// 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: presaleev.sol
pragma solidity ^0.8.0;
contract Presale {
IERC20 public usdcToken; // USDC token contract interface
address public owner;
uint256 public maxContribution = 500 * 1e6; // 500 USDC in smallest units (assuming 6 decimals)
uint256 public hardCap = 100000 * 1e6; // Hard cap set at 100,000 USDC
uint256 public totalContributions;
mapping(address => uint256) public contributions;
// Event that logs the contribution
event Contributed(address contributor, uint256 amount);
constructor(address _usdcTokenAddress) {
usdcToken = IERC20(_usdcTokenAddress);
owner = msg.sender;
}
function contribute(uint256 amount) public {
require(totalContributions + amount <= hardCap, "Contribution would exceed hard cap");
require(contributions[msg.sender] + amount <= maxContribution, "Contribution exceeds max allowance per wallet");
// Transfer USDC tokens from contributor to this contract
bool success = usdcToken.transferFrom(msg.sender, address(this), amount);
require(success, "USDC transfer failed");
contributions[msg.sender] += amount;
totalContributions += amount;
emit Contributed(msg.sender, amount);
}
// Function to withdraw the funds (USDC tokens) to the owner's address
function withdrawFunds() public {
require(msg.sender == owner, "Only the owner can withdraw funds");
uint256 balance = usdcToken.balanceOf(address(this));
bool success = usdcToken.transfer(owner, balance);
require(success, "Failed to withdraw funds");
}
// Modifier to restrict certain functions to only the owner
modifier onlyOwner() {
require(msg.sender == owner, "Only the owner is allowed to perform this action");
_;
}
}
{
"compilationTarget": {
"Presale.sol": "Presale"
},
"evmVersion": "cancun",
"libraries": {},
"metadata": {
"bytecodeHash": "ipfs"
},
"optimizer": {
"enabled": false,
"runs": 200
},
"remappings": []
}
[{"inputs":[{"internalType":"address","name":"_usdcTokenAddress","type":"address"}],"stateMutability":"nonpayable","type":"constructor"},{"anonymous":false,"inputs":[{"indexed":false,"internalType":"address","name":"contributor","type":"address"},{"indexed":false,"internalType":"uint256","name":"amount","type":"uint256"}],"name":"Contributed","type":"event"},{"inputs":[{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"contribute","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"","type":"address"}],"name":"contributions","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"hardCap","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"maxContribution","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"owner","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"totalContributions","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"usdcToken","outputs":[{"internalType":"contract IERC20","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"withdrawFunds","outputs":[],"stateMutability":"nonpayable","type":"function"}]