Contract Diff Checker

Contract Name:
SFC

Contract Source Code:

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (access/Ownable.sol)

pragma solidity ^0.8.20;

import {ContextUpgradeable} from "../utils/ContextUpgradeable.sol";
import {Initializable} from "../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.
 *
 * The initial owner is set to the address provided by the deployer. 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 {
    /// @custom:storage-location erc7201:openzeppelin.storage.Ownable
    struct OwnableStorage {
        address _owner;
    }

    // keccak256(abi.encode(uint256(keccak256("openzeppelin.storage.Ownable")) - 1)) & ~bytes32(uint256(0xff))
    bytes32 private constant OwnableStorageLocation = 0x9016d09d72d40fdae2fd8ceac6b6234c7706214fd39c1cd1e609a0528c199300;

    function _getOwnableStorage() private pure returns (OwnableStorage storage $) {
        assembly {
            $.slot := OwnableStorageLocation
        }
    }

    /**
     * @dev The caller account is not authorized to perform an operation.
     */
    error OwnableUnauthorizedAccount(address account);

    /**
     * @dev The owner is not a valid owner account. (eg. `address(0)`)
     */
    error OwnableInvalidOwner(address owner);

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

    /**
     * @dev Initializes the contract setting the address provided by the deployer as the initial owner.
     */
    function __Ownable_init(address initialOwner) internal onlyInitializing {
        __Ownable_init_unchained(initialOwner);
    }

    function __Ownable_init_unchained(address initialOwner) internal onlyInitializing {
        if (initialOwner == address(0)) {
            revert OwnableInvalidOwner(address(0));
        }
        _transferOwnership(initialOwner);
    }

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

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

    /**
     * @dev Throws if the sender is not the owner.
     */
    function _checkOwner() internal view virtual {
        if (owner() != _msgSender()) {
            revert OwnableUnauthorizedAccount(_msgSender());
        }
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby disabling any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        if (newOwner == address(0)) {
            revert OwnableInvalidOwner(address(0));
        }
        _transferOwnership(newOwner);
    }

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

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (proxy/utils/Initializable.sol)

pragma solidity ^0.8.20;

/**
 * @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 proxied contracts do not make use of 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.
 *
 * The initialization functions use a version number. Once a version number is used, it is consumed and cannot be
 * reused. This mechanism prevents re-execution of each "step" but allows the creation of new initialization steps in
 * case an upgrade adds a module that needs to be initialized.
 *
 * For example:
 *
 * [.hljs-theme-light.nopadding]
 * ```solidity
 * contract MyToken is ERC20Upgradeable {
 *     function initialize() initializer public {
 *         __ERC20_init("MyToken", "MTK");
 *     }
 * }
 *
 * contract MyTokenV2 is MyToken, ERC20PermitUpgradeable {
 *     function initializeV2() reinitializer(2) public {
 *         __ERC20Permit_init("MyToken");
 *     }
 * }
 * ```
 *
 * 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.
 *
 * [CAUTION]
 * ====
 * Avoid leaving a contract uninitialized.
 *
 * An uninitialized contract can be taken over by an attacker. This applies to both a proxy and its implementation
 * contract, which may impact the proxy. To prevent the implementation contract from being used, you should invoke
 * the {_disableInitializers} function in the constructor to automatically lock it when it is deployed:
 *
 * [.hljs-theme-light.nopadding]
 * ```
 * /// @custom:oz-upgrades-unsafe-allow constructor
 * constructor() {
 *     _disableInitializers();
 * }
 * ```
 * ====
 */
abstract contract Initializable {
    /**
     * @dev Storage of the initializable contract.
     *
     * It's implemented on a custom ERC-7201 namespace to reduce the risk of storage collisions
     * when using with upgradeable contracts.
     *
     * @custom:storage-location erc7201:openzeppelin.storage.Initializable
     */
    struct InitializableStorage {
        /**
         * @dev Indicates that the contract has been initialized.
         */
        uint64 _initialized;
        /**
         * @dev Indicates that the contract is in the process of being initialized.
         */
        bool _initializing;
    }

    // keccak256(abi.encode(uint256(keccak256("openzeppelin.storage.Initializable")) - 1)) & ~bytes32(uint256(0xff))
    bytes32 private constant INITIALIZABLE_STORAGE = 0xf0c57e16840df040f15088dc2f81fe391c3923bec73e23a9662efc9c229c6a00;

    /**
     * @dev The contract is already initialized.
     */
    error InvalidInitialization();

    /**
     * @dev The contract is not initializing.
     */
    error NotInitializing();

    /**
     * @dev Triggered when the contract has been initialized or reinitialized.
     */
    event Initialized(uint64 version);

    /**
     * @dev A modifier that defines a protected initializer function that can be invoked at most once. In its scope,
     * `onlyInitializing` functions can be used to initialize parent contracts.
     *
     * Similar to `reinitializer(1)`, except that in the context of a constructor an `initializer` may be invoked any
     * number of times. This behavior in the constructor can be useful during testing and is not expected to be used in
     * production.
     *
     * Emits an {Initialized} event.
     */
    modifier initializer() {
        // solhint-disable-next-line var-name-mixedcase
        InitializableStorage storage $ = _getInitializableStorage();

        // Cache values to avoid duplicated sloads
        bool isTopLevelCall = !$._initializing;
        uint64 initialized = $._initialized;

        // Allowed calls:
        // - initialSetup: the contract is not in the initializing state and no previous version was
        //                 initialized
        // - construction: the contract is initialized at version 1 (no reininitialization) and the
        //                 current contract is just being deployed
        bool initialSetup = initialized == 0 && isTopLevelCall;
        bool construction = initialized == 1 && address(this).code.length == 0;

        if (!initialSetup && !construction) {
            revert InvalidInitialization();
        }
        $._initialized = 1;
        if (isTopLevelCall) {
            $._initializing = true;
        }
        _;
        if (isTopLevelCall) {
            $._initializing = false;
            emit Initialized(1);
        }
    }

    /**
     * @dev A modifier that defines a protected reinitializer function that can be invoked at most once, and only if the
     * contract hasn't been initialized to a greater version before. In its scope, `onlyInitializing` functions can be
     * used to initialize parent contracts.
     *
     * A reinitializer may be used after the original initialization step. This is essential to configure modules that
     * are added through upgrades and that require initialization.
     *
     * When `version` is 1, this modifier is similar to `initializer`, except that functions marked with `reinitializer`
     * cannot be nested. If one is invoked in the context of another, execution will revert.
     *
     * Note that versions can jump in increments greater than 1; this implies that if multiple reinitializers coexist in
     * a contract, executing them in the right order is up to the developer or operator.
     *
     * WARNING: Setting the version to 2**64 - 1 will prevent any future reinitialization.
     *
     * Emits an {Initialized} event.
     */
    modifier reinitializer(uint64 version) {
        // solhint-disable-next-line var-name-mixedcase
        InitializableStorage storage $ = _getInitializableStorage();

        if ($._initializing || $._initialized >= version) {
            revert InvalidInitialization();
        }
        $._initialized = version;
        $._initializing = true;
        _;
        $._initializing = false;
        emit Initialized(version);
    }

    /**
     * @dev Modifier to protect an initialization function so that it can only be invoked by functions with the
     * {initializer} and {reinitializer} modifiers, directly or indirectly.
     */
    modifier onlyInitializing() {
        _checkInitializing();
        _;
    }

    /**
     * @dev Reverts if the contract is not in an initializing state. See {onlyInitializing}.
     */
    function _checkInitializing() internal view virtual {
        if (!_isInitializing()) {
            revert NotInitializing();
        }
    }

    /**
     * @dev Locks the contract, preventing any future reinitialization. This cannot be part of an initializer call.
     * Calling this in the constructor of a contract will prevent that contract from being initialized or reinitialized
     * to any version. It is recommended to use this to lock implementation contracts that are designed to be called
     * through proxies.
     *
     * Emits an {Initialized} event the first time it is successfully executed.
     */
    function _disableInitializers() internal virtual {
        // solhint-disable-next-line var-name-mixedcase
        InitializableStorage storage $ = _getInitializableStorage();

        if ($._initializing) {
            revert InvalidInitialization();
        }
        if ($._initialized != type(uint64).max) {
            $._initialized = type(uint64).max;
            emit Initialized(type(uint64).max);
        }
    }

    /**
     * @dev Returns the highest version that has been initialized. See {reinitializer}.
     */
    function _getInitializedVersion() internal view returns (uint64) {
        return _getInitializableStorage()._initialized;
    }

    /**
     * @dev Returns `true` if the contract is currently initializing. See {onlyInitializing}.
     */
    function _isInitializing() internal view returns (bool) {
        return _getInitializableStorage()._initializing;
    }

    /**
     * @dev Returns a pointer to the storage namespace.
     */
    // solhint-disable-next-line var-name-mixedcase
    function _getInitializableStorage() private pure returns (InitializableStorage storage $) {
        assembly {
            $.slot := INITIALIZABLE_STORAGE
        }
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.1.0) (proxy/utils/UUPSUpgradeable.sol)

pragma solidity ^0.8.20;

import {IERC1822Proxiable} from "@openzeppelin/contracts/interfaces/draft-IERC1822.sol";
import {ERC1967Utils} from "@openzeppelin/contracts/proxy/ERC1967/ERC1967Utils.sol";
import {Initializable} from "./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.
 */
abstract contract UUPSUpgradeable is Initializable, IERC1822Proxiable {
    /// @custom:oz-upgrades-unsafe-allow state-variable-immutable
    address private immutable __self = address(this);

    /**
     * @dev The version of the upgrade interface of the contract. If this getter is missing, both `upgradeTo(address)`
     * and `upgradeToAndCall(address,bytes)` are present, and `upgradeTo` must be used if no function should be called,
     * while `upgradeToAndCall` will invoke the `receive` function if the second argument is the empty byte string.
     * If the getter returns `"5.0.0"`, only `upgradeToAndCall(address,bytes)` is present, and the second argument must
     * be the empty byte string if no function should be called, making it impossible to invoke the `receive` function
     * during an upgrade.
     */
    string public constant UPGRADE_INTERFACE_VERSION = "5.0.0";

    /**
     * @dev The call is from an unauthorized context.
     */
    error UUPSUnauthorizedCallContext();

    /**
     * @dev The storage `slot` is unsupported as a UUID.
     */
    error UUPSUnsupportedProxiableUUID(bytes32 slot);

    /**
     * @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 ERC-1967) 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 ERC-1167 minimal proxies (clones) would not normally pass this test, but is not guaranteed to
     * fail.
     */
    modifier onlyProxy() {
        _checkProxy();
        _;
    }

    /**
     * @dev Check that the execution is not being performed through a delegate call. This allows a function to be
     * callable on the implementing contract but not through proxies.
     */
    modifier notDelegated() {
        _checkNotDelegated();
        _;
    }

    function __UUPSUpgradeable_init() internal onlyInitializing {
    }

    function __UUPSUpgradeable_init_unchained() internal onlyInitializing {
    }
    /**
     * @dev Implementation of the ERC-1822 {proxiableUUID} function. This returns the storage slot used by the
     * implementation. It is used to validate the implementation's compatibility when performing an upgrade.
     *
     * IMPORTANT: A proxy pointing at a proxiable contract should not be considered proxiable itself, because this risks
     * bricking a proxy that upgrades to it, by delegating to itself until out of gas. Thus it is critical that this
     * function revert if invoked through a proxy. This is guaranteed by the `notDelegated` modifier.
     */
    function proxiableUUID() external view virtual notDelegated returns (bytes32) {
        return ERC1967Utils.IMPLEMENTATION_SLOT;
    }

    /**
     * @dev Upgrade the implementation of the proxy to `newImplementation`, and subsequently execute the function call
     * encoded in `data`.
     *
     * Calls {_authorizeUpgrade}.
     *
     * Emits an {Upgraded} event.
     *
     * @custom:oz-upgrades-unsafe-allow-reachable delegatecall
     */
    function upgradeToAndCall(address newImplementation, bytes memory data) public payable virtual onlyProxy {
        _authorizeUpgrade(newImplementation);
        _upgradeToAndCallUUPS(newImplementation, data);
    }

    /**
     * @dev Reverts if the execution is not performed via delegatecall or the execution
     * context is not of a proxy with an ERC-1967 compliant implementation pointing to self.
     * See {_onlyProxy}.
     */
    function _checkProxy() internal view virtual {
        if (
            address(this) == __self || // Must be called through delegatecall
            ERC1967Utils.getImplementation() != __self // Must be called through an active proxy
        ) {
            revert UUPSUnauthorizedCallContext();
        }
    }

    /**
     * @dev Reverts if the execution is performed via delegatecall.
     * See {notDelegated}.
     */
    function _checkNotDelegated() internal view virtual {
        if (address(this) != __self) {
            // Must not be called through delegatecall
            revert UUPSUnauthorizedCallContext();
        }
    }

    /**
     * @dev Function that should revert when `msg.sender` is not authorized to upgrade the contract. Called by
     * {upgradeToAndCall}.
     *
     * Normally, this function will use an xref:access.adoc[access control] modifier such as {Ownable-onlyOwner}.
     *
     * ```solidity
     * function _authorizeUpgrade(address) internal onlyOwner {}
     * ```
     */
    function _authorizeUpgrade(address newImplementation) internal virtual;

    /**
     * @dev Performs an implementation upgrade with a security check for UUPS proxies, and additional setup call.
     *
     * As a security check, {proxiableUUID} is invoked in the new implementation, and the return value
     * is expected to be the implementation slot in ERC-1967.
     *
     * Emits an {IERC1967-Upgraded} event.
     */
    function _upgradeToAndCallUUPS(address newImplementation, bytes memory data) private {
        try IERC1822Proxiable(newImplementation).proxiableUUID() returns (bytes32 slot) {
            if (slot != ERC1967Utils.IMPLEMENTATION_SLOT) {
                revert UUPSUnsupportedProxiableUUID(slot);
            }
            ERC1967Utils.upgradeToAndCall(newImplementation, data);
        } catch {
            // The implementation is not UUPS
            revert ERC1967Utils.ERC1967InvalidImplementation(newImplementation);
        }
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.1) (utils/Context.sol)

pragma solidity ^0.8.20;
import {Initializable} from "../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 onlyInitializing {
    }

    function __Context_init_unchained() internal onlyInitializing {
    }
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

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

    function _contextSuffixLength() internal view virtual returns (uint256) {
        return 0;
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (access/Ownable.sol)

pragma solidity ^0.8.20;

import {Context} from "../utils/Context.sol";

/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * The initial owner is set to the address provided by the deployer. 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;

    /**
     * @dev The caller account is not authorized to perform an operation.
     */
    error OwnableUnauthorizedAccount(address account);

    /**
     * @dev The owner is not a valid owner account. (eg. `address(0)`)
     */
    error OwnableInvalidOwner(address owner);

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

    /**
     * @dev Initializes the contract setting the address provided by the deployer as the initial owner.
     */
    constructor(address initialOwner) {
        if (initialOwner == address(0)) {
            revert OwnableInvalidOwner(address(0));
        }
        _transferOwnership(initialOwner);
    }

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

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

    /**
     * @dev Throws if the sender is not the owner.
     */
    function _checkOwner() internal view virtual {
        if (owner() != _msgSender()) {
            revert OwnableUnauthorizedAccount(_msgSender());
        }
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby disabling any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        if (newOwner == address(0)) {
            revert OwnableInvalidOwner(address(0));
        }
        _transferOwnership(newOwner);
    }

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

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.1.0) (interfaces/draft-IERC1822.sol)

pragma solidity ^0.8.20;

/**
 * @dev ERC-1822: Universal Upgradeable Proxy Standard (UUPS) documents a method for upgradeability through a simplified
 * proxy whose upgrades are fully controlled by the current implementation.
 */
interface IERC1822Proxiable {
    /**
     * @dev Returns the storage slot that the proxiable contract assumes is being used to store the implementation
     * address.
     *
     * IMPORTANT: A proxy pointing at a proxiable contract should not be considered proxiable itself, because this risks
     * bricking a proxy that upgrades to it, by delegating to itself until out of gas. Thus it is critical that this
     * function revert if invoked through a proxy.
     */
    function proxiableUUID() external view returns (bytes32);
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (interfaces/IERC1967.sol)

pragma solidity ^0.8.20;

/**
 * @dev ERC-1967: Proxy Storage Slots. This interface contains the events defined in the ERC.
 */
interface IERC1967 {
    /**
     * @dev Emitted when the implementation is upgraded.
     */
    event Upgraded(address indexed implementation);

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

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

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (proxy/beacon/IBeacon.sol)

pragma solidity ^0.8.20;

/**
 * @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.
     *
     * {UpgradeableBeacon} will check that this address is a contract.
     */
    function implementation() external view returns (address);
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.1.0) (proxy/ERC1967/ERC1967Utils.sol)

pragma solidity ^0.8.21;

import {IBeacon} from "../beacon/IBeacon.sol";
import {IERC1967} from "../../interfaces/IERC1967.sol";
import {Address} from "../../utils/Address.sol";
import {StorageSlot} from "../../utils/StorageSlot.sol";

/**
 * @dev This library provides getters and event emitting update functions for
 * https://eips.ethereum.org/EIPS/eip-1967[ERC-1967] slots.
 */
library ERC1967Utils {
    /**
     * @dev Storage slot with the address of the current implementation.
     * This is the keccak-256 hash of "eip1967.proxy.implementation" subtracted by 1.
     */
    // solhint-disable-next-line private-vars-leading-underscore
    bytes32 internal constant IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;

    /**
     * @dev The `implementation` of the proxy is invalid.
     */
    error ERC1967InvalidImplementation(address implementation);

    /**
     * @dev The `admin` of the proxy is invalid.
     */
    error ERC1967InvalidAdmin(address admin);

    /**
     * @dev The `beacon` of the proxy is invalid.
     */
    error ERC1967InvalidBeacon(address beacon);

    /**
     * @dev An upgrade function sees `msg.value > 0` that may be lost.
     */
    error ERC1967NonPayable();

    /**
     * @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 ERC-1967 implementation slot.
     */
    function _setImplementation(address newImplementation) private {
        if (newImplementation.code.length == 0) {
            revert ERC1967InvalidImplementation(newImplementation);
        }
        StorageSlot.getAddressSlot(IMPLEMENTATION_SLOT).value = newImplementation;
    }

    /**
     * @dev Performs implementation upgrade with additional setup call if data is nonempty.
     * This function is payable only if the setup call is performed, otherwise `msg.value` is rejected
     * to avoid stuck value in the contract.
     *
     * Emits an {IERC1967-Upgraded} event.
     */
    function upgradeToAndCall(address newImplementation, bytes memory data) internal {
        _setImplementation(newImplementation);
        emit IERC1967.Upgraded(newImplementation);

        if (data.length > 0) {
            Address.functionDelegateCall(newImplementation, data);
        } else {
            _checkNonPayable();
        }
    }

    /**
     * @dev Storage slot with the admin of the contract.
     * This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1.
     */
    // solhint-disable-next-line private-vars-leading-underscore
    bytes32 internal constant ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;

    /**
     * @dev Returns the current admin.
     *
     * TIP: To get this value clients can read directly from the storage slot shown below (specified by ERC-1967) using
     * the https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
     * `0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103`
     */
    function getAdmin() internal view returns (address) {
        return StorageSlot.getAddressSlot(ADMIN_SLOT).value;
    }

    /**
     * @dev Stores a new address in the ERC-1967 admin slot.
     */
    function _setAdmin(address newAdmin) private {
        if (newAdmin == address(0)) {
            revert ERC1967InvalidAdmin(address(0));
        }
        StorageSlot.getAddressSlot(ADMIN_SLOT).value = newAdmin;
    }

    /**
     * @dev Changes the admin of the proxy.
     *
     * Emits an {IERC1967-AdminChanged} event.
     */
    function changeAdmin(address newAdmin) internal {
        emit IERC1967.AdminChanged(getAdmin(), newAdmin);
        _setAdmin(newAdmin);
    }

    /**
     * @dev The storage slot of the UpgradeableBeacon contract which defines the implementation for this proxy.
     * This is the keccak-256 hash of "eip1967.proxy.beacon" subtracted by 1.
     */
    // solhint-disable-next-line private-vars-leading-underscore
    bytes32 internal constant BEACON_SLOT = 0xa3f0ad74e5423aebfd80d3ef4346578335a9a72aeaee59ff6cb3582b35133d50;

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

    /**
     * @dev Stores a new beacon in the ERC-1967 beacon slot.
     */
    function _setBeacon(address newBeacon) private {
        if (newBeacon.code.length == 0) {
            revert ERC1967InvalidBeacon(newBeacon);
        }

        StorageSlot.getAddressSlot(BEACON_SLOT).value = newBeacon;

        address beaconImplementation = IBeacon(newBeacon).implementation();
        if (beaconImplementation.code.length == 0) {
            revert ERC1967InvalidImplementation(beaconImplementation);
        }
    }

    /**
     * @dev Change the beacon and trigger a setup call if data is nonempty.
     * This function is payable only if the setup call is performed, otherwise `msg.value` is rejected
     * to avoid stuck value in the contract.
     *
     * Emits an {IERC1967-BeaconUpgraded} event.
     *
     * CAUTION: Invoking this function has no effect on an instance of {BeaconProxy} since v5, since
     * it uses an immutable beacon without looking at the value of the ERC-1967 beacon slot for
     * efficiency.
     */
    function upgradeBeaconToAndCall(address newBeacon, bytes memory data) internal {
        _setBeacon(newBeacon);
        emit IERC1967.BeaconUpgraded(newBeacon);

        if (data.length > 0) {
            Address.functionDelegateCall(IBeacon(newBeacon).implementation(), data);
        } else {
            _checkNonPayable();
        }
    }

    /**
     * @dev Reverts if `msg.value` is not zero. It can be used to avoid `msg.value` stuck in the contract
     * if an upgrade doesn't perform an initialization call.
     */
    function _checkNonPayable() private {
        if (msg.value > 0) {
            revert ERC1967NonPayable();
        }
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.1.0) (utils/Address.sol)

pragma solidity ^0.8.20;

import {Errors} from "./Errors.sol";

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev There's no code at `target` (it is not a contract).
     */
    error AddressEmptyCode(address target);

    /**
     * @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://consensys.net/diligence/blog/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/v0.8.20/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        if (address(this).balance < amount) {
            revert Errors.InsufficientBalance(address(this).balance, amount);
        }

        (bool success, ) = recipient.call{value: amount}("");
        if (!success) {
            revert Errors.FailedCall();
        }
    }

    /**
     * @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 or custom error, it is bubbled
     * up by this function (like regular Solidity function calls). However, if
     * the call reverted with no returned reason, this function reverts with a
     * {Errors.FailedCall} error.
     *
     * 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.
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0);
    }

    /**
     * @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`.
     */
    function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
        if (address(this).balance < value) {
            revert Errors.InsufficientBalance(address(this).balance, value);
        }
        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResultFromTarget(target, success, returndata);
    }

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

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

    /**
     * @dev Tool to verify that a low level call to smart-contract was successful, and reverts if the target
     * was not a contract or bubbling up the revert reason (falling back to {Errors.FailedCall}) in case
     * of an unsuccessful call.
     */
    function verifyCallResultFromTarget(
        address target,
        bool success,
        bytes memory returndata
    ) internal view returns (bytes memory) {
        if (!success) {
            _revert(returndata);
        } else {
            // only check if target is a contract if the call was successful and the return data is empty
            // otherwise we already know that it was a contract
            if (returndata.length == 0 && target.code.length == 0) {
                revert AddressEmptyCode(target);
            }
            return returndata;
        }
    }

    /**
     * @dev Tool to verify that a low level call was successful, and reverts if it wasn't, either by bubbling the
     * revert reason or with a default {Errors.FailedCall} error.
     */
    function verifyCallResult(bool success, bytes memory returndata) internal pure returns (bytes memory) {
        if (!success) {
            _revert(returndata);
        } else {
            return returndata;
        }
    }

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

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.1) (utils/Context.sol)

pragma solidity ^0.8.20;

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

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

    function _contextSuffixLength() internal view virtual returns (uint256) {
        return 0;
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.1.0) (utils/Errors.sol)

pragma solidity ^0.8.20;

/**
 * @dev Collection of common custom errors used in multiple contracts
 *
 * IMPORTANT: Backwards compatibility is not guaranteed in future versions of the library.
 * It is recommended to avoid relying on the error API for critical functionality.
 *
 * _Available since v5.1._
 */
library Errors {
    /**
     * @dev The ETH balance of the account is not enough to perform the operation.
     */
    error InsufficientBalance(uint256 balance, uint256 needed);

    /**
     * @dev A call to an address target failed. The target may have reverted.
     */
    error FailedCall();

    /**
     * @dev The deployment failed.
     */
    error FailedDeployment();

    /**
     * @dev A necessary precompile is missing.
     */
    error MissingPrecompile(address);
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.1.0) (utils/StorageSlot.sol)
// This file was procedurally generated from scripts/generate/templates/StorageSlot.js.

pragma solidity ^0.8.20;

/**
 * @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 ERC-1967 implementation slot:
 * ```solidity
 * contract ERC1967 {
 *     // Define the slot. Alternatively, use the SlotDerivation library to derive the slot.
 *     bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
 *
 *     function _getImplementation() internal view returns (address) {
 *         return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
 *     }
 *
 *     function _setImplementation(address newImplementation) internal {
 *         require(newImplementation.code.length > 0);
 *         StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
 *     }
 * }
 * ```
 *
 * TIP: Consider using this library along with {SlotDerivation}.
 */
library StorageSlot {
    struct AddressSlot {
        address value;
    }

    struct BooleanSlot {
        bool value;
    }

    struct Bytes32Slot {
        bytes32 value;
    }

    struct Uint256Slot {
        uint256 value;
    }

    struct Int256Slot {
        int256 value;
    }

    struct StringSlot {
        string value;
    }

    struct BytesSlot {
        bytes value;
    }

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

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

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

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

    /**
     * @dev Returns a `Int256Slot` with member `value` located at `slot`.
     */
    function getInt256Slot(bytes32 slot) internal pure returns (Int256Slot storage r) {
        assembly ("memory-safe") {
            r.slot := slot
        }
    }

    /**
     * @dev Returns a `StringSlot` with member `value` located at `slot`.
     */
    function getStringSlot(bytes32 slot) internal pure returns (StringSlot storage r) {
        assembly ("memory-safe") {
            r.slot := slot
        }
    }

    /**
     * @dev Returns an `StringSlot` representation of the string storage pointer `store`.
     */
    function getStringSlot(string storage store) internal pure returns (StringSlot storage r) {
        assembly ("memory-safe") {
            r.slot := store.slot
        }
    }

    /**
     * @dev Returns a `BytesSlot` with member `value` located at `slot`.
     */
    function getBytesSlot(bytes32 slot) internal pure returns (BytesSlot storage r) {
        assembly ("memory-safe") {
            r.slot := slot
        }
    }

    /**
     * @dev Returns an `BytesSlot` representation of the bytes storage pointer `store`.
     */
    function getBytesSlot(bytes storage store) internal pure returns (BytesSlot storage r) {
        assembly ("memory-safe") {
            r.slot := store.slot
        }
    }
}

// SPDX-License-Identifier: UNLICENSED
pragma solidity 0.8.27;

/**
 * @custom:security-contact [email protected]
 */
library Decimal {
    // unit is used for decimals, e.g. 0.123456
    function unit() internal pure returns (uint256) {
        return 1e18;
    }
}

// SPDX-License-Identifier: UNLICENSED
pragma solidity 0.8.27;

/**
 * @title EVM Writer Interface
 * @notice Allows the NodeDriver contract to write into the state database.
 * @dev Implemented in the native code of the Sonic client.
 * @custom:security-contact [email protected]
 */
interface IEVMWriter {
    function setBalance(address acc, uint256 value) external;

    function copyCode(address acc, address from) external;

    function swapCode(address acc, address where) external;

    function setStorage(address acc, bytes32 key, bytes32 value) external;

    function incNonce(address acc, uint256 diff) external;
}

// SPDX-License-Identifier: UNLICENSED
pragma solidity 0.8.27;

/**
 * @title Node Driver Contract Interface
 * @notice Ensures interaction of on-chain contracts with the Sonic client itself.
 * @dev Methods with onlyNode modifier are called by Sonic internal txs during epoch sealing.
 * @custom:security-contact [email protected]
 */
interface INodeDriver {
    /// Set an initial validator. Called only as part of network initialization/genesis file generating.
    function setGenesisValidator(
        address auth,
        uint256 validatorID,
        bytes calldata pubkey,
        uint256 createdTime
    ) external;

    /// Set an initial delegation. Called only as part of network initialization/genesis file generating.
    function setGenesisDelegation(address delegator, uint256 toValidatorID, uint256 stake) external;

    /// Deactivate a validator. Called by network node when a double-sign of the given validator is registered.
    /// Is called before sealEpoch() call.
    function deactivateValidator(uint256 validatorID, uint256 status) external;

    /// Seal epoch. Called BEFORE epoch sealing made by the client itself.
    function sealEpoch(
        uint256[] calldata offlineTimes,
        uint256[] calldata offlineBlocks,
        uint256[] calldata uptimes,
        uint256[] calldata originatedTxsFee
    ) external;

    /// Seal epoch. Called AFTER epoch sealing made by the client itself.
    function sealEpochValidators(uint256[] calldata nextValidatorIDs) external;
}

// SPDX-License-Identifier: UNLICENSED
pragma solidity 0.8.27;

/**
 * @title Node Driver Executable
 * @notice A batch of operations to be executed with NodeDriver permissions.
 * @notice Contracts implementing this interface should be executed using NodeDriverAuth.execute() or mutExecute().
 * @custom:security-contact [email protected]
 */
interface INodeDriverExecutable {
    function execute() external;
}

// SPDX-License-Identifier: UNLICENSED
pragma solidity 0.8.27;

/**
 * @title Special Fee Contract for Sonic network
 * @notice The SFC maintains a list of validators and delegators and distributes rewards to them.
 * @custom:security-contact [email protected]
 */
interface ISFC {
    event CreatedValidator(
        uint256 indexed validatorID,
        address indexed auth,
        uint256 createdEpoch,
        uint256 createdTime
    );
    event Delegated(address indexed delegator, uint256 indexed toValidatorID, uint256 amount);
    event Undelegated(address indexed delegator, uint256 indexed toValidatorID, uint256 indexed wrID, uint256 amount);
    event Withdrawn(
        address indexed delegator,
        uint256 indexed toValidatorID,
        uint256 indexed wrID,
        uint256 amount,
        uint256 penalty
    );
    event ClaimedRewards(address indexed delegator, uint256 indexed toValidatorID, uint256 rewards);
    event RestakedRewards(address indexed delegator, uint256 indexed toValidatorID, uint256 rewards);
    event BurntFTM(uint256 amount);
    event UpdatedSlashingRefundRatio(uint256 indexed validatorID, uint256 refundRatio);
    event RefundedSlashedLegacyDelegation(address indexed delegator, uint256 indexed validatorID, uint256 amount);

    event DeactivatedValidator(uint256 indexed validatorID, uint256 deactivatedEpoch, uint256 deactivatedTime);
    event ChangedValidatorStatus(uint256 indexed validatorID, uint256 status);
    event AnnouncedRedirection(address indexed from, address indexed to);

    function currentSealedEpoch() external view returns (uint256);

    function getEpochSnapshot(
        uint256
    )
        external
        view
        returns (
            uint256 endTime,
            uint256 endBlock,
            uint256 epochFee,
            uint256 baseRewardPerSecond,
            uint256 totalStake,
            uint256 totalSupply
        );

    function getStake(address, uint256) external view returns (uint256);

    function getValidator(
        uint256
    )
        external
        view
        returns (
            uint256 status,
            uint256 receivedStake,
            address auth,
            uint256 createdEpoch,
            uint256 createdTime,
            uint256 deactivatedTime,
            uint256 deactivatedEpoch
        );

    function getValidatorID(address) external view returns (uint256);

    function getValidatorPubkey(uint256) external view returns (bytes memory);

    function pubkeyAddressToValidatorID(address pubkeyAddress) external view returns (uint256);

    function getWithdrawalRequest(
        address,
        uint256,
        uint256
    ) external view returns (uint256 epoch, uint256 time, uint256 amount);

    function isOwner() external view returns (bool);

    function lastValidatorID() external view returns (uint256);

    function minGasPrice() external view returns (uint256);

    function owner() external view returns (address);

    function renounceOwnership() external;

    function slashingRefundRatio(uint256) external view returns (uint256);

    function stashedRewardsUntilEpoch(address, uint256) external view returns (uint256);

    function totalActiveStake() external view returns (uint256);

    function totalStake() external view returns (uint256);

    function totalSupply() external view returns (uint256);

    function transferOwnership(address newOwner) external;

    function treasuryAddress() external view returns (address);

    function version() external pure returns (bytes3);

    function currentEpoch() external view returns (uint256);

    function updateConstsAddress(address v) external;

    function constsAddress() external view returns (address);

    function getEpochValidatorIDs(uint256 epoch) external view returns (uint256[] memory);

    function getEpochReceivedStake(uint256 epoch, uint256 validatorID) external view returns (uint256);

    function getEpochAccumulatedRewardPerToken(uint256 epoch, uint256 validatorID) external view returns (uint256);

    function getEpochAccumulatedUptime(uint256 epoch, uint256 validatorID) external view returns (uint256);

    function getEpochAverageUptime(uint256 epoch, uint256 validatorID) external view returns (uint32);

    function getEpochAccumulatedOriginatedTxsFee(uint256 epoch, uint256 validatorID) external view returns (uint256);

    function getEpochOfflineTime(uint256 epoch, uint256 validatorID) external view returns (uint256);

    function getEpochOfflineBlocks(uint256 epoch, uint256 validatorID) external view returns (uint256);

    function getEpochEndBlock(uint256 epoch) external view returns (uint256);

    function rewardsStash(address delegator, uint256 validatorID) external view returns (uint256);

    function createValidator(bytes calldata pubkey) external payable;

    function getSelfStake(uint256 validatorID) external view returns (uint256);

    function delegate(uint256 toValidatorID) external payable;

    function undelegate(uint256 toValidatorID, uint256 wrID, uint256 amount) external;

    function isSlashed(uint256 validatorID) external view returns (bool);

    function withdraw(uint256 toValidatorID, uint256 wrID) external;

    function deactivateValidator(uint256 validatorID, uint256 status) external;

    function pendingRewards(address delegator, uint256 toValidatorID) external view returns (uint256);

    function stashRewards(address delegator, uint256 toValidatorID) external;

    function claimRewards(uint256 toValidatorID) external;

    function restakeRewards(uint256 toValidatorID) external;

    function updateSlashingRefundRatio(uint256 validatorID, uint256 refundRatio) external;

    function updateTreasuryAddress(address v) external;

    function burnFTM(uint256 amount) external;

    function sealEpoch(
        uint256[] calldata offlineTime,
        uint256[] calldata offlineBlocks,
        uint256[] calldata uptimes,
        uint256[] calldata originatedTxsFee
    ) external;

    function sealEpochValidators(uint256[] calldata nextValidatorIDs) external;

    function initialize(
        uint256 sealedEpoch,
        uint256 _totalSupply,
        address nodeDriver,
        address consts,
        address _owner
    ) external;

    function setGenesisValidator(
        address auth,
        uint256 validatorID,
        bytes calldata pubkey,
        uint256 createdTime
    ) external;

    function setGenesisDelegation(address delegator, uint256 toValidatorID, uint256 stake) external;

    function updateStakeSubscriberAddress(address v) external;

    function stakeSubscriberAddress() external view returns (address);

    function setRedirectionAuthorizer(address v) external;

    function announceRedirection(address to) external;

    function initiateRedirection(address from, address to) external;

    function redirect(address to) external;
}

// SPDX-License-Identifier: UNLICENSED
pragma solidity 0.8.27;

import {Ownable} from "@openzeppelin/contracts/access/Ownable.sol";
import {Decimal} from "../common/Decimal.sol";

/**
 * @custom:security-contact [email protected]
 */
contract ConstantsManager is Ownable {
    // Minimum amount of stake for a validator, i.e., 500000 FTM
    uint256 public minSelfStake;
    // Maximum ratio of delegations a validator can have, say, 15 times of self-stake
    uint256 public maxDelegatedRatio;
    // The commission fee in percentage a validator will get from a delegation, e.g., 15%
    uint256 public validatorCommission;
    // The percentage of fees to burn, e.g., 20%
    uint256 public burntFeeShare;
    // The percentage of fees to transfer to treasury address, e.g., 10%
    uint256 public treasuryFeeShare;
    // the number of epochs that undelegated stake is locked for
    uint256 public withdrawalPeriodEpochs;
    // the number of seconds that undelegated stake is locked for
    uint256 public withdrawalPeriodTime;

    uint256 public baseRewardPerSecond;
    uint256 public offlinePenaltyThresholdBlocksNum;
    uint256 public offlinePenaltyThresholdTime;
    uint256 public targetGasPowerPerSecond;
    uint256 public gasPriceBalancingCounterweight;

    // The number of epochs to calculate the average uptime ratio from, acceptable bound [10, 87600].
    // Is also the minimum number of epochs necessary for deactivation of offline validators.
    uint32 public averageUptimeEpochWindow;

    // Minimum average uptime ratio in fixed-point format; acceptable bounds [0,0.9].
    // Zero to disable validators deactivation by this metric.
    uint64 public minAverageUptime;

    // The address of the recipient that receives issued tokens
    // as a counterparty to the burnt FTM tokens
    address public issuedTokensRecipient;

    /**
     * @dev Given value is too small
     */
    error ValueTooSmall();

    /**
     * @dev Given value is too large
     */
    error ValueTooLarge();

    constructor(address owner) Ownable(owner) {}

    function updateMinSelfStake(uint256 v) external virtual onlyOwner {
        if (v < 100000 * 1e18) {
            revert ValueTooSmall();
        }
        if (v > 10000000 * 1e18) {
            revert ValueTooLarge();
        }
        minSelfStake = v;
    }

    function updateMaxDelegatedRatio(uint256 v) external virtual onlyOwner {
        if (v < Decimal.unit()) {
            revert ValueTooSmall();
        }
        if (v > 31 * Decimal.unit()) {
            revert ValueTooLarge();
        }
        maxDelegatedRatio = v;
    }

    function updateValidatorCommission(uint256 v) external virtual onlyOwner {
        if (v > Decimal.unit() / 2) {
            revert ValueTooLarge();
        }
        validatorCommission = v;
    }

    function updateBurntFeeShare(uint256 v) external virtual onlyOwner {
        if (v > Decimal.unit() / 2) {
            revert ValueTooLarge();
        }
        burntFeeShare = v;
    }

    function updateTreasuryFeeShare(uint256 v) external virtual onlyOwner {
        if (v > Decimal.unit() / 2) {
            revert ValueTooLarge();
        }
        treasuryFeeShare = v;
    }

    function updateWithdrawalPeriodEpochs(uint256 v) external virtual onlyOwner {
        if (v < 2) {
            revert ValueTooSmall();
        }
        if (v > 100) {
            revert ValueTooLarge();
        }
        withdrawalPeriodEpochs = v;
    }

    function updateWithdrawalPeriodTime(uint256 v) external virtual onlyOwner {
        if (v < 86400) {
            revert ValueTooSmall();
        }
        if (v > 30 * 86400) {
            revert ValueTooLarge();
        }
        withdrawalPeriodTime = v;
    }

    function updateBaseRewardPerSecond(uint256 v) external virtual onlyOwner {
        if (v < 0.5 * 1e18) {
            revert ValueTooSmall();
        }
        if (v > 32 * 1e18) {
            revert ValueTooLarge();
        }
        baseRewardPerSecond = v;
    }

    function updateOfflinePenaltyThresholdTime(uint256 v) external virtual onlyOwner {
        if (v < 86400) {
            revert ValueTooSmall();
        }
        if (v > 10 * 86400) {
            revert ValueTooLarge();
        }
        offlinePenaltyThresholdTime = v;
    }

    function updateOfflinePenaltyThresholdBlocksNum(uint256 v) external virtual onlyOwner {
        if (v < 100) {
            revert ValueTooSmall();
        }
        if (v > 1000000) {
            revert ValueTooLarge();
        }
        offlinePenaltyThresholdBlocksNum = v;
    }

    function updateTargetGasPowerPerSecond(uint256 v) external virtual onlyOwner {
        if (v < 1000000) {
            revert ValueTooSmall();
        }
        if (v > 500000000) {
            revert ValueTooLarge();
        }
        targetGasPowerPerSecond = v;
    }

    function updateGasPriceBalancingCounterweight(uint256 v) external virtual onlyOwner {
        if (v < 100) {
            revert ValueTooSmall();
        }
        if (v > 10 * 86400) {
            revert ValueTooLarge();
        }
        gasPriceBalancingCounterweight = v;
    }

    function updateAverageUptimeEpochWindow(uint32 v) external virtual onlyOwner {
        if (v < 10) {
            // needs to be long enough to allow permissible downtime for validators maintenance
            revert ValueTooSmall();
        }
        if (v > 87600) {
            revert ValueTooLarge();
        }
        averageUptimeEpochWindow = v;
    }

    function updateMinAverageUptime(uint64 v) external virtual onlyOwner {
        if (v > ((Decimal.unit() * 9) / 10)) {
            revert ValueTooLarge();
        }
        minAverageUptime = v;
    }

    function updateIssuedTokensRecipient(address v) external virtual onlyOwner {
        issuedTokensRecipient = v;
    }
}

// SPDX-License-Identifier: UNLICENSED
pragma solidity 0.8.27;

import {UUPSUpgradeable} from "@openzeppelin/contracts-upgradeable/proxy/utils/UUPSUpgradeable.sol";
import {OwnableUpgradeable} from "@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol";
import {NodeDriverAuth} from "./NodeDriverAuth.sol";
import {IEVMWriter} from "../interfaces/IEVMWriter.sol";
import {INodeDriver} from "../interfaces/INodeDriver.sol";

/**
 * @title Node Driver Contract
 * @notice Ensures interaction of on-chain contracts with the Sonic client itself.
 * @dev Methods with onlyNode modifier are called by Sonic internal txs during epoch sealing.
 * @custom:security-contact [email protected]
 */
contract NodeDriver is OwnableUpgradeable, UUPSUpgradeable, INodeDriver {
    NodeDriverAuth internal backend;
    IEVMWriter internal evmWriter;

    error NotNode();
    error NotBackend();

    /// Callable only by NodeDriverAuth (which mediates calls from SFC and from admins)
    modifier onlyBackend() {
        if (msg.sender != address(backend)) {
            revert NotBackend();
        }
        _;
    }

    event UpdateValidatorWeight(uint256 indexed validatorID, uint256 weight);
    event UpdateValidatorPubkey(uint256 indexed validatorID, bytes pubkey);

    event UpdateNetworkRules(bytes diff);
    event UpdateNetworkVersion(uint256 version);
    event AdvanceEpochs(uint256 num);

    /// @custom:oz-upgrades-unsafe-allow constructor
    constructor() {
        _disableInitializers();
    }

    /// Initialization is called only once, after the contract deployment.
    /// Because the contract code is written directly into genesis, constructor cannot be used.
    function initialize(address _backend, address _evmWriterAddress, address _owner) external initializer {
        __Ownable_init(_owner);
        __UUPSUpgradeable_init();
        backend = NodeDriverAuth(_backend);
        evmWriter = IEVMWriter(_evmWriterAddress);
    }

    /// Override the upgrade authorization check to allow upgrades only from the owner.
    // solhint-disable-next-line no-empty-blocks
    function _authorizeUpgrade(address) internal override onlyOwner {}

    function setBalance(address acc, uint256 value) external onlyBackend {
        evmWriter.setBalance(acc, value);
    }

    function copyCode(address acc, address from) external onlyBackend {
        evmWriter.copyCode(acc, from);
    }

    function swapCode(address acc, address where) external onlyBackend {
        evmWriter.swapCode(acc, where);
    }

    function setStorage(address acc, bytes32 key, bytes32 value) external onlyBackend {
        evmWriter.setStorage(acc, key, value);
    }

    function incNonce(address acc, uint256 diff) external onlyBackend {
        evmWriter.incNonce(acc, diff);
    }

    /// Update network rules configuring the chain.
    /// Emitted event is being observed by Sonic client.
    function updateNetworkRules(bytes calldata diff) external onlyBackend {
        emit UpdateNetworkRules(diff);
    }

    /// Update advertised version of the network.
    /// Emitted event is being observed by Sonic client.
    function updateNetworkVersion(uint256 version) external onlyBackend {
        emit UpdateNetworkVersion(version);
    }

    /// Enforce sealing given number of epochs.
    /// Emitted event is being observed by Sonic client.
    function advanceEpochs(uint256 num) external onlyBackend {
        emit AdvanceEpochs(num);
    }

    /// Update weight of a validator. Used to propagate a stake change from SFC to the client.
    /// Emitted event is being observed by Sonic client.
    function updateValidatorWeight(uint256 validatorID, uint256 value) external onlyBackend {
        emit UpdateValidatorWeight(validatorID, value);
    }

    /// Update public key of a validator. Used to propagate a change from SFC to the client.
    /// Emitted event is being observed by Sonic client.
    function updateValidatorPubkey(uint256 validatorID, bytes calldata pubkey) external onlyBackend {
        emit UpdateValidatorPubkey(validatorID, pubkey);
    }

    /// Callable only from Sonic client itself as an internal tx.
    /// Used for propagating network event (validator doublesign, epoch sealing) from node to SFC.
    modifier onlyNode() {
        if (msg.sender != address(0)) {
            revert NotNode();
        }
        _;
    }

    // Methods which are called only by the node

    /// Set an initial validator. Called only as part of network initialization/genesis file generating.
    function setGenesisValidator(
        address auth,
        uint256 validatorID,
        bytes calldata pubkey,
        uint256 createdTime
    ) external onlyNode {
        backend.setGenesisValidator(auth, validatorID, pubkey, createdTime);
    }

    /// Set an initial delegation. Called only as part of network initialization/genesis file generating.
    function setGenesisDelegation(address delegator, uint256 toValidatorID, uint256 stake) external onlyNode {
        backend.setGenesisDelegation(delegator, toValidatorID, stake);
    }

    /// Deactivate a validator. Called by network node when a double-sign of the given validator is registered.
    /// Is called before sealEpoch() call.
    function deactivateValidator(uint256 validatorID, uint256 status) external onlyNode {
        backend.deactivateValidator(validatorID, status);
    }

    /// Seal epoch. Called BEFORE epoch sealing made by the client itself.
    function sealEpoch(
        uint256[] calldata offlineTimes,
        uint256[] calldata offlineBlocks,
        uint256[] calldata uptimes,
        uint256[] calldata originatedTxsFee
    ) external onlyNode {
        backend.sealEpoch(offlineTimes, offlineBlocks, uptimes, originatedTxsFee);
    }

    /// Seal epoch. Called AFTER epoch sealing made by the client itself.
    function sealEpochValidators(uint256[] calldata nextValidatorIDs) external onlyNode {
        backend.sealEpochValidators(nextValidatorIDs);
    }

    uint256[50] private __gap;
}

// SPDX-License-Identifier: UNLICENSED
pragma solidity 0.8.27;

import {UUPSUpgradeable} from "@openzeppelin/contracts-upgradeable/proxy/utils/UUPSUpgradeable.sol";
import {OwnableUpgradeable} from "@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol";
import {ISFC} from "../interfaces/ISFC.sol";
import {NodeDriver} from "./NodeDriver.sol";
import {INodeDriverExecutable} from "../interfaces/INodeDriverExecutable.sol";

/**
 * @custom:security-contact [email protected]
 */
contract NodeDriverAuth is OwnableUpgradeable, UUPSUpgradeable {
    ISFC internal sfc;
    NodeDriver internal driver;

    error NotSFC();
    error NotDriver();
    error NotContract();
    error SelfCodeHashMismatch();
    error DriverCodeHashMismatch();
    error RecipientNotSFC();

    /// @custom:oz-upgrades-unsafe-allow constructor
    constructor() {
        _disableInitializers();
    }

    // Initialize NodeDriverAuth, NodeDriver and SFC in one call to allow fewer genesis transactions
    function initialize(address payable _sfc, address _driver, address _owner) external initializer {
        __Ownable_init(_owner);
        __UUPSUpgradeable_init();
        driver = NodeDriver(_driver);
        sfc = ISFC(_sfc);
    }

    /// Override the upgrade authorization check to allow upgrades only from the owner.
    // solhint-disable-next-line no-empty-blocks
    function _authorizeUpgrade(address) internal override onlyOwner {}

    /// Callable only by SFC contract.
    modifier onlySFC() {
        if (msg.sender != address(sfc)) {
            revert NotSFC();
        }
        _;
    }

    /// Callable only by NodeDriver (mediates messages from the network client)
    modifier onlyDriver() {
        if (msg.sender != address(driver)) {
            revert NotDriver();
        }
        _;
    }

    function _execute(address executable, address newOwner, bytes32 selfCodeHash, bytes32 driverCodeHash) internal {
        _transferOwnership(executable);
        INodeDriverExecutable(executable).execute();
        _transferOwnership(newOwner);
        //require(driver.backend() == address(this), "ownership of driver is lost");
        if (_getCodeHash(address(this)) != selfCodeHash) {
            revert SelfCodeHashMismatch();
        }
        if (_getCodeHash(address(driver)) != driverCodeHash) {
            revert DriverCodeHashMismatch();
        }
    }

    /// Execute a batch update of network configuration.
    /// Run given contract with a permission of the NodeDriverAuth owner.
    /// Does not allow changing NodeDriver and NodeDriverAuth code.
    function execute(address executable) external onlyOwner {
        _execute(executable, owner(), _getCodeHash(address(this)), _getCodeHash(address(driver)));
    }

    /// Execute a batch update of network configuration.
    /// Run given contract with a permission of the NodeDriverAuth owner.
    /// Allows changing NodeDriver and NodeDriverAuth code.
    function mutExecute(
        address executable,
        address newOwner,
        bytes32 selfCodeHash,
        bytes32 driverCodeHash
    ) external onlyOwner {
        _execute(executable, newOwner, selfCodeHash, driverCodeHash);
    }

    /// Mint native token. To be used by SFC for minting validators rewards.
    function incBalance(address acc, uint256 diff) external onlySFC {
        driver.setBalance(acc, address(acc).balance + diff);
    }

    /// Upgrade code of given contract by coping it from other deployed contract.
    /// Avoids setting code to an external address.
    function upgradeCode(address acc, address from) external onlyOwner {
        if (!isContract(acc) || !isContract(from)) {
            revert NotContract();
        }
        driver.copyCode(acc, from);
    }

    /// Upgrade code of given contract by coping it from other deployed contract.
    /// Does not avoid setting code to an external address. (DANGEROUS!)
    function copyCode(address acc, address from) external onlyOwner {
        driver.copyCode(acc, from);
    }

    /// Increment nonce of the given account.
    function incNonce(address acc, uint256 diff) external onlyOwner {
        driver.incNonce(acc, diff);
    }

    /// Update network rules by providing a JSON patch.
    function updateNetworkRules(bytes calldata diff) external onlyOwner {
        driver.updateNetworkRules(diff);
    }

    /// Update advertised network version.
    function updateNetworkVersion(uint256 version) external onlyOwner {
        driver.updateNetworkVersion(version);
    }

    /// Enforce sealing given number of epochs.
    function advanceEpochs(uint256 num) external onlyOwner {
        driver.advanceEpochs(num);
    }

    /// Update weight of a validator. Used to propagate a stake change from SFC to the client.
    function updateValidatorWeight(uint256 validatorID, uint256 value) external onlySFC {
        driver.updateValidatorWeight(validatorID, value);
    }

    /// Update public key of a validator. Used to propagate a change from SFC to the client.
    function updateValidatorPubkey(uint256 validatorID, bytes calldata pubkey) external onlySFC {
        driver.updateValidatorPubkey(validatorID, pubkey);
    }

    /// Set an initial validator into SFC. Called only as part of network initialization/genesis file generating.
    function setGenesisValidator(
        address auth,
        uint256 validatorID,
        bytes calldata pubkey,
        uint256 createdTime
    ) external onlyDriver {
        sfc.setGenesisValidator(auth, validatorID, pubkey, createdTime);
    }

    /// Set an initial delegation. Called only as part of network initialization/genesis file generating.
    function setGenesisDelegation(address delegator, uint256 toValidatorID, uint256 stake) external onlyDriver {
        sfc.setGenesisDelegation(delegator, toValidatorID, stake);
    }

    /// Deactivate a validator. Called by network node when a double-sign of the given validator is registered.
    /// Is called before sealEpoch() call.
    function deactivateValidator(uint256 validatorID, uint256 status) external onlyDriver {
        sfc.deactivateValidator(validatorID, status);
    }

    /// Seal epoch. Called BEFORE epoch sealing made by the client itself.
    function sealEpoch(
        uint256[] calldata offlineTimes,
        uint256[] calldata offlineBlocks,
        uint256[] calldata uptimes,
        uint256[] calldata originatedTxsFee
    ) external onlyDriver {
        sfc.sealEpoch(offlineTimes, offlineBlocks, uptimes, originatedTxsFee);
    }

    /// Seal epoch. Called AFTER epoch sealing made by the client itself.
    function sealEpochValidators(uint256[] calldata nextValidatorIDs) external onlyDriver {
        sfc.sealEpochValidators(nextValidatorIDs);
    }

    function isContract(address account) internal view returns (bool) {
        uint256 size;
        // solhint-disable-next-line no-inline-assembly
        assembly {
            size := extcodesize(account)
        }
        return size > 0;
    }

    function _getCodeHash(address addr) internal view returns (bytes32) {
        bytes32 codeHash;
        assembly {
            codeHash := extcodehash(addr)
        }
        return codeHash;
    }

    uint256[50] private __gap;
}

// SPDX-License-Identifier: UNLICENSED
pragma solidity 0.8.27;

import {UUPSUpgradeable} from "@openzeppelin/contracts-upgradeable/proxy/utils/UUPSUpgradeable.sol";
import {OwnableUpgradeable} from "@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol";
import {Decimal} from "../common/Decimal.sol";
import {NodeDriverAuth} from "./NodeDriverAuth.sol";
import {ConstantsManager} from "./ConstantsManager.sol";
import {Version} from "../version/Version.sol";

/**
 * @title Special Fee Contract for Sonic network
 * @notice The SFC maintains a list of validators and delegators and distributes rewards to them.
 * @custom:security-contact [email protected]
 */
contract SFC is OwnableUpgradeable, UUPSUpgradeable, Version {
    uint256 internal constant OK_STATUS = 0;
    uint256 internal constant WITHDRAWN_BIT = 1;
    uint256 internal constant OFFLINE_BIT = 1 << 3;
    uint256 internal constant OFFLINE_AVG_BIT = 1 << 4;
    uint256 internal constant DOUBLESIGN_BIT = 1 << 7;
    uint256 internal constant CHEATER_MASK = DOUBLESIGN_BIT;

    /**
     * @dev The staking for validation
     */
    struct Validator {
        uint256 status;
        uint256 receivedStake; // from all delegators (weight of the validator)
        address auth; // self-stake delegator
        uint256 createdEpoch;
        uint256 createdTime;
        uint256 deactivatedTime;
        uint256 deactivatedEpoch;
    }

    NodeDriverAuth internal node;

    // last sealed epoch (currentEpoch - 1)
    uint256 public currentSealedEpoch;
    mapping(uint256 validatorID => Validator) public getValidator;
    mapping(address auth => uint256 validatorID) public getValidatorID;
    mapping(uint256 validatorID => bytes pubkey) public getValidatorPubkey;

    uint256 public lastValidatorID;

    // total stake of all validators - includes slashed/offline validators
    uint256 public totalStake;

    // total stake of active (OK_STATUS) validators (total weight)
    uint256 public totalActiveStake;

    // unresolved fees that failed to be send to the treasury
    uint256 public unresolvedTreasuryFees;

    // delegator => validator ID => stashed rewards (to be claimed/restaked)
    mapping(address delegator => mapping(uint256 validatorID => uint256 stashedRewards)) internal _rewardsStash;

    // delegator => validator ID => last epoch number for which were rewards stashed
    mapping(address delegator => mapping(uint256 validatorID => uint256 epoch)) public stashedRewardsUntilEpoch;

    struct WithdrawalRequest {
        uint256 epoch; // epoch where undelegated
        uint256 time; // when undelegated
        uint256 amount;
    }

    // delegator => validator ID => withdrawal ID => withdrawal request
    mapping(address delegator => mapping(uint256 validatorID => mapping(uint256 wrID => WithdrawalRequest)))
        public getWithdrawalRequest;

    // delegator => validator ID => current stake
    mapping(address delegator => mapping(uint256 validatorID => uint256 stake)) public getStake;

    // data structure to compute average uptime for each active validator
    struct AverageUptime {
        // average uptime ratio as a value between 0 and 1e18
        uint64 averageUptime;
        // remainder from the division in the average calculation
        uint32 remainder;
        // number of epochs in the average (at most averageUptimeEpochsWindow)
        uint32 epochs;
    }

    struct EpochSnapshot {
        // validator ID => validator weight in the epoch
        mapping(uint256 => uint256) receivedStake;
        // validator ID => accumulated ( delegatorsReward * 1e18 / receivedStake )
        mapping(uint256 => uint256) accumulatedRewardPerToken;
        // validator ID => accumulated online time
        mapping(uint256 => uint256) accumulatedUptime;
        // validator ID => average uptime as a percentage
        mapping(uint256 => AverageUptime) averageUptime;
        // validator ID => gas fees from txs originated by the validator
        mapping(uint256 => uint256) accumulatedOriginatedTxsFee;
        mapping(uint256 => uint256) offlineTime;
        mapping(uint256 => uint256) offlineBlocks;
        uint256[] validatorIDs;
        uint256 endTime;
        uint256 endBlock;
        uint256 epochFee; // gas fees from txs in the epoch
        uint256 baseRewardPerSecond; // the base reward to divide among validators for each second of the epoch
        uint256 totalStake; // total weight of all validators
        uint256 totalSupply; // total supply of native tokens
    }

    // the total supply of native tokens in the chain
    uint256 public totalSupply;

    // epoch id => epoch snapshot
    mapping(uint256 epoch => EpochSnapshot) public getEpochSnapshot;

    // validator ID -> slashing refund ratio (allows to withdraw slashed stake)
    mapping(uint256 validatorID => uint256 refundRatio) public slashingRefundRatio;

    // the treasure contract (receives unlock penalties and a part of epoch fees)
    address public treasuryAddress;

    ConstantsManager internal c;

    // the contract subscribed to stake changes notifications
    address public stakeSubscriberAddress;

    // address derived from the validator pubkey => validator id
    mapping(address pubkeyAddress => uint256 validatorID) public pubkeyAddressToValidatorID;

    // address authorized to initiate redirection
    address public redirectionAuthorizer;

    // delegator => withdrawals receiver
    mapping(address delegator => address receiver) public getRedirectionRequest;

    // delegator => withdrawals receiver
    mapping(address delegator => address receiver) public getRedirection;

    struct SealEpochRewardsCtx {
        uint256[] baseRewardWeights;
        uint256 totalBaseRewardWeight;
        uint256[] txRewardWeights;
        uint256 totalTxRewardWeight;
        uint256 epochFee;
    }

    // auth
    error NotDriverAuth();
    error NotAuthorized();

    // addresses
    error ZeroAddress();
    error SameAddress();

    // values
    error ZeroAmount();
    error ZeroRewards();
    error ValueTooLarge();

    // pubkeys
    error PubkeyUsedByOtherValidator();
    error MalformedPubkey();

    // redirections
    error AlreadyRedirected();
    error SameRedirectionAuthorizer();
    error Redirected();

    // validators
    error ValidatorNotExists();
    error ValidatorExists();
    error ValidatorNotActive();
    error ValidatorDelegationLimitExceeded();
    error NotDeactivatedStatus();

    // requests
    error RequestExists();
    error RequestNotExists();

    // transfers
    error TransfersNotAllowed();
    error TransferFailed();

    // stake changes subscriber
    error StakeSubscriberFailed();

    // staking
    error InsufficientSelfStake();
    error NotEnoughTimePassed();
    error NotEnoughEpochsPassed();
    error StakeIsFullySlashed();

    // stashing
    error NothingToStash();

    // slashing
    error ValidatorNotSlashed();
    error RefundRatioTooHigh();

    // treasury
    error TreasuryNotSet();
    error NoUnresolvedTreasuryFees();

    event DeactivatedValidator(uint256 indexed validatorID, uint256 deactivatedEpoch, uint256 deactivatedTime);
    event ChangedValidatorStatus(uint256 indexed validatorID, uint256 status);
    event CreatedValidator(
        uint256 indexed validatorID,
        address indexed auth,
        uint256 createdEpoch,
        uint256 createdTime
    );
    event Delegated(address indexed delegator, uint256 indexed toValidatorID, uint256 amount);
    event Undelegated(address indexed delegator, uint256 indexed toValidatorID, uint256 indexed wrID, uint256 amount);
    event Withdrawn(
        address indexed delegator,
        uint256 indexed toValidatorID,
        uint256 indexed wrID,
        uint256 amount,
        uint256 penalty
    );
    event ClaimedRewards(address indexed delegator, uint256 indexed toValidatorID, uint256 rewards);
    event RestakedRewards(address indexed delegator, uint256 indexed toValidatorID, uint256 rewards);
    event BurntNativeTokens(uint256 amount);
    event UpdatedSlashingRefundRatio(uint256 indexed validatorID, uint256 refundRatio);
    event RefundedSlashedLegacyDelegation(address indexed delegator, uint256 indexed validatorID, uint256 amount);
    event AnnouncedRedirection(address indexed from, address indexed to);
    event TreasuryFeesResolved(uint256 amount);

    modifier onlyDriver() {
        if (!isNode(msg.sender)) {
            revert NotDriverAuth();
        }
        _;
    }

    /// @custom:oz-upgrades-unsafe-allow constructor
    constructor() {
        _disableInitializers();
    }

    /// Initialization is called only once, after the contract deployment.
    /// Because the contract code is written directly into genesis, constructor cannot be used.
    function initialize(
        uint256 sealedEpoch,
        uint256 _totalSupply,
        address nodeDriver,
        address _c,
        address owner
    ) external initializer {
        __Ownable_init(owner);
        __UUPSUpgradeable_init();
        currentSealedEpoch = sealedEpoch;
        node = NodeDriverAuth(nodeDriver);
        c = ConstantsManager(_c);
        totalSupply = _totalSupply;
        getEpochSnapshot[sealedEpoch].endTime = _now();
    }

    /// Override the upgrade authorization check to allow upgrades only from the owner.
    // solhint-disable-next-line no-empty-blocks
    function _authorizeUpgrade(address) internal override onlyOwner {}

    /// Receive fallback to revert transfers.
    receive() external payable {
        revert TransfersNotAllowed();
    }

    /// Set admin address responsible for initiating redirections.
    function setRedirectionAuthorizer(address v) external onlyOwner {
        if (redirectionAuthorizer == v) {
            revert SameRedirectionAuthorizer();
        }
        redirectionAuthorizer = v;
    }

    /// Announce redirection of address to be called by validator whose auth key was compromised.
    /// Produced events are used to notify redirect authorizer about redirection request.
    /// Redirect authorizer then initiates creating of appropriate redirect by calling initiateRedirection().
    function announceRedirection(address to) external {
        emit AnnouncedRedirection(msg.sender, to);
    }

    /// Initiate redirection of withdrawals/claims for a compromised validator account.
    /// Needs to be accepted by validator key holder before the redirect is active.
    function initiateRedirection(address from, address to) external {
        if (msg.sender != redirectionAuthorizer) {
            revert NotAuthorized();
        }
        if (getRedirection[from] == to) {
            revert AlreadyRedirected();
        }
        if (from == to) {
            revert SameAddress();
        }
        getRedirectionRequest[from] = to;
    }

    /// Accept redirection proposal.
    /// Redirection must by accepted by the validator key holder before it start to be applied.
    function redirect(address to) external {
        address from = msg.sender;
        if (to == address(0)) {
            revert ZeroAddress();
        }
        if (getRedirectionRequest[from] != to) {
            revert RequestNotExists();
        }
        getRedirection[from] = to;
        getRedirectionRequest[from] = address(0);
    }

    /// Seal current epoch - deactivate validators who were offline too long, create an epoch snapshot
    /// for the current epoch (provides information for rewards calculation), calculate new minimal gas price.
    /// This method is called BEFORE the epoch sealing made by the client itself.
    function sealEpoch(
        uint256[] calldata offlineTime,
        uint256[] calldata offlineBlocks,
        uint256[] calldata uptimes,
        uint256[] calldata originatedTxsFee
    ) external onlyDriver {
        EpochSnapshot storage snapshot = getEpochSnapshot[currentEpoch()];
        uint256[] memory validatorIDs = snapshot.validatorIDs;

        _sealEpochOffline(snapshot, validatorIDs, offlineTime, offlineBlocks);
        {
            EpochSnapshot storage prevSnapshot = getEpochSnapshot[currentSealedEpoch];
            uint256 epochDuration = 1;
            if (_now() > prevSnapshot.endTime) {
                epochDuration = _now() - prevSnapshot.endTime;
            }
            _sealEpochRewards(epochDuration, snapshot, prevSnapshot, validatorIDs, uptimes, originatedTxsFee);
            _sealEpochAverageUptime(epochDuration, snapshot, prevSnapshot, validatorIDs, uptimes);
        }

        currentSealedEpoch = currentEpoch();
        snapshot.endTime = _now();
        snapshot.endBlock = block.number;
        snapshot.baseRewardPerSecond = c.baseRewardPerSecond();
        snapshot.totalSupply = totalSupply;
    }

    /// Finish epoch sealing - store validators of the new epoch into a snapshot.
    /// This method is called AFTER the epoch sealing made by the client itself.
    function sealEpochValidators(uint256[] calldata nextValidatorIDs) external onlyDriver {
        EpochSnapshot storage snapshot = getEpochSnapshot[currentEpoch()];
        // fill data for the next snapshot
        for (uint256 i = 0; i < nextValidatorIDs.length; i++) {
            uint256 validatorID = nextValidatorIDs[i];
            uint256 receivedStake = getValidator[validatorID].receivedStake;
            snapshot.receivedStake[validatorID] = receivedStake;
            snapshot.totalStake = snapshot.totalStake + receivedStake;
        }
        snapshot.validatorIDs = nextValidatorIDs;
    }

    /// Set an initial validator.
    /// Called only as part of network initialization/genesis file generating.
    function setGenesisValidator(
        address auth,
        uint256 validatorID,
        bytes calldata pubkey,
        uint256 createdTime
    ) external onlyDriver {
        _rawCreateValidator(
            auth,
            validatorID,
            pubkey,
            OK_STATUS,
            0, // createdEpoch
            createdTime,
            0, // deactivatedEpoch - not deactivated
            0 // deactivatedTime - not deactivated
        );
        if (validatorID > lastValidatorID) {
            lastValidatorID = validatorID;
        }
    }

    /// Set an initial delegation.
    /// Called only as part of network initialization/genesis file generating.
    function setGenesisDelegation(address delegator, uint256 toValidatorID, uint256 stake) external onlyDriver {
        _rawDelegate(delegator, toValidatorID, stake, false);
        _mintNativeToken(stake);
    }

    /// Create a validator with a given public key while using attached value as the validator's self-stake.
    function createValidator(bytes calldata pubkey) external payable {
        if (msg.value < c.minSelfStake()) {
            revert InsufficientSelfStake();
        }
        if (pubkey.length != 66 || pubkey[0] != 0xc0) {
            revert MalformedPubkey();
        }
        if (pubkeyAddressToValidatorID[_pubkeyToAddress(pubkey)] != 0) {
            revert PubkeyUsedByOtherValidator();
        }
        _createValidator(msg.sender, pubkey);
        _delegate(msg.sender, lastValidatorID, msg.value);
    }

    /// Update slashing refund ratio for a validator.
    /// The refund ratio is used to calculate the amount of stake that can be withdrawn after slashing.
    function updateSlashingRefundRatio(uint256 validatorID, uint256 refundRatio) external onlyOwner {
        if (!isSlashed(validatorID)) {
            revert ValidatorNotSlashed();
        }
        if (refundRatio > Decimal.unit()) {
            revert RefundRatioTooHigh();
        }
        slashingRefundRatio[validatorID] = refundRatio;
        emit UpdatedSlashingRefundRatio(validatorID, refundRatio);
    }

    /// Delegate stake to a validator.
    function delegate(uint256 toValidatorID) external payable {
        _delegate(msg.sender, toValidatorID, msg.value);
    }

    /// Withdraw stake from a validator after its un-delegation.
    /// Un-delegated stake is locked for a certain period of time.
    function withdraw(uint256 toValidatorID, uint256 wrID) public {
        _withdraw(msg.sender, toValidatorID, wrID, _receiverOf(msg.sender));
    }

    /// Deactivate a validator.
    /// Called by the chain client when a client misbehavior is observed.
    function deactivateValidator(uint256 validatorID, uint256 status) external onlyDriver {
        if (status == OK_STATUS) {
            revert NotDeactivatedStatus();
        }

        _setValidatorDeactivated(validatorID, status);
        _syncValidator(validatorID, false);
        address validatorAddr = getValidator[validatorID].auth;
        _notifyStakeSubscriber(validatorAddr, validatorAddr, false);
    }

    /// Stash rewards for a delegator.
    function stashRewards(address delegator, uint256 toValidatorID) external {
        if (!_stashRewards(delegator, toValidatorID)) {
            revert NothingToStash();
        }
    }

    /// Resolve failed treasury transfers and send the unresolved fees to the treasury address.
    function resolveTreasuryFees() external {
        if (treasuryAddress == address(0)) {
            revert TreasuryNotSet();
        }
        if (unresolvedTreasuryFees == 0) {
            revert NoUnresolvedTreasuryFees();
        }

        // zero the fees before sending to prevent re-entrancy
        uint256 fees = unresolvedTreasuryFees;
        unresolvedTreasuryFees = 0;

        (bool success, ) = treasuryAddress.call{value: fees, gas: 1000000}("");
        if (!success) {
            revert TransferFailed();
        }

        emit TreasuryFeesResolved(fees);
    }

    /// Burn native tokens by sending them to the SFC contract.
    function burnNativeTokens() external payable {
        if (msg.value == 0) {
            revert ZeroAmount();
        }
        _burnNativeTokens(msg.value);
    }

    /// Issue tokens to the issued tokens recipient as a counterparty to the burnt FTM tokens.
    function issueTokens(uint256 amount) external onlyOwner {
        if (c.issuedTokensRecipient() == address(0)) {
            revert ZeroAddress();
        }
        node.incBalance(c.issuedTokensRecipient(), amount);
        totalSupply += amount;
    }

    /// Update treasury address.
    function updateTreasuryAddress(address v) external onlyOwner {
        treasuryAddress = v;
    }

    /// Update consts address.
    function updateConstsAddress(address v) external onlyOwner {
        c = ConstantsManager(v);
    }

    /// Update voteBook address.
    function updateStakeSubscriberAddress(address v) external onlyOwner {
        stakeSubscriberAddress = v;
    }

    /// Get consts address.
    function constsAddress() external view returns (address) {
        return address(c);
    }

    /// Claim rewards for stake delegated to a validator.
    function claimRewards(uint256 toValidatorID) public {
        address delegator = msg.sender;
        uint256 rewards = _claimRewards(delegator, toValidatorID);
        // It's important that we transfer after erasing (protection against Re-Entrancy)
        (bool sent, ) = _receiverOf(delegator).call{value: rewards}("");
        if (!sent) {
            revert TransferFailed();
        }

        emit ClaimedRewards(delegator, toValidatorID, rewards);
    }

    /// Get amount of currently stashed rewards.
    function rewardsStash(address delegator, uint256 validatorID) public view returns (uint256) {
        return _rewardsStash[delegator][validatorID];
    }

    /// Un-delegate stake from a validator.
    function undelegate(uint256 toValidatorID, uint256 wrID, uint256 amount) public {
        address delegator = msg.sender;

        _stashRewards(delegator, toValidatorID);

        if (amount == 0) {
            revert ZeroAmount();
        }

        if (getWithdrawalRequest[delegator][toValidatorID][wrID].amount != 0) {
            revert RequestExists();
        }

        _rawUndelegate(delegator, toValidatorID, amount, true, false, true);

        getWithdrawalRequest[delegator][toValidatorID][wrID].amount = amount;
        getWithdrawalRequest[delegator][toValidatorID][wrID].epoch = currentEpoch();
        getWithdrawalRequest[delegator][toValidatorID][wrID].time = _now();

        _syncValidator(toValidatorID, false);

        emit Undelegated(delegator, toValidatorID, wrID, amount);
    }

    /// Re-stake rewards - claim rewards for staking and delegate it immediately
    /// to the same validator - add it to the current stake.
    function restakeRewards(uint256 toValidatorID) public {
        address delegator = msg.sender;
        uint256 rewards = _claimRewards(delegator, toValidatorID);

        _delegate(delegator, toValidatorID, rewards);
        emit RestakedRewards(delegator, toValidatorID, rewards);
    }

    /// Get the current epoch number.
    function currentEpoch() public view returns (uint256) {
        return currentSealedEpoch + 1;
    }

    /// Get self-stake of a validator.
    function getSelfStake(uint256 validatorID) public view returns (uint256) {
        return getStake[getValidator[validatorID].auth][validatorID];
    }

    /// Get validator IDs for given epoch.
    function getEpochValidatorIDs(uint256 epoch) public view returns (uint256[] memory) {
        return getEpochSnapshot[epoch].validatorIDs;
    }

    /// Get received stake for a validator in a given epoch.
    function getEpochReceivedStake(uint256 epoch, uint256 validatorID) public view returns (uint256) {
        return getEpochSnapshot[epoch].receivedStake[validatorID];
    }

    /// Get accumulated reward per token for a validator in a given epoch.
    function getEpochAccumulatedRewardPerToken(uint256 epoch, uint256 validatorID) public view returns (uint256) {
        return getEpochSnapshot[epoch].accumulatedRewardPerToken[validatorID];
    }

    /// Get accumulated uptime for a validator in a given epoch.
    function getEpochAccumulatedUptime(uint256 epoch, uint256 validatorID) public view returns (uint256) {
        return getEpochSnapshot[epoch].accumulatedUptime[validatorID];
    }

    /// Get average uptime for a validator in a given epoch.
    function getEpochAverageUptime(uint256 epoch, uint256 validatorID) public view returns (uint64) {
        return getEpochSnapshot[epoch].averageUptime[validatorID].averageUptime;
    }

    /// Get accumulated originated txs fee for a validator in a given epoch.
    function getEpochAccumulatedOriginatedTxsFee(uint256 epoch, uint256 validatorID) public view returns (uint256) {
        return getEpochSnapshot[epoch].accumulatedOriginatedTxsFee[validatorID];
    }

    /// Get offline time for a validator in a given epoch.
    function getEpochOfflineTime(uint256 epoch, uint256 validatorID) public view returns (uint256) {
        return getEpochSnapshot[epoch].offlineTime[validatorID];
    }

    /// Get offline blocks for a validator in a given epoch.
    function getEpochOfflineBlocks(uint256 epoch, uint256 validatorID) public view returns (uint256) {
        return getEpochSnapshot[epoch].offlineBlocks[validatorID];
    }

    /// Get end block for a given epoch.
    function getEpochEndBlock(uint256 epoch) public view returns (uint256) {
        return getEpochSnapshot[epoch].endBlock;
    }

    /// Check whether the given validator is slashed - the stake (or its part) cannot
    /// be withdrawn because of misbehavior (double-sign) of the validator.
    function isSlashed(uint256 validatorID) public view returns (bool) {
        return getValidator[validatorID].status & CHEATER_MASK != 0;
    }

    /// Get the amount of rewards which can be currently claimed by the given delegator for the given validator.
    function pendingRewards(address delegator, uint256 toValidatorID) public view returns (uint256) {
        uint256 reward = _newRewards(delegator, toValidatorID);
        return _rewardsStash[delegator][toValidatorID] + reward;
    }

    /// Check whether the self-stake covers the required fraction of all delegations for the given validator.
    function _checkDelegatedStakeLimit(uint256 validatorID) internal view returns (bool) {
        return
            getValidator[validatorID].receivedStake <=
            (getSelfStake(validatorID) * c.maxDelegatedRatio()) / Decimal.unit();
    }

    /// Check if an address is the NodeDriverAuth contract.
    function isNode(address addr) internal view virtual returns (bool) {
        return addr == address(node);
    }

    /// Delegate stake to a validator.
    function _delegate(address delegator, uint256 toValidatorID, uint256 amount) internal {
        if (!_validatorExists(toValidatorID)) {
            revert ValidatorNotExists();
        }
        if (getValidator[toValidatorID].status != OK_STATUS) {
            revert ValidatorNotActive();
        }
        _rawDelegate(delegator, toValidatorID, amount, true);
        if (!_checkDelegatedStakeLimit(toValidatorID)) {
            revert ValidatorDelegationLimitExceeded();
        }
    }

    /// Delegate stake to a validator without checking delegation limit.
    function _rawDelegate(address delegator, uint256 toValidatorID, uint256 amount, bool strict) internal {
        if (amount == 0) {
            revert ZeroAmount();
        }

        _stashRewards(delegator, toValidatorID);

        getStake[delegator][toValidatorID] = getStake[delegator][toValidatorID] + amount;
        uint256 origStake = getValidator[toValidatorID].receivedStake;
        getValidator[toValidatorID].receivedStake = origStake + amount;
        totalStake = totalStake + amount;
        if (getValidator[toValidatorID].status == OK_STATUS) {
            totalActiveStake = totalActiveStake + amount;
        }

        _syncValidator(toValidatorID, origStake == 0);

        emit Delegated(delegator, toValidatorID, amount);

        _notifyStakeSubscriber(delegator, getValidator[toValidatorID].auth, strict);
    }

    /// Un-delegate stake from a validator.
    function _rawUndelegate(
        address delegator,
        uint256 toValidatorID,
        uint256 amount,
        bool strict,
        bool forceful,
        bool checkDelegatedStake
    ) internal {
        getStake[delegator][toValidatorID] -= amount;
        getValidator[toValidatorID].receivedStake = getValidator[toValidatorID].receivedStake - amount;
        totalStake = totalStake - amount;
        if (getValidator[toValidatorID].status == OK_STATUS) {
            totalActiveStake = totalActiveStake - amount;
        }

        uint256 selfStakeAfterwards = getSelfStake(toValidatorID);
        if (selfStakeAfterwards != 0 && getValidator[toValidatorID].status == OK_STATUS) {
            if (!(selfStakeAfterwards >= c.minSelfStake())) {
                if (forceful) {
                    revert InsufficientSelfStake();
                } else {
                    _setValidatorDeactivated(toValidatorID, WITHDRAWN_BIT);
                }
            }
            if (checkDelegatedStake && !_checkDelegatedStakeLimit(toValidatorID)) {
                revert ValidatorDelegationLimitExceeded();
            }
        } else {
            _setValidatorDeactivated(toValidatorID, WITHDRAWN_BIT);
        }

        _notifyStakeSubscriber(delegator, getValidator[toValidatorID].auth, strict);
    }

    /// Get slashing penalty for a stake.
    function getSlashingPenalty(
        uint256 amount,
        bool isCheater,
        uint256 refundRatio
    ) internal pure returns (uint256 penalty) {
        if (!isCheater || refundRatio >= Decimal.unit()) {
            return 0;
        }
        // round penalty upwards (ceiling) to prevent dust amount attacks
        penalty = (amount * (Decimal.unit() - refundRatio)) / Decimal.unit() + 1;
        if (penalty > amount) {
            return amount;
        }
        return penalty;
    }

    /// Withdraw stake from a validator.
    /// The stake must be undelegated first.
    function _withdraw(address delegator, uint256 toValidatorID, uint256 wrID, address payable receiver) private {
        WithdrawalRequest memory request = getWithdrawalRequest[delegator][toValidatorID][wrID];
        if (request.epoch == 0) {
            revert RequestNotExists();
        }

        uint256 requestTime = request.time;
        uint256 requestEpoch = request.epoch;
        if (
            getValidator[toValidatorID].deactivatedTime != 0 &&
            getValidator[toValidatorID].deactivatedTime < requestTime
        ) {
            requestTime = getValidator[toValidatorID].deactivatedTime;
            requestEpoch = getValidator[toValidatorID].deactivatedEpoch;
        }

        if (_now() < requestTime + c.withdrawalPeriodTime()) {
            revert NotEnoughTimePassed();
        }

        if (currentEpoch() < requestEpoch + c.withdrawalPeriodEpochs()) {
            revert NotEnoughEpochsPassed();
        }

        uint256 amount = getWithdrawalRequest[delegator][toValidatorID][wrID].amount;
        bool isCheater = isSlashed(toValidatorID);
        uint256 penalty = getSlashingPenalty(amount, isCheater, slashingRefundRatio[toValidatorID]);
        delete getWithdrawalRequest[delegator][toValidatorID][wrID];

        if (amount <= penalty) {
            revert StakeIsFullySlashed();
        }
        // It's important that we transfer after erasing (protection against Re-Entrancy)
        (bool sent, ) = receiver.call{value: amount - penalty}("");
        if (!sent) {
            revert TransferFailed();
        }
        _burnNativeTokens(penalty);

        emit Withdrawn(delegator, toValidatorID, wrID, amount - penalty, penalty);
    }

    /// Get highest epoch for which can be claimed rewards for the given validator.
    // If the validator is deactivated, the highest payable epoch is the deactivation epoch
    // or the current epoch, whichever is lower
    function _highestPayableEpoch(uint256 validatorID) internal view returns (uint256) {
        if (getValidator[validatorID].deactivatedEpoch != 0) {
            if (currentSealedEpoch < getValidator[validatorID].deactivatedEpoch) {
                return currentSealedEpoch;
            }
            return getValidator[validatorID].deactivatedEpoch;
        }
        return currentSealedEpoch;
    }

    /// Get new rewards for a delegator.
    /// The rewards are calculated from the last stashed epoch until the highest payable epoch.
    function _newRewards(address delegator, uint256 toValidatorID) internal view returns (uint256) {
        uint256 stashedUntil = stashedRewardsUntilEpoch[delegator][toValidatorID];
        uint256 payableUntil = _highestPayableEpoch(toValidatorID);
        uint256 wholeStake = getStake[delegator][toValidatorID];
        uint256 fullReward = _newRewardsOf(wholeStake, toValidatorID, stashedUntil, payableUntil);
        return fullReward;
    }

    /// Get new rewards for a delegator for a given stake amount and epoch range.
    function _newRewardsOf(
        uint256 stakeAmount,
        uint256 toValidatorID,
        uint256 fromEpoch,
        uint256 toEpoch
    ) internal view returns (uint256) {
        if (fromEpoch >= toEpoch) {
            return 0;
        }
        uint256 stashedRate = getEpochSnapshot[fromEpoch].accumulatedRewardPerToken[toValidatorID];
        uint256 currentRate = getEpochSnapshot[toEpoch].accumulatedRewardPerToken[toValidatorID];
        return ((currentRate - stashedRate) * stakeAmount) / Decimal.unit();
    }

    /// Stash rewards for a delegator.
    function _stashRewards(address delegator, uint256 toValidatorID) internal returns (bool updated) {
        uint256 nonStashedReward = _newRewards(delegator, toValidatorID);
        stashedRewardsUntilEpoch[delegator][toValidatorID] = _highestPayableEpoch(toValidatorID);
        _rewardsStash[delegator][toValidatorID] += nonStashedReward;
        return nonStashedReward != 0;
    }

    /// Claim rewards for a delegator.
    function _claimRewards(address delegator, uint256 toValidatorID) internal returns (uint256) {
        _stashRewards(delegator, toValidatorID);
        uint256 rewards = _rewardsStash[delegator][toValidatorID];
        if (rewards == 0) {
            revert ZeroRewards();
        }
        delete _rewardsStash[delegator][toValidatorID];
        // It's important that we mint after erasing (protection against Re-Entrancy)
        _mintNativeToken(rewards);
        return rewards;
    }

    /// Burn native tokens.
    /// The tokens are sent to the zero address.
    function _burnNativeTokens(uint256 amount) internal {
        if (amount != 0) {
            if (amount > totalSupply) {
                revert ValueTooLarge();
            }
            totalSupply -= amount;
            payable(address(0)).transfer(amount);
            emit BurntNativeTokens(amount);
        }
    }

    /// Get epoch end time.
    function epochEndTime(uint256 epoch) internal view returns (uint256) {
        return getEpochSnapshot[epoch].endTime;
    }

    /// Check if an address is redirected.
    function _redirected(address addr) internal view returns (bool) {
        return getRedirection[addr] != address(0);
    }

    /// Get address which should receive rewards and withdrawn stake for the given delegator.
    /// The delegator is usually the receiver, unless a redirection is created.
    function _receiverOf(address addr) internal view returns (address payable) {
        address to = getRedirection[addr];
        if (to == address(0)) {
            return payable(address(uint160(addr)));
        }
        return payable(address(uint160(to)));
    }

    /// Seal epoch - sync validators.
    function _sealEpochOffline(
        EpochSnapshot storage snapshot,
        uint256[] memory validatorIDs,
        uint256[] memory offlineTime,
        uint256[] memory offlineBlocks
    ) internal {
        // mark offline nodes
        for (uint256 i = 0; i < validatorIDs.length; i++) {
            if (
                offlineBlocks[i] > c.offlinePenaltyThresholdBlocksNum() &&
                offlineTime[i] >= c.offlinePenaltyThresholdTime()
            ) {
                _setValidatorDeactivated(validatorIDs[i], OFFLINE_BIT);
                _syncValidator(validatorIDs[i], false);
            }
            // log data
            snapshot.offlineTime[validatorIDs[i]] = offlineTime[i];
            snapshot.offlineBlocks[validatorIDs[i]] = offlineBlocks[i];
        }
    }

    /// Seal epoch - calculate rewards.
    function _sealEpochRewards(
        uint256 epochDuration,
        EpochSnapshot storage snapshot,
        EpochSnapshot storage prevSnapshot,
        uint256[] memory validatorIDs,
        uint256[] memory uptimes,
        uint256[] memory accumulatedOriginatedTxsFee
    ) internal {
        SealEpochRewardsCtx memory ctx = SealEpochRewardsCtx(
            new uint256[](validatorIDs.length),
            0,
            new uint256[](validatorIDs.length),
            0,
            0
        );

        for (uint256 i = 0; i < validatorIDs.length; i++) {
            uint256 prevAccumulatedTxsFee = prevSnapshot.accumulatedOriginatedTxsFee[validatorIDs[i]];
            uint256 originatedTxsFee = 0;
            if (accumulatedOriginatedTxsFee[i] > prevAccumulatedTxsFee) {
                originatedTxsFee = accumulatedOriginatedTxsFee[i] - prevAccumulatedTxsFee;
            }
            // txRewardWeight = {originatedTxsFee} * {uptime}
            // originatedTxsFee is roughly proportional to {uptime} * {stake}, so the whole formula is roughly
            // {stake} * {uptime} ^ 2
            ctx.txRewardWeights[i] = (originatedTxsFee * uptimes[i]) / epochDuration;
            ctx.totalTxRewardWeight = ctx.totalTxRewardWeight + ctx.txRewardWeights[i];
            ctx.epochFee = ctx.epochFee + originatedTxsFee;
        }

        for (uint256 i = 0; i < validatorIDs.length; i++) {
            // baseRewardWeight = {stake} * {uptime ^ 2}
            ctx.baseRewardWeights[i] =
                (((snapshot.receivedStake[validatorIDs[i]] * uptimes[i]) / epochDuration) * uptimes[i]) /
                epochDuration;
            ctx.totalBaseRewardWeight = ctx.totalBaseRewardWeight + ctx.baseRewardWeights[i];
        }

        for (uint256 i = 0; i < validatorIDs.length; i++) {
            uint256 rawReward = _calcRawValidatorEpochBaseReward(
                epochDuration,
                c.baseRewardPerSecond(),
                ctx.baseRewardWeights[i],
                ctx.totalBaseRewardWeight
            );
            rawReward =
                rawReward +
                _calcRawValidatorEpochTxReward(ctx.epochFee, ctx.txRewardWeights[i], ctx.totalTxRewardWeight);

            uint256 validatorID = validatorIDs[i];
            address validatorAddr = getValidator[validatorID].auth;
            // accounting validator's commission
            uint256 commissionRewardFull = _calcValidatorCommission(rawReward, c.validatorCommission());
            uint256 selfStake = getStake[validatorAddr][validatorID];
            if (selfStake != 0) {
                _rewardsStash[validatorAddr][validatorID] += commissionRewardFull;
            }
            // accounting reward per token for delegators
            uint256 delegatorsReward = rawReward - commissionRewardFull;
            // note: use latest stake for the sake of rewards distribution accuracy, not snapshot.receivedStake
            uint256 receivedStake = getValidator[validatorID].receivedStake;
            uint256 rewardPerToken = 0;
            if (receivedStake != 0) {
                rewardPerToken = (delegatorsReward * Decimal.unit()) / receivedStake;
            }
            snapshot.accumulatedRewardPerToken[validatorID] =
                prevSnapshot.accumulatedRewardPerToken[validatorID] +
                rewardPerToken;

            snapshot.accumulatedOriginatedTxsFee[validatorID] = accumulatedOriginatedTxsFee[i];
            snapshot.accumulatedUptime[validatorID] = prevSnapshot.accumulatedUptime[validatorID] + uptimes[i];
        }

        snapshot.epochFee = ctx.epochFee;
        if (totalSupply > snapshot.epochFee) {
            totalSupply -= snapshot.epochFee;
        } else {
            totalSupply = 0;
        }

        // transfer 10% of fees to treasury
        if (treasuryAddress != address(0)) {
            uint256 feeShare = (ctx.epochFee * c.treasuryFeeShare()) / Decimal.unit();
            _mintNativeToken(feeShare);
            (bool success, ) = treasuryAddress.call{value: feeShare, gas: 1000000}("");
            // solhint-disable-next-line no-empty-blocks
            if (!success) {
                // ignore treasury transfer failure
                // the treasury failure must not endanger the epoch sealing

                // store the unresolved treasury fees to be resolved later
                unresolvedTreasuryFees += feeShare;
            }
        }
    }

    /// Seal epoch - recalculate average uptime time of validators
    function _sealEpochAverageUptime(
        uint256 epochDuration,
        EpochSnapshot storage snapshot,
        EpochSnapshot storage prevSnapshot,
        uint256[] memory validatorIDs,
        uint256[] memory uptimes
    ) internal {
        for (uint256 i = 0; i < validatorIDs.length; i++) {
            uint256 validatorID = validatorIDs[i];
            // compute normalised uptime as a percentage in the fixed-point format
            uint256 normalisedUptime = (uptimes[i] * Decimal.unit()) / epochDuration;
            if (normalisedUptime > Decimal.unit()) {
                normalisedUptime = Decimal.unit();
            }
            AverageUptime memory previous = prevSnapshot.averageUptime[validatorID];
            AverageUptime memory current = _addElementIntoAverageUptime(uint64(normalisedUptime), previous);
            snapshot.averageUptime[validatorID] = current;

            // remove validator if average uptime drops below min average uptime
            // (by setting minAverageUptime to zero, this check is ignored)
            if (current.averageUptime < c.minAverageUptime() && current.epochs >= c.averageUptimeEpochWindow()) {
                _setValidatorDeactivated(validatorID, OFFLINE_AVG_BIT);
                _syncValidator(validatorID, false);
            }
        }
    }

    function _addElementIntoAverageUptime(
        uint64 newValue,
        AverageUptime memory prev
    ) private view returns (AverageUptime memory) {
        AverageUptime memory cur;
        if (prev.epochs == 0) {
            cur.averageUptime = newValue; // the only element for the average
            cur.epochs = 1;
            return cur;
        }

        // the number of elements the average is calculated from
        uint128 n = prev.epochs + 1;
        // add new value into the average
        uint128 tmp = (n - 1) * uint128(prev.averageUptime) + uint128(newValue) + prev.remainder;

        cur.averageUptime = uint64(tmp / n);
        cur.remainder = uint32(tmp % n);

        if (cur.averageUptime > Decimal.unit()) {
            cur.averageUptime = uint64(Decimal.unit());
        }
        if (prev.epochs < c.averageUptimeEpochWindow()) {
            cur.epochs = prev.epochs + 1;
        } else {
            cur.epochs = prev.epochs;
        }
        return cur;
    }

    /// Create a new validator.
    function _createValidator(address auth, bytes calldata pubkey) internal {
        uint256 validatorID = ++lastValidatorID;
        _rawCreateValidator(auth, validatorID, pubkey, OK_STATUS, currentEpoch(), _now(), 0, 0);
    }

    /// Create a new validator without incrementing lastValidatorID.
    function _rawCreateValidator(
        address auth,
        uint256 validatorID,
        bytes calldata pubkey,
        uint256 status,
        uint256 createdEpoch,
        uint256 createdTime,
        uint256 deactivatedEpoch,
        uint256 deactivatedTime
    ) internal {
        if (getValidatorID[auth] != 0) {
            revert ValidatorExists();
        }
        getValidatorID[auth] = validatorID;
        getValidator[validatorID].status = status;
        getValidator[validatorID].createdEpoch = createdEpoch;
        getValidator[validatorID].createdTime = createdTime;
        getValidator[validatorID].deactivatedTime = deactivatedTime;
        getValidator[validatorID].deactivatedEpoch = deactivatedEpoch;
        getValidator[validatorID].auth = auth;
        getValidatorPubkey[validatorID] = pubkey;
        pubkeyAddressToValidatorID[_pubkeyToAddress(pubkey)] = validatorID;

        emit CreatedValidator(validatorID, auth, createdEpoch, createdTime);
        if (deactivatedEpoch != 0) {
            emit DeactivatedValidator(validatorID, deactivatedEpoch, deactivatedTime);
        }
        if (status != 0) {
            emit ChangedValidatorStatus(validatorID, status);
        }
    }

    /// Calculate raw validator epoch transaction reward.
    function _calcRawValidatorEpochTxReward(
        uint256 epochFee,
        uint256 txRewardWeight,
        uint256 totalTxRewardWeight
    ) internal view returns (uint256) {
        if (txRewardWeight == 0) {
            return 0;
        }
        uint256 txReward = (epochFee * txRewardWeight) / totalTxRewardWeight;
        // fee reward except burntFeeShare and treasuryFeeShare
        return (txReward * (Decimal.unit() - c.burntFeeShare() - c.treasuryFeeShare())) / Decimal.unit();
    }

    /// Calculate raw validator epoch base reward.
    function _calcRawValidatorEpochBaseReward(
        uint256 epochDuration,
        uint256 _baseRewardPerSecond,
        uint256 baseRewardWeight,
        uint256 totalBaseRewardWeight
    ) internal pure returns (uint256) {
        if (baseRewardWeight == 0) {
            return 0;
        }
        uint256 totalReward = epochDuration * _baseRewardPerSecond;
        return (totalReward * baseRewardWeight) / totalBaseRewardWeight;
    }

    /// Mint native token.
    function _mintNativeToken(uint256 amount) internal {
        // balance will be increased after the transaction is processed
        node.incBalance(address(this), amount);
        totalSupply = totalSupply + amount;
    }

    /// Notify stake subscriber about staking changes.
    /// Used to recount votes from delegators in the governance contract.
    function _notifyStakeSubscriber(address delegator, address validatorAuth, bool strict) internal {
        if (stakeSubscriberAddress != address(0)) {
            // Don't allow announceStakeChange to use up all the gas
            // solhint-disable-next-line avoid-low-level-calls
            (bool success, ) = stakeSubscriberAddress.call{gas: 8000000}(
                abi.encodeWithSignature("announceStakeChange(address,address)", delegator, validatorAuth)
            );
            // Don't revert if announceStakeChange failed unless strict mode enabled
            if (!success && strict) {
                revert StakeSubscriberFailed();
            }
        }
    }

    /// Set validator deactivated status.
    function _setValidatorDeactivated(uint256 validatorID, uint256 status) internal {
        if (getValidator[validatorID].status == OK_STATUS && status != OK_STATUS) {
            totalActiveStake = totalActiveStake - getValidator[validatorID].receivedStake;
        }
        // status as a number is proportional to severity
        if (status > getValidator[validatorID].status) {
            getValidator[validatorID].status = status;
            if (getValidator[validatorID].deactivatedEpoch == 0) {
                getValidator[validatorID].deactivatedEpoch = currentEpoch();
                getValidator[validatorID].deactivatedTime = _now();
                emit DeactivatedValidator(
                    validatorID,
                    getValidator[validatorID].deactivatedEpoch,
                    getValidator[validatorID].deactivatedTime
                );
            }
            emit ChangedValidatorStatus(validatorID, status);
        }
    }

    /// Sync validator with node.
    function _syncValidator(uint256 validatorID, bool syncPubkey) public {
        if (!_validatorExists(validatorID)) {
            revert ValidatorNotExists();
        }
        // emit special log for node
        uint256 weight = getValidator[validatorID].receivedStake;
        if (getValidator[validatorID].status != OK_STATUS) {
            weight = 0;
        }
        node.updateValidatorWeight(validatorID, weight);
        if (syncPubkey && weight != 0) {
            node.updateValidatorPubkey(validatorID, getValidatorPubkey[validatorID]);
        }
    }

    /// Check if a validator exists.
    function _validatorExists(uint256 validatorID) internal view returns (bool) {
        return getValidator[validatorID].createdTime != 0;
    }

    /// Calculate validator commission.
    function _calcValidatorCommission(uint256 rawReward, uint256 commission) internal pure returns (uint256) {
        return (rawReward * commission) / Decimal.unit();
    }

    /// Derive address from validator private key
    function _pubkeyToAddress(bytes calldata pubkey) private pure returns (address) {
        return address(uint160(uint256(keccak256(pubkey[2:]))));
    }

    /// Get current time.
    function _now() internal view virtual returns (uint256) {
        return block.timestamp;
    }

    uint256[50] private __gap;
}

// SPDX-License-Identifier: UNLICENSED
pragma solidity 0.8.27;

/**
 * @dev Version contract gives the versioning information of the implementation contract
 */
contract Version {
    /**
     * @dev Returns the version of the SFC contract
     */
    function version() public pure returns (bytes3) {
        return 0x040000; // version 4.0.0
    }
}

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