelegates[_to], _value);
    // fire a minted event
    emit Minted(msg.sender, _to, _value);
    // emit an improved transfer event
    emit Transferred(msg.sender, address(0), _to, _value);
    // fire ERC20 compliant transfer event
    emit Transfer(address(0), _to, _value);
  }
  /**
   * @dev Burns (destroys) some tokens from the address specified
   * @dev The value specified is treated as is without taking
   *      into account what `decimals` value is
   * @dev Behaves effectively as `burnFrom` function, allowing
   *      to specify an address to burn tokens from
   * @dev Requires sender to have `ROLE_TOKEN_DESTROYER` permission
   *
   * @param _from an address to burn some tokens from
   * @param _value an amount of tokens to burn (destroy)
   */
  function burn(address _from, uint256 _value) public {
    // check if caller has sufficient permissions to burn tokens
    // and if not - check for possibility to burn own tokens or to burn on behalf
    if(!isSenderInRole(ROLE_TOKEN_DESTROYER)) {
      // if `_from` is equal to sender, require own burns feature to be enabled
      // otherwise require burns on behalf feature to be enabled
      require(_from == msg.sender && isFeatureEnabled(FEATURE_OWN_BURNS)
           || _from != msg.sender && isFeatureEnabled(FEATURE_BURNS_ON_BEHALF),
              _from == msg.sender? "burns are disabled": "burns on behalf are disabled");
      // in case of burn on behalf
      if(_from != msg.sender) {
        // read allowance value - the amount of tokens allowed to be burnt - into the stack
        uint256 _allowance = transferAllowances[_from][msg.sender];
        // verify sender has an allowance to burn amount of tokens requested
        require(_allowance >= _value, "ERC20: burn amount exceeds allowance"); // Zeppelin msg
        // update allowance value on the stack
        _allowance -= _value;
        // update the allowance value in storage
        transferAllowances[_from][msg.sender] = _allowance;
        // emit an improved atomic approve event
        emit Approved(msg.sender, _from, _allowance + _value, _allowance);
        // emit an ERC20 approval event to reflect the decrease
        emit Approval(_from, msg.sender, _allowance);
      }
    }
    // at this point we know that either sender is ROLE_TOKEN_DESTROYER or
    // we burn own tokens or on behalf (in latest case we already checked and updated allowances)
    // we have left to execute balance checks and burning logic itself
    // non-zero burn value check
    require(_value != 0, "zero value burn");
    // non-zero source address check - Zeppelin
    require(_from != address(0), "ERC20: burn from the zero address"); // Zeppelin msg
    // verify `_from` address has enough tokens to destroy
    // (basically this is a arithmetic overflow check)
    require(tokenBalances[_from] >= _value, "ERC20: burn amount exceeds balance"); // Zeppelin msg
    // perform burn:
    // decrease `_from` address balance
    tokenBalances[_from] -= _value;
    // decrease total amount of tokens value
    totalSupply -= _value;
    // destroy voting power associated with the tokens burnt
    __moveVotingPower(votingDelegates[_from], address(0), _value);
    // fire a burnt event
    emit Burnt(msg.sender, _from, _value);
    // emit an improved transfer event
    emit Transferred(msg.sender, _from, address(0), _value);
    // fire ERC20 compliant transfer event
    emit Transfer(_from, address(0), _value);
  }
  // ===== End: Minting/burning extension =====
  // ===== Start: DAO Support (Compound-like voting delegation) =====
  /**
   * @notice Gets current voting power of the account `_of`
   * @param _of the address of account to get voting power of
   * @return current cumulative voting power of the account,
   *      sum of token balances of all its voting delegators
   */
  function getVotingPower(address _of) public view returns (uint256) {
    // get a link to an array of voting power history records for an address specified
    VotingPowerRecord[] storage history = votingPowerHistory[_of];
    // lookup the history and return latest element
    return history.length == 0? 0: history[history.length - 1].votingPower;
  }
  /**
   * @notice Gets past voting power of the account `_of` at some block `_blockNum`
   * @dev Throws if `_blockNum` is not in the past (not the finalized block)
   * @param _of the address of account to get voting power of
   * @param _blockNum block number to get the voting power at
   * @return past cumulative voting power of the account,
   *      sum of token balances of all its voting delegators at block number `_blockNum`
   */
  function getVotingPowerAt(address _of, uint256 _blockNum) public view returns (uint256) {
    // make sure block number is not in the past (not the finalized block)
    require(_blockNum < block.number, "not yet determined"); // Compound msg
    // get a link to an array of voting power history records for an address specified
    VotingPowerRecord[] storage history = votingPowerHistory[_of];
    // if voting power history for the account provided is empty
    if(history.length == 0) {
      // than voting power is zero - return the result
      return 0;
    }
    // check latest voting power history record block number:
    // if history was not updated after the block of interest
    if(history[history.length - 1].blockNumber <= _blockNum) {
      // we're done - return last voting power record
      return getVotingPower(_of);
    }
    // check first voting power history record block number:
    // if history was never updated before the block of interest
    if(history[0].blockNumber > _blockNum) {
      // we're done - voting power at the block num of interest was zero
      return 0;
    }
    // `votingPowerHistory[_of]` is an array ordered by `blockNumber`, ascending;
    // apply binary search on `votingPowerHistory[_of]` to find such an entry number `i`, that
    // `votingPowerHistory[_of][i].blockNumber <= _blockNum`, but in the same time
    // `votingPowerHistory[_of][i + 1].blockNumber > _blockNum`
    // return the result - voting power found at index `i`
    return history[__binaryLookup(_of, _blockNum)].votingPower;
  }
  /**
   * @dev Reads an entire voting power history array for the delegate specified
   *
   * @param _of delegate to query voting power history for
   * @return voting power history array for the delegate of interest
   */
  function getVotingPowerHistory(address _of) public view returns(VotingPowerRecord[] memory) {
    // return an entire array as memory
    return votingPowerHistory[_of];
  }
  /**
   * @dev Returns length of the voting power history array for the delegate specified;
   *      useful since reading an entire array just to get its length is expensive (gas cost)
   *
   * @param _of delegate to query voting power history length for
   * @return voting power history array length for the delegate of interest
   */
  function getVotingPowerHistoryLength(address _of) public view returns(uint256) {
    // read array length and return
    return votingPowerHistory[_of].length;
  }
  /**
   * @notice Delegates voting power of the delegator `msg.sender` to the delegate `_to`
   *
   * @dev Accepts zero value address to delegate voting power to, effectively
   *      removing the delegate in that case
   *
   * @param _to address to delegate voting power to
   */
  function delegate(address _to) public {
    // verify delegations are enabled
    require(isFeatureEnabled(FEATURE_DELEGATIONS), "delegations are disabled");
    // delegate call to `__delegate`
    __delegate(msg.sender, _to);
  }
  /**
   * @notice Delegates voting power of the delegator (represented by its signature) to the delegate `_to`
   *
   * @dev Accepts zero value address to delegate voting power to, effectively
   *      removing the delegate in that case
   *
   * @dev Compliant with EIP-712: Ethereum typed structured data hashing and signing,
   *      see https://eips.ethereum.org/EIPS/eip-712
   *
   * @param _to address to delegate voting power to
   * @param _nonce nonce used to construct the signature, and used to validate it;
   *      nonce is increased by one after successful signature validation and vote delegation
   * @param _exp signature expiration time
   * @param v the recovery byte of the signature
   * @param r half of the ECDSA signature pair
   * @param s half of the ECDSA signature pair
   */
  function delegateWithSig(address _to, uint256 _nonce, uint256 _exp, uint8 v, bytes32 r, bytes32 s) public {
    // verify delegations on behalf are enabled
    require(isFeatureEnabled(FEATURE_DELEGATIONS_ON_BEHALF), "delegations on behalf are disabled");
    // build the EIP-712 contract domain separator
    bytes32 domainSeparator = keccak256(abi.encode(DOMAIN_TYPEHASH, keccak256(bytes(name)), block.chainid, address(this)));
    // build the EIP-712 hashStruct of the delegation message
    bytes32 hashStruct = keccak256(abi.encode(DELEGATION_TYPEHASH, _to, _nonce, _exp));
    // calculate the EIP-712 digest "\\x19\\x01" ‖ domainSeparator ‖ hashStruct(message)
    bytes32 digest = keccak256(abi.encodePacked("\\x19\\x01", domainSeparator, hashStruct));
    // recover the address who signed the message with v, r, s
    address signer = ecrecover(digest, v, r, s);
    // perform message integrity and security validations
    require(signer != address(0), "invalid signature"); // Compound msg
    require(_nonce == nonces[signer], "invalid nonce"); // Compound msg
    require(block.timestamp < _exp, "signature expired"); // Compound msg
    // update the nonce for that particular signer to avoid replay attack
    nonces[signer]++;
    // delegate call to `__delegate` - execute the logic required
    __delegate(signer, _to);
  }
  /**
   * @dev Auxiliary function to delegate delegator's `_from` voting power to the delegate `_to`
   * @dev Writes to `votingDelegates` and `votingPowerHistory` mappings
   *
   * @param _from delegator who delegates his voting power
   * @param _to delegate who receives the voting power
   */
  function __delegate(address _from, address _to) private {
    // read current delegate to be replaced by a new one
    address _fromDelegate = votingDelegates[_from];
    // read current voting power (it is equal to token balance)
    uint256 _value = tokenBalances[_from];
    // reassign voting delegate to `_to`
    votingDelegates[_from] = _to;
    // update voting power for `_fromDelegate` and `_to`
    __moveVotingPower(_fromDelegate, _to, _value);
    // emit an event
    emit DelegateChanged(_from, _fromDelegate, _to);
  }
  /**
   * @dev Auxiliary function to move voting power `_value`
   *      from delegate `_from` to the delegate `_to`
   *
   * @dev Doesn't have any effect if `_from == _to`, or if `_value == 0`
   *
   * @param _from delegate to move voting power from
   * @param _to delegate to move voting power to
   * @param _value voting power to move from `_from` to `_to`
   */
  function __moveVotingPower(address _from, address _to, uint256 _value) private {
    // if there is no move (`_from == _to`) or there is nothing to move (`_value == 0`)
    if(_from == _to || _value == 0) {
      // return silently with no action
      return;
    }
    // if source address is not zero - decrease its voting power
    if(_from != address(0)) {
      // read current source address voting power
      uint256 _fromVal = getVotingPower(_from);
      // calculate decreased voting power
      // underflow is not possible by design:
      // voting power is limited by token balance which is checked by the callee
      uint256 _toVal = _fromVal - _value;
      // update source voting power from `_fromVal` to `_toVal`
      __updateVotingPower(_from, _fromVal, _toVal);
    }
    // if destination address is not zero - increase its voting power
    if(_to != address(0)) {
      // read current destination address voting power
      uint256 _fromVal = getVotingPower(_to);
      // calculate increased voting power
      // overflow is not possible by design:
      // max token supply limits the cumulative voting power
      uint256 _toVal = _fromVal + _value;
      // update destination voting power from `_fromVal` to `_toVal`
      __updateVotingPower(_to, _fromVal, _toVal);
    }
  }
  /**
   * @dev Auxiliary function to update voting power of the delegate `_of`
   *      from value `_fromVal` to value `_toVal`
   *
   * @param _of delegate to update its voting power
   * @param _fromVal old voting power of the delegate
   * @param _toVal new voting power of the delegate
   */
  function __updateVotingPower(address _of, uint256 _fromVal, uint256 _toVal) private {
    // get a link to an array of voting power history records for an address specified
    VotingPowerRecord[] storage history = votingPowerHistory[_of];
    // if there is an existing voting power value stored for current block
    if(history.length != 0 && history[history.length - 1].blockNumber == block.number) {
      // update voting power which is already stored in the current block
      history[history.length - 1].votingPower = uint192(_toVal);
    }
    // otherwise - if there is no value stored for current block
    else {
      // add new element into array representing the value for current block
      history.push(VotingPowerRecord(uint64(block.number), uint192(_toVal)));
    }
    // emit an event
    emit VotingPowerChanged(_of, _fromVal, _toVal);
  }
  /**
   * @dev Auxiliary function to lookup an element in a sorted (asc) array of elements
   *
   * @dev This function finds the closest element in an array to the value
   *      of interest (not exceeding that value) and returns its index within an array
   *
   * @dev An array to search in is `votingPowerHistory[_to][i].blockNumber`,
   *      it is sorted in ascending order (blockNumber increases)
   *
   * @param _to an address of the delegate to get an array for
   * @param n value of interest to look for
   * @return an index of the closest element in an array to the value
   *      of interest (not exceeding that value)
   */
  function __binaryLookup(address _to, uint256 n) private view returns(uint256) {
    // get a link to an array of voting power history records for an address specified
    VotingPowerRecord[] storage history = votingPowerHistory[_to];
    // left bound of the search interval, originally start of the array
    uint256 i = 0;
    // right bound of the search interval, originally end of the array
    uint256 j = history.length - 1;
    // the iteration process narrows down the bounds by
    // splitting the interval in a half oce per each iteration
    while(j > i) {
      // get an index in the middle of the interval [i, j]
      uint256 k = j - (j - i) / 2;
      // read an element to compare it with the value of interest
      VotingPowerRecord memory cp = history[k];
      // if we've got a strict equal - we're lucky and done
      if(cp.blockNumber == n) {
        // just return the result - index `k`
        return k;
      }
      // if the value of interest is bigger - move left bound to the middle
      else if (cp.blockNumber < n) {
        // move left bound `i` to the middle position `k`
        i = k;
      }
      // otherwise, when the value of interest is smaller - move right bound to the middle
      else {
        // move right bound `j` to the middle position `k - 1`:
        // element at position `k` is bigger and cannot be the result
        j = k - 1;
      }
    }
    // reaching that point means no exact match found
    // since we're interested in the element which is not bigger than the
    // element of interest, we return the lower bound `i`
    return i;
  }
}
// ===== End: DAO Support (Compound-like voting delegation) =====
// SPDX-License-Identifier: MIT
pragma solidity 0.8.1;
/**
 * @title Address Utils
 *
 * @dev Utility library of inline functions on addresses
 *
 * @author Basil Gorin
 */
library AddressUtils {
  /**
   * @notice Checks if the target address is a contract
   * @dev This function will return false if invoked during the constructor of a contract,
   *      as the code is not actually created until after the constructor finishes.
   * @param addr address to check
   * @return whether the target address is a contract
   */
  function isContract(address addr) internal view returns (bool) {
    // a variable to load `extcodesize` to
    uint256 size = 0;
    // XXX Currently there is no better way to check if there is a contract in an address
    // than to check the size of the code at that address.
    // See https://ethereum.stackexchange.com/a/14016/36603 for more details about how this works.
    // TODO: Check this again before the Serenity release, because all addresses will be contracts.
    // solium-disable-next-line security/no-inline-assembly
    assembly {
      // retrieve the size of the code at address `addr`
      size := extcodesize(addr)
    }
    // positive size indicates a smart contract address
    return size > 0;
  }
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.1;
/**
 * @title Access Control List
 *
 * @notice Access control smart contract provides an API to check
 *      if specific operation is permitted globally and/or
 *      if particular user has a permission to execute it.
 *
 * @notice It deals with two main entities: features and roles.
 *
 * @notice Features are designed to be used to enable/disable specific
 *      functions (public functions) of the smart contract for everyone.
 * @notice User roles are designed to restrict access to specific
 *      functions (restricted functions) of the smart contract to some users.
 *
 * @notice Terms "role", "permissions" and "set of permissions" have equal meaning
 *      in the documentation text and may be used interchangeably.
 * @notice Terms "permission", "single permission" implies only one permission bit set.
 *
 * @dev This smart contract is designed to be inherited by other
 *      smart contracts which require access control management capabilities.
 *
 * @author Basil Gorin
 */
contract AccessControl {
  /**
   * @notice Access manager is responsible for assigning the roles to users,
   *      enabling/disabling global features of the smart contract
   * @notice Access manager can add, remove and update user roles,
   *      remove and update global features
   *
   * @dev Role ROLE_ACCESS_MANAGER allows modifying user roles and global features
   * @dev Role ROLE_ACCESS_MANAGER has single bit at position 255 enabled
   */
  uint256 public constant ROLE_ACCESS_MANAGER = 0x8000000000000000000000000000000000000000000000000000000000000000;
  /**
   * @dev Bitmask representing all the possible permissions (super admin role)
   * @dev Has all the bits are enabled (2^256 - 1 value)
   */
  uint256 private constant FULL_PRIVILEGES_MASK = type(uint256).max; // before 0.8.0: uint256(-1) overflows to 0xFFFF...
  /**
   * @notice Privileged addresses with defined roles/permissions
   * @notice In the context of ERC20/ERC721 tokens these can be permissions to
   *      allow minting or burning tokens, transferring on behalf and so on
   *
   * @dev Maps user address to the permissions bitmask (role), where each bit
   *      represents a permission
   * @dev Bitmask 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
   *      represents all possible permissions
   * @dev Zero address mapping represents global features of the smart contract
   */
  mapping(address => uint256) public userRoles;
  /**
   * @dev Fired in updateRole() and updateFeatures()
   *
   * @param _by operator which called the function
   * @param _to address which was granted/revoked permissions
   * @param _requested permissions requested
   * @param _actual permissions effectively set
   */
  event RoleUpdated(address indexed _by, address indexed _to, uint256 _requested, uint256 _actual);
  /**
   * @notice Creates an access control instance,
   *      setting contract creator to have full privileges
   */
  constructor() {
    // contract creator has full privileges
    userRoles[msg.sender] = FULL_PRIVILEGES_MASK;
  }
  /**
   * @notice Retrieves globally set of features enabled
   *
   * @dev Auxiliary getter function to maintain compatibility with previous
   *      versions of the Access Control List smart contract, where
   *      features was a separate uint256 public field
   *
   * @return 256-bit bitmask of the features enabled
   */
  function features() public view returns(uint256) {
    // according to new design features are stored in zero address
    // mapping of `userRoles` structure
    return userRoles[address(0)];
  }
  /**
   * @notice Updates set of the globally enabled features (`features`),
   *      taking into account sender's permissions
   *
   * @dev Requires transaction sender to have `ROLE_ACCESS_MANAGER` permission
   * @dev Function is left for backward compatibility with older versions
   *
   * @param _mask bitmask representing a set of features to enable/disable
   */
  function updateFeatures(uint256 _mask) public {
    // delegate call to `updateRole`
    updateRole(address(0), _mask);
  }
  /**
   * @notice Updates set of permissions (role) for a given user,
   *      taking into account sender's permissions.
   *
   * @dev Setting role to zero is equivalent to removing an all permissions
   * @dev Setting role to `FULL_PRIVILEGES_MASK` is equivalent to
   *      copying senders' permissions (role) to the user
   * @dev Requires transaction sender to have `ROLE_ACCESS_MANAGER` permission
   *
   * @param operator address of a user to alter permissions for or zero
   *      to alter global features of the smart contract
   * @param role bitmask representing a set of permissions to
   *      enable/disable for a user specified
   */
  function updateRole(address operator, uint256 role) public {
    // caller must have a permission to update user roles
    require(isSenderInRole(ROLE_ACCESS_MANAGER), "insufficient privileges (ROLE_ACCESS_MANAGER required)");
    // evaluate the role and reassign it
    userRoles[operator] = evaluateBy(msg.sender, userRoles[operator], role);
    // fire an event
    emit RoleUpdated(msg.sender, operator, role, userRoles[operator]);
  }
  /**
   * @notice Determines the permission bitmask an operator can set on the
   *      target permission set
   * @notice Used to calculate the permission bitmask to be set when requested
   *     in `updateRole` and `updateFeatures` functions
   *
   * @dev Calculated based on:
   *      1) operator's own permission set read from userRoles[operator]
   *      2) target permission set - what is already set on the target
   *      3) desired permission set - what do we want set target to
   *
   * @dev Corner cases:
   *      1) Operator is super admin and its permission set is `FULL_PRIVILEGES_MASK`:
   *        `desired` bitset is returned regardless of the `target` permission set value
   *        (what operator sets is what they get)
   *      2) Operator with no permissions (zero bitset):
   *        `target` bitset is returned regardless of the `desired` value
   *        (operator has no authority and cannot modify anything)
   *
   * @dev Example:
   *      Consider an operator with the permissions bitmask     00001111
   *      is about to modify the target permission set          01010101
   *      Operator wants to set that permission set to          00110011
   *      Based on their role, an operator has the permissions
   *      to update only lowest 4 bits on the target, meaning that
   *      high 4 bits of the target set in this example is left
   *      unchanged and low 4 bits get changed as desired:      01010011
   *
   * @param operator address of the contract operator which is about to set the permissions
   * @param target input set of permissions to operator is going to modify
   * @param desired desired set of permissions operator would like to set
   * @return resulting set of permissions given operator will set
   */
  function evaluateBy(address operator, uint256 target, uint256 desired) public view returns(uint256) {
    // read operator's permissions
    uint256 p = userRoles[operator];
    // taking into account operator's permissions,
    // 1) enable the permissions desired on the `target`
    target |= p & desired;
    // 2) disable the permissions desired on the `target`
    target &= FULL_PRIVILEGES_MASK ^ (p & (FULL_PRIVILEGES_MASK ^ desired));
    // return calculated result
    return target;
  }
  /**
   * @notice Checks if requested set of features is enabled globally on the contract
   *
   * @param required set of features to check against
   * @return true if all the features requested are enabled, false otherwise
   */
  function isFeatureEnabled(uint256 required) public view returns(bool) {
    // delegate call to `__hasRole`, passing `features` property
    return __hasRole(features(), required);
  }
  /**
   * @notice Checks if transaction sender `msg.sender` has all the permissions required
   *
   * @param required set of permissions (role) to check against
   * @return true if all the permissions requested are enabled, false otherwise
   */
  function isSenderInRole(uint256 required) public view returns(bool) {
    // delegate call to `isOperatorInRole`, passing transaction sender
    return isOperatorInRole(msg.sender, required);
  }
  /**
   * @notice Checks if operator has all the permissions (role) required
   *
   * @param operator address of the user to check role for
   * @param required set of permissions (role) to check
   * @return true if all the permissions requested are enabled, false otherwise
   */
  function isOperatorInRole(address operator, uint256 required) public view returns(bool) {
    // delegate call to `__hasRole`, passing operator's permissions (role)
    return __hasRole(userRoles[operator], required);
  }
  /**
   * @dev Checks if role `actual` contains all the permissions required `required`
   *
   * @param actual existent role
   * @param required required role
   * @return true if actual has required role (all permissions), false otherwise
   */
  function __hasRole(uint256 actual, uint256 required) internal pure returns(bool) {
    // check the bitmask for the role required and return the result
    return actual & required == required;
  }
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.1;
/**
 * @title ERC20 token receiver interface
 *
 * @dev Interface for any contract that wants to support safe transfers
 *      from ERC20 token smart contracts.
 * @dev Inspired by ERC721 and ERC223 token standards
 *
 * @dev See https://github.com/ethereum/EIPs/blob/master/EIPS/eip-721.md
 * @dev See https://github.com/ethereum/EIPs/issues/223
 *
 * @author Basil Gorin
 */
interface ERC20Receiver {
  /**
   * @notice Handle the receipt of a ERC20 token(s)
   * @dev The ERC20 smart contract calls this function on the recipient
   *      after a successful transfer (`safeTransferFrom`).
   *      This function MAY throw to revert and reject the transfer.
   *      Return of other than the magic value MUST result in the transaction being reverted.
   * @notice The contract address is always the message sender.
   *      A wallet/broker/auction application MUST implement the wallet interface
   *      if it will accept safe transfers.
   * @param _operator The address which called `safeTransferFrom` function
   * @param _from The address which previously owned the token
   * @param _value amount of tokens which is being transferred
   * @param _data additional data with no specified format
   * @return `bytes4(keccak256("onERC20Received(address,address,uint256,bytes)"))` unless throwing
   */
  function onERC20Received(address _operator, address _from, uint256 _value, bytes calldata _data) external returns(bytes4);
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.1;
import "../interfaces/IERC20.sol";
/**
 * @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}.
 */
// Copied from Open Zeppelin
contract ERC20 is IERC20 {
    mapping(address => uint256) private _balances;
    mapping(address => mapping(address => uint256)) private _allowances;
    uint256 private _totalSupply;
    string private _name;
    string private _symbol;
    uint8 private _decimals;
    /**
     * @notice Token creator is responsible for creating (minting)
     *      tokens to an arbitrary address
     * @dev Role ROLE_TOKEN_CREATOR allows minting tokens
     *      (calling `mint` function)
     */
    uint32 public constant ROLE_TOKEN_CREATOR = 0x0001_0000;
    /**
     * @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_) {
        _name = name_;
        _symbol = symbol_;
        _decimals = 18;
    }
    /**
     * @dev Returns the name of the token.
     */
    function name() public view virtual returns (string memory) {
        return _name;
    }
    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view virtual 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 virtual returns (uint8) {
        return _decimals;
    }
    /**
     * @dev See {IERC20-totalSupply}.
     */
    function totalSupply() public view virtual override returns (uint256) {
        return _totalSupply;
    }
    /**
     * @dev See {IERC20-balanceOf}.
     */
    function balanceOf(address account) public view virtual 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(msg.sender, 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(msg.sender, 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, msg.sender, _allowances[sender][msg.sender] - amount);
        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(msg.sender, spender, _allowances[msg.sender][spender] + 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(msg.sender, spender, _allowances[msg.sender][spender] - subtractedValue);
        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] - amount;
        _balances[recipient] = _balances[recipient] + 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 + amount;
        _balances[account] = _balances[account] + 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] - amount;
        _totalSupply = _totalSupply - 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 virtual {
        _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 {}
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.1;
/**
 * @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);
}
// SPDX-License-Identifier: MIT
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
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize, which returns 0 for contracts in
        // construction, since the code is only stored at the end of the
        // constructor execution.
        uint256 size;
        // solhint-disable-next-line no-inline-assembly
        assembly {
            size := extcodesize(account)
        }
        return size > 0;
    }
    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");
        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
        (bool success, ) = recipient.call{ value: amount }("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }
    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain`call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCall(target, data, "Address: low-level call failed");
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }
    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        require(isContract(target), "Address: call to non-contract");
        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.call{ value: value }(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");
        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.staticcall(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.3._
     */
    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 v3.3._
     */
    function functionDelegateCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(isContract(target), "Address: delegate call to non-contract");
        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }
    function _verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) private pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly
                // solhint-disable-next-line no-inline-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

/**
 * @dev This abstract contract provides a fallback function that delegates all calls to another contract using the EVM
 * instruction `delegatecall`. We refer to the second contract as the _implementation_ behind the proxy, and it has to
 * be specified by overriding the virtual {_implementation} function.
 *
 * Additionally, delegation to the implementation can be triggered manually through the {_fallback} function, or to a
 * different contract through the {_delegate} function.
 *
 * The success and return data of the delegated call will be returned back to the caller of the proxy.
 */
abstract contract Proxy {
    /**
     * @dev Delegates the current call to `implementation`.
     *
     * This function does not return to its internall call site, it will return directly to the external caller.
     */
    function _delegate(address implementation) internal virtual {
        // solhint-disable-next-line no-inline-assembly
        assembly {
        // Copy msg.data. We take full control of memory in this inline assembly
        // block because it will not return to Solidity code. We overwrite the
        // Solidity scratch pad at memory position 0.
            calldatacopy(0, 0, calldatasize())

        // Call the implementation.
        // out and outsize are 0 because we don't know the size yet.
            let result := delegatecall(gas(), implementation, 0, calldatasize(), 0, 0)

        // Copy the returned data.
            returndatacopy(0, 0, returndatasize())

            switch result
            // delegatecall returns 0 on error.
            case 0 { revert(0, returndatasize()) }
            default { return(0, returndatasize()) }
        }
    }

    /**
     * @dev This is a virtual function that should be overriden so it returns the address to which the fallback function
     * and {_fallback} should delegate.
     */
    function _implementation() internal view virtual returns (address);

    /**
     * @dev Delegates the current call to the address returned by `_implementation()`.
     *
     * This function does not return to its internall call site, it will return directly to the external caller.
     */
    function _fallback() internal virtual {
        _beforeFallback();
        _delegate(_implementation());
    }

    /**
     * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if no other
     * function in the contract matches the call data.
     */
    fallback () external payable virtual {
        _fallback();
    }

    /**
     * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if call data
     * is empty.
     */
    receive () external payable virtual {
        _fallback();
    }

    /**
     * @dev Hook that is called before falling back to the implementation. Can happen as part of a manual `_fallback`
     * call, or as part of the Solidity `fallback` or `receive` functions.
     *
     * If overriden should call `super._beforeFallback()`.
     */
    function _beforeFallback() internal virtual {
    }
}


/**
 * @dev This abstract contract provides getters and event emitting update functions for
 * https://eips.ethereum.org/EIPS/eip-1967[EIP1967] slots.
 *
 * _Available since v4.1._
 *
 */
abstract contract ERC1967Upgrade {
    // This is the keccak-256 hash of "eip1967.proxy.rollback" subtracted by 1
    bytes32 private constant _ROLLBACK_SLOT = 0x4910fdfa16fed3260ed0e7147f7cc6da11a60208b5b9406d12a635614ffd9143;

    /**
     * @dev Storage slot with the address of the current implementation.
     * This is the keccak-256 hash of "eip1967.proxy.implementation" subtracted by 1, and is
     * validated in the constructor.
     */
    bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;

    /**
     * @dev Emitted when the implementation is upgraded.
     */
    event Upgraded(address indexed implementation);

    /**
     * @dev Returns the current implementation address.
     */
    function _getImplementation() internal view returns (address) {
        return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
    }

    /**
     * @dev Stores a new address in the EIP1967 implementation slot.
     */
    function _setImplementation(address newImplementation) private {
        require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
        StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
    }

    /**
     * @dev Perform implementation upgrade
     *
     * Emits an {Upgraded} event.
     */
    function _upgradeTo(address newImplementation) internal {
        _setImplementation(newImplementation);
        emit Upgraded(newImplementation);
    }

    /**
     * @dev Perform implementation upgrade with additional setup call.
     *
     * Emits an {Upgraded} event.
     */
    function _upgradeToAndCall(address newImplementation, bytes memory data, bool forceCall) internal {
        _setImplementation(newImplementation);
        emit Upgraded(newImplementation);
        if (data.length > 0 || forceCall) {
            Address.functionDelegateCall(newImplementation, data);
        }
    }

    /**
     * @dev Perform implementation upgrade with security checks for UUPS proxies, and additional setup call.
     *
     * Emits an {Upgraded} event.
     */
    function _upgradeToAndCallSecure(address newImplementation, bytes memory data, bool forceCall) internal {
        address oldImplementation = _getImplementation();

        // Initial upgrade and setup call
        _setImplementation(newImplementation);
        if (data.length > 0 || forceCall) {
            Address.functionDelegateCall(newImplementation, data);
        }

        // Perform rollback test if not already in progress
        StorageSlot.BooleanSlot storage rollbackTesting = StorageSlot.getBooleanSlot(_ROLLBACK_SLOT);
        if (!rollbackTesting.value) {
            // Trigger rollback using upgradeTo from the new implementation
            rollbackTesting.value = true;
            Address.functionDelegateCall(
                newImplementation,
                abi.encodeWithSignature(
                    "upgradeTo(address)",
                    oldImplementation
                )
            );
            rollbackTesting.value = false;
            // Check rollback was effective
            require(oldImplementation == _getImplementation(), "ERC1967Upgrade: upgrade breaks further upgrades");
            // Finally reset to the new implementation and log the upgrade
            _setImplementation(newImplementation);
            emit Upgraded(newImplementation);
        }
    }

    /**
     * @dev Perform beacon upgrade with additional setup call. Note: This upgrades the address of the beacon, it does
     * not upgrade the implementation contained in the beacon (see {UpgradeableBeacon-_setImplementation} for that).
     *
     * Emits a {BeaconUpgraded} event.
     */
    function _upgradeBeaconToAndCall(address newBeacon, bytes memory data, bool forceCall) internal {
        _setBeacon(newBeacon);
        emit BeaconUpgraded(newBeacon);
        if (data.length > 0 || forceCall) {
            Address.functionDelegateCall(IBeacon(newBeacon).implementation(), data);
        }
    }

    /**
     * @dev Storage slot with the admin of the contract.
     * This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is
     * validated in the constructor.
     */
    bytes32 internal constant _ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;

    /**
     * @dev Emitted when the admin account has changed.
     */
    event AdminChanged(address previousAdmin, address newAdmin);

    /**
     * @dev Returns the current admin.
     */
    function _getAdmin() internal view returns (address) {
        return StorageSlot.getAddressSlot(_ADMIN_SLOT).value;
    }

    /**
     * @dev Stores a new address in the EIP1967 admin slot.
     */
    function _setAdmin(address newAdmin) private {
        require(newAdmin != address(0), "ERC1967: new admin is the zero address");
        StorageSlot.getAddressSlot(_ADMIN_SLOT).value = newAdmin;
    }

    /**
     * @dev Changes the admin of the proxy.
     *
     * Emits an {AdminChanged} event.
     */
    function _changeAdmin(address newAdmin) internal {
        emit AdminChanged(_getAdmin(), newAdmin);
        _setAdmin(newAdmin);
    }

    /**
     * @dev The storage slot of the UpgradeableBeacon contract which defines the implementation for this proxy.
     * This is bytes32(uint256(keccak256('eip1967.proxy.beacon')) - 1)) and is validated in the constructor.
     */
    bytes32 internal constant _BEACON_SLOT = 0xa3f0ad74e5423aebfd80d3ef4346578335a9a72aeaee59ff6cb3582b35133d50;

    /**
     * @dev Emitted when the beacon is upgraded.
     */
    event BeaconUpgraded(address indexed beacon);

    /**
     * @dev Returns the current beacon.
     */
    function _getBeacon() internal view returns (address) {
        return StorageSlot.getAddressSlot(_BEACON_SLOT).value;
    }

    /**
     * @dev Stores a new beacon in the EIP1967 beacon slot.
     */
    function _setBeacon(address newBeacon) private {
        require(
            Address.isContract(newBeacon),
            "ERC1967: new beacon is not a contract"
        );
        require(
            Address.isContract(IBeacon(newBeacon).implementation()),
            "ERC1967: beacon implementation is not a contract"
        );
        StorageSlot.getAddressSlot(_BEACON_SLOT).value = newBeacon;
    }
}

/**
 * @dev This is the interface that {BeaconProxy} expects of its beacon.
 */
interface IBeacon {
    /**
     * @dev Must return an address that can be used as a delegate call target.
     *
     * {BeaconProxy} will check that this address is a contract.
     */
    function implementation() external view returns (address);
}

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize, which returns 0 for contracts in
        // construction, since the code is only stored at the end of the
        // constructor execution.

        uint256 size;
        // solhint-disable-next-line no-inline-assembly
        assembly { size := extcodesize(account) }
        return size > 0;
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
        (bool success, ) = recipient.call{ value: amount }("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

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

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

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

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

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.call{ value: value }(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

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

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data, string memory errorMessage) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.staticcall(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

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

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
        require(isContract(target), "Address: delegate call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

    function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns(bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly

                // solhint-disable-next-line no-inline-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

/**
 * @dev Library for reading and writing primitive types to specific storage slots.
 *
 * Storage slots are often used to avoid storage conflict when dealing with upgradeable contracts.
 * This library helps with reading and writing to such slots without the need for inline assembly.
 *
 * The functions in this library return Slot structs that contain a `value` member that can be used to read or write.
 *
 * Example usage to set ERC1967 implementation slot:
 * ```
 * contract ERC1967 {
 *     bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
 *
 *     function _getImplementation() internal view returns (address) {
 *         return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
 *     }
 *
 *     function _setImplementation(address newImplementation) internal {
 *         require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
 *         StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
 *     }
 * }
 * ```
 *
 * _Available since v4.1 for `address`, `bool`, `bytes32`, and `uint256`._
 */
library StorageSlot {
    struct AddressSlot {
        address value;
    }

    struct BooleanSlot {
        bool value;
    }

    struct Bytes32Slot {
        bytes32 value;
    }

    struct Uint256Slot {
        uint256 value;
    }

    /**
     * @dev Returns an `AddressSlot` with member `value` located at `slot`.
     */
    function getAddressSlot(bytes32 slot) internal pure returns (AddressSlot storage r) {
        assembly {
            r.slot := slot
        }
    }

    /**
     * @dev Returns an `BooleanSlot` with member `value` located at `slot`.
     */
    function getBooleanSlot(bytes32 slot) internal pure returns (BooleanSlot storage r) {
        assembly {
            r.slot := slot
        }
    }

    /**
     * @dev Returns an `Bytes32Slot` with member `value` located at `slot`.
     */
    function getBytes32Slot(bytes32 slot) internal pure returns (Bytes32Slot storage r) {
        assembly {
            r.slot := slot
        }
    }

    /**
     * @dev Returns an `Uint256Slot` with member `value` located at `slot`.
     */
    function getUint256Slot(bytes32 slot) internal pure returns (Uint256Slot storage r) {
        assembly {
            r.slot := slot
        }
    }
}

/*
 * @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) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}

/**
 * @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 () {
        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), msgSender);
    }

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

/**
 * @dev This is an auxiliary contract meant to be assigned as the admin of a {TransparentUpgradeableProxy}. For an
 * explanation of why you would want to use this see the documentation for {TransparentUpgradeableProxy}.
 */
contract ProxyAdmin is Ownable {

    /**
     * @dev Returns the current implementation of `proxy`.
     *
     * Requirements:
     *
     * - This contract must be the admin of `proxy`.
     */
    function getProxyImplementation(TransparentUpgradeableProxy proxy) public view virtual returns (address) {
        // We need to manually run the static call since the getter cannot be flagged as view
        // bytes4(keccak256("implementation()")) == 0x5c60da1b
        (bool success, bytes memory returndata) = address(proxy).staticcall(hex"5c60da1b");
        require(success);
        return abi.decode(returndata, (address));
    }

    /**
     * @dev Returns the current admin of `proxy`.
     *
     * Requirements:
     *
     * - This contract must be the admin of `proxy`.
     */
    function getProxyAdmin(TransparentUpgradeableProxy proxy) public view virtual returns (address) {
        // We need to manually run the static call since the getter cannot be flagged as view
        // bytes4(keccak256("admin()")) == 0xf851a440
        (bool success, bytes memory returndata) = address(proxy).staticcall(hex"f851a440");
        require(success);
        return abi.decode(returndata, (address));
    }

    /**
     * @dev Changes the admin of `proxy` to `newAdmin`.
     *
     * Requirements:
     *
     * - This contract must be the current admin of `proxy`.
     */
    function changeProxyAdmin(TransparentUpgradeableProxy proxy, address newAdmin) public virtual onlyOwner {
        proxy.changeAdmin(newAdmin);
    }

    /**
     * @dev Upgrades `proxy` to `implementation`. See {TransparentUpgradeableProxy-upgradeTo}.
     *
     * Requirements:
     *
     * - This contract must be the admin of `proxy`.
     */
    function upgrade(TransparentUpgradeableProxy proxy, address implementation) public virtual onlyOwner {
        proxy.upgradeTo(implementation);
    }

    /**
     * @dev Upgrades `proxy` to `implementation` and calls a function on the new implementation. See
     * {TransparentUpgradeableProxy-upgradeToAndCall}.
     *
     * Requirements:
     *
     * - This contract must be the admin of `proxy`.
     */
    function upgradeAndCall(TransparentUpgradeableProxy proxy, address implementation, bytes memory data) public payable virtual onlyOwner {
        proxy.upgradeToAndCall{value: msg.value}(implementation, data);
    }
}


/**
 * @dev Base contract for building openzeppelin-upgrades compatible implementations for the {ERC1967Proxy}. It includes
 * publicly available upgrade functions that are called by the plugin and by the secure upgrade mechanism to verify
 * continuation of the upgradability.
 *
 * The {_authorizeUpgrade} function MUST be overridden to include access restriction to the upgrade mechanism.
 *
 * _Available since v4.1._
 */
abstract contract UUPSUpgradeable is ERC1967Upgrade {
    function upgradeTo(address newImplementation) external virtual {
        _authorizeUpgrade(newImplementation);
        _upgradeToAndCallSecure(newImplementation, bytes(""), false);
    }

    function upgradeToAndCall(address newImplementation, bytes memory data) external payable virtual {
        _authorizeUpgrade(newImplementation);
        _upgradeToAndCallSecure(newImplementation, data, true);
    }

    function _authorizeUpgrade(address newImplementation) internal virtual;
}


abstract contract Proxiable is UUPSUpgradeable {
    function _authorizeUpgrade(address newImplementation) internal override {
        _beforeUpgrade(newImplementation);
    }

    function _beforeUpgrade(address newImplementation) internal virtual;
}

contract ChildOfProxiable is Proxiable {
    function _beforeUpgrade(address newImplementation) internal virtual override {}
}


/**
 * @dev This contract implements an upgradeable proxy. It is upgradeable because calls are delegated to an
 * implementation address that can be changed. This address is stored in storage in the location specified by
 * https://eips.ethereum.org/EIPS/eip-1967[EIP1967], so that it doesn't conflict with the storage layout of the
 * implementation behind the proxy.
 */
contract ERC1967Proxy is Proxy, ERC1967Upgrade {
    /**
     * @dev Initializes the upgradeable proxy with an initial implementation specified by `_logic`.
     *
     * If `_data` is nonempty, it's used as data in a delegate call to `_logic`. This will typically be an encoded
     * function call, and allows initializating the storage of the proxy like a Solidity constructor.
     */
    constructor(address _logic, bytes memory _data) payable {
        assert(_IMPLEMENTATION_SLOT == bytes32(uint256(keccak256("eip1967.proxy.implementation")) - 1));
        _upgradeToAndCall(_logic, _data, false);
    }

    /**
     * @dev Returns the current implementation address.
     */
    function _implementation() internal view virtual override returns (address impl) {
        return ERC1967Upgrade._getImplementation();
    }
}

/**
 * @dev This contract implements a proxy that is upgradeable by an admin.
 *
 * To avoid https://medium.com/nomic-labs-blog/malicious-backdoors-in-ethereum-proxies-62629adf3357[proxy selector
 * clashing], which can potentially be used in an attack, this contract uses the
 * https://blog.openzeppelin.com/the-transparent-proxy-pattern/[transparent proxy pattern]. This pattern implies two
 * things that go hand in hand:
 *
 * 1. If any account other than the admin calls the proxy, the call will be forwarded to the implementation, even if
 * that call matches one of the admin functions exposed by the proxy itself.
 * 2. If the admin calls the proxy, it can access the admin functions, but its calls will never be forwarded to the
 * implementation. If the admin tries to call a function on the implementation it will fail with an error that says
 * "admin cannot fallback to proxy target".
 *
 * These properties mean that the admin account can only be used for admin actions like upgrading the proxy or changing
 * the admin, so it's best if it's a dedicated account that is not used for anything else. This will avoid headaches due
 * to sudden errors when trying to call a function from the proxy implementation.
 *
 * Our recommendation is for the dedicated account to be an instance of the {ProxyAdmin} contract. If set up this way,
 * you should think of the `ProxyAdmin` instance as the real administrative interface of your proxy.
 */
contract TransparentUpgradeableProxy is ERC1967Proxy {
    /**
     * @dev Initializes an upgradeable proxy managed by `_admin`, backed by the implementation at `_logic`, and
     * optionally initialized with `_data` as explained in {ERC1967Proxy-constructor}.
     */
    constructor(address _logic, address admin_, bytes memory _data) payable ERC1967Proxy(_logic, _data) {
        assert(_ADMIN_SLOT == bytes32(uint256(keccak256("eip1967.proxy.admin")) - 1));
        _changeAdmin(admin_);
    }

    /**
     * @dev Modifier used internally that will delegate the call to the implementation unless the sender is the admin.
     */
    modifier ifAdmin() {
        if (msg.sender == _getAdmin()) {
            _;
        } else {
            _fallback();
        }
    }

    /**
     * @dev Returns the current admin.
     *
     * NOTE: Only the admin can call this function. See {ProxyAdmin-getProxyAdmin}.
     *
     * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
     * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
     * `0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103`
     */
    function admin() external ifAdmin returns (address admin_) {
        admin_ = _getAdmin();
    }

    /**
     * @dev Returns the current implementation.
     *
     * NOTE: Only the admin can call this function. See {ProxyAdmin-getProxyImplementation}.
     *
     * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
     * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
     * `0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc`
     */
    function implementation() external ifAdmin returns (address implementation_) {
        implementation_ = _implementation();
    }

    /**
     * @dev Changes the admin of the proxy.
     *
     * Emits an {AdminChanged} event.
     *
     * NOTE: Only the admin can call this function. See {ProxyAdmin-changeProxyAdmin}.
     */
    function changeAdmin(address newAdmin) external virtual ifAdmin {
        _changeAdmin(newAdmin);
    }

    /**
     * @dev Upgrade the implementation of the proxy.
     *
     * NOTE: Only the admin can call this function. See {ProxyAdmin-upgrade}.
     */
    function upgradeTo(address newImplementation) external ifAdmin {
        _upgradeToAndCall(newImplementation, bytes(""), false);
    }

    /**
     * @dev Upgrade the implementation of the proxy, and then call a function from the new implementation as specified
     * by `data`, which should be an encoded function call. This is useful to initialize new storage variables in the
     * proxied contract.
     *
     * NOTE: Only the admin can call this function. See {ProxyAdmin-upgradeAndCall}.
     */
    function upgradeToAndCall(address newImplementation, bytes calldata data) external payable ifAdmin {
        _upgradeToAndCall(newImplementation, data, true);
    }

    /**
     * @dev Returns the current admin.
     */
    function _admin() internal view virtual returns (address) {
        return _getAdmin();
    }

    /**
     * @dev Makes sure the admin cannot access the fallback function. See {Proxy-_beforeFallback}.
     */
    function _beforeFallback() internal virtual override {
        require(msg.sender != _getAdmin(), "TransparentUpgradeableProxy: admin cannot fallback to proxy target");
        super._beforeFallback();
    }
}


// Kept for backwards compatibility with older versions of Hardhat and Truffle plugins.
contract AdminUpgradeabilityProxy is TransparentUpgradeableProxy {
    constructor(address logic, address admin, bytes memory data) payable TransparentUpgradeableProxy(logic, admin, data) {}
}

// SPDX-License-Identifier: MIT
pragma solidity 0.8.4;
import { Initializable } from "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
import { UUPSUpgradeable } from "@openzeppelin/contracts-upgradeable/proxy/utils/UUPSUpgradeable.sol";
import { OwnableUpgradeable } from "@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol";
import { SafeCast } from "./libraries/SafeCast.sol";
import { Timestamp } from "./base/Timestamp.sol";
import { ICorePool } from "./interfaces/ICorePool.sol";
import { IERC20Mintable } from "./interfaces/IERC20Mintable.sol";
import { ErrorHandler } from "./libraries/ErrorHandler.sol";
/**
 * @title Pool Factory V2
 *
 * @dev Pool Factory manages Illuvium staking pools, provides a single
 *      public interface to access the pools, provides an interface for the pools
 *      to mint yield rewards, access pool-related info, update weights, etc.
 *
 * @dev The factory is authorized (via its owner) to register new pools, change weights
 *      of the existing pools, removing the pools (by changing their weights to zero).
 *
 * @dev The factory requires ROLE_TOKEN_CREATOR permission on the ILV and sILV tokens to mint yield
 *      (see `mintYieldTo` function).
 *
 * @notice The contract uses Ownable implementation, so only the eDAO is able to handle
 *         admin activities, such as registering new pools, doing contract upgrades,
 *         changing pool weights, managing emission schedules and so on.
 *
 */
contract PoolFactory is Initializable, UUPSUpgradeable, OwnableUpgradeable, Timestamp {
    using ErrorHandler for bytes4;
    using SafeCast for uint256;
    /// @dev Auxiliary data structure used only in getPoolData() view function
    struct PoolData {
        // @dev pool token address (like ILV)
        address poolToken;
        // @dev pool address (like deployed core pool instance)
        address poolAddress;
        // @dev pool weight (200 for ILV pools, 800 for ILV/ETH pools - set during deployment)
        uint32 weight;
        // @dev flash pool flag
        bool isFlashPool;
    }
    /**
     * @dev ILV/second determines yield farming reward base
     *      used by the yield pools controlled by the factory.
     */
    uint192 public ilvPerSecond;
    /**
     * @dev The yield is distributed proportionally to pool weights;
     *      total weight is here to help in determining the proportion.
     */
    uint32 public totalWeight;
    /**
     * @dev ILV/second decreases by 3% every seconds/update
     *      an update is triggered by executing `updateILVPerSecond` public function.
     */
    uint32 public secondsPerUpdate;
    /**
     * @dev End time is the last timestamp when ILV/second can be decreased;
     *      it is implied that yield farming stops after that timestamp.
     */
    uint32 public endTime;
    /**
     * @dev Each time the ILV/second ratio gets updated, the timestamp
     *      when the operation has occurred gets recorded into `lastRatioUpdate`.
     * @dev This timestamp is then used to check if seconds/update `secondsPerUpdate`
     *      has passed when decreasing yield reward by 3%.
     */
    uint32 public lastRatioUpdate;
    /// @dev ILV token address.
    address private _ilv;
    /// @dev sILV token address
    address private _silv;
    /// @dev Maps pool token address (like ILV) -> pool address (like core pool instance).
    mapping(address => address) public pools;
    /// @dev Keeps track of registered pool addresses, maps pool address -> exists flag.
    mapping(address => bool) public poolExists;
    /**
     * @dev Fired in registerPool()
     *
     * @param by an address which executed an action
     * @param poolToken pool token address (like ILV)
     * @param poolAddress deployed pool instance address
     * @param weight pool weight
     * @param isFlashPool flag indicating if pool is a flash pool
     */
    event LogRegisterPool(
        address indexed by,
        address indexed poolToken,
        address indexed poolAddress,
        uint64 weight,
        bool isFlashPool
    );
    /**
     * @dev Fired in `changePoolWeight()`.
     *
     * @param by an address which executed an action
     * @param poolAddress deployed pool instance address
     * @param weight new pool weight
     */
    event LogChangePoolWeight(address indexed by, address indexed poolAddress, uint32 weight);
    /**
     * @dev Fired in `updateILVPerSecond()`.
     *
     * @param by an address which executed an action
     * @param newIlvPerSecond new ILV/second value
     */
    event LogUpdateILVPerSecond(address indexed by, uint256 newIlvPerSecond);
    /**
     * @dev Fired in `setEndTime()`.
     *
     * @param by an address which executed the action
     * @param endTime new endTime value
     */
    event LogSetEndTime(address indexed by, uint32 endTime);
    /**
     * @dev Initializes a factory instance
     *
     * @param ilv_ ILV ERC20 token address
     * @param silv_ sILV ERC20 token address
     * @param _ilvPerSecond initial ILV/second value for rewards
     * @param _secondsPerUpdate how frequently the rewards gets updated (decreased by 3%), seconds
     * @param _initTime timestamp to measure _secondsPerUpdate from
     * @param _endTime timestamp number when farming stops and rewards cannot be updated anymore
     */
    function initialize(
        address ilv_,
        address silv_,
        uint192 _ilvPerSecond,
        uint32 _secondsPerUpdate,
        uint32 _initTime,
        uint32 _endTime
    ) external initializer {
        bytes4 fnSelector = this.initialize.selector;
        // verify the inputs are set correctly
        fnSelector.verifyNonZeroInput(uint160(ilv_), 0);
        fnSelector.verifyNonZeroInput(uint160(silv_), 1);
        fnSelector.verifyNonZeroInput(_ilvPerSecond, 2);
        fnSelector.verifyNonZeroInput(_secondsPerUpdate, 3);
        fnSelector.verifyNonZeroInput(_initTime, 4);
        fnSelector.verifyInput(_endTime > _now256(), 5);
        __Ownable_init();
        // save the inputs into internal state variables
        _ilv = ilv_;
        _silv = silv_;
        ilvPerSecond = _ilvPerSecond;
        secondsPerUpdate = _secondsPerUpdate;
        lastRatioUpdate = _initTime;
        endTime = _endTime;
    }
    /**
     * @notice Given a pool token retrieves corresponding pool address.
     *
     * @dev A shortcut for `pools` mapping.
     *
     * @param poolToken pool token address (like ILV) to query pool address for
     * @return pool address for the token specified
     */
    function getPoolAddress(address poolToken) external view virtual returns (address) {
        // read the mapping and return
        return address(pools[poolToken]);
    }
    /**
     * @notice Reads pool information for the pool defined by its pool token address,
     *      designed to simplify integration with the front ends.
     *
     * @param _poolToken pool token address to query pool information for.
     * @return pool information packed in a PoolData struct.
     */
    function getPoolData(address _poolToken) public view virtual returns (PoolData memory) {
        bytes4 fnSelector = this.getPoolData.selector;
        // get the pool address from the mapping
        ICorePool pool = ICorePool(pools[_poolToken]);
        // throw if there is no pool registered for the token specified
        fnSelector.verifyState(uint160(address(pool)) != 0, 0);
        // read pool information from the pool smart contract
        // via the pool interface (ICorePool)
        address poolToken = pool.poolToken();
        bool isFlashPool = pool.isFlashPool();
        uint32 weight = pool.weight();
        // create the in-memory structure and return it
        return PoolData({ poolToken: poolToken, poolAddress: address(pool), weight: weight, isFlashPool: isFlashPool });
    }
    /**
     * @dev Verifies if `secondsPerUpdate` has passed since last ILV/second
     *      ratio update and if ILV/second reward can be decreased by 3%.
     *
     * @return true if enough time has passed and `updateILVPerSecond` can be executed.
     */
    function shouldUpdateRatio() public view virtual returns (bool) {
        // if yield farming period has ended
        if (_now256() > endTime) {
            // ILV/second reward cannot be updated anymore
            return false;
        }
        // check if seconds/update have passed since last update
        return _now256() >= lastRatioUpdate + secondsPerUpdate;
    }
    /**
     * @dev Registers an already deployed pool instance within the factory.
     *
     * @dev Can be executed by the pool factory owner only.
     *
     * @param pool address of the already deployed pool instance
     */
    function registerPool(address pool) public virtual onlyOwner {
        // read pool information from the pool smart contract
        // via the pool interface (ICorePool)
        address poolToken = ICorePool(pool).poolToken();
        bool isFlashPool = ICorePool(pool).isFlashPool();
        uint32 weight = ICorePool(pool).weight();
        // create pool structure, register it within the factory
        pools[poolToken] = pool;
        poolExists[pool] = true;
        // update total pool weight of the factory
        totalWeight += weight;
        // emit an event
        emit LogRegisterPool(msg.sender, poolToken, address(pool), weight, isFlashPool);
    }
    /**
     * @notice Decreases ILV/second reward by 3%, can be executed
     *      no more than once per `secondsPerUpdate` seconds.
     */
    function updateILVPerSecond() external virtual {
        bytes4 fnSelector = this.updateILVPerSecond.selector;
        // checks if ratio can be updated i.e. if seconds/update have passed
        fnSelector.verifyState(shouldUpdateRatio(), 0);
        // decreases ILV/second reward by 3%.
        // To achieve that we multiply by 97 and then
        // divide by 100
        ilvPerSecond = (ilvPerSecond * 97) / 100;
        // set current timestamp as the last ratio update timestamp
        lastRatioUpdate = (_now256()).toUint32();
        // emit an event
        emit LogUpdateILVPerSecond(msg.sender, ilvPerSecond);
    }
    /**
     * @dev Mints ILV tokens; executed by ILV Pool only.
     *
     * @dev Requires factory to have ROLE_TOKEN_CREATOR permission
     *      on the ILV ERC20 token instance.
     *
     * @param _to an address to mint tokens to
     * @param _value amount of ILV tokens to mint
     * @param _useSILV whether ILV or sILV should be minted
     */
    function mintYieldTo(
        address _to,
        uint256 _value,
        bool _useSILV
    ) external virtual {
        bytes4 fnSelector = this.mintYieldTo.selector;
        // verify that sender is a pool registered withing the factory
        fnSelector.verifyState(poolExists[msg.sender], 0);
        // mints the requested token to the indicated address
        if (!_useSILV) {
            IERC20Mintable(_ilv).mint(_to, _value);
        } else {
            IERC20Mintable(_silv).mint(_to, _value);
        }
    }
    /**
     * @dev Changes the weight of the pool;
     *      executed by the pool itself or by the factory owner.
     *
     * @param pool address of the pool to change weight for
     * @param weight new weight value to set to
     */
    function changePoolWeight(address pool, uint32 weight) external virtual {
        bytes4 fnSelector = this.changePoolWeight.selector;
        // verify function is executed either by factory owner or by the pool itself
        fnSelector.verifyAccess(msg.sender == owner() || poolExists[msg.sender]);
        // recalculate total weight
        totalWeight = totalWeight + weight - ICorePool(pool).weight();
        // set the new pool weight
        ICorePool(pool).setWeight(weight);
        // emit an event
        emit LogChangePoolWeight(msg.sender, address(pool), weight);
    }
    /**
     * @dev Updates yield generation ending timestamp.
     *
     * @param _endTime new end time value to be stored
     */
    function setEndTime(uint32 _endTime) external virtual onlyOwner {
        bytes4 fnSelector = this.setEndTime.selector;
        // checks if _endTime is a timestap after the last time that
        // ILV/second has been updated
        fnSelector.verifyInput(_endTime > lastRatioUpdate, 0);
        // updates endTime state var
        endTime = _endTime;
        // emits an event
        emit LogSetEndTime(msg.sender, _endTime);
    }
    /**
     * @dev Overrides `Ownable.renounceOwnership()`, to avoid accidentally
     *      renouncing ownership of the PoolFactory contract.
     */
    function renounceOwnership() public virtual override {}
    /// @dev See `CorePool._authorizeUpgrade()`
    function _authorizeUpgrade(address) internal virtual override onlyOwner {}
    /**
     * @dev Empty reserved space in storage. The size of the __gap array is calculated so that
     *      the amount of storage used by a contract always adds up to the 50.
     *      See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[45] private __gap;
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
 * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
 * behind a proxy. Since a proxied contract can't have a constructor, it's common to move constructor logic to an
 * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
 * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
 *
 * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
 * possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}.
 *
 * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
 * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
 */
abstract contract Initializable {
    /**
     * @dev Indicates that the contract has been initialized.
     */
    bool private _initialized;
    /**
     * @dev Indicates that the contract is in the process of being initialized.
     */
    bool private _initializing;
    /**
     * @dev Modifier to protect an initializer function from being invoked twice.
     */
    modifier initializer() {
        require(_initializing || !_initialized, "Initializable: contract is already initialized");
        bool isTopLevelCall = !_initializing;
        if (isTopLevelCall) {
            _initializing = true;
            _initialized = true;
        }
        _;
        if (isTopLevelCall) {
            _initializing = false;
        }
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "../ERC1967/ERC1967UpgradeUpgradeable.sol";
import "./Initializable.sol";
/**
 * @dev An upgradeability mechanism designed for UUPS proxies. The functions included here can perform an upgrade of an
 * {ERC1967Proxy}, when this contract is set as the implementation behind such a proxy.
 *
 * A security mechanism ensures that an upgrade does not turn off upgradeability accidentally, although this risk is
 * reinstated if the upgrade retains upgradeability but removes the security mechanism, e.g. by replacing
 * `UUPSUpgradeable` with a custom implementation of upgrades.
 *
 * The {_authorizeUpgrade} function must be overridden to include access restriction to the upgrade mechanism.
 *
 * _Available since v4.1._
 */
abstract contract UUPSUpgradeable is Initializable, ERC1967UpgradeUpgradeable {
    function __UUPSUpgradeable_init() internal initializer {
        __ERC1967Upgrade_init_unchained();
        __UUPSUpgradeable_init_unchained();
    }
    function __UUPSUpgradeable_init_unchained() internal initializer {
    }
    /// @custom:oz-upgrades-unsafe-allow state-variable-immutable state-variable-assignment
    address private immutable __self = address(this);
    /**
     * @dev Check that the execution is being performed through a delegatecall call and that the execution context is
     * a proxy contract with an implementation (as defined in ERC1967) pointing to self. This should only be the case
     * for UUPS and transparent proxies that are using the current contract as their implementation. Execution of a
     * function through ERC1167 minimal proxies (clones) would not normally pass this test, but is not guaranteed to
     * fail.
     */
    modifier onlyProxy() {
        require(address(this) != __self, "Function must be called through delegatecall");
        require(_getImplementation() == __self, "Function must be called through active proxy");
        _;
    }
    /**
     * @dev Upgrade the implementation of the proxy to `newImplementation`.
     *
     * Calls {_authorizeUpgrade}.
     *
     * Emits an {Upgraded} event.
     */
    function upgradeTo(address newImplementation) external virtual onlyProxy {
        _authorizeUpgrade(newImplementation);
        _upgradeToAndCallSecure(newImplementation, new bytes(0), false);
    }
    /**
     * @dev Upgrade the implementation of the proxy to `newImplementation`, and subsequently execute the function call
     * encoded in `data`.
     *
     * Calls {_authorizeUpgrade}.
     *
     * Emits an {Upgraded} event.
     */
    function upgradeToAndCall(address newImplementation, bytes memory data) external payable virtual onlyProxy {
        _authorizeUpgrade(newImplementation);
        _upgradeToAndCallSecure(newImplementation, data, true);
    }
    /**
     * @dev Function that should revert when `msg.sender` is not authorized to upgrade the contract. Called by
     * {upgradeTo} and {upgradeToAndCall}.
     *
     * Normally, this function will use an xref:access.adoc[access control] modifier such as {Ownable-onlyOwner}.
     *
     * ```solidity
     * function _authorizeUpgrade(address) internal override onlyOwner {}
     * ```
     */
    function _authorizeUpgrade(address newImplementation) internal virtual;
    uint256[50] private __gap;
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "../utils/ContextUpgradeable.sol";
import "../proxy/utils/Initializable.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 OwnableUpgradeable is Initializable, ContextUpgradeable {
    address private _owner;
    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    function __Ownable_init() internal initializer {
        __Context_init_unchained();
        __Ownable_init_unchained();
    }
    function __Ownable_init_unchained() internal initializer {
        _setOwner(_msgSender());
    }
    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual 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 {
        _setOwner(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");
        _setOwner(newOwner);
    }
    function _setOwner(address newOwner) private {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
    uint256[49] private __gap;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/math/SafeCast.sol)
pragma solidity 0.8.4;
import { ErrorHandler } from "./ErrorHandler.sol";
/**
 * @notice Copied from OpenZeppelin's SafeCast.sol, adapted to use just in the required
 * uint sizes.
 * @dev Wrappers over Solidity's uintXX/intXX casting operators with added overflow
 * checks.
 *
 * Downcasting from uint256/int256 in Solidity does not revert on overflow. This can
 * easily result in undesired exploitation or bugs, since developers usually
 * assume that overflows raise errors. `SafeCast` restores this intuition by
 * reverting the transaction when such 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.
 *
 * Can be combined with {SafeMath} and {SignedSafeMath} to extend it to smaller types, by performing
 * all math on `uint256` and `int256` and then downcasting.
 */
library SafeCast {
    using ErrorHandler for bytes4;
    /**
     * @dev Returns the downcasted uint248 from uint256, reverting on
     * overflow (when the input is greater than largest uint248).
     *
     * Counterpart to Solidity's `uint248` operator.
     *
     * Requirements:
     *
     * - input must fit into 248 bits
     */
    function toUint248(uint256 _value) internal pure returns (uint248) {
        // we're using selector to simplify input and state validation
        // internal function simulated selector is `bytes4(keccak256("toUint248(uint256))"))`
        bytes4 fnSelector = 0x3fd72672;
        fnSelector.verifyInput(_value <= type(uint248).max, 0);
        return uint248(_value);
    }
    /**
     * @dev Returns the downcasted uint128 from uint256, reverting on
     * overflow (when the input is greater than largest uint128).
     *
     * Counterpart to Solidity's `uint128` operator.
     *
     * Requirements:
     *
     * - input must fit into 128 bits
     */
    function toUint128(uint256 _value) internal pure returns (uint128) {
        // we're using selector to simplify input and state validation
        // internal function simulated selector is `bytes4(keccak256("toUint128(uint256))"))`
        bytes4 fnSelector = 0x809fdd33;
        fnSelector.verifyInput(_value <= type(uint128).max, 0);
        return uint128(_value);
    }
    /**
     * @dev Returns the downcasted uint120 from uint256, reverting on
     * overflow (when the input is greater than largest uint120).
     *
     * Counterpart to Solidity's `uint120` operator.
     *
     * Requirements:
     *
     * - input must fit into 120 bits
     */
    function toUint120(uint256 _value) internal pure returns (uint120) {
        // we're using selector to simplify input and state validation
        // internal function simulated selector is `bytes4(keccak256("toUint120(uint256))"))`
        bytes4 fnSelector = 0x1e4e4bad;
        fnSelector.verifyInput(_value <= type(uint120).max, 0);
        return uint120(_value);
    }
    /**
     * @dev Returns the downcasted uint64 from uint256, reverting on
     * overflow (when the input is greater than largest uint64).
     *
     * Counterpart to Solidity's `uint64` operator.
     *
     * Requirements:
     *
     * - input must fit into 64 bits
     */
    function toUint64(uint256 _value) internal pure returns (uint64) {
        // we're using selector to simplify input and state validation
        // internal function simulated selector is `bytes4(keccak256("toUint64(uint256))"))`
        bytes4 fnSelector = 0x2665fad0;
        fnSelector.verifyInput(_value <= type(uint64).max, 0);
        return uint64(_value);
    }
    /**
     * @dev Returns the downcasted uint32 from uint256, reverting on
     * overflow (when the input is greater than largest uint32).
     *
     * Counterpart to Solidity's `uint32` operator.
     *
     * Requirements:
     *
     * - input must fit into 32 bits
     */
    function toUint32(uint256 _value) internal pure returns (uint32) {
        // we're using selector to simplify input and state validation
        // internal function simulated selector is `bytes4(keccak256("toUint32(uint256))"))`
        bytes4 fnSelector = 0xc8193255;
        fnSelector.verifyInput(_value <= type(uint32).max, 0);
        return uint32(_value);
    }
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.4;
/// @title Function for getting block timestamp.
/// @dev Base contract that is overridden for tests.
abstract contract Timestamp {
    /**
     * @dev Testing time-dependent functionality is difficult and the best way of
     *      doing it is to override time in helper test smart contracts.
     *
     * @return `block.timestamp` in mainnet, custom values in testnets (if overridden).
     */
    function _now256() internal view virtual returns (uint256) {
        // return current block timestamp
        return block.timestamp;
    }
    /**
     * @dev Empty reserved space in storage. The size of the __gap array is calculated so that
     *      the amount of storage used by a contract always adds up to the 50.
     *      See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[50] private __gap;
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.4;
import { Stake } from "../libraries/Stake.sol";
interface ICorePool {
    function users(address _user)
        external
        view
        returns (
            uint128,
            uint128,
            uint128,
            uint248,
            uint8,
            uint256,
            uint256
        );
    function poolToken() external view returns (address);
    function isFlashPool() external view returns (bool);
    function weight() external view returns (uint32);
    function lastYieldDistribution() external view returns (uint64);
    function yieldRewardsPerWeight() external view returns (uint256);
    function globalWeight() external view returns (uint256);
    function pendingRewards(address _user) external view returns (uint256, uint256);
    function poolTokenReserve() external view returns (uint256);
    function balanceOf(address _user) external view returns (uint256);
    function getTotalReserves() external view returns (uint256);
    function getStake(address _user, uint256 _stakeId) external view returns (Stake.Data memory);
    function getStakesLength(address _user) external view returns (uint256);
    function sync() external;
    function setWeight(uint32 _weight) external;
    function receiveVaultRewards(uint256 value) external;
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.4;
import { IERC20Upgradeable } from "@openzeppelin/contracts-upgradeable/token/ERC20/IERC20Upgradeable.sol";
interface IERC20Mintable is IERC20Upgradeable {
    function mint(address _to, uint256 _value) external;
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.4;
/**
 * @title Errors Library.
 *
 * @notice Introduces some very common input and state validation for smart contracts,
 *      such as non-zero input validation, general boolean expression validation, access validation.
 *
 * @notice Throws pre-defined errors instead of string error messages to reduce gas costs.
 *
 * @notice Since the library handles only very common errors, concrete smart contracts may
 *      also introduce their own error types and handling.
 *
 * @author Basil Gorin
 */
library ErrorHandler {
    /**
     * @notice Thrown on zero input at index specified in a function specified.
     *
     * @param fnSelector function selector, defines a function where error was thrown
     * @param paramIndex function parameter index which caused an error thrown
     */
    error ZeroInput(bytes4 fnSelector, uint8 paramIndex);
    /**
     * @notice Thrown on invalid input at index specified in a function specified.
     *
     * @param fnSelector function selector, defines a function where error was thrown
     * @param paramIndex function parameter index which caused an error thrown
     */
    error InvalidInput(bytes4 fnSelector, uint8 paramIndex);
    /**
     * @notice Thrown on invalid state in a function specified.
     *
     * @param fnSelector function selector, defines a function where error was thrown
     * @param errorCode unique error code determining the exact place in code where error was thrown
     */
    error InvalidState(bytes4 fnSelector, uint256 errorCode);
    /**
     * @notice Thrown on invalid access to a function specified.
     *
     * @param fnSelector function selector, defines a function where error was thrown
     * @param addr an address which access was denied, usually transaction sender
     */
    error AccessDenied(bytes4 fnSelector, address addr);
    /**
     * @notice Verifies an input is set (non-zero).
     *
     * @param fnSelector function selector, defines a function which called the verification
     * @param value a value to check if it's set (non-zero)
     * @param paramIndex function parameter index which is verified
     */
    function verifyNonZeroInput(
        bytes4 fnSelector,
        uint256 value,
        uint8 paramIndex
    ) internal pure {
        if (value == 0) {
            revert ZeroInput(fnSelector, paramIndex);
        }
    }
    /**
     * @notice Verifies an input is correct.
     *
     * @param fnSelector function selector, defines a function which called the verification
     * @param expr a boolean expression used to verify the input
     * @param paramIndex function parameter index which is verified
     */
    function verifyInput(
        bytes4 fnSelector,
        bool expr,
        uint8 paramIndex
    ) internal pure {
        if (!expr) {
            revert InvalidInput(fnSelector, paramIndex);
        }
    }
    /**
     * @notice Verifies smart contract state is correct.
     *
     * @param fnSelector function selector, defines a function which called the verification
     * @param expr a boolean expression used to verify the contract state
     * @param errorCode unique error code determining the exact place in code which is verified
     */
    function verifyState(
        bytes4 fnSelector,
        bool expr,
        uint256 errorCode
    ) internal pure {
        if (!expr) {
            revert InvalidState(fnSelector, errorCode);
        }
    }
    /**
     * @notice Verifies an access to the function.
     *
     * @param fnSelector function selector, defines a function which called the verification
     * @param expr a boolean expression used to verify the access
     */
    function verifyAccess(bytes4 fnSelector, bool expr) internal view {
        if (!expr) {
            revert AccessDenied(fnSelector, msg.sender);
        }
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.2;
import "../beacon/IBeaconUpgradeable.sol";
import "../../utils/AddressUpgradeable.sol";
import "../../utils/StorageSlotUpgradeable.sol";
import "../utils/Initializable.sol";
/**
 * @dev This abstract contract provides getters and event emitting update functions for
 * https://eips.ethereum.org/EIPS/eip-1967[EIP1967] slots.
 *
 * _Available since v4.1._
 *
 * @custom:oz-upgrades-unsafe-allow delegatecall
 */
abstract contract ERC1967UpgradeUpgradeable is Initializable {
    function __ERC1967Upgrade_init() internal initializer {
        __ERC1967Upgrade_init_unchained();
    }
    function __ERC1967Upgrade_init_unchained() internal initializer {
    }
    // This is the keccak-256 hash of "eip1967.proxy.rollback" subtracted by 1
    bytes32 private constant _ROLLBACK_SLOT = 0x4910fdfa16fed3260ed0e7147f7cc6da11a60208b5b9406d12a635614ffd9143;
    /**
     * @dev Storage slot with the address of the current implementation.
     * This is the keccak-256 hash of "eip1967.proxy.implementation" subtracted by 1, and is
     * validated in the constructor.
     */
    bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
    /**
     * @dev Emitted when the implementation is upgraded.
     */
    event Upgraded(address indexed implementation);
    /**
     * @dev Returns the current implementation address.
     */
    function _getImplementation() internal view returns (address) {
        return StorageSlotUpgradeable.getAddressSlot(_IMPLEMENTATION_SLOT).value;
    }
    /**
     * @dev Stores a new address in the EIP1967 implementation slot.
     */
    function _setImplementation(address newImplementation) private {
        require(AddressUpgradeable.isContract(newImplementation), "ERC1967: new implementation is not a contract");
        StorageSlotUpgradeable.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
    }
    /**
     * @dev Perform implementation upgrade
     *
     * Emits an {Upgraded} event.
     */
    function _upgradeTo(address newImplementation) internal {
        _setImplementation(newImplementation);
        emit Upgraded(newImplementation);
    }
    /**
     * @dev Perform implementation upgrade with additional setup call.
     *
     * Emits an {Upgraded} event.
     */
    function _upgradeToAndCall(
        address newImplementation,
        bytes memory data,
        bool forceCall
    ) internal {
        _upgradeTo(newImplementation);
        if (data.length > 0 || forceCall) {
            _functionDelegateCall(newImplementation, data);
        }
    }
    /**
     * @dev Perform implementation upgrade with security checks for UUPS proxies, and additional setup call.
     *
     * Emits an {Upgraded} event.
     */
    function _upgradeToAndCallSecure(
        address newImplementation,
        bytes memory data,
        bool forceCall
    ) internal {
        address oldImplementation = _getImplementation();
        // Initial upgrade and setup call
        _setImplementation(newImplementation);
        if (data.length > 0 || forceCall) {
            _functionDelegateCall(newImplementation, data);
        }
        // Perform rollback test if not already in progress
        StorageSlotUpgradeable.BooleanSlot storage rollbackTesting = StorageSlotUpgradeable.getBooleanSlot(_ROLLBACK_SLOT);
        if (!rollbackTesting.value) {
            // Trigger rollback using upgradeTo from the new implementation
            rollbackTesting.value = true;
            _functionDelegateCall(
                newImplementation,
                abi.encodeWithSignature("upgradeTo(address)", oldImplementation)
            );
            rollbackTesting.value = false;
            // Check rollback was effective
            require(oldImplementation == _getImplementation(), "ERC1967Upgrade: upgrade breaks further upgrades");
            // Finally reset to the new implementation and log the upgrade
            _upgradeTo(newImplementation);
        }
    }
    /**
     * @dev Storage slot with the admin of the contract.
     * This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is
     * validated in the constructor.
     */
    bytes32 internal constant _ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;
    /**
     * @dev Emitted when the admin account has changed.
     */
    event AdminChanged(address previousAdmin, address newAdmin);
    /**
     * @dev Returns the current admin.
     */
    function _getAdmin() internal view returns (address) {
        return StorageSlotUpgradeable.getAddressSlot(_ADMIN_SLOT).value;
    }
    /**
     * @dev Stores a new address in the EIP1967 admin slot.
     */
    function _setAdmin(address newAdmin) private {
        require(newAdmin != address(0), "ERC1967: new admin is the zero address");
        StorageSlotUpgradeable.getAddressSlot(_ADMIN_SLOT).value = newAdmin;
    }
    /**
     * @dev Changes the admin of the proxy.
     *
     * Emits an {AdminChanged} event.
     */
    function _changeAdmin(address newAdmin) internal {
        emit AdminChanged(_getAdmin(), newAdmin);
        _setAdmin(newAdmin);
    }
    /**
     * @dev The storage slot of the UpgradeableBeacon contract which defines the implementation for this proxy.
     * This is bytes32(uint256(keccak256('eip1967.proxy.beacon')) - 1)) and is validated in the constructor.
     */
    bytes32 internal constant _BEACON_SLOT = 0xa3f0ad74e5423aebfd80d3ef4346578335a9a72aeaee59ff6cb3582b35133d50;
    /**
     * @dev Emitted when the beacon is upgraded.
     */
    event BeaconUpgraded(address indexed beacon);
    /**
     * @dev Returns the current beacon.
     */
    function _getBeacon() internal view returns (address) {
        return StorageSlotUpgradeable.getAddressSlot(_BEACON_SLOT).value;
    }
    /**
     * @dev Stores a new beacon in the EIP1967 beacon slot.
     */
    function _setBeacon(address newBeacon) private {
        require(AddressUpgradeable.isContract(newBeacon), "ERC1967: new beacon is not a contract");
        require(
            AddressUpgradeable.isContract(IBeaconUpgradeable(newBeacon).implementation()),
            "ERC1967: beacon implementation is not a contract"
        );
        StorageSlotUpgradeable.getAddressSlot(_BEACON_SLOT).value = newBeacon;
    }
    /**
     * @dev Perform beacon upgrade with additional setup call. Note: This upgrades the address of the beacon, it does
     * not upgrade the implementation contained in the beacon (see {UpgradeableBeacon-_setImplementation} for that).
     *
     * Emits a {BeaconUpgraded} event.
     */
    function _upgradeBeaconToAndCall(
        address newBeacon,
        bytes memory data,
        bool forceCall
    ) internal {
        _setBeacon(newBeacon);
        emit BeaconUpgraded(newBeacon);
        if (data.length > 0 || forceCall) {
            _functionDelegateCall(IBeaconUpgradeable(newBeacon).implementation(), data);
        }
    }
    /**
     * @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) private returns (bytes memory) {
        require(AddressUpgradeable.isContract(target), "Address: delegate call to non-contract");
        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return AddressUpgradeable.verifyCallResult(success, returndata, "Address: low-level delegate call failed");
    }
    uint256[50] private __gap;
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
 * @dev This is the interface that {BeaconProxy} expects of its beacon.
 */
interface IBeaconUpgradeable {
    /**
     * @dev Must return an address that can be used as a delegate call target.
     *
     * {BeaconProxy} will check that this address is a contract.
     */
    function implementation() external view returns (address);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
 * @dev Collection of functions related to the address type
 */
library AddressUpgradeable {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize, which returns 0 for contracts in
        // construction, since the code is only stored at the end of the
        // constructor execution.
        uint256 size;
        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");
        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }
    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain `call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCall(target, data, "Address: low-level call failed");
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }
    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        require(isContract(target), "Address: call to non-contract");
        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResult(success, returndata, errorMessage);
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }
    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");
        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }
    /**
     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason 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 {
            // 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
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
 * @dev Library for reading and writing primitive types to specific storage slots.
 *
 * Storage slots are often used to avoid storage conflict when dealing with upgradeable contracts.
 * This library helps with reading and writing to such slots without the need for inline assembly.
 *
 * The functions in this library return Slot structs that contain a `value` member that can be used to read or write.
 *
 * Example usage to set ERC1967 implementation slot:
 * ```
 * contract ERC1967 {
 *     bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
 *
 *     function _getImplementation() internal view returns (address) {
 *         return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
 *     }
 *
 *     function _setImplementation(address newImplementation) internal {
 *         require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
 *         StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
 *     }
 * }
 * ```
 *
 * _Available since v4.1 for `address`, `bool`, `bytes32`, and `uint256`._
 */
library StorageSlotUpgradeable {
    struct AddressSlot {
        address value;
    }
    struct BooleanSlot {
        bool value;
    }
    struct Bytes32Slot {
        bytes32 value;
    }
    struct Uint256Slot {
        uint256 value;
    }
    /**
     * @dev Returns an `AddressSlot` with member `value` located at `slot`.
     */
    function getAddressSlot(bytes32 slot) internal pure returns (AddressSlot storage r) {
        assembly {
            r.slot := slot
        }
    }
    /**
     * @dev Returns an `BooleanSlot` with member `value` located at `slot`.
     */
    function getBooleanSlot(bytes32 slot) internal pure returns (BooleanSlot storage r) {
        assembly {
            r.slot := slot
        }
    }
    /**
     * @dev Returns an `Bytes32Slot` with member `value` located at `slot`.
     */
    function getBytes32Slot(bytes32 slot) internal pure returns (Bytes32Slot storage r) {
        assembly {
            r.slot := slot
        }
    }
    /**
     * @dev Returns an `Uint256Slot` with member `value` located at `slot`.
     */
    function getUint256Slot(bytes32 slot) internal pure returns (Uint256Slot storage r) {
        assembly {
            r.slot := slot
        }
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "../proxy/utils/Initializable.sol";
/**
 * @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 ContextUpgradeable is Initializable {
    function __Context_init() internal initializer {
        __Context_init_unchained();
    }
    function __Context_init_unchained() internal initializer {
    }
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }
    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
    uint256[50] private __gap;
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.4;
/**
 * @dev Stake library used by ILV pool and Sushi LP Pool.
 *
 * @dev Responsible to manage weight calculation and store important constants
 *      related to stake period, base weight and multipliers utilized.
 */
library Stake {
    struct Data {
        /// @dev token amount staked
        uint120 value;
        /// @dev locking period - from
        uint64 lockedFrom;
        /// @dev locking period - until
        uint64 lockedUntil;
        /// @dev indicates if the stake was created as a yield reward
        bool isYield;
    }
    /**
     * @dev Stake weight is proportional to stake value and time locked, precisely
     *      "stake value wei multiplied by (fraction of the year locked plus one)".
     * @dev To avoid significant precision loss due to multiplication by "fraction of the year" [0, 1],
     *      weight is stored multiplied by 1e6 constant, as an integer.
     * @dev Corner case 1: if time locked is zero, weight is stake value multiplied by 1e6 + base weight
     * @dev Corner case 2: if time locked is two years, division of
            (lockedUntil - lockedFrom) / MAX_STAKE_PERIOD is 1e6, and
     *      weight is a stake value multiplied by 2 * 1e6.
     */
    uint256 internal constant WEIGHT_MULTIPLIER = 1e6;
    /**
     * @dev Minimum weight value, if result of multiplication using WEIGHT_MULTIPLIER
     *      is 0 (e.g stake flexible), then BASE_WEIGHT is used.
     */
    uint256 internal constant BASE_WEIGHT = 1e6;
    /**
     * @dev Minimum period that someone can lock a stake for.
     */
    uint256 internal constant MIN_STAKE_PERIOD = 30 days;
    /**
     * @dev Maximum period that someone can lock a stake for.
     */
    uint256 internal constant MAX_STAKE_PERIOD = 365 days;
    /**
     * @dev Rewards per weight are stored multiplied by 1e20 as uint.
     */
    uint256 internal constant REWARD_PER_WEIGHT_MULTIPLIER = 1e20;
    /**
     * @dev When we know beforehand that staking is done for yield instead of
     *      executing `weight()` function we use the following constant.
     */
    uint256 internal constant YIELD_STAKE_WEIGHT_MULTIPLIER = 2 * 1e6;
    function weight(Data storage _self) internal view returns (uint256) {
        return
            uint256(
                (((_self.lockedUntil - _self.lockedFrom) * WEIGHT_MULTIPLIER) / MAX_STAKE_PERIOD + BASE_WEIGHT) *
                    _self.value
            );
    }
    /**
     * @dev Converts stake weight (not to be mixed with the pool weight) to
     *      ILV reward value, applying the 10^12 division on weight
     *
     * @param _weight stake weight
     * @param _rewardPerWeight ILV reward per weight
     * @param _rewardPerWeightPaid last reward per weight value used for user earnings
     * @return reward value normalized to 10^12
     */
    function earned(
        uint256 _weight,
        uint256 _rewardPerWeight,
        uint256 _rewardPerWeightPaid
    ) internal pure returns (uint256) {
        // apply the formula and return
        return (_weight * (_rewardPerWeight - _rewardPerWeightPaid)) / REWARD_PER_WEIGHT_MULTIPLIER;
    }
    /**
     * @dev Converts reward ILV value to stake weight (not to be mixed with the pool weight),
     *      applying the 10^12 multiplication on the reward.
     *      - OR -
     * @dev Converts reward ILV value to reward/weight if stake weight is supplied as second
     *      function parameter instead of reward/weight.
     *
     * @param _reward yield reward
     * @param _globalWeight total weight in the pool
     * @return reward per weight value
     */
    function getRewardPerWeight(uint256 _reward, uint256 _globalWeight) internal pure returns (uint256) {
        // apply the reverse formula and return
        return (_reward * REWARD_PER_WEIGHT_MULTIPLIER) / _globalWeight;
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20Upgradeable {
    /**
     * @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);
}

// SPDX-License-Identifier: MIT
pragma solidity 0.8.1;
/**
 * @title ERC20 token receiver interface
 *
 * @dev Interface for any contract that wants to support safe transfers
 *      from ERC20 token smart contracts.
 * @dev Inspired by ERC721 and ERC223 token standards
 *
 * @dev See https://github.com/ethereum/EIPs/blob/master/EIPS/eip-721.md
 * @dev See https://github.com/ethereum/EIPs/issues/223
 *
 * @author Basil Gorin
 */
interface ERC20Receiver {
  /**
   * @notice Handle the receipt of a ERC20 token(s)
   * @dev The ERC20 smart contract calls this function on the recipient
   *      after a successful transfer (`safeTransferFrom`).
   *      This function MAY throw to revert and reject the transfer.
   *      Return of other than the magic value MUST result in the transaction being reverted.
   * @notice The contract address is always the message sender.
   *      A wallet/broker/auction application MUST implement the wallet interface
   *      if it will accept safe transfers.
   * @param _operator The address which called `safeTransferFrom` function
   * @param _from The address which previously owned the token
   * @param _value amount of tokens which is being transferred
   * @param _data additional data with no specified format
   * @return `bytes4(keccak256("onERC20Received(address,address,uint256,bytes)"))` unless throwing
   */
  function onERC20Received(address _operator, address _from, uint256 _value, bytes calldata _data) external returns(bytes4);
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.1;
import "../utils/AddressUtils.sol";
import "../utils/AccessControl.sol";
import "./ERC20Receiver.sol";
/**
 * @title Illuvium (ILV) ERC20 token
 *
 * @notice Illuvium is a core ERC20 token powering the game.
 *      It serves as an in-game currency, is tradable on exchanges,
 *      it powers up the governance protocol (Illuvium DAO) and participates in Yield Farming.
 *
 * @dev Token Summary:
 *      - Symbol: ILV
 *      - Name: Illuvium
 *      - Decimals: 18
 *      - Initial token supply: 7,000,000 ILV
 *      - Maximum final token supply: 10,000,000 ILV
 *          - Up to 3,000,000 ILV may get minted in 3 years period via yield farming
 *      - Mintable: total supply may increase
 *      - Burnable: total supply may decrease
 *
 * @dev Token balances and total supply are effectively 192 bits long, meaning that maximum
 *      possible total supply smart contract is able to track is 2^192 (close to 10^40 tokens)
 *
 * @dev Smart contract doesn't use safe math. All arithmetic operations are overflow/underflow safe.
 *      Additionally, Solidity 0.8.1 enforces overflow/underflow safety.
 *
 * @dev ERC20: reviewed according to https://eips.ethereum.org/EIPS/eip-20
 *
 * @dev ERC20: contract has passed OpenZeppelin ERC20 tests,
 *      see https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/test/token/ERC20/ERC20.behavior.js
 *      see https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/test/token/ERC20/ERC20.test.js
 *      see adopted copies of these tests in the `test` folder
 *
 * @dev ERC223/ERC777: not supported;
 *      send tokens via `safeTransferFrom` and implement `ERC20Receiver.onERC20Received` on the receiver instead
 *
 * @dev Multiple Withdrawal Attack on ERC20 Tokens (ISBN:978-1-7281-3027-9) - resolved
 *      Related events and functions are marked with "ISBN:978-1-7281-3027-9" tag:
 *        - event Transferred(address indexed _by, address indexed _from, address indexed _to, uint256 _value)
 *        - event Approved(address indexed _owner, address indexed _spender, uint256 _oldValue, uint256 _value)
 *        - function increaseAllowance(address _spender, uint256 _value) public returns (bool)
 *        - function decreaseAllowance(address _spender, uint256 _value) public returns (bool)
 *      See: https://ieeexplore.ieee.org/document/8802438
 *      See: https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
 *
 * @author Basil Gorin
 */
contract IlluviumERC20 is AccessControl {
  /**
   * @dev Smart contract unique identifier, a random number
   * @dev Should be regenerated each time smart contact source code is changed
   *      and changes smart contract itself is to be redeployed
   * @dev Generated using https://www.random.org/bytes/
   */
  uint256 public constant TOKEN_UID = 0x83ecb176af7c4f35a45ff0018282e3a05a1018065da866182df12285866f5a2c;
  /**
   * @notice Name of the token: Illuvium
   *
   * @notice ERC20 name of the token (long name)
   *
   * @dev ERC20 `function name() public view returns (string)`
   *
   * @dev Field is declared public: getter name() is created when compiled,
   *      it returns the name of the token.
   */
  string public constant name = "Illuvium";
  /**
   * @notice Symbol of the token: ILV
   *
   * @notice ERC20 symbol of that token (short name)
   *
   * @dev ERC20 `function symbol() public view returns (string)`
   *
   * @dev Field is declared public: getter symbol() is created when compiled,
   *      it returns the symbol of the token
   */
  string public constant symbol = "ILV";
  /**
   * @notice Decimals of the token: 18
   *
   * @dev ERC20 `function decimals() public view returns (uint8)`
   *
   * @dev Field is declared public: getter decimals() is created when compiled,
   *      it returns the number of decimals used to get its user representation.
   *      For example, if `decimals` equals `6`, a balance of `1,500,000` tokens should
   *      be displayed to a user as `1,5` (`1,500,000 / 10 ** 6`).
   *
   * @dev NOTE: This information is only used for _display_ purposes: it in
   *      no way affects any of the arithmetic of the contract, including balanceOf() and transfer().
   */
  uint8 public constant decimals = 18;
  /**
   * @notice Total supply of the token: initially 7,000,000,
   *      with the potential to grow up to 10,000,000 during yield farming period (3 years)
   *
   * @dev ERC20 `function totalSupply() public view returns (uint256)`
   *
   * @dev Field is declared public: getter totalSupply() is created when compiled,
   *      it returns the amount of tokens in existence.
   */
  uint256 public totalSupply; // is set to 7 million * 10^18 in the constructor
  /**
   * @dev A record of all the token balances
   * @dev This mapping keeps record of all token owners:
   *      owner => balance
   */
  mapping(address => uint256) public tokenBalances;
  /**
   * @notice A record of each account's voting delegate
   *
   * @dev Auxiliary data structure used to sum up an account's voting power
   *
   * @dev This mapping keeps record of all voting power delegations:
   *      voting delegator (token owner) => voting delegate
   */
  mapping(address => address) public votingDelegates;
  /**
   * @notice A voting power record binds voting power of a delegate to a particular
   *      block when the voting power delegation change happened
   */
  struct VotingPowerRecord {
    /*
     * @dev block.number when delegation has changed; starting from
     *      that block voting power value is in effect
     */
    uint64 blockNumber;
    /*
     * @dev cumulative voting power a delegate has obtained starting
     *      from the block stored in blockNumber
     */
    uint192 votingPower;
  }
  /**
   * @notice A record of each account's voting power
   *
   * @dev Primarily data structure to store voting power for each account.
   *      Voting power sums up from the account's token balance and delegated
   *      balances.
   *
   * @dev Stores current value and entire history of its changes.
   *      The changes are stored as an array of checkpoints.
   *      Checkpoint is an auxiliary data structure containing voting
   *      power (number of votes) and block number when the checkpoint is saved
   *
   * @dev Maps voting delegate => voting power record
   */
  mapping(address => VotingPowerRecord[]) public votingPowerHistory;
  /**
   * @dev A record of nonces for signing/validating signatures in `delegateWithSig`
   *      for every delegate, increases after successful validation
   *
   * @dev Maps delegate address => delegate nonce
   */
  mapping(address => uint256) public nonces;
  /**
   * @notice A record of all the allowances to spend tokens on behalf
   * @dev Maps token owner address to an address approved to spend
   *      some tokens on behalf, maps approved address to that amount
   * @dev owner => spender => value
   */
  mapping(address => mapping(address => uint256)) public transferAllowances;
  /**
   * @notice Enables ERC20 transfers of the tokens
   *      (transfer by the token owner himself)
   * @dev Feature FEATURE_TRANSFERS must be enabled in order for
   *      `transfer()` function to succeed
   */
  uint32 public constant FEATURE_TRANSFERS = 0x0000_0001;
  /**
   * @notice Enables ERC20 transfers on behalf
   *      (transfer by someone else on behalf of token owner)
   * @dev Feature FEATURE_TRANSFERS_ON_BEHALF must be enabled in order for
   *      `transferFrom()` function to succeed
   * @dev Token owner must call `approve()` first to authorize
   *      the transfer on behalf
   */
  uint32 public constant FEATURE_TRANSFERS_ON_BEHALF = 0x0000_0002;
  /**
   * @dev Defines if the default behavior of `transfer` and `transferFrom`
   *      checks if the receiver smart contract supports ERC20 tokens
   * @dev When feature FEATURE_UNSAFE_TRANSFERS is enabled the transfers do not
   *      check if the receiver smart contract supports ERC20 tokens,
   *      i.e. `transfer` and `transferFrom` behave like `unsafeTransferFrom`
   * @dev When feature FEATURE_UNSAFE_TRANSFERS is disabled (default) the transfers
   *      check if the receiver smart contract supports ERC20 tokens,
   *      i.e. `transfer` and `transferFrom` behave like `safeTransferFrom`
   */
  uint32 public constant FEATURE_UNSAFE_TRANSFERS = 0x0000_0004;
  /**
   * @notice Enables token owners to burn their own tokens,
   *      including locked tokens which are burnt first
   * @dev Feature FEATURE_OWN_BURNS must be enabled in order for
   *      `burn()` function to succeed when called by token owner
   */
  uint32 public constant FEATURE_OWN_BURNS = 0x0000_0008;
  /**
   * @notice Enables approved operators to burn tokens on behalf of their owners,
   *      including locked tokens which are burnt first
   * @dev Feature FEATURE_OWN_BURNS must be enabled in order for
   *      `burn()` function to succeed when called by approved operator
   */
  uint32 public constant FEATURE_BURNS_ON_BEHALF = 0x0000_0010;
  /**
   * @notice Enables delegators to elect delegates
   * @dev Feature FEATURE_DELEGATIONS must be enabled in order for
   *      `delegate()` function to succeed
   */
  uint32 public constant FEATURE_DELEGATIONS = 0x0000_0020;
  /**
   * @notice Enables delegators to elect delegates on behalf
   *      (via an EIP712 signature)
   * @dev Feature FEATURE_DELEGATIONS must be enabled in order for
   *      `delegateWithSig()` function to succeed
   */
  uint32 public constant FEATURE_DELEGATIONS_ON_BEHALF = 0x0000_0040;
  /**
   * @notice Token creator is responsible for creating (minting)
   *      tokens to an arbitrary address
   * @dev Role ROLE_TOKEN_CREATOR allows minting tokens
   *      (calling `mint` function)
   */
  uint32 public constant ROLE_TOKEN_CREATOR = 0x0001_0000;
  /**
   * @notice Token destroyer is responsible for destroying (burning)
   *      tokens owned by an arbitrary address
   * @dev Role ROLE_TOKEN_DESTROYER allows burning tokens
   *      (calling `burn` function)
   */
  uint32 public constant ROLE_TOKEN_DESTROYER = 0x0002_0000;
  /**
   * @notice ERC20 receivers are allowed to receive tokens without ERC20 safety checks,
   *      which may be useful to simplify tokens transfers into "legacy" smart contracts
   * @dev When `FEATURE_UNSAFE_TRANSFERS` is not enabled addresses having
   *      `ROLE_ERC20_RECEIVER` permission are allowed to receive tokens
   *      via `transfer` and `transferFrom` functions in the same way they
   *      would via `unsafeTransferFrom` function
   * @dev When `FEATURE_UNSAFE_TRANSFERS` is enabled `ROLE_ERC20_RECEIVER` permission
   *      doesn't affect the transfer behaviour since
   *      `transfer` and `transferFrom` behave like `unsafeTransferFrom` for any receiver
   * @dev ROLE_ERC20_RECEIVER is a shortening for ROLE_UNSAFE_ERC20_RECEIVER
   */
  uint32 public constant ROLE_ERC20_RECEIVER = 0x0004_0000;
  /**
   * @notice ERC20 senders are allowed to send tokens without ERC20 safety checks,
   *      which may be useful to simplify tokens transfers into "legacy" smart contracts
   * @dev When `FEATURE_UNSAFE_TRANSFERS` is not enabled senders having
   *      `ROLE_ERC20_SENDER` permission are allowed to send tokens
   *      via `transfer` and `transferFrom` functions in the same way they
   *      would via `unsafeTransferFrom` function
   * @dev When `FEATURE_UNSAFE_TRANSFERS` is enabled `ROLE_ERC20_SENDER` permission
   *      doesn't affect the transfer behaviour since
   *      `transfer` and `transferFrom` behave like `unsafeTransferFrom` for any receiver
   * @dev ROLE_ERC20_SENDER is a shortening for ROLE_UNSAFE_ERC20_SENDER
   */
  uint32 public constant ROLE_ERC20_SENDER = 0x0008_0000;
  /**
   * @dev Magic value to be returned by ERC20Receiver upon successful reception of token(s)
   * @dev Equal to `bytes4(keccak256("onERC20Received(address,address,uint256,bytes)"))`,
   *      which can be also obtained as `ERC20Receiver(address(0)).onERC20Received.selector`
   */
  bytes4 private constant ERC20_RECEIVED = 0x4fc35859;
  /**
   * @notice EIP-712 contract's domain typeHash, see https://eips.ethereum.org/EIPS/eip-712#rationale-for-typehash
   */
  bytes32 public constant DOMAIN_TYPEHASH = keccak256("EIP712Domain(string name,uint256 chainId,address verifyingContract)");
  /**
   * @notice EIP-712 delegation struct typeHash, see https://eips.ethereum.org/EIPS/eip-712#rationale-for-typehash
   */
  bytes32 public constant DELEGATION_TYPEHASH = keccak256("Delegation(address delegate,uint256 nonce,uint256 expiry)");
  /**
   * @dev Fired in transfer(), transferFrom() and some other (non-ERC20) functions
   *
   * @dev ERC20 `event Transfer(address indexed _from, address indexed _to, uint256 _value)`
   *
   * @param _from an address tokens were consumed from
   * @param _to an address tokens were sent to
   * @param _value number of tokens transferred
   */
  event Transfer(address indexed _from, address indexed _to, uint256 _value);
  /**
   * @dev Fired in approve() and approveAtomic() functions
   *
   * @dev ERC20 `event Approval(address indexed _owner, address indexed _spender, uint256 _value)`
   *
   * @param _owner an address which granted a permission to transfer
   *      tokens on its behalf
   * @param _spender an address which received a permission to transfer
   *      tokens on behalf of the owner `_owner`
   * @param _value amount of tokens granted to transfer on behalf
   */
  event Approval(address indexed _owner, address indexed _spender, uint256 _value);
  /**
   * @dev Fired in mint() function
   *
   * @param _by an address which minted some tokens (transaction sender)
   * @param _to an address the tokens were minted to
   * @param _value an amount of tokens minted
   */
  event Minted(address indexed _by, address indexed _to, uint256 _value);
  /**
   * @dev Fired in burn() function
   *
   * @param _by an address which burned some tokens (transaction sender)
   * @param _from an address the tokens were burnt from
   * @param _value an amount of tokens burnt
   */
  event Burnt(address indexed _by, address indexed _from, uint256 _value);
  /**
   * @dev Resolution for the Multiple Withdrawal Attack on ERC20 Tokens (ISBN:978-1-7281-3027-9)
   *
   * @dev Similar to ERC20 Transfer event, but also logs an address which executed transfer
   *
   * @dev Fired in transfer(), transferFrom() and some other (non-ERC20) functions
   *
   * @param _by an address which performed the transfer
   * @param _from an address tokens were consumed from
   * @param _to an address tokens were sent to
   * @param _value number of tokens transferred
   */
  event Transferred(address indexed _by, address indexed _from, address indexed _to, uint256 _value);
  /**
   * @dev Resolution for the Multiple Withdrawal Attack on ERC20 Tokens (ISBN:978-1-7281-3027-9)
   *
   * @dev Similar to ERC20 Approve event, but also logs old approval value
   *
   * @dev Fired in approve() and approveAtomic() functions
   *
   * @param _owner an address which granted a permission to transfer
   *      tokens on its behalf
   * @param _spender an address which received a permission to transfer
   *      tokens on behalf of the owner `_owner`
   * @param _oldValue previously granted amount of tokens to transfer on behalf
   * @param _value new granted amount of tokens to transfer on behalf
   */
  event Approved(address indexed _owner, address indexed _spender, uint256 _oldValue, uint256 _value);
  /**
   * @dev Notifies that a key-value pair in `votingDelegates` mapping has changed,
   *      i.e. a delegator address has changed its delegate address
   *
   * @param _of delegator address, a token owner
   * @param _from old delegate, an address which delegate right is revoked
   * @param _to new delegate, an address which received the voting power
   */
  event DelegateChanged(address indexed _of, address indexed _from, address indexed _to);
  /**
   * @dev Notifies that a key-value pair in `votingPowerHistory` mapping has changed,
   *      i.e. a delegate's voting power has changed.
   *
   * @param _of delegate whose voting power has changed
   * @param _fromVal previous number of votes delegate had
   * @param _toVal new number of votes delegate has
   */
  event VotingPowerChanged(address indexed _of, uint256 _fromVal, uint256 _toVal);
  /**
   * @dev Deploys the token smart contract,
   *      assigns initial token supply to the address specified
   *
   * @param _initialHolder owner of the initial token supply
   */
  constructor(address _initialHolder) {
    // verify initial holder address non-zero (is set)
    require(_initialHolder != address(0), "_initialHolder not set (zero address)");
    // mint initial supply
    mint(_initialHolder, 7_000_000e18);
  }
  // ===== Start: ERC20/ERC223/ERC777 functions =====
  /**
   * @notice Gets the balance of a particular address
   *
   * @dev ERC20 `function balanceOf(address _owner) public view returns (uint256 balance)`
   *
   * @param _owner the address to query the the balance for
   * @return balance an amount of tokens owned by the address specified
   */
  function balanceOf(address _owner) public view returns (uint256 balance) {
    // read the balance and return
    return tokenBalances[_owner];
  }
  /**
   * @notice Transfers some tokens to an external address or a smart contract
   *
   * @dev ERC20 `function transfer(address _to, uint256 _value) public returns (bool success)`
   *
   * @dev Called by token owner (an address which has a
   *      positive token balance tracked by this smart contract)
   * @dev Throws on any error like
   *      * insufficient token balance or
   *      * incorrect `_to` address:
   *          * zero address or
   *          * self address or
   *          * smart contract which doesn't support ERC20
   *
   * @param _to an address to transfer tokens to,
   *      must be either an external address or a smart contract,
   *      compliant with the ERC20 standard
   * @param _value amount of tokens to be transferred, must
   *      be greater than zero
   * @return success true on success, throws otherwise
   */
  function transfer(address _to, uint256 _value) public returns (bool success) {
    // just delegate call to `transferFrom`,
    // `FEATURE_TRANSFERS` is verified inside it
    return transferFrom(msg.sender, _to, _value);
  }
  /**
   * @notice Transfers some tokens on behalf of address `_from' (token owner)
   *      to some other address `_to`
   *
   * @dev ERC20 `function transferFrom(address _from, address _to, uint256 _value) public returns (bool success)`
   *
   * @dev Called by token owner on his own or approved address,
   *      an address approved earlier by token owner to
   *      transfer some amount of tokens on its behalf
   * @dev Throws on any error like
   *      * insufficient token balance or
   *      * incorrect `_to` address:
   *          * zero address or
   *          * same as `_from` address (self transfer)
   *          * smart contract which doesn't support ERC20
   *
   * @param _from token owner which approved caller (transaction sender)
   *      to transfer `_value` of tokens on its behalf
   * @param _to an address to transfer tokens to,
   *      must be either an external address or a smart contract,
   *      compliant with the ERC20 standard
   * @param _value amount of tokens to be transferred, must
   *      be greater than zero
   * @return success true on success, throws otherwise
   */
  function transferFrom(address _from, address _to, uint256 _value) public returns (bool success) {
    // depending on `FEATURE_UNSAFE_TRANSFERS` we execute either safe (default)
    // or unsafe transfer
    // if `FEATURE_UNSAFE_TRANSFERS` is enabled
    // or receiver has `ROLE_ERC20_RECEIVER` permission
    // or sender has `ROLE_ERC20_SENDER` permission
    if(isFeatureEnabled(FEATURE_UNSAFE_TRANSFERS)
      || isOperatorInRole(_to, ROLE_ERC20_RECEIVER)
      || isSenderInRole(ROLE_ERC20_SENDER)) {
      // we execute unsafe transfer - delegate call to `unsafeTransferFrom`,
      // `FEATURE_TRANSFERS` is verified inside it
      unsafeTransferFrom(_from, _to, _value);
    }
    // otherwise - if `FEATURE_UNSAFE_TRANSFERS` is disabled
    // and receiver doesn't have `ROLE_ERC20_RECEIVER` permission
    else {
      // we execute safe transfer - delegate call to `safeTransferFrom`, passing empty `_data`,
      // `FEATURE_TRANSFERS` is verified inside it
      safeTransferFrom(_from, _to, _value, "");
    }
    // both `unsafeTransferFrom` and `safeTransferFrom` throw on any error, so
    // if we're here - it means operation successful,
    // just return true
    return true;
  }
  /**
   * @notice Transfers some tokens on behalf of address `_from' (token owner)
   *      to some other address `_to`
   *
   * @dev Inspired by ERC721 safeTransferFrom, this function allows to
   *      send arbitrary data to the receiver on successful token transfer
   * @dev Called by token owner on his own or approved address,
   *      an address approved earlier by token owner to
   *      transfer some amount of tokens on its behalf
   * @dev Throws on any error like
   *      * insufficient token balance or
   *      * incorrect `_to` address:
   *          * zero address or
   *          * same as `_from` address (self transfer)
   *          * smart contract which doesn't support ERC20Receiver interface
   * @dev Returns silently on success, throws otherwise
   *
   * @param _from token owner which approved caller (transaction sender)
   *      to transfer `_value` of tokens on its behalf
   * @param _to an address to transfer tokens to,
   *      must be either an external address or a smart contract,
   *      compliant with the ERC20 standard
   * @param _value amount of tokens to be transferred, must
   *      be greater than zero
   * @param _data [optional] additional data with no specified format,
   *      sent in onERC20Received call to `_to` in case if its a smart contract
   */
  function safeTransferFrom(address _from, address _to, uint256 _value, bytes memory _data) public {
    // first delegate call to `unsafeTransferFrom`
    // to perform the unsafe token(s) transfer
    unsafeTransferFrom(_from, _to, _value);
    // after the successful transfer - check if receiver supports
    // ERC20Receiver and execute a callback handler `onERC20Received`,
    // reverting whole transaction on any error:
    // check if receiver `_to` supports ERC20Receiver interface
    if(AddressUtils.isContract(_to)) {
      // if `_to` is a contract - execute onERC20Received
      bytes4 response = ERC20Receiver(_to).onERC20Received(msg.sender, _from, _value, _data);
      // expected response is ERC20_RECEIVED
      require(response == ERC20_RECEIVED, "invalid onERC20Received response");
    }
  }
  /**
   * @notice Transfers some tokens on behalf of address `_from' (token owner)
   *      to some other address `_to`
   *
   * @dev In contrast to `safeTransferFrom` doesn't check recipient
   *      smart contract to support ERC20 tokens (ERC20Receiver)
   * @dev Designed to be used by developers when the receiver is known
   *      to support ERC20 tokens but doesn't implement ERC20Receiver interface
   * @dev Called by token owner on his own or approved address,
   *      an address approved earlier by token owner to
   *      transfer some amount of tokens on its behalf
   * @dev Throws on any error like
   *      * insufficient token balance or
   *      * incorrect `_to` address:
   *          * zero address or
   *          * same as `_from` address (self transfer)
   * @dev Returns silently on success, throws otherwise
   *
   * @param _from token owner which approved caller (transaction sender)
   *      to transfer `_value` of tokens on its behalf
   * @param _to an address to transfer tokens to,
   *      must be either an external address or a smart contract,
   *      compliant with the ERC20 standard
   * @param _value amount of tokens to be transferred, must
   *      be greater than zero
   */
  function unsafeTransferFrom(address _from, address _to, uint256 _value) public {
    // if `_from` is equal to sender, require transfers feature to be enabled
    // otherwise require transfers on behalf feature to be enabled
    require(_from == msg.sender && isFeatureEnabled(FEATURE_TRANSFERS)
         || _from != msg.sender && isFeatureEnabled(FEATURE_TRANSFERS_ON_BEHALF),
            _from == msg.sender? "transfers are disabled": "transfers on behalf are disabled");
    // non-zero source address check - Zeppelin
    // obviously, zero source address is a client mistake
    // it's not part of ERC20 standard but it's reasonable to fail fast
    // since for zero value transfer transaction succeeds otherwise
    require(_from != address(0), "ERC20: transfer from the zero address"); // Zeppelin msg
    // non-zero recipient address check
    require(_to != address(0), "ERC20: transfer to the zero address"); // Zeppelin msg
    // sender and recipient cannot be the same
    require(_from != _to, "sender and recipient are the same (_from = _to)");
    // sending tokens to the token smart contract itself is a client mistake
    require(_to != address(this), "invalid recipient (transfer to the token smart contract itself)");
    // according to ERC-20 Token Standard, https://eips.ethereum.org/EIPS/eip-20
    // "Transfers of 0 values MUST be treated as normal transfers and fire the Transfer event."
    if(_value == 0) {
      // emit an ERC20 transfer event
      emit Transfer(_from, _to, _value);
      // don't forget to return - we're done
      return;
    }
    // no need to make arithmetic overflow check on the _value - by design of mint()
    // in case of transfer on behalf
    if(_from != msg.sender) {
      // read allowance value - the amount of tokens allowed to transfer - into the stack
      uint256 _allowance = transferAllowances[_from][msg.sender];
      // verify sender has an allowance to transfer amount of tokens requested
      require(_allowance >= _value, "ERC20: transfer amount exceeds allowance"); // Zeppelin msg
      // update allowance value on the stack
      _allowance -= _value;
      // update the allowance value in storage
      transferAllowances[_from][msg.sender] = _allowance;
      // emit an improved atomic approve event
      emit Approved(_from, msg.sender, _allowance + _value, _allowance);
      // emit an ERC20 approval event to reflect the decrease
      emit Approval(_from, msg.sender, _allowance);
    }
    // verify sender has enough tokens to transfer on behalf
    require(tokenBalances[_from] >= _value, "ERC20: transfer amount exceeds balance"); // Zeppelin msg
    // perform the transfer:
    // decrease token owner (sender) balance
    tokenBalances[_from] -= _value;
    // increase `_to` address (receiver) balance
    tokenBalances[_to] += _value;
    // move voting power associated with the tokens transferred
    __moveVotingPower(votingDelegates[_from], votingDelegates[_to], _value);
    // emit an improved transfer event
    emit Transferred(msg.sender, _from, _to, _value);
    // emit an ERC20 transfer event
    emit Transfer(_from, _to, _value);
  }
  /**
   * @notice Approves address called `_spender` to transfer some amount
   *      of tokens on behalf of the owner
   *
   * @dev ERC20 `function approve(address _spender, uint256 _value) public returns (bool success)`
   *
   * @dev Caller must not necessarily own any tokens to grant the permission
   *
   * @param _spender an address approved by the caller (token owner)
   *      to spend some tokens on its behalf
   * @param _value an amount of tokens spender `_spender` is allowed to
   *      transfer on behalf of the token owner
   * @return success true on success, throws otherwise
   */
  function approve(address _spender, uint256 _value) public returns (bool success) {
    // non-zero spender address check - Zeppelin
    // obviously, zero spender address is a client mistake
    // it's not part of ERC20 standard but it's reasonable to fail fast
    require(_spender != address(0), "ERC20: approve to the zero address"); // Zeppelin msg
    // read old approval value to emmit an improved event (ISBN:978-1-7281-3027-9)
    uint256 _oldValue = transferAllowances[msg.sender][_spender];
    // perform an operation: write value requested into the storage
    transferAllowances[msg.sender][_spender] = _value;
    // emit an improved atomic approve event (ISBN:978-1-7281-3027-9)
    emit Approved(msg.sender, _spender, _oldValue, _value);
    // emit an ERC20 approval event
    emit Approval(msg.sender, _spender, _value);
    // operation successful, return true
    return true;
  }
  /**
   * @notice Returns the amount which _spender is still allowed to withdraw from _owner.
   *
   * @dev ERC20 `function allowance(address _owner, address _spender) public view returns (uint256 remaining)`
   *
   * @dev A function to check an amount of tokens owner approved
   *      to transfer on its behalf by some other address called "spender"
   *
   * @param _owner an address which approves transferring some tokens on its behalf
   * @param _spender an address approved to transfer some tokens on behalf
   * @return remaining an amount of tokens approved address `_spender` can transfer on behalf
   *      of token owner `_owner`
   */
  function allowance(address _owner, address _spender) public view returns (uint256 remaining) {
    // read the value from storage and return
    return transferAllowances[_owner][_spender];
  }
  // ===== End: ERC20/ERC223/ERC777 functions =====
  // ===== Start: Resolution for the Multiple Withdrawal Attack on ERC20 Tokens (ISBN:978-1-7281-3027-9) =====
  /**
   * @notice Increases the allowance granted to `spender` by the transaction sender
   *
   * @dev Resolution for the Multiple Withdrawal Attack on ERC20 Tokens (ISBN:978-1-7281-3027-9)
   *
   * @dev Throws if value to increase by is zero or too big and causes arithmetic overflow
   *
   * @param _spender an address approved by the caller (token owner)
   *      to spend some tokens on its behalf
   * @param _value an amount of tokens to increase by
   * @return success true on success, throws otherwise
   */
  function increaseAllowance(address _spender, uint256 _value) public virtual returns (bool) {
    // read current allowance value
    uint256 currentVal = transferAllowances[msg.sender][_spender];
    // non-zero _value and arithmetic overflow check on the allowance
    require(currentVal + _value > currentVal, "zero value approval increase or arithmetic overflow");
    // delegate call to `approve` with the new value
    return approve(_spender, currentVal + _value);
  }
  /**
   * @notice Decreases the allowance granted to `spender` by the caller.
   *
   * @dev Resolution for the Multiple Withdrawal Attack on ERC20 Tokens (ISBN:978-1-7281-3027-9)
   *
   * @dev Throws if value to decrease by is zero or is bigger than currently allowed value
   *
   * @param _spender an address approved by the caller (token owner)
   *      to spend some tokens on its behalf
   * @param _value an amount of tokens to decrease by
   * @return success true on success, throws otherwise
   */
  function decreaseAllowance(address _spender, uint256 _value) public virtual returns (bool) {
    // read current allowance value
    uint256 currentVal = transferAllowances[msg.sender][_spender];
    // non-zero _value check on the allowance
    require(_value > 0, "zero value approval decrease");
    // verify allowance decrease doesn't underflow
    require(currentVal >= _value, "ERC20: decreased allowance below zero");
    // delegate call to `approve` with the new value
    return approve(_spender, currentVal - _value);
  }
  // ===== End: Resolution for the Multiple Withdrawal Attack on ERC20 Tokens (ISBN:978-1-7281-3027-9) =====
  // ===== Start: Minting/burning extension =====
  /**
   * @dev Mints (creates) some tokens to address specified
   * @dev The value specified is treated as is without taking
   *      into account what `decimals` value is
   * @dev Behaves effectively as `mintTo` function, allowing
   *      to specify an address to mint tokens to
   * @dev Requires sender to have `ROLE_TOKEN_CREATOR` permission
   *
   * @dev Throws on overflow, if totalSupply + _value doesn't fit into uint256
   *
   * @param _to an address to mint tokens to
   * @param _value an amount of tokens to mint (create)
   */
  function mint(address _to, uint256 _value) public {
    // check if caller has sufficient permissions to mint tokens
    require(isSenderInRole(ROLE_TOKEN_CREATOR), "insufficient privileges (ROLE_TOKEN_CREATOR required)");
    // non-zero recipient address check
    require(_to != address(0), "ERC20: mint to the zero address"); // Zeppelin msg
    // non-zero _value and arithmetic overflow check on the total supply
    // this check automatically secures arithmetic overflow on the individual balance
    require(totalSupply + _value > totalSupply, "zero value mint or arithmetic overflow");
    // uint192 overflow check (required by voting delegation)
    require(totalSupply + _value <= type(uint192).max, "total supply overflow (uint192)");
    // perform mint:
    // increase total amount of tokens value
    totalSupply += _value;
    // increase `_to` address balance
    tokenBalances[_to] += _value;
    // create voting power associated with the tokens minted
    __moveVotingPower(address(0), votingDelegates[_to], _value);
    // fire a minted event
    emit Minted(msg.sender, _to, _value);
    // emit an improved transfer event
    emit Transferred(msg.sender, address(0), _to, _value);
    // fire ERC20 compliant transfer event
    emit Transfer(address(0), _to, _value);
  }
  /**
   * @dev Burns (destroys) some tokens from the address specified
   * @dev The value specified is treated as is without taking
   *      into account what `decimals` value is
   * @dev Behaves effectively as `burnFrom` function, allowing
   *      to specify an address to burn tokens from
   * @dev Requires sender to have `ROLE_TOKEN_DESTROYER` permission
   *
   * @param _from an address to burn some tokens from
   * @param _value an amount of tokens to burn (destroy)
   */
  function burn(address _from, uint256 _value) public {
    // check if caller has sufficient permissions to burn tokens
    // and if not - check for possibility to burn own tokens or to burn on behalf
    if(!isSenderInRole(ROLE_TOKEN_DESTROYER)) {
      // if `_from` is equal to sender, require own burns feature to be enabled
      // otherwise require burns on behalf feature to be enabled
      require(_from == msg.sender && isFeatureEnabled(FEATURE_OWN_BURNS)
           || _from != msg.sender && isFeatureEnabled(FEATURE_BURNS_ON_BEHALF),
              _from == msg.sender? "burns are disabled": "burns on behalf are disabled");
      // in case of burn on behalf
      if(_from != msg.sender) {
        // read allowance value - the amount of tokens allowed to be burnt - into the stack
        uint256 _allowance = transferAllowances[_from][msg.sender];
        // verify sender has an allowance to burn amount of tokens requested
        require(_allowance >= _value, "ERC20: burn amount exceeds allowance"); // Zeppelin msg
        // update allowance value on the stack
        _allowance -= _value;
        // update the allowance value in storage
        transferAllowances[_from][msg.sender] = _allowance;
        // emit an improved atomic approve event
        emit Approved(msg.sender, _from, _allowance + _value, _allowance);
        // emit an ERC20 approval event to reflect the decrease
        emit Approval(_from, msg.sender, _allowance);
      }
    }
    // at this point we know that either sender is ROLE_TOKEN_DESTROYER or
    // we burn own tokens or on behalf (in latest case we already checked and updated allowances)
    // we have left to execute balance checks and burning logic itself
    // non-zero burn value check
    require(_value != 0, "zero value burn");
    // non-zero source address check - Zeppelin
    require(_from != address(0), "ERC20: burn from the zero address"); // Zeppelin msg
    // verify `_from` address has enough tokens to destroy
    // (basically this is a arithmetic overflow check)
    require(tokenBalances[_from] >= _value, "ERC20: burn amount exceeds balance"); // Zeppelin msg
    // perform burn:
    // decrease `_from` address balance
    tokenBalances[_from] -= _value;
    // decrease total amount of tokens value
    totalSupply -= _value;
    // destroy voting power associated with the tokens burnt
    __moveVotingPower(votingDelegates[_from], address(0), _value);
    // fire a burnt event
    emit Burnt(msg.sender, _from, _value);
    // emit an improved transfer event
    emit Transferred(msg.sender, _from, address(0), _value);
    // fire ERC20 compliant transfer event
    emit Transfer(_from, address(0), _value);
  }
  // ===== End: Minting/burning extension =====
  // ===== Start: DAO Support (Compound-like voting delegation) =====
  /**
   * @notice Gets current voting power of the account `_of`
   * @param _of the address of account to get voting power of
   * @return current cumulative voting power of the account,
   *      sum of token balances of all its voting delegators
   */
  function getVotingPower(address _of) public view returns (uint256) {
    // get a link to an array of voting power history records for an address specified
    VotingPowerRecord[] storage history = votingPowerHistory[_of];
    // lookup the history and return latest element
    return history.length == 0? 0: history[history.length - 1].votingPower;
  }
  /**
   * @notice Gets past voting power of the account `_of` at some block `_blockNum`
   * @dev Throws if `_blockNum` is not in the past (not the finalized block)
   * @param _of the address of account to get voting power of
   * @param _blockNum block number to get the voting power at
   * @return past cumulative voting power of the account,
   *      sum of token balances of all its voting delegators at block number `_blockNum`
   */
  function getVotingPowerAt(address _of, uint256 _blockNum) public view returns (uint256) {
    // make sure block number is not in the past (not the finalized block)
    require(_blockNum < block.number, "not yet determined"); // Compound msg
    // get a link to an array of voting power history records for an address specified
    VotingPowerRecord[] storage history = votingPowerHistory[_of];
    // if voting power history for the account provided is empty
    if(history.length == 0) {
      // than voting power is zero - return the result
      return 0;
    }
    // check latest voting power history record block number:
    // if history was not updated after the block of interest
    if(history[history.length - 1].blockNumber <= _blockNum) {
      // we're done - return last voting power record
      return getVotingPower(_of);
    }
    // check first voting power history record block number:
    // if history was never updated before the block of interest
    if(history[0].blockNumber > _blockNum) {
      // we're done - voting power at the block num of interest was zero
      return 0;
    }
    // `votingPowerHistory[_of]` is an array ordered by `blockNumber`, ascending;
    // apply binary search on `votingPowerHistory[_of]` to find such an entry number `i`, that
    // `votingPowerHistory[_of][i].blockNumber <= _blockNum`, but in the same time
    // `votingPowerHistory[_of][i + 1].blockNumber > _blockNum`
    // return the result - voting power found at index `i`
    return history[__binaryLookup(_of, _blockNum)].votingPower;
  }
  /**
   * @dev Reads an entire voting power history array for the delegate specified
   *
   * @param _of delegate to query voting power history for
   * @return voting power history array for the delegate of interest
   */
  function getVotingPowerHistory(address _of) public view returns(VotingPowerRecord[] memory) {
    // return an entire array as memory
    return votingPowerHistory[_of];
  }
  /**
   * @dev Returns length of the voting power history array for the delegate specified;
   *      useful since reading an entire array just to get its length is expensive (gas cost)
   *
   * @param _of delegate to query voting power history length for
   * @return voting power history array length for the delegate of interest
   */
  function getVotingPowerHistoryLength(address _of) public view returns(uint256) {
    // read array length and return
    return votingPowerHistory[_of].length;
  }
  /**
   * @notice Delegates voting power of the delegator `msg.sender` to the delegate `_to`
   *
   * @dev Accepts zero value address to delegate voting power to, effectively
   *      removing the delegate in that case
   *
   * @param _to address to delegate voting power to
   */
  function delegate(address _to) public {
    // verify delegations are enabled
    require(isFeatureEnabled(FEATURE_DELEGATIONS), "delegations are disabled");
    // delegate call to `__delegate`
    __delegate(msg.sender, _to);
  }
  /**
   * @notice Delegates voting power of the delegator (represented by its signature) to the delegate `_to`
   *
   * @dev Accepts zero value address to delegate voting power to, effectively
   *      removing the delegate in that case
   *
   * @dev Compliant with EIP-712: Ethereum typed structured data hashing and signing,
   *      see https://eips.ethereum.org/EIPS/eip-712
   *
   * @param _to address to delegate voting power to
   * @param _nonce nonce used to construct the signature, and used to validate it;
   *      nonce is increased by one after successful signature validation and vote delegation
   * @param _exp signature expiration time
   * @param v the recovery byte of the signature
   * @param r half of the ECDSA signature pair
   * @param s half of the ECDSA signature pair
   */
  function delegateWithSig(address _to, uint256 _nonce, uint256 _exp, uint8 v, bytes32 r, bytes32 s) public {
    // verify delegations on behalf are enabled
    require(isFeatureEnabled(FEATURE_DELEGATIONS_ON_BEHALF), "delegations on behalf are disabled");
    // build the EIP-712 contract domain separator
    bytes32 domainSeparator = keccak256(abi.encode(DOMAIN_TYPEHASH, keccak256(bytes(name)), block.chainid, address(this)));
    // build the EIP-712 hashStruct of the delegation message
    bytes32 hashStruct = keccak256(abi.encode(DELEGATION_TYPEHASH, _to, _nonce, _exp));
    // calculate the EIP-712 digest "\\x19\\x01" ‖ domainSeparator ‖ hashStruct(message)
    bytes32 digest = keccak256(abi.encodePacked("\\x19\\x01", domainSeparator, hashStruct));
    // recover the address who signed the message with v, r, s
    address signer = ecrecover(digest, v, r, s);
    // perform message integrity and security validations
    require(signer != address(0), "invalid signature"); // Compound msg
    require(_nonce == nonces[signer], "invalid nonce"); // Compound msg
    require(block.timestamp < _exp, "signature expired"); // Compound msg
    // update the nonce for that particular signer to avoid replay attack
    nonces[signer]++;
    // delegate call to `__delegate` - execute the logic required
    __delegate(signer, _to);
  }
  /**
   * @dev Auxiliary function to delegate delegator's `_from` voting power to the delegate `_to`
   * @dev Writes to `votingDelegates` and `votingPowerHistory` mappings
   *
   * @param _from delegator who delegates his voting power
   * @param _to delegate who receives the voting power
   */
  function __delegate(address _from, address _to) private {
    // read current delegate to be replaced by a new one
    address _fromDelegate = votingDelegates[_from];
    // read current voting power (it is equal to token balance)
    uint256 _value = tokenBalances[_from];
    // reassign voting delegate to `_to`
    votingDelegates[_from] = _to;
    // update voting power for `_fromDelegate` and `_to`
    __moveVotingPower(_fromDelegate, _to, _value);
    // emit an event
    emit DelegateChanged(_from, _fromDelegate, _to);
  }
  /**
   * @dev Auxiliary function to move voting power `_value`
   *      from delegate `_from` to the delegate `_to`
   *
   * @dev Doesn't have any effect if `_from == _to`, or if `_value == 0`
   *
   * @param _from delegate to move voting power from
   * @param _to delegate to move voting power to
   * @param _value voting power to move from `_from` to `_to`
   */
  function __moveVotingPower(address _from, address _to, uint256 _value) private {
    // if there is no move (`_from == _to`) or there is nothing to move (`_value == 0`)
    if(_from == _to || _value == 0) {
      // return silently with no action
      return;
    }
    // if source address is not zero - decrease its voting power
    if(_from != address(0)) {
      // read current source address voting power
      uint256 _fromVal = getVotingPower(_from);
      // calculate decreased voting power
      // underflow is not possible by design:
      // voting power is limited by token balance which is checked by the callee
      uint256 _toVal = _fromVal - _value;
      // update source voting power from `_fromVal` to `_toVal`
      __updateVotingPower(_from, _fromVal, _toVal);
    }
    // if destination address is not zero - increase its voting power
    if(_to != address(0)) {
      // read current destination address voting power
      uint256 _fromVal = getVotingPower(_to);
      // calculate increased voting power
      // overflow is not possible by design:
      // max token supply limits the cumulative voting power
      uint256 _toVal = _fromVal + _value;
      // update destination voting power from `_fromVal` to `_toVal`
      __updateVotingPower(_to, _fromVal, _toVal);
    }
  }
  /**
   * @dev Auxiliary function to update voting power of the delegate `_of`
   *      from value `_fromVal` to value `_toVal`
   *
   * @param _of delegate to update its voting power
   * @param _fromVal old voting power of the delegate
   * @param _toVal new voting power of the delegate
   */
  function __updateVotingPower(address _of, uint256 _fromVal, uint256 _toVal) private {
    // get a link to an array of voting power history records for an address specified
    VotingPowerRecord[] storage history = votingPowerHistory[_of];
    // if there is an existing voting power value stored for current block
    if(history.length != 0 && history[history.length - 1].blockNumber == block.number) {
      // update voting power which is already stored in the current block
      history[history.length - 1].votingPower = uint192(_toVal);
    }
    // otherwise - if there is no value stored for current block
    else {
      // add new element into array representing the value for current block
      history.push(VotingPowerRecord(uint64(block.number), uint192(_toVal)));
    }
    // emit an event
    emit VotingPowerChanged(_of, _fromVal, _toVal);
  }
  /**
   * @dev Auxiliary function to lookup an element in a sorted (asc) array of elements
   *
   * @dev This function finds the closest element in an array to the value
   *      of interest (not exceeding that value) and returns its index within an array
   *
   * @dev An array to search in is `votingPowerHistory[_to][i].blockNumber`,
   *      it is sorted in ascending order (blockNumber increases)
   *
   * @param _to an address of the delegate to get an array for
   * @param n value of interest to look for
   * @return an index of the closest element in an array to the value
   *      of interest (not exceeding that value)
   */
  function __binaryLookup(address _to, uint256 n) private view returns(uint256) {
    // get a link to an array of voting power history records for an address specified
    VotingPowerRecord[] storage history = votingPowerHistory[_to];
    // left bound of the search interval, originally start of the array
    uint256 i = 0;
    // right bound of the search interval, originally end of the array
    uint256 j = history.length - 1;
    // the iteration process narrows down the bounds by
    // splitting the interval in a half oce per each iteration
    while(j > i) {
      // get an index in the middle of the interval [i, j]
      uint256 k = j - (j - i) / 2;
      // read an element to compare it with the value of interest
      VotingPowerRecord memory cp = history[k];
      // if we've got a strict equal - we're lucky and done
      if(cp.blockNumber == n) {
        // just return the result - index `k`
        return k;
      }
      // if the value of interest is bigger - move left bound to the middle
      else if (cp.blockNumber < n) {
        // move left bound `i` to the middle position `k`
        i = k;
      }
      // otherwise, when the value of interest is smaller - move right bound to the middle
      else {
        // move right bound `j` to the middle position `k - 1`:
        // element at position `k` is bigger and cannot be the result
        j = k - 1;
      }
    }
    // reaching that point means no exact match found
    // since we're interested in the element which is not bigger than the
    // element of interest, we return the lower bound `i`
    return i;
  }
}
// ===== End: DAO Support (Compound-like voting delegation) =====
// SPDX-License-Identifier: MIT
pragma solidity 0.8.1;
/**
 * @title Access Control List
 *
 * @notice Access control smart contract provides an API to check
 *      if specific operation is permitted globally and/or
 *      if particular user has a permission to execute it.
 *
 * @notice It deals with two main entities: features and roles.
 *
 * @notice Features are designed to be used to enable/disable specific
 *      functions (public functions) of the smart contract for everyone.
 * @notice User roles are designed to restrict access to specific
 *      functions (restricted functions) of the smart contract to some users.
 *
 * @notice Terms "role", "permissions" and "set of permissions" have equal meaning
 *      in the documentation text and may be used interchangeably.
 * @notice Terms "permission", "single permission" implies only one permission bit set.
 *
 * @dev This smart contract is designed to be inherited by other
 *      smart contracts which require access control management capabilities.
 *
 * @author Basil Gorin
 */
contract AccessControl {
  /**
   * @notice Access manager is responsible for assigning the roles to users,
   *      enabling/disabling global features of the smart contract
   * @notice Access manager can add, remove and update user roles,
   *      remove and update global features
   *
   * @dev Role ROLE_ACCESS_MANAGER allows modifying user roles and global features
   * @dev Role ROLE_ACCESS_MANAGER has single bit at position 255 enabled
   */
  uint256 public constant ROLE_ACCESS_MANAGER = 0x8000000000000000000000000000000000000000000000000000000000000000;
  /**
   * @dev Bitmask representing all the possible permissions (super admin role)
   * @dev Has all the bits are enabled (2^256 - 1 value)
   */
  uint256 private constant FULL_PRIVILEGES_MASK = type(uint256).max; // before 0.8.0: uint256(-1) overflows to 0xFFFF...
  /**
   * @notice Privileged addresses with defined roles/permissions
   * @notice In the context of ERC20/ERC721 tokens these can be permissions to
   *      allow minting or burning tokens, transferring on behalf and so on
   *
   * @dev Maps user address to the permissions bitmask (role), where each bit
   *      represents a permission
   * @dev Bitmask 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
   *      represents all possible permissions
   * @dev Zero address mapping represents global features of the smart contract
   */
  mapping(address => uint256) public userRoles;
  /**
   * @dev Fired in updateRole() and updateFeatures()
   *
   * @param _by operator which called the function
   * @param _to address which was granted/revoked permissions
   * @param _requested permissions requested
   * @param _actual permissions effectively set
   */
  event RoleUpdated(address indexed _by, address indexed _to, uint256 _requested, uint256 _actual);
  /**
   * @notice Creates an access control instance,
   *      setting contract creator to have full privileges
   */
  constructor() {
    // contract creator has full privileges
    userRoles[msg.sender] = FULL_PRIVILEGES_MASK;
  }
  /**
   * @notice Retrieves globally set of features enabled
   *
   * @dev Auxiliary getter function to maintain compatibility with previous
   *      versions of the Access Control List smart contract, where
   *      features was a separate uint256 public field
   *
   * @return 256-bit bitmask of the features enabled
   */
  function features() public view returns(uint256) {
    // according to new design features are stored in zero address
    // mapping of `userRoles` structure
    return userRoles[address(0)];
  }
  /**
   * @notice Updates set of the globally enabled features (`features`),
   *      taking into account sender's permissions
   *
   * @dev Requires transaction sender to have `ROLE_ACCESS_MANAGER` permission
   * @dev Function is left for backward compatibility with older versions
   *
   * @param _mask bitmask representing a set of features to enable/disable
   */
  function updateFeatures(uint256 _mask) public {
    // delegate call to `updateRole`
    updateRole(address(0), _mask);
  }
  /**
   * @notice Updates set of permissions (role) for a given user,
   *      taking into account sender's permissions.
   *
   * @dev Setting role to zero is equivalent to removing an all permissions
   * @dev Setting role to `FULL_PRIVILEGES_MASK` is equivalent to
   *      copying senders' permissions (role) to the user
   * @dev Requires transaction sender to have `ROLE_ACCESS_MANAGER` permission
   *
   * @param operator address of a user to alter permissions for or zero
   *      to alter global features of the smart contract
   * @param role bitmask representing a set of permissions to
   *      enable/disable for a user specified
   */
  function updateRole(address operator, uint256 role) public {
    // caller must have a permission to update user roles
    require(isSenderInRole(ROLE_ACCESS_MANAGER), "insufficient privileges (ROLE_ACCESS_MANAGER required)");
    // evaluate the role and reassign it
    userRoles[operator] = evaluateBy(msg.sender, userRoles[operator], role);
    // fire an event
    emit RoleUpdated(msg.sender, operator, role, userRoles[operator]);
  }
  /**
   * @notice Determines the permission bitmask an operator can set on the
   *      target permission set
   * @notice Used to calculate the permission bitmask to be set when requested
   *     in `updateRole` and `updateFeatures` functions
   *
   * @dev Calculated based on:
   *      1) operator's own permission set read from userRoles[operator]
   *      2) target permission set - what is already set on the target
   *      3) desired permission set - what do we want set target to
   *
   * @dev Corner cases:
   *      1) Operator is super admin and its permission set is `FULL_PRIVILEGES_MASK`:
   *        `desired` bitset is returned regardless of the `target` permission set value
   *        (what operator sets is what they get)
   *      2) Operator with no permissions (zero bitset):
   *        `target` bitset is returned regardless of the `desired` value
   *        (operator has no authority and cannot modify anything)
   *
   * @dev Example:
   *      Consider an operator with the permissions bitmask     00001111
   *      is about to modify the target permission set          01010101
   *      Operator wants to set that permission set to          00110011
   *      Based on their role, an operator has the permissions
   *      to update only lowest 4 bits on the target, meaning that
   *      high 4 bits of the target set in this example is left
   *      unchanged and low 4 bits get changed as desired:      01010011
   *
   * @param operator address of the contract operator which is about to set the permissions
   * @param target input set of permissions to operator is going to modify
   * @param desired desired set of permissions operator would like to set
   * @return resulting set of permissions given operator will set
   */
  function evaluateBy(address operator, uint256 target, uint256 desired) public view returns(uint256) {
    // read operator's permissions
    uint256 p = userRoles[operator];
    // taking into account operator's permissions,
    // 1) enable the permissions desired on the `target`
    target |= p & desired;
    // 2) disable the permissions desired on the `target`
    target &= FULL_PRIVILEGES_MASK ^ (p & (FULL_PRIVILEGES_MASK ^ desired));
    // return calculated result
    return target;
  }
  /**
   * @notice Checks if requested set of features is enabled globally on the contract
   *
   * @param required set of features to check against
   * @return true if all the features requested are enabled, false otherwise
   */
  function isFeatureEnabled(uint256 required) public view returns(bool) {
    // delegate call to `__hasRole`, passing `features` property
    return __hasRole(features(), required);
  }
  /**
   * @notice Checks if transaction sender `msg.sender` has all the permissions required
   *
   * @param required set of permissions (role) to check against
   * @return true if all the permissions requested are enabled, false otherwise
   */
  function isSenderInRole(uint256 required) public view returns(bool) {
    // delegate call to `isOperatorInRole`, passing transaction sender
    return isOperatorInRole(msg.sender, required);
  }
  /**
   * @notice Checks if operator has all the permissions (role) required
   *
   * @param operator address of the user to check role for
   * @param required set of permissions (role) to check
   * @return true if all the permissions requested are enabled, false otherwise
   */
  function isOperatorInRole(address operator, uint256 required) public view returns(bool) {
    // delegate call to `__hasRole`, passing operator's permissions (role)
    return __hasRole(userRoles[operator], required);
  }
  /**
   * @dev Checks if role `actual` contains all the permissions required `required`
   *
   * @param actual existent role
   * @param required required role
   * @return true if actual has required role (all permissions), false otherwise
   */
  function __hasRole(uint256 actual, uint256 required) internal pure returns(bool) {
    // check the bitmask for the role required and return the result
    return actual & required == required;
  }
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.1;
/**
 * @title Address Utils
 *
 * @dev Utility library of inline functions on addresses
 *
 * @author Basil Gorin
 */
library AddressUtils {
  /**
   * @notice Checks if the target address is a contract
   * @dev This function will return false if invoked during the constructor of a contract,
   *      as the code is not actually created until after the constructor finishes.
   * @param addr address to check
   * @return whether the target address is a contract
   */
  function isContract(address addr) internal view returns (bool) {
    // a variable to load `extcodesize` to
    uint256 size = 0;
    // XXX Currently there is no better way to check if there is a contract in an address
    // than to check the size of the code at that address.
    // See https://ethereum.stackexchange.com/a/14016/36603 for more details about how this works.
    // TODO: Check this again before the Serenity release, because all addresses will be contracts.
    // solium-disable-next-line security/no-inline-assembly
    assembly {
      // retrieve the size of the code at address `addr`
      size := extcodesize(addr)
    }
    // positive size indicates a smart contract address
    return size > 0;
  }
}