pragma ever -solidity ^0.62.0;

/**
 * @dev Interface defines a callback function that can be used by a token wallet
 * contract to notify its owner when a burn operation is reverted.
 *
 * Chain of calls:
 *
 * walletOwner -> IBurnableTokenWallet(walletOwner).burn(...) ->
 *                ITokenRoot(root).acceptBurn(...)  ->
 *                TokenWalletBase.onBounce(...) ->
 *                IBounceTokensBurnCallback(callbackTo).onBounceTokensBurn(...) ->
 *
 */
interface IBounceTokensBurnCallback {

    /**
     * @dev Invoked by the token wallet when a burn operation is reverted.
     * @param tokenRoot Address of the TokenRoot contract.
     * @param amount Reverted tokens amount.
     *
     * NOTE: This callback function has no implementation in the main contracts.
     * However, you can see an example of its implementation in the test contract.
     * See {TestWalletCallback-onBounceTokensBurn}.
    */
    function onBounceTokensBurn(
        address tokenRoot,
        uint128 amount
    ) external;
}