pragma ever-solidity ^0.62.0;

pragma AbiHeader expire;
pragma AbiHeader pubkey;

import "./TokenRootBase.tsol";
import "../interfaces/IBurnableByRootTokenRoot.tsol";
import "../interfaces/IBurnableByRootTokenWallet.tsol";
import "../libraries/TokenErrors.tsol";
import "../libraries/TokenMsgFlag.tsol";

/**
 * @dev Implementation of the {IBurnableByRootTokenRoot} interface.
 *
 * This abstraction extends the functionality of {TokenRootBase} and increases
 * the capabilities of TokenRoot, namely burning tokens of any wallet, disabling
 * the ability to burn tokens through the TokenRoot
 * And a view method that returns the state of 'burnByRootDisabled_'.
 */
abstract contract TokenRootBurnableByRootBase is TokenRootBase, IBurnableByRootTokenRoot {

    bool burnByRootDisabled_;

    /**
     * @dev See {IBurnableByRootTokenRoot-burnTokens}.
     *
     * Preconditions:
     *
     * - `burnByRootDisabled_` must be `false`.
     * - `amount` must be greater than zero.
     * - `walletOwner` must be a non-zero address.
     *
     * For burning calls the {IBurnableByRootTokenWallet-burnByRoot} method of the wallet,
     * so the TokenWallet must implement this method.
     *
     * NOTE: We pass the bounce `true` flag to the wallet, but this Bounce
     * is not covered by the TokenRoot
     */
    function burnTokens(
        uint128 amount,
        address walletOwner,
        address remainingGasTo,
        address callbackTo,
        TvmCell payload
    )
        override
        external
        onlyRootOwner
    {
        require(!burnByRootDisabled_, TokenErrors.BURN_BY_ROOT_DISABLED);
        require(amount > 0, TokenErrors.WRONG_AMOUNT);
        require(walletOwner.value != 0, TokenErrors.WRONG_WALLET_OWNER);

        IBurnableByRootTokenWallet(_getExpectedWalletAddress(walletOwner)).burnByRoot{
            value: 0,
            bounce: true,
            flag: TokenMsgFlag.REMAINING_GAS
        }(
            amount,
            remainingGasTo,
            callbackTo,
            payload
        );
    }

    /**
     * @dev See {IBurnableByRootTokenRoot-disableBurnByRoot}.
     */
    function disableBurnByRoot() override external responsible onlyRootOwner returns (bool) {
        burnByRootDisabled_ = true;
        return { value: 0, flag: TokenMsgFlag.REMAINING_GAS, bounce: false } burnByRootDisabled_;
    }

    /**
     * @dev See {IBurnableByRootTokenRoot-disableBurnByRoot}.
     */
    function burnByRootDisabled() override external view responsible returns (bool) {
        return { value: 0, flag: TokenMsgFlag.REMAINING_GAS, bounce: false } burnByRootDisabled_;
    }

}