Token_Swap

WT_Token과 NWT_Token을 교환 해주는 컨트렉트

 

// SPDX-License-Identifier: GPL-3.0
pragma solidity ^0.8.10;

import "../node_modules/@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "../node_modules/@openzeppelin/contracts/token/ERC20/ERC20.sol";

contract TokenSwap{
    IERC20 public token1;  // stable coin
    IERC20 public token2;  // 유동성 코인
    address public owner2; // server address

    constructor (address _token1, address _token2, address serverAddress) public {
        token1 = IERC20(_token1);
        token2 = IERC20(_token2);
        owner2 = serverAddress; 
    }

    function swap(uint256 _amount, address user, address spender, address _contract1, address _contract2) public {
        uint256 tokenAmount = _amount * 1e18;

        //_exchangeToken(user, spender, _contract1);
        //_exchangeToken(owner2, spender, _contract2);

        require(msg.sender == owner2, "Not authorized");

        require(token1.allowance(user, address(this)) >= tokenAmount, "Token 1 allowance too low");
        require(token2.allowance(owner2, address(this)) >= tokenAmount/5, "Token 2 allowance too low");

        _safeTransferFrom(token1, user, owner2, tokenAmount);
        _safeTransferFrom(token2, owner2, user, tokenAmount/5);

    }

   {*/ function _exchangeToken(address owner,address spender, address _contract)public returns(uint){
        (bool data, ) = _contract.call(abi.encodeWithSignature("approveToken(address,address)",owner,spender));
        if(data == true){
            return 1;
        }
    }
    /*}

    function _safeTransferFrom(IERC20 token, address sender, address recipient, uint256 amount) private {
        bool sent = token.transferFrom(sender, recipient, amount);
        require(sent, "Token transfer failed");
    }
}

---

IERC20 public token1; // stable coin

IERC20 public token2; // 유동성 코인

address public owner2; // server address

constructor (address _token1, address _token2, address serverAddress) public {

token1 = IERC20(_token1);

token2 = IERC20(_token2);

owner2 = serverAddress;

}

---

function swap

function swap(uint256 _amount, address user, address spender, address _contract1, address _contract2) public {

uint256 tokenAmount = _amount * 1e18;

require(msg.sender == owner2, "Not authorized");

require(token1.allowance(user, address(this)) >= tokenAmount, "Token 1 allowance too low");

• token1에 해당하는 컨트렉트에서 allowance를 실행하여 user가 이 컨트렉트에게 양도 설정한 토큰의 양을 확인

require(token2.allowance(owner2, address(this)) >= tokenAmount/5, "Token 2 allowance too low");

• token2에 해당하는 컨트렉트에서 allowance를 실행하여 user가 이 컨트렉트에게 양도 설정한 토큰의 양을 확인
• tokenAmount/5 => 우리 플랫폼은 WT와 NWT의 비율을 1:5로 하기에 이렇게 설정하여 체크
• 추후 거래소 가격 추적으로 비율 조정 가능하게 수정할 필요가 있음

 

• _safeTransferFrom 함수 실행

_safeTransferFrom(token1, user, owner2, tokenAmount);

• user가 owner2 = serverAddress에게 tokenAmount만큼 전송

_safeTransferFrom(token2, owner2, user, tokenAmount/5);

•  owner2 = serverAddress가 user에게 tokenAmount/5 ( 1:5 ) 의 비율 만큼 전송

}

---

function_safeTransferFrom

function _safeTransferFrom(IERC20 token, address sender, address recipient, uint256 amount) private {

bool sent = token.transferFrom(sender, recipient, amount);

• token => 위에서 token1, token2를 받고 각 컨트렉트에서 transferFrom을 실행해준다

require(sent, "Token transfer failed");

• bool sent : 아무 값이 없으면 false기 때문에 "Token transfer failed" 

}