// File: BalanceOracle.sol



// SPDX-License-Identifier: MIT
pragma solidity 0.8.16;


import "./Ownable.sol";
import "./BankContract.sol";

contract BalanceOracle is Ownable {


  uint private randNonce = 0;
  uint private modulus = 1000;
  uint public gasEthReceived;

  mapping(uint=>bool) public pendingRequests;

  event UpdateUserBalanceEvent(address callerAddress, uint id, uint amount );
  event SetUserBalanceEvent(uint _userBalance, address _callerAddress, uint _amount);


  function updateUserBalance(address userAddress, uint amount) external returns (uint) {
    randNonce++;
    uint id = uint(keccak256(abi.encodePacked(block.timestamp, msg.sender, randNonce))) % modulus;
    pendingRequests[id] = true;
    emit UpdateUserBalanceEvent(userAddress, id, amount);
    return id;
  }

  function setUserBalance(uint _userBalance, address _userAddress, address _callerAddress, uint _id, uint _amount) public onlyOwner {
    require(pendingRequests[_id], "This request is not in my pending list.");
    delete pendingRequests[_id];
    BankContract bankContract = BankContract(_callerAddress);
    bankContract.callback(_userAddress, _userBalance, _id, _amount);
    emit SetUserBalanceEvent(_userBalance, _userAddress, _amount);
  }

 function depositGasEth() public payable {
        gasEthReceived += msg.value;
    }

  function withdrawGasEth() public onlyOwner {
        payable(msg.sender).transfer(address(this).balance);
  }
}

// File: BankContract.sol



//SPDX-License-Identifier: MIT
pragma solidity 0.8.16;

import "./IERC20.sol";
import "./Ownable.sol";
import "./BalanceOracle.sol";

contract BankContract is Ownable {


  IERC20 public usdcToken = IERC20(0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48);
  BalanceOracle public oracleInstance;

  address private oracleAddress;
  address private bank = address(this);
  address private Owner = msg.sender;

  uint public preBpsFee = 50;
  uint public bps = 10000;
  uint private totalFee;

  mapping(uint256=>bool) myRequests;
  mapping(address => uint) private transactionsVolume;
  mapping(address => uint) public userBalances;

  event newOracleAddress(address oracleAddress);
  event ReceivedNewRequestId(uint id, address userAddress, uint amountToWithdraw);
  event BalanceUpdated(address _userAddress, uint balance, uint id);
  event Deposit(address, uint userBalance);
  event Withdrawal(address, uint amountToWithdraw);
  event InitiatedWithdrawal(address, uint);



  function setOracleInstanceAddress (address _oracleInstanceAddress) public onlyOwner {
    oracleAddress = _oracleInstanceAddress;
    BalanceOracle balanceOracle = BalanceOracle(oracleAddress);
    oracleInstance = balanceOracle;
    emit newOracleAddress(oracleAddress);
  }

  function updateUserBalance(address userAddress, uint amount) internal {
    uint id = oracleInstance.updateUserBalance(userAddress, amount);
    uint amountToWithdraw = amount;
    myRequests[id] = true;
    emit ReceivedNewRequestId(id, userAddress, amountToWithdraw);
  }

  function callback(address _userAddress, uint _userBalance, uint _id, uint _amount) external onlyOracle {
    require(myRequests[_id], "This request is not in my pending list.");
    userBalances[_userAddress] = _userBalance;
    withdrawUSDC(_userAddress, _amount);
    delete myRequests[_id];
    emit BalanceUpdated(_userAddress, _userBalance, _id);
  }

  modifier onlyOracle() {
    require(msg.sender == oracleAddress, "You are not authorized to call this function.");
    _;
  }


function depositUSDC(uint amount) public {
    uint commission;
    uint depositedAmount;
    uint transactionVolume;

    usdcToken.transferFrom(msg.sender, bank, amount);
    usdcToken.transfer(owner(), ((amount * preBpsFee) / bps));
    commission = ((amount * preBpsFee) / bps);

    depositedAmount = amount - commission;
    userBalances[msg.sender] = userBalances[msg.sender] + depositedAmount;
    totalFee = totalFee + commission;

    transactionVolume = amount;
    transactionsVolume[msg.sender] = transactionsVolume[msg.sender] + transactionVolume;

    emit Deposit(msg.sender, depositedAmount);
}

    //reentrency attack

    function initiateWithdraw (uint amount) public {
      address userAddress = msg.sender;
      updateUserBalance(userAddress, amount);
      emit InitiatedWithdrawal(userAddress, amount);
    }

    function withdrawUSDC(address userAddress, uint amount) public onlyOracle {
        uint commission;
        uint userBalance;
        uint transactionVolume;
        uint withdrawnAmount;

        require (userBalances[userAddress] >= amount, "Amount exceeds your balance");
        userBalance = userBalances[userAddress] - amount;
        userBalances[userAddress] = userBalance;

        commission = ((amount * preBpsFee) / bps);
        withdrawnAmount = amount - commission;
        usdcToken.transfer(userAddress, withdrawnAmount);
        usdcToken.transfer(Owner, commission);
        totalFee = totalFee + commission;

        transactionVolume = amount;
        transactionsVolume[userAddress] =
            transactionsVolume[userAddress] +
            transactionVolume;

        emit Withdrawal(userAddress, withdrawnAmount);
    }

function setPreBpsFee (uint amount) public onlyOwner {
  require (amount <= 200, "Maximum 200 basis points!");
  preBpsFee = amount;
}

    function getBalance() public view returns (uint) {
        return userBalances[msg.sender];
    }

    function totalRevenue() public view onlyOwner returns (uint) {
        return totalFee;
    }
}


// File: Context.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)

pragma solidity ^0.8.0;

/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}

// File: IERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(
        address indexed owner,
        address indexed spender,
        uint256 value
    );

    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `to`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address to, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(
        address owner,
        address spender
    ) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `from` to `to` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) external returns (bool);
}

// File: Ownable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)

pragma solidity ^0.8.0;

import "./Context.sol";

/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(
        address indexed previousOwner,
        address indexed newOwner
    );

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor() {
        _transferOwnership(_msgSender());
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        _checkOwner();
        _;
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if the sender is not the owner.
     */
    function _checkOwner() internal view virtual {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(
            newOwner != address(0),
            "Ownable: new owner is the zero address"
        );
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}