HeliosDEX
Personal Rating: Medium
Getting Started
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.28;
/***
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/ / / /__ / (_)___ _____/ __ \/ ____/ |/ /
/ /_/ / _ \/ / / __ \/ ___/ / / / __/ | /
/ __ / __/ / / /_/ (__ ) /_/ / /___ / |
/_/ /_/\___/_/_/\____/____/_____/_____//_/|_|
Today's item listing:
* Eldorion Fang (ELD): A shard of a Eldorion's fang, said to imbue the holder with courage and the strength of the ancient beast. A symbol of valor in battle.
* Malakar Essence (MAL): A dark, viscous substance, pulsing with the corrupted power of Malakar. Use with extreme caution, as it whispers promises of forbidden strength. MAY CAUSE HALLUCINATIONS.
* Helios Lumina Shards (HLS): Fragments of pure, solidified light, radiating the warmth and energy of Helios. These shards are key to powering Eldoria's invisible eye.
***/
import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import "@openzeppelin/contracts/utils/math/Math.sol";
contract EldorionFang is ERC20 {
constructor(uint256 initialSupply) ERC20("EldorionFang", "ELD") {
_mint(msg.sender, initialSupply);
}
}
contract MalakarEssence is ERC20 {
constructor(uint256 initialSupply) ERC20("MalakarEssence", "MAL") {
_mint(msg.sender, initialSupply);
}
}
contract HeliosLuminaShards is ERC20 {
constructor(uint256 initialSupply) ERC20("HeliosLuminaShards", "HLS") {
_mint(msg.sender, initialSupply);
}
}
contract HeliosDEX {
EldorionFang public eldorionFang;
MalakarEssence public malakarEssence;
HeliosLuminaShards public heliosLuminaShards;
uint256 public reserveELD;
uint256 public reserveMAL;
uint256 public reserveHLS;
uint256 public immutable exchangeRatioELD = 2;
uint256 public immutable exchangeRatioMAL = 4;
uint256 public immutable exchangeRatioHLS = 10;
uint256 public immutable feeBps = 25;
mapping(address => bool) public hasRefunded;
bool public _tradeLock = false;
event HeliosBarter(address item, uint256 inAmount, uint256 outAmount);
event HeliosRefund(address item, uint256 inAmount, uint256 ethOut);
constructor(uint256 initialSupplies) payable {
eldorionFang = new EldorionFang(initialSupplies);
malakarEssence = new MalakarEssence(initialSupplies);
heliosLuminaShards = new HeliosLuminaShards(initialSupplies);
reserveELD = initialSupplies;
reserveMAL = initialSupplies;
reserveHLS = initialSupplies;
}
modifier underHeliosEye {
require(msg.value > 0, "HeliosDEX: Helios sees your empty hand! Only true offerings are worthy of a HeliosBarter");
_;
}
modifier heliosGuardedTrade() {
require(_tradeLock != true, "HeliosDEX: Helios shields this trade! Another transaction is already underway. Patience, traveler");
_tradeLock = true;
_;
_tradeLock = false;
}
function swapForELD() external payable underHeliosEye {
uint256 grossELD = Math.mulDiv(msg.value, exchangeRatioELD, 1e18, Math.Rounding(0));
uint256 fee = (grossELD * feeBps) / 10_000;
uint256 netELD = grossELD - fee;
require(netELD <= reserveELD, "HeliosDEX: Helios grieves that the ELD reserves are not plentiful enough for this exchange. A smaller offering would be most welcome");
reserveELD -= netELD;
eldorionFang.transfer(msg.sender, netELD);
emit HeliosBarter(address(eldorionFang), msg.value, netELD);
}
function swapForMAL() external payable underHeliosEye {
uint256 grossMal = Math.mulDiv(msg.value, exchangeRatioMAL, 1e18, Math.Rounding(1));
uint256 fee = (grossMal * feeBps) / 10_000;
uint256 netMal = grossMal - fee;
require(netMal <= reserveMAL, "HeliosDEX: Helios grieves that the MAL reserves are not plentiful enough for this exchange. A smaller offering would be most welcome");
reserveMAL -= netMal;
malakarEssence.transfer(msg.sender, netMal);
emit HeliosBarter(address(malakarEssence), msg.value, netMal);
}
function swapForHLS() external payable underHeliosEye {
uint256 grossHLS = Math.mulDiv(msg.value, exchangeRatioHLS, 1e18, Math.Rounding(3));
uint256 fee = (grossHLS * feeBps) / 10_000;
uint256 netHLS = grossHLS - fee;
require(netHLS <= reserveHLS, "HeliosDEX: Helios grieves that the HSL reserves are not plentiful enough for this exchange. A smaller offering would be most welcome");
reserveHLS -= netHLS;
heliosLuminaShards.transfer(msg.sender, netHLS);
emit HeliosBarter(address(heliosLuminaShards), msg.value, netHLS);
}
function oneTimeRefund(address item, uint256 amount) external heliosGuardedTrade {
require(!hasRefunded[msg.sender], "HeliosDEX: refund already bestowed upon thee");
require(amount > 0, "HeliosDEX: naught for naught is no trade. Offer substance, or be gone!");
uint256 exchangeRatio;
if (item == address(eldorionFang)) {
exchangeRatio = exchangeRatioELD;
require(eldorionFang.transferFrom(msg.sender, address(this), amount), "ELD transfer failed");
reserveELD += amount;
} else if (item == address(malakarEssence)) {
exchangeRatio = exchangeRatioMAL;
require(malakarEssence.transferFrom(msg.sender, address(this), amount), "MAL transfer failed");
reserveMAL += amount;
} else if (item == address(heliosLuminaShards)) {
exchangeRatio = exchangeRatioHLS;
require(heliosLuminaShards.transferFrom(msg.sender, address(this), amount), "HLS transfer failed");
reserveHLS += amount;
} else {
revert("HeliosDEX: Helios descries forbidden offering");
}
uint256 grossEth = Math.mulDiv(amount, 1e18, exchangeRatio);
uint256 fee = (grossEth * feeBps) / 10_000;
uint256 netEth = grossEth - fee;
hasRefunded[msg.sender] = true;
payable(msg.sender).transfer(netEth);
emit HeliosRefund(item, amount, netEth);
}
}
Understanding how the Contracts Work
Building the Commands
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