Implement wETH from scratch

solidity

// SPDX-License-Identifier: MIT
pragma solidity 0.8.20;

contract WrappedEther {
    string public name = "Wrapped ETH";
    string public symbol = "MFT";
    uint public decimals = 18;
    uint public totalSupply = 0;

    mapping(address owner => uint amount) public balances;
    mapping(address owner => mapping(address spender => uint amount)) allowances;

    event Transfer(address indexed from, address indexed to, uint256 amount);
    event Approval(address indexed owner, address indexed spender, uint256 amount);

    // Eth to token
    function deposit() public payable returns (bool success) {
        address owner = msg.sender;
        uint amount = msg.value;

        // minting
        balances[owner] += amount;
        totalSupply += amount;
        emit Transfer(address(0), owner, amount);

        return true;
    }
    // Token to Ether
    function withdraw(uint amount) public returns (bool success) {
        address owner = msg.sender;
        require(balances[owner] >= amount);

        // Token Data
        balances[owner] -= amount;
        totalSupply -= amount;

        // Ether (CA -> owner)
        payable(owner).transfer(amount);

        emit Transfer(owner, address(0), amount);

        return true;
    }

   function balanceOf(address owner) public view returns (uint amount) {
        return balances[owner];
    }

    function transfer(address to, uint amount) public returns (bool success) {
        address owner = msg.sender;
        require(balances[owner] >= amount);
        balances[owner] -= amount;
        balances[to] += amount;
        emit Transfer(owner, to, amount);
        return true;
    }

    function transferFrom(address owner, address to, uint amount) public returns (bool success) {
        address spender = msg.sender;
        require(balances[owner] >= amount);
        require(allowances[owner][spender] >= amount);
        balances[owner] -= amount;
        balances[to] += amount;
        allowances[owner][spender] -= amount;
        emit Transfer(owner, to, amount);
        return true;
    }

    function approve (address spender, uint amount) public returns (bool success) {
        address owner = msg.sender;
        allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
        return true;
    }

    function allowance (address owner, address spender) public view returns (uint amount) {
        return allowances[owner][spender];
    }
 }