// SPDX-License-Identifier: CC0-1.0
// Sample Solidity contract — samplefiles.com (for testing tools only; never deployed)
pragma solidity ^0.8.24;

contract CustomerRegistry {
    struct Customer {
        uint256 id;
        string name;
        uint256 balanceCents;
    }

    uint256 public constant VIP_THRESHOLD_CENTS = 1_000_000;
    address public immutable owner;
    Customer[] private customers;

    event CustomerAdded(uint256 indexed id, string name, uint256 balanceCents);

    error NotOwner();

    modifier onlyOwner() {
        if (msg.sender != owner) revert NotOwner();
        _;
    }

    constructor() {
        owner = msg.sender;
    }

    function addCustomer(string calldata name, uint256 balanceCents) external onlyOwner returns (uint256 id) {
        id = customers.length + 1;
        customers.push(Customer(id, name, balanceCents));
        emit CustomerAdded(id, name, balanceCents);
    }

    function isVip(uint256 id) external view returns (bool) {
        return customers[id - 1].balanceCents >= VIP_THRESHOLD_CENTS;
    }

    function totalBalanceCents() external view returns (uint256 total) {
        for (uint256 i = 0; i < customers.length; i++) {
            total += customers[i].balanceCents;
        }
    }
}