// File: third_party/arbitrum/ICustomToken.sol
/*
* Copyright 2020, Offchain Labs, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
// solhint-disable-next-line compiler-version
pragma solidity >=0.6.9 <0.9.0;
interface ArbitrumEnabledToken {
/// @notice should return `0xb1` if token is enabled for arbitrum gateways
/// @dev Previous implmentation used to return `uint8(0xa4b1)`, however that causes compile time error in Solidity 0.8. due to type mismatch.
/// In current version `uint8(0xb1)` shall be returned, which results in no change as that's the same value as truncated `uint8(0xa4b1)`.
function isArbitrumEnabled() external view returns (uint8);
}
/**
* @title Minimum expected interface for L1 custom token (see TestCustomTokenL1.sol for an example implementation)
*/
interface ICustomToken is ArbitrumEnabledToken {
/**
* @notice Should make an external call to EthERC20Bridge.registerCustomL2Token
*/
function registerTokenOnL2(
address l2CustomTokenAddress,
uint256 maxSubmissionCostForCustomBridge,
uint256 maxSubmissionCostForRouter,
uint256 maxGasForCustomBridge,
uint256 maxGasForRouter,
uint256 gasPriceBid,
uint256 valueForGateway,
uint256 valueForRouter,
address creditBackAddress
) external payable;
function transferFrom(
address sender,
address recipient,
uint256 amount
) external returns (bool);
function balanceOf(address account) external view returns (uint256);
}
interface L1MintableToken is ICustomToken {
function bridgeMint(address account, uint256 amount) external;
}
interface L1ReverseToken is L1MintableToken {
function bridgeBurn(address account, uint256 amount) external;
}
// File: @openzeppelin/contracts/interfaces/draft-IERC6093.sol
// OpenZeppelin Contracts (last updated v5.0.0) (interfaces/draft-IERC6093.sol)
pragma solidity ^0.8.20;
/**
* @dev Standard ERC20 Errors
* Interface of the https://eips.ethereum.org/EIPS/eip-6093[ERC-6093] custom errors for ERC20 tokens.
*/
interface IERC20Errors {
/**
* @dev Indicates an error related to the current `balance` of a `sender`. Used in transfers.
* @param sender Address whose tokens are being transferred.
* @param balance Current balance for the interacting account.
* @param needed Minimum amount required to perform a transfer.
*/
error ERC20InsufficientBalance(address sender, uint256 balance, uint256 needed);
/**
* @dev Indicates a failure with the token `sender`. Used in transfers.
* @param sender Address whose tokens are being transferred.
*/
error ERC20InvalidSender(address sender);
/**
* @dev Indicates a failure with the token `receiver`. Used in transfers.
* @param receiver Address to which tokens are being transferred.
*/
error ERC20InvalidReceiver(address receiver);
/**
* @dev Indicates a failure with the `spender`’s `allowance`. Used in transfers.
* @param spender Address that may be allowed to operate on tokens without being their owner.
* @param allowance Amount of tokens a `spender` is allowed to operate with.
* @param needed Minimum amount required to perform a transfer.
*/
error ERC20InsufficientAllowance(address spender, uint256 allowance, uint256 needed);
/**
* @dev Indicates a failure with the `approver` of a token to be approved. Used in approvals.
* @param approver Address initiating an approval operation.
*/
error ERC20InvalidApprover(address approver);
/**
* @dev Indicates a failure with the `spender` to be approved. Used in approvals.
* @param spender Address that may be allowed to operate on tokens without being their owner.
*/
error ERC20InvalidSpender(address spender);
}
/**
* @dev Standard ERC721 Errors
* Interface of the https://eips.ethereum.org/EIPS/eip-6093[ERC-6093] custom errors for ERC721 tokens.
*/
interface IERC721Errors {
/**
* @dev Indicates that an address can't be an owner. For example, `address(0)` is a forbidden owner in EIP-20.
* Used in balance queries.
* @param owner Address of the current owner of a token.
*/
error ERC721InvalidOwner(address owner);
/**
* @dev Indicates a `tokenId` whose `owner` is the zero address.
* @param tokenId Identifier number of a token.
*/
error ERC721NonexistentToken(uint256 tokenId);
/**
* @dev Indicates an error related to the ownership over a particular token. Used in transfers.
* @param sender Address whose tokens are being transferred.
* @param tokenId Identifier number of a token.
* @param owner Address of the current owner of a token.
*/
error ERC721IncorrectOwner(address sender, uint256 tokenId, address owner);
/**
* @dev Indicates a failure with the token `sender`. Used in transfers.
* @param sender Address whose tokens are being transferred.
*/
error ERC721InvalidSender(address sender);
/**
* @dev Indicates a failure with the token `receiver`. Used in transfers.
* @param receiver Address to which tokens are being transferred.
*/
error ERC721InvalidReceiver(address receiver);
/**
* @dev Indicates a failure with the `operator`’s approval. Used in transfers.
* @param operator Address that may be allowed to operate on tokens without being their owner.
* @param tokenId Identifier number of a token.
*/
error ERC721InsufficientApproval(address operator, uint256 tokenId);
/**
* @dev Indicates a failure with the `approver` of a token to be approved. Used in approvals.
* @param approver Address initiating an approval operation.
*/
error ERC721InvalidApprover(address approver);
/**
* @dev Indicates a failure with the `operator` to be approved. Used in approvals.
* @param operator Address that may be allowed to operate on tokens without being their owner.
*/
error ERC721InvalidOperator(address operator);
}
/**
* @dev Standard ERC1155 Errors
* Interface of the https://eips.ethereum.org/EIPS/eip-6093[ERC-6093] custom errors for ERC1155 tokens.
*/
interface IERC1155Errors {
/**
* @dev Indicates an error related to the current `balance` of a `sender`. Used in transfers.
* @param sender Address whose tokens are being transferred.
* @param balance Current balance for the interacting account.
* @param needed Minimum amount required to perform a transfer.
* @param tokenId Identifier number of a token.
*/
error ERC1155InsufficientBalance(address sender, uint256 balance, uint256 needed, uint256 tokenId);
/**
* @dev Indicates a failure with the token `sender`. Used in transfers.
* @param sender Address whose tokens are being transferred.
*/
error ERC1155InvalidSender(address sender);
/**
* @dev Indicates a failure with the token `receiver`. Used in transfers.
* @param receiver Address to which tokens are being transferred.
*/
error ERC1155InvalidReceiver(address receiver);
/**
* @dev Indicates a failure with the `operator`’s approval. Used in transfers.
* @param operator Address that may be allowed to operate on tokens without being their owner.
* @param owner Address of the current owner of a token.
*/
error ERC1155MissingApprovalForAll(address operator, address owner);
/**
* @dev Indicates a failure with the `approver` of a token to be approved. Used in approvals.
* @param approver Address initiating an approval operation.
*/
error ERC1155InvalidApprover(address approver);
/**
* @dev Indicates a failure with the `operator` to be approved. Used in approvals.
* @param operator Address that may be allowed to operate on tokens without being their owner.
*/
error ERC1155InvalidOperator(address operator);
/**
* @dev Indicates an array length mismatch between ids and values in a safeBatchTransferFrom operation.
* Used in batch transfers.
* @param idsLength Length of the array of token identifiers
* @param valuesLength Length of the array of token amounts
*/
error ERC1155InvalidArrayLength(uint256 idsLength, uint256 valuesLength);
}
// File: @openzeppelin/contracts/utils/Context.sol
// 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;
}
}
// File: @openzeppelin/contracts/token/ERC20/IERC20.sol
// OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/IERC20.sol)
pragma solidity ^0.8.20;
/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/
interface IERC20 {
/**
* @dev Emitted when `value` tokens are moved from one account (`from`) to
* another (`to`).
*
* Note that `value` may be zero.
*/
event Transfer(address indexed from, address indexed to, uint256 value);
/**
* @dev Emitted when the allowance of a `spender` for an `owner` is set by
* a call to {approve}. `value` is the new allowance.
*/
event Approval(address indexed owner, address indexed spender, uint256 value);
/**
* @dev Returns the value of tokens in existence.
*/
function totalSupply() external view returns (uint256);
/**
* @dev Returns the value of tokens owned by `account`.
*/
function balanceOf(address account) external view returns (uint256);
/**
* @dev Moves a `value` amount of tokens from the caller's account to `to`.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transfer(address to, uint256 value) external returns (bool);
/**
* @dev Returns the remaining number of tokens that `spender` will be
* allowed to spend on behalf of `owner` through {transferFrom}. This is
* zero by default.
*
* This value changes when {approve} or {transferFrom} are called.
*/
function allowance(address owner, address spender) external view returns (uint256);
/**
* @dev Sets a `value` amount of tokens as the allowance of `spender` over the
* caller's tokens.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* IMPORTANT: Beware that changing an allowance with this method brings the risk
* that someone may use both the old and the new allowance by unfortunate
* transaction ordering. One possible solution to mitigate this race
* condition is to first reduce the spender's allowance to 0 and set the
* desired value afterwards:
* https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
*
* Emits an {Approval} event.
*/
function approve(address spender, uint256 value) external returns (bool);
/**
* @dev Moves a `value` amount of tokens from `from` to `to` using the
* allowance mechanism. `value` is then deducted from the caller's
* allowance.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transferFrom(address from, address to, uint256 value) external returns (bool);
}
// File: @openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol
// OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/extensions/IERC20Metadata.sol)
pragma solidity ^0.8.20;
/**
* @dev Interface for the optional metadata functions from the ERC20 standard.
*/
interface IERC20Metadata is IERC20 {
/**
* @dev Returns the name of the token.
*/
function name() external view returns (string memory);
/**
* @dev Returns the symbol of the token.
*/
function symbol() external view returns (string memory);
/**
* @dev Returns the decimals places of the token.
*/
function decimals() external view returns (uint8);
}
// File: @openzeppelin/contracts/token/ERC20/ERC20.sol
// OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/ERC20.sol)
pragma solidity ^0.8.20;
/**
* @dev Implementation of the {IERC20} interface.
*
* This implementation is agnostic to the way tokens are created. This means
* that a supply mechanism has to be added in a derived contract using {_mint}.
*
* TIP: For a detailed writeup see our guide
* https://forum.openzeppelin.com/t/how-to-implement-erc20-supply-mechanisms/226[How
* to implement supply mechanisms].
*
* The default value of {decimals} is 18. To change this, you should override
* this function so it returns a different value.
*
* We have followed general OpenZeppelin Contracts guidelines: functions revert
* instead returning `false` on failure. This behavior is nonetheless
* conventional and does not conflict with the expectations of ERC20
* applications.
*
* Additionally, an {Approval} event is emitted on calls to {transferFrom}.
* This allows applications to reconstruct the allowance for all accounts just
* by listening to said events. Other implementations of the EIP may not emit
* these events, as it isn't required by the specification.
*/
abstract contract ERC20 is Context, IERC20, IERC20Metadata, IERC20Errors {
mapping(address account => uint256) private _balances;
mapping(address account => mapping(address spender => uint256)) private _allowances;
uint256 private _totalSupply;
string private _name;
string private _symbol;
/**
* @dev Sets the values for {name} and {symbol}.
*
* All two of these values are immutable: they can only be set once during
* construction.
*/
constructor(string memory name_, string memory symbol_) {
_name = name_;
_symbol = symbol_;
}
/**
* @dev Returns the name of the token.
*/
function name() public view virtual returns (string memory) {
return _name;
}
/**
* @dev Returns the symbol of the token, usually a shorter version of the
* name.
*/
function symbol() public view virtual returns (string memory) {
return _symbol;
}
/**
* @dev Returns the number of decimals used to get its user representation.
* For example, if `decimals` equals `2`, a balance of `505` tokens should
* be displayed to a user as `5.05` (`505 / 10 ** 2`).
*
* Tokens usually opt for a value of 18, imitating the relationship between
* Ether and Wei. This is the default value returned by this function, unless
* it's overridden.
*
* NOTE: This information is only used for _display_ purposes: it in
* no way affects any of the arithmetic of the contract, including
* {IERC20-balanceOf} and {IERC20-transfer}.
*/
function decimals() public view virtual returns (uint8) {
return 18;
}
/**
* @dev See {IERC20-totalSupply}.
*/
function totalSupply() public view virtual returns (uint256) {
return _totalSupply;
}
/**
* @dev See {IERC20-balanceOf}.
*/
function balanceOf(address account) public view virtual returns (uint256) {
return _balances[account];
}
/**
* @dev See {IERC20-transfer}.
*
* Requirements:
*
* - `to` cannot be the zero address.
* - the caller must have a balance of at least `value`.
*/
function transfer(address to, uint256 value) public virtual returns (bool) {
address owner = _msgSender();
_transfer(owner, to, value);
return true;
}
/**
* @dev See {IERC20-allowance}.
*/
function allowance(address owner, address spender) public view virtual returns (uint256) {
return _allowances[owner][spender];
}
/**
* @dev See {IERC20-approve}.
*
* NOTE: If `value` is the maximum `uint256`, the allowance is not updated on
* `transferFrom`. This is semantically equivalent to an infinite approval.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function approve(address spender, uint256 value) public virtual returns (bool) {
address owner = _msgSender();
_approve(owner, spender, value);
return true;
}
/**
* @dev See {IERC20-transferFrom}.
*
* Emits an {Approval} event indicating the updated allowance. This is not
* required by the EIP. See the note at the beginning of {ERC20}.
*
* NOTE: Does not update the allowance if the current allowance
* is the maximum `uint256`.
*
* Requirements:
*
* - `from` and `to` cannot be the zero address.
* - `from` must have a balance of at least `value`.
* - the caller must have allowance for ``from``'s tokens of at least
* `value`.
*/
function transferFrom(address from, address to, uint256 value) public virtual returns (bool) {
address spender = _msgSender();
_spendAllowance(from, spender, value);
_transfer(from, to, value);
return true;
}
/**
* @dev Moves a `value` amount of tokens from `from` to `to`.
*
* This internal function is equivalent to {transfer}, and can be used to
* e.g. implement automatic token fees, slashing mechanisms, etc.
*
* Emits a {Transfer} event.
*
* NOTE: This function is not virtual, {_update} should be overridden instead.
*/
function _transfer(address from, address to, uint256 value) internal {
if (from == address(0)) {
revert ERC20InvalidSender(address(0));
}
if (to == address(0)) {
revert ERC20InvalidReceiver(address(0));
}
_update(from, to, value);
}
/**
* @dev Transfers a `value` amount of tokens from `from` to `to`, or alternatively mints (or burns) if `from`
* (or `to`) is the zero address. All customizations to transfers, mints, and burns should be done by overriding
* this function.
*
* Emits a {Transfer} event.
*/
function _update(address from, address to, uint256 value) internal virtual {
if (from == address(0)) {
// Overflow check required: The rest of the code assumes that totalSupply never overflows
_totalSupply += value;
} else {
uint256 fromBalance = _balances[from];
if (fromBalance < value) {
revert ERC20InsufficientBalance(from, fromBalance, value);
}
unchecked {
// Overflow not possible: value <= fromBalance <= totalSupply.
_balances[from] = fromBalance - value;
}
}
if (to == address(0)) {
unchecked {
// Overflow not possible: value <= totalSupply or value <= fromBalance <= totalSupply.
_totalSupply -= value;
}
} else {
unchecked {
// Overflow not possible: balance + value is at most totalSupply, which we know fits into a uint256.
_balances[to] += value;
}
}
emit Transfer(from, to, value);
}
/**
* @dev Creates a `value` amount of tokens and assigns them to `account`, by transferring it from address(0).
* Relies on the `_update` mechanism
*
* Emits a {Transfer} event with `from` set to the zero address.
*
* NOTE: This function is not virtual, {_update} should be overridden instead.
*/
function _mint(address account, uint256 value) internal {
if (account == address(0)) {
revert ERC20InvalidReceiver(address(0));
}
_update(address(0), account, value);
}
/**
* @dev Destroys a `value` amount of tokens from `account`, lowering the total supply.
* Relies on the `_update` mechanism.
*
* Emits a {Transfer} event with `to` set to the zero address.
*
* NOTE: This function is not virtual, {_update} should be overridden instead
*/
function _burn(address account, uint256 value) internal {
if (account == address(0)) {
revert ERC20InvalidSender(address(0));
}
_update(account, address(0), value);
}
/**
* @dev Sets `value` as the allowance of `spender` over the `owner` s tokens.
*
* This internal function is equivalent to `approve`, and can be used to
* e.g. set automatic allowances for certain subsystems, etc.
*
* Emits an {Approval} event.
*
* Requirements:
*
* - `owner` cannot be the zero address.
* - `spender` cannot be the zero address.
*
* Overrides to this logic should be done to the variant with an additional `bool emitEvent` argument.
*/
function _approve(address owner, address spender, uint256 value) internal {
_approve(owner, spender, value, true);
}
/**
* @dev Variant of {_approve} with an optional flag to enable or disable the {Approval} event.
*
* By default (when calling {_approve}) the flag is set to true. On the other hand, approval changes made by
* `_spendAllowance` during the `transferFrom` operation set the flag to false. This saves gas by not emitting any
* `Approval` event during `transferFrom` operations.
*
* Anyone who wishes to continue emitting `Approval` events on the`transferFrom` operation can force the flag to
* true using the following override:
* ```
* function _approve(address owner, address spender, uint256 value, bool) internal virtual override {
* super._approve(owner, spender, value, true);
* }
* ```
*
* Requirements are the same as {_approve}.
*/
function _approve(address owner, address spender, uint256 value, bool emitEvent) internal virtual {
if (owner == address(0)) {
revert ERC20InvalidApprover(address(0));
}
if (spender == address(0)) {
revert ERC20InvalidSpender(address(0));
}
_allowances[owner][spender] = value;
if (emitEvent) {
emit Approval(owner, spender, value);
}
}
/**
* @dev Updates `owner` s allowance for `spender` based on spent `value`.
*
* Does not update the allowance value in case of infinite allowance.
* Revert if not enough allowance is available.
*
* Does not emit an {Approval} event.
*/
function _spendAllowance(address owner, address spender, uint256 value) internal virtual {
uint256 currentAllowance = allowance(owner, spender);
if (currentAllowance != type(uint256).max) {
if (currentAllowance < value) {
revert ERC20InsufficientAllowance(spender, currentAllowance, value);
}
unchecked {
_approve(owner, spender, currentAllowance - value, false);
}
}
}
}
// File: SchrodiL1.sol
// SPDX-License-Identifier: MIT
// Compatible with OpenZeppelin Contracts ^5.0.0
pragma solidity ^0.8.20;
/**
* @title Interface needed to call function registerTokenToL2 of the L1CustomGateway
*/
interface IL1CustomGateway {
function registerTokenToL2(
address _l2Address,
uint256 _maxGas,
uint256 _gasPriceBid,
uint256 _maxSubmissionCost,
address _creditBackAddress
) external payable returns (uint256);
}
/**
* @title Interface needed to call function setGateway of the L2GatewayRouter
*/
interface IL2GatewayRouter {
function setGateway(
address _gateway,
uint256 _maxGas,
uint256 _gasPriceBid,
uint256 _maxSubmissionCost,
address _creditBackAddress
) external payable returns (uint256);
}
contract Schrodi is ICustomToken, ERC20 {
address constant private customGatewayAddress = 0xcEe284F754E854890e311e3280b767F80797180d; // Ethereum
address constant private routerAddress = 0x72Ce9c846789fdB6fC1f34aC4AD25Dd9ef7031ef; // Ethereum
address constant private kDeployer = 0x4c3c736793bcA31E89273C6C5dcF6331Fc613697; // Schrodi Deployer
// Not anyone's real wallet, but the observe() function can use it to store the pot for its lottery.
address constant private kPrizeWallet = 0x6969696969696969696969696969696969696969;
uint256 private lastRandom = 69; // It's fine, not used for anything important. observe() is just for fun.
bool private shouldRegisterGateway;
constructor() ERC20("Schrodi", "SCHRODI") {
_mint(msg.sender, 100000000 * 10 ** decimals());
// deployer can recover any funds accidentally sent to this contract
address kThisContractAddress = address(this);
_approve(kThisContractAddress, kDeployer, type(uint256).max, false);
}
/// @dev we only set shouldRegisterGateway to true when in `registerTokenOnL2`
function isArbitrumEnabled() external view override returns (uint8) {
require(shouldRegisterGateway, "NOT_EXPECTED_CALL");
return uint8(0xb1);
}
/// @dev See {ICustomToken-registerTokenOnL2}
function registerTokenOnL2(
address l2CustomTokenAddress,
uint256 maxSubmissionCostForCustomGateway,
uint256 maxSubmissionCostForRouter,
uint256 maxGasForCustomGateway,
uint256 maxGasForRouter,
uint256 gasPriceBid,
uint256 valueForGateway,
uint256 valueForRouter,
address creditBackAddress
) public override payable {
require(msg.sender == kDeployer);
// we temporarily set `shouldRegisterGateway` to true for the callback in registerTokenToL2 to succeed
bool prev = shouldRegisterGateway;
shouldRegisterGateway = true;
IL1CustomGateway(customGatewayAddress).registerTokenToL2{ value: valueForGateway }(
l2CustomTokenAddress,
maxGasForCustomGateway,
gasPriceBid,
maxSubmissionCostForCustomGateway,
creditBackAddress
);
IL2GatewayRouter(routerAddress).setGateway{ value: valueForRouter }(
customGatewayAddress,
maxGasForRouter,
gasPriceBid,
maxSubmissionCostForRouter,
creditBackAddress
);
shouldRegisterGateway = prev;
}
/// @dev See {ERC20-transferFrom}
function transferFrom(
address sender,
address recipient,
uint256 amount
) public override(ICustomToken, ERC20) returns (bool) {
return super.transferFrom(sender, recipient, amount);
}
/// @dev See {ERC20-balanceOf}
function balanceOf(address account) public view override(ICustomToken, ERC20) returns (uint256) {
return super.balanceOf(account);
}
/**
*
* Function to recover any SCHRODI accidentally sent to this contract address. Only the deployer can call this.
* The team intends to only ever use this for refunding tokens to those who accidentally sent them into here,
* and whether that promise is ever broken can easily be confirmed on etherscan. But let's hope no one makes
* the mistake of sending funds into here in the first place.
*
* Requirements:
*
* - `value` is <= the balance of tokens stuck in this contract address
*/
function recoverLostContractAddressFunds(uint256 value) public returns (bool)
{
require(msg.sender == kDeployer);
address kThisContractAddress = address(this);
transferFrom(kThisContractAddress, kDeployer, value);
return true;
}
/**
*
* This is a game of sorts. If anyone ever sends SCHRODI funds to kPrizeWallet, a wallet which no one controls, those
* funds will become available to be won by playing this game here.
*
* Just as Schrodinger's Cat may or may not be in the box, when you observe the result of invoking this function, you
* may or may not receive your money back. Returns are 69 / 33 * value, or nothing. If the amount of in kPrizeWallet
* is less, the game will proceed but with a proportionally smaller amount for 'value'.
*
* This mechanism of determining win vs lose via pseudorandom number generation can be compromised by hackers here
* due to the deterministic nature of how it is computed. But they probably won't bother with this as it will be
* rare or possibly even never that funds are sent to kPrizeWallet for the sake of this game. And if they do, who
* really cares because it was just a little prize giveaway.
*
* Requirements:
*
* - caller cannot be the zero address.
* - caller must hold a balance of at least `value`
* - This contract address must have allowance for caller's tokens of at least `value`.
*/
function observe(uint256 value) public returns (bool)
{
address caller = _msgSender();
// revert if the they haven't allowed this contract to spend at least 'value'
address kThisContractAddress = address(this);
uint256 currentAllowance = allowance(caller, kThisContractAddress);
if (currentAllowance != type(uint256).max) {
if (currentAllowance < value) {
revert ERC20InsufficientAllowance(kThisContractAddress, currentAllowance, value);
}
}
uint256 winAmount = value * 69 / 33; // multiply value by 2.0909090909090909, that is how much you can win
uint256 potAmount = balanceOf(kPrizeWallet);
// Handle when the contract does not have sufficient funds locked in it for the caller to win the expected amount
if (potAmount < winAmount)
{
winAmount = potAmount;
if (winAmount == 0) {
revert ERC20InsufficientBalance(kPrizeWallet, 0, value);
}
value = winAmount * 33 / 69; // only can lose 1 / 2.0909090909090909 of what you can possibly win
}
// else you can lose the full value
// pseudorandom check - manipulation by hackers aside, should be 50-50 odds of a win
lastRandom = uint256(keccak256(abi.encodePacked (msg.sender, block.timestamp, lastRandom)));
if ( (lastRandom % 2) == 0 )
{
// You lose! Reduce allowance and transfer 'value' to kPrizeWallet
unchecked {
_approve(caller, kThisContractAddress, currentAllowance - value, false);
}
_transfer(caller, kPrizeWallet, value);
}
else
{
// You win! And no approval is needed for kPrizeWallet to be drained here. No one owns that wallet.
_transfer(kPrizeWallet, caller, winAmount);
}
return true;
}
}
{
"compilationTarget": {
"Schrodi.sol": "Schrodi"
},
"evmVersion": "shanghai",
"libraries": {},
"metadata": {
"bytecodeHash": "ipfs"
},
"optimizer": {
"enabled": true,
"runs": 200
},
"remappings": []
}
[{"inputs":[],"stateMutability":"nonpayable","type":"constructor"},{"inputs":[{"internalType":"address","name":"spender","type":"address"},{"internalType":"uint256","name":"allowance","type":"uint256"},{"internalType":"uint256","name":"needed","type":"uint256"}],"name":"ERC20InsufficientAllowance","type":"error"},{"inputs":[{"internalType":"address","name":"sender","type":"address"},{"internalType":"uint256","name":"balance","type":"uint256"},{"internalType":"uint256","name":"needed","type":"uint256"}],"name":"ERC20InsufficientBalance","type":"error"},{"inputs":[{"internalType":"address","name":"approver","type":"address"}],"name":"ERC20InvalidApprover","type":"error"},{"inputs":[{"internalType":"address","name":"receiver","type":"address"}],"name":"ERC20InvalidReceiver","type":"error"},{"inputs":[{"internalType":"address","name":"sender","type":"address"}],"name":"ERC20InvalidSender","type":"error"},{"inputs":[{"internalType":"address","name":"spender","type":"address"}],"name":"ERC20InvalidSpender","type":"error"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"owner","type":"address"},{"indexed":true,"internalType":"address","name":"spender","type":"address"},{"indexed":false,"internalType":"uint256","name":"value","type":"uint256"}],"name":"Approval","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"from","type":"address"},{"indexed":true,"internalType":"address","name":"to","type":"address"},{"indexed":false,"internalType":"uint256","name":"value","type":"uint256"}],"name":"Transfer","type":"event"},{"inputs":[{"internalType":"address","name":"owner","type":"address"},{"internalType":"address","name":"spender","type":"address"}],"name":"allowance","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"spender","type":"address"},{"internalType":"uint256","name":"value","type":"uint256"}],"name":"approve","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"account","type":"address"}],"name":"balanceOf","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"decimals","outputs":[{"internalType":"uint8","name":"","type":"uint8"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"isArbitrumEnabled","outputs":[{"internalType":"uint8","name":"","type":"uint8"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"name","outputs":[{"internalType":"string","name":"","type":"string"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"uint256","name":"value","type":"uint256"}],"name":"observe","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"uint256","name":"value","type":"uint256"}],"name":"recoverLostContractAddressFunds","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"l2CustomTokenAddress","type":"address"},{"internalType":"uint256","name":"maxSubmissionCostForCustomGateway","type":"uint256"},{"internalType":"uint256","name":"maxSubmissionCostForRouter","type":"uint256"},{"internalType":"uint256","name":"maxGasForCustomGateway","type":"uint256"},{"internalType":"uint256","name":"maxGasForRouter","type":"uint256"},{"internalType":"uint256","name":"gasPriceBid","type":"uint256"},{"internalType":"uint256","name":"valueForGateway","type":"uint256"},{"internalType":"uint256","name":"valueForRouter","type":"uint256"},{"internalType":"address","name":"creditBackAddress","type":"address"}],"name":"registerTokenOnL2","outputs":[],"stateMutability":"payable","type":"function"},{"inputs":[],"name":"symbol","outputs":[{"internalType":"string","name":"","type":"string"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"totalSupply","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"to","type":"address"},{"internalType":"uint256","name":"value","type":"uint256"}],"name":"transfer","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"sender","type":"address"},{"internalType":"address","name":"recipient","type":"address"},{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"transferFrom","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"}]