contract Fragment is ERC1155, ReentrancyGuard, Ownable {

    event Activate();
    event Deactivate();

    event Approval(address indexed contactAddress, address indexed tokenOwner, uint tokens);

    uint256 constant private fragmentId = 1;
    
    uint256 constant public maxFragments = 50000;
    uint256 public numSmeltedFragments;
        
    address public traceContract;
    address constant public burnAddress = 0x0000000000000000000000000000000000000000;
    uint256 constant public traceThreshold = 20;
    
    bool public isSaleActive = false;
    
    uint256 constant private _smeltPrice = 0.05 ether;

    constructor() ERC1155("https://arweave.net/_AmiElq9b_FKa6Gdd2GCz22D-KNfJ1-liabhmiJkKk0") {}

    //
    // Activate the public sale
    //
    function initializeSale(address traceContract_) public onlyOwner {
        require(!isSaleActive, "First disable the Fragment smelting to re-initialize.");

        isSaleActive = true;
        traceContract = traceContract_;

        emit Activate();
    }

    //
    // Owner withdraw funds
    //
    function withdrawBalance() public onlyOwner {
        uint256 balance = address(this).balance;
        payable(msg.sender).transfer(balance);
    }

    //
    // Toggle Activate/Deactivate ability to smelt fragments
    //
    function toggleSale() public onlyOwner {
        isSaleActive = !isSaleActive;

        if (isSaleActive == true) {
            emit Activate();
        } else {
            emit Deactivate();
        }
    }
    
    //
    // Mint the Fragment
    //
    function smeltFragment(uint256 numFragmentsRequested) external payable nonReentrant {
        IERC20 traceTokenImpl = IERC20(traceContract);
        uint256 traceBurnAmount = numFragmentsRequested * 20;

        require(isSaleActive, "Smelting Fragments is not active at this point in time.");
        require(numFragmentsRequested > 0, "You must smelt at least 1 whole Fragment.");
        require((numSmeltedFragments + numFragmentsRequested) <= maxFragments, "Requested count for Fragments exceeds the maximum smeltable Fragments.");
       
        require(msg.value >= (numFragmentsRequested * _smeltPrice), "Invalid amount of ETH sent.");
        
        require(traceTokenImpl.balanceOf(msg.sender) >= (traceBurnAmount), "You do not have enough $TRCE to mint a Fragment.");

        try traceTokenImpl.transferFrom(msg.sender, address(burnAddress), traceBurnAmount) {
        } catch (bytes memory) {
            revert("Failed to burn $TRCE - Please verify that you have approved the correct number of tokens. Reverting.");
        }
        
        numSmeltedFragments += numFragmentsRequested;
        _mint(msg.sender, fragmentId, numFragmentsRequested, "");
    }
}
function withdrawBalance() public onlyOwner {
    uint256 balance = address(this).balance;
    payable(msg.sender).transfer(balance);
}

//
// Owner withdraw funds
//