// 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;
    }
}

// SPDX-License-Identifier: BUSL-1.1

pragma solidity 0.8.19;

import "@openzeppelin/contracts/utils/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.
 *
 * Modified version from openzeppelin/contracts/access/Ownable.sol that allows to
 * initialize the owner using a parameter in the constructor
 */
abstract contract Ownable is Context {
    address private _owner;

    address private _ownerCandidate;

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

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
        _;
    }

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor(address _initialOwner) {
        _setOwner(_initialOwner);
    }

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

    function acceptTransferOwnership() public virtual {
        require(_ownerCandidate == _msgSender(), "Ownable: not owner candidate");
        _setOwner(_ownerCandidate);
        delete _ownerCandidate;
    }

    function cancelTransferOwnership() public virtual onlyOwner {
        delete _ownerCandidate;
    }

    function rejectTransferOwnership() public virtual {
        require(_ownerCandidate == _msgSender(), "Ownable: not owner candidate");
        delete _ownerCandidate;
    }

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

    /**
     * @dev Sets the owner.
     */
    function _setOwner(address _newOwner) internal {
        address oldOwner = _owner;
        _owner = _newOwner;
        emit OwnershipTransferred(oldOwner, _newOwner);
    }
}

// SPDX-License-Identifier: BUSL-1.1

pragma solidity 0.8.19;

import "./utils/Ownable.sol";

/**
 * @title TokenUtilityAccounting
 * @author NFTfi
 * @dev
 */
contract TokenUtilityAccounting is Ownable {
    mapping(address => bool) public tokenLocks;

    mapping(address => uint256) public weightedAvgLockTimes;
    mapping(address => uint256) public amounts;

    // these two only needed if we wanted to distribute a finite,
    // given amount of rewards proportionally for locking times and amounts acrued
    uint256 public totalWeightedAvgLockTime;
    uint256 public totalAmount;

    event Update(
        address indexed _user,
        uint256 _weightedAvgLockTime,
        uint256 _acruedUserAmount,
        uint256 _totalWeightedAvgLockTime,
        uint256 _totalAmount
    );

    constructor(address _admin, address[] memory _tokenLockAddresses) Ownable(_admin) {
        _addTokenLocks(_tokenLockAddresses);
    }

    modifier onlyTokenLock() {
        require(tokenLocks[msg.sender], "Only token lock");
        _;
    }

    function lock(address _user, uint256 _amount) external onlyTokenLock {
        _updateUserWeightedAvgLockTime(_user, _amount);
        _updateTotalWeightedAvgLockTime(_amount);
        amounts[_user] += _amount;
        totalAmount += _amount;
        emit Update(_user, weightedAvgLockTimes[_user], amounts[_user], totalWeightedAvgLockTime, totalAmount);
    }

    function unlock(address _user, uint256 _amount) external onlyTokenLock {
        amounts[_user] -= _amount;
        totalAmount -= _amount;
        emit Update(_user, weightedAvgLockTimes[_user], amounts[_user], totalWeightedAvgLockTime, totalAmount);
    }

    /**
     * @dev updates weighted avg lock time for a given user based on the added amount
     * @param _user -
     * @param _amount - amount added
     */
    function _updateUserWeightedAvgLockTime(address _user, uint256 _amount) internal {
        weightedAvgLockTimes[_user] = _calculateWeightedAvgLockTime(
            _amount,
            amounts[_user],
            weightedAvgLockTimes[_user]
        );
    }

    /**
     * @dev updates weighted avg lock time for the whole system based on the added amount
     * @param _amount - amount added
     */
    function _updateTotalWeightedAvgLockTime(uint256 _amount) internal {
        totalWeightedAvgLockTime = _calculateWeightedAvgLockTime(_amount, totalAmount, totalWeightedAvgLockTime);
    }

    /**
     * @dev calculates weightedAvgMultiplier virtual timestamp value with
     * a new data point of token _amount weight and the current time
     * This function is either called by _updateAvgMultiplierStart or has to be called after
     * an explicit stake() or a deleteWithdrawRequest(), or any other possible instances,
     * The function takes the existing average and it's weight (existing balance) then calculates
     * it with the new value and weight with a weighted avg calculation between the 2 datapoints.
     * @param _amount - amount added
     * @param _oldAmount - cumulative amount before
     * @param _oldWeightedAvgLockTime -
     */
    function _calculateWeightedAvgLockTime(
        uint256 _amount,
        uint256 _oldAmount,
        uint256 _oldWeightedAvgLockTime
    ) internal view returns (uint256) {
        if (_oldAmount == 0 || _oldWeightedAvgLockTime == 0) {
            // if we are at initial state with just 1 datapoint
            return block.timestamp;
        } else {
            uint256 totalWeight = _oldAmount + _amount;
            // weighted avg calculation between the old value and the new lock timestamp
            return (_oldAmount * _oldWeightedAvgLockTime + _amount * block.timestamp) / totalWeight;
        }
    }

    function _addTokenLocks(address[] memory _tokenLockAddresses) internal {
        for (uint256 index = 0; index < _tokenLockAddresses.length; ++index) {
            tokenLocks[_tokenLockAddresses[index]] = true;
        }
    }

    function addTokenLocks(address[] memory _tokenLockAddresses) external onlyOwner {
        _addTokenLocks(_tokenLockAddresses);
    }

    function removeTokenLocks(address[] memory _tokenLockAddresses) external onlyOwner {
        for (uint256 index = 0; index < _tokenLockAddresses.length; ++index) {
            tokenLocks[_tokenLockAddresses[index]] = false;
        }
    }
}

{
  "compilationTarget": {
    "contracts/TokenUtilityAccounting.sol": "TokenUtilityAccounting"
  },
  "evmVersion": "paris",
  "libraries": {},
  "metadata": {
    "bytecodeHash": "none",
    "useLiteralContent": true
  },
  "optimizer": {
    "enabled": true,
    "runs": 200
  },
  "remappings": []
}