// SPDX-License-Identifier: MIT
pragma solidity ^0.8.19;
import {IRouterClient} from "@chainlink/contracts-ccip/src/v0.8/ccip/interfaces/IRouterClient.sol";
import {OwnerIsCreator} from "@chainlink/contracts-ccip/src/v0.8/shared/access/OwnerIsCreator.sol";
import {Client} from "@chainlink/contracts-ccip/src/v0.8/ccip/libraries/Client.sol";
import {IERC20} from "@chainlink/contracts-ccip/src/v0.8/vendor/openzeppelin-solidity/v4.8.0/token/ERC20/IERC20.sol";
import {SafeERC20} from "@chainlink/contracts-ccip/src/v0.8/vendor/openzeppelin-solidity/v4.8.0/token/ERC20/utils/SafeERC20.sol";
/**
* THIS IS AN EXAMPLE CONTRACT THAT USES HARDCODED VALUES FOR CLARITY.
* THIS IS AN EXAMPLE CONTRACT THAT USES UN-AUDITED CODE.
* DO NOT USE THIS CODE IN PRODUCTION.
*/
contract TransferUSDC is OwnerIsCreator {
using SafeERC20 for IERC20;
error NotEnoughBalance(uint256 currentBalance, uint256 calculatedFees);
error DestinationChainNotAllowlisted(uint64 destinationChainSelector);
error NothingToWithdraw();
IRouterClient private immutable i_ccipRouter;
IERC20 private immutable i_linkToken;
IERC20 private immutable i_usdcToken;
mapping(uint64 => bool) public allowlistedChains;
modifier onlyAllowlistedChain(uint64 _destinationChainSelector) {
if (!allowlistedChains[_destinationChainSelector])
revert DestinationChainNotAllowlisted(_destinationChainSelector);
_;
}
event UsdcTransferred(
bytes32 messageId,
uint64 destinationChainSelector,
address receiver,
uint256 amount,
uint256 ccipFee
);
constructor(address ccipRouter, address linkToken, address usdcToken) {
i_ccipRouter = IRouterClient(ccipRouter);
i_linkToken = IERC20(linkToken);
i_usdcToken = IERC20(usdcToken);
}
function allowlistDestinationChain(
uint64 _destinationChainSelector,
bool _allowed
) external onlyOwner {
allowlistedChains[_destinationChainSelector] = _allowed;
}
function transferUsdc(
uint64 _destinationChainSelector,
address _receiver,
uint256 _amount,
uint64 _gasLimit
)
external
onlyOwner
onlyAllowlistedChain(_destinationChainSelector)
returns (bytes32 messageId)
{
Client.EVMTokenAmount[]
memory tokenAmounts = new Client.EVMTokenAmount[](1);
Client.EVMTokenAmount memory tokenAmount = Client.EVMTokenAmount({
token: address(i_usdcToken),
amount: _amount
});
tokenAmounts[0] = tokenAmount;
Client.EVM2AnyMessage memory message = Client.EVM2AnyMessage({
receiver: abi.encode(_receiver),
data: "",
tokenAmounts: tokenAmounts,
extraArgs: Client._argsToBytes(
Client.EVMExtraArgsV1({gasLimit: _gasLimit})
),
feeToken: address(i_linkToken)
});
uint256 ccipFee = i_ccipRouter.getFee(
_destinationChainSelector,
message
);
if (ccipFee > i_linkToken.balanceOf(address(this)))
revert NotEnoughBalance(
i_linkToken.balanceOf(address(this)),
ccipFee
);
i_linkToken.approve(address(i_ccipRouter), ccipFee);
i_usdcToken.safeTransferFrom(msg.sender, address(this), _amount);
i_usdcToken.approve(address(i_ccipRouter), _amount);
// Send CCIP Message
messageId = i_ccipRouter.ccipSend(_destinationChainSelector, message);
emit UsdcTransferred(
messageId,
_destinationChainSelector,
_receiver,
_amount,
ccipFee
);
}
function withdrawToken(
address _beneficiary,
address _token
) public onlyOwner {
uint256 amount = IERC20(_token).balanceOf(address(this));
if (amount == 0) revert NothingToWithdraw();
IERC20(_token).transfer(_beneficiary, amount);
}
}
