// SPDX-License-Identifier: MIT
pragma solidity ^0.8.19;

interface IPrice {
    function latestAnswer() external view returns (int256);
}

contract OracleVault {
    IPrice public oracle;
    uint256 public collateral;

    constructor(address _oracle) {
        oracle = IPrice(_oracle);
    }

    function borrow(uint256 amount) external {
        uint256 spot = uint256(oracle.latestAnswer()); // no staleness/validation
        require(collateral * spot >= amount * 1e18, "not enough collateral");
        payable(msg.sender).transfer(amount);
    }

    receive() external payable {
        collateral += msg.value;
    }
}