// SPDX-License-Identifier: CC0-1.0
pragma solidity ^0.8.24;

import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import {IERC20Metadata} from "@openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol";

interface IERC20Checkpointed is IERC20, IERC20Metadata {
    /**
     * @dev Error thrown when querying a checkpoint that is in the future.
     * @param checkpoint The requested checkpoint.
     * @param currentCheckpoint The current checkpoint nonce.
     */
    error ERC20FutureCheckpoint(uint48 checkpoint, uint48 currentCheckpoint);

    /**
     * @dev Returns the value of tokens in existence at specified checkpoint.
     * @param checkpoint The checkpoint to get the total supply at.
     * @notice Reverts with ERC20FutureCheckpoint if checkpoint > checkpointNonce().
     */
    function totalSupplyAt(uint48 checkpoint) external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account` at specified checkpoint.
     * @param account The account to get the balance of.
     * @param checkpoint The checkpoint to get the balance at.
     * @notice Reverts with ERC20FutureCheckpoint if checkpoint > checkpointNonce().
     */
    function balanceOfAt(address account, uint48 checkpoint) external view returns (uint256);

    /**
     * @dev Returns the current checkpoint nonce.
     */
    function checkpointNonce() external view returns (uint48);
}