how to deploy a contract by sending ether to it's address

Question

I'm trying to build a payment gateway and I generated address of a contract before deploying it with create2. how to deploy the contract by sending ether to new generated address?

pragma solidity 0.8.14;

contract A{
    receive() payable external{
        set = "hello";
    }
    string public set;
    constructor() payable {
        set = "world";
    }

}

contract B{

    event deploy(address addr);
    function Deploy(uint _salt) external{
        A me = new A{salt: bytes32(_salt)}();
        emit deploy(address(me));
    }

    function getaddress(uint _salt) public view returns(address){
    bytes32 hash = keccak256(abi.encodePacked(bytes1(0xFF),address(this),_salt , keccak256(getBytecode(msg.sender))));
    return address(uint160(uint(hash)));
    }

    function getBytecode(address _owner) public pure returns(bytes memory){
    bytes memory bytecode = type(A).creationCode;
    return abi.encodePacked(bytecode , abi.encode(_owner));
    }

}

here is the code. i know the address of contract A before deploying it using getaddress function , i want to send ether to contract A using the calculated address and then contract A deploy and trigger something like emit an event that contract received the funds.

Answer 1

based on your latest comment ... there are a few moving parts and choices / ways to skin the cat, but ...

you'd want to monitor the predetermined addresses off-chain and could use a node like alchemy + javascript + ethers to check the predetermined addresses for non-zero balances. When a non-zero balance is found your deploy script is called passing the target address to deploy to.

here's some rough demo code that checks addresses for a balance. uses: nodejs, ethers, dotenv (just for the alchemy URL)

// todo: schedule this task or loop on timer or something

require("dotenv").config();
const NODE_URL = process.env.NODE_URL
var ethers = require('ethers');
var url = NODE_URL;
var provider = new ethers.providers.JsonRpcProvider(url);

const TARGET_ADDRESS1 = "0x3C283D39436c8F5B48E84740e938C745a45c2Ab1";
const TARGET_ADDRESS2 = "0x0eE4A43F8E4eaf59886E1118f61c919F9815f59B";
const TARGET_ADDRESS3 = "0x97ed92E744C10FdD5D403A756239C4069e415e79";
const addresses = [TARGET_ADDRESS1, TARGET_ADDRESS2, TARGET_ADDRESS3];

for(let address of addresses) getBalance(address);

async function getBalance(address) {
    const balance = await provider.getBalance(address);
    console.log(`balance at ${address}: ${balance}`);

    if(balance > 0) {
        console.log(`deploying contract to : ${address}`)
        // pseudo code
        // run deploy script passing deployment address
    }
}

output:

$ node monitor.js
balance at 0x3C283D39436c8F5B48E84740e938C745a45c2Ab1: 0
balance at 0x0eE4A43F8E4eaf59886E1118f61c919F9815f59B: 0
balance at 0x97ed92E744C10FdD5D403A756239C4069e415e79: 80000000000000000
deploying contract to : 0x97ed92E744C10FdD5D403A756239C4069e415e79