// SPDX-License-Identifier: No License

import "./ERC20.sol";
import "./Ownable.sol";

pragma solidity ^0.8.0;

library SafeMathUint {
  function toInt256Safe(uint256 a) internal pure returns (int256) {
    int256 b = int256(a);
    require(b >= 0);
    return b;
  }
}

library SafeMathInt {
  function toUint256Safe(int256 a) internal pure returns (uint256) {
    require(a >= 0);
    return uint256(a);
  }
}

/// @title Dividend-Paying Token Interface
/// @author Roger Wu (https://github.com/roger-wu)
/// @dev An interface for a dividend-paying token contract.
interface DividendPayingTokenInterface {

  function dividendOf(address _owner) external view returns (uint256);

  event DividendsDistributed(address indexed from, uint256 weiAmount);

  event DividendWithdrawn(address indexed to, uint256 weiAmount);
}

/// @title Dividend-Paying Token Optional Interface
/// @author Roger Wu (https://github.com/roger-wu)
/// @dev OPTIONAL functions for a dividend-paying token contract.
interface DividendPayingTokenOptionalInterface {

  function withdrawableDividendOf(address _owner) external view returns (uint256);

  function withdrawnDividendOf(address _owner) external view returns (uint256);

  function accumulativeDividendOf(address _owner) external view returns (uint256);
}

/// @title Dividend-Paying Token
/// @author Roger Wu (https://github.com/roger-wu)
/// @dev A mintable ERC20 token that allows anyone to pay and distribute ether
/// to token holders as dividends and allows token holders to withdraw their dividends.
/// Reference: the source code of PoWH3D: https://etherscan.io/address/0xB3775fB83F7D12A36E0475aBdD1FCA35c091efBe#code
contract DividendPayingToken is ERC20, DividendPayingTokenInterface, DividendPayingTokenOptionalInterface {
  using SafeMathUint for uint256;
  using SafeMathInt for int256;

  uint256 constant internal magnitude = 2**128;

  uint256 internal magnifiedDividendPerShare;

  mapping(address => int256) internal magnifiedDividendCorrections;
  mapping(address => uint256) internal withdrawnDividends;

  uint256 public totalDividendsDistributed;

  constructor(string memory _name, string memory _symbol) ERC20(_name, _symbol) {}

  receive() external payable {
    distributeDividends();
  }

  function distributeDividends() public payable {
    require(totalSupply() > 0);

    if (msg.value > 0) {
      magnifiedDividendPerShare = magnifiedDividendPerShare + (msg.value * magnitude / totalSupply());

      emit DividendsDistributed(msg.sender, msg.value);

      totalDividendsDistributed = totalDividendsDistributed + msg.value;
    }
  }

  function _withdrawDividend(address account) internal returns(uint256) {
    uint256 withdrawableDividend = withdrawableDividendOf(account);

    if (withdrawableDividend > 0) {
      withdrawnDividends[account] = withdrawnDividends[account] + withdrawableDividend;

      bool success = payable(account).send(withdrawableDividend);
     
      if (success) {
        emit DividendWithdrawn(account, withdrawableDividend);

        return withdrawableDividend;
      } else {
        withdrawnDividends[account] = withdrawnDividends[account] - withdrawableDividend;

        return 0;
      }
    }

    return 0;
  }

  function dividendOf(address account) public view override returns(uint256) {
    return withdrawableDividendOf(account);
  }

  function withdrawableDividendOf(address account) public view override returns(uint256) {
    return accumulativeDividendOf(account) - withdrawnDividends[account];
  }

  function withdrawnDividendOf(address account) public view override returns(uint256) {
    return withdrawnDividends[account];
  }

  function accumulativeDividendOf(address account) public view override returns(uint256) {
    return ((magnifiedDividendPerShare * balanceOf(account)).toInt256Safe() + magnifiedDividendCorrections[account]).toUint256Safe() / magnitude;
  }

  function _mint(address account, uint256 value) internal override {
    super._mint(account, value);

    magnifiedDividendCorrections[account] = magnifiedDividendCorrections[account] - (magnifiedDividendPerShare * value).toInt256Safe();
  }

  function _burn(address account, uint256 value) internal override {
    super._burn(account, value);

    magnifiedDividendCorrections[account] = magnifiedDividendCorrections[account] + (magnifiedDividendPerShare * value).toInt256Safe();
  }

  function _setBalance(address account, uint256 newBalance) internal {
    uint256 currentBalance = balanceOf(account);

    if(newBalance > currentBalance) _mint(account, newBalance - currentBalance);
    else if(newBalance < currentBalance) _burn(account, currentBalance - newBalance);
  }
}

library IterableMapping {
  // Iterable mapping from address to uint;
  struct Map {
    address[] keys;
    mapping(address => uint) values;
    mapping(address => uint) indexOf;
    mapping(address => bool) inserted;
  }

  function get(Map storage map, address key) public view returns (uint) {
    return map.values[key];
  }

  function getIndexOfKey(Map storage map, address key) public view returns (int) {
    if(!map.inserted[key]) {
        return -1;
    }
    return int(map.indexOf[key]);
  }

  function getKeyAtIndex(Map storage map, uint index) public view returns (address) {
    return map.keys[index];
  }

  function size(Map storage map) public view returns (uint) {
    return map.keys.length;
  }

  function set(Map storage map, address key, uint val) public {
    if (map.inserted[key]) {
      map.values[key] = val;
    } else {
      map.inserted[key] = true;
      map.values[key] = val;
      map.indexOf[key] = map.keys.length;
      map.keys.push(key);
    }
  }

  function remove(Map storage map, address key) public {
    if (!map.inserted[key]) {
      return;
    }

    delete map.inserted[key];
    delete map.values[key];

    uint index = map.indexOf[key];
    uint lastIndex = map.keys.length - 1;
    address lastKey = map.keys[lastIndex];

    map.indexOf[lastKey] = index;
    delete map.indexOf[key];

    map.keys[index] = lastKey;
    map.keys.pop();
  }
}

contract DividendTracker is Ownable, DividendPayingToken {
  using IterableMapping for IterableMapping.Map;

  IterableMapping.Map private tokenHoldersMap;
  uint256 public lastProcessedIndex;

  mapping(address => bool) public isExcludedFromDividends;
  mapping(address => uint256) public lastClaimTimes;

  uint256 public claimWait;
  uint256 public minimumTokenBalanceForDividends;

  event ExcludeFromDividends(address indexed account, bool isExcluded);
  event ClaimWaitUpdated(uint256 claimWait);
  event ProcessedDividendTracker(uint256 iterations, uint256 claims);

  constructor(uint256 _claimWait, uint256 _minimumTokenBalance) DividendPayingToken("DividendTracker", "DividendTracker") {
    claimWaitSetup(_claimWait);
    minimumTokenBalanceForDividends = _minimumTokenBalance;
  }

  function excludeFromDividends(address account, uint256 balance, bool isExcluded) external onlyOwner {
    if (isExcluded) {
      require(!isExcludedFromDividends[account], "DividendTracker: This address is already excluded from dividends");
      isExcludedFromDividends[account] = true;

      _setBalance(account, 0);
      tokenHoldersMap.remove(account);
    } else {
      require(isExcludedFromDividends[account], "DividendTracker: This address is already included in dividends");
      isExcludedFromDividends[account] = false;

      setBalance(account, balance);
    }

    emit ExcludeFromDividends(account, isExcluded);
  }

  function claimWaitSetup(uint256 newClaimWait) public onlyOwner {
    require(newClaimWait >= 60 && newClaimWait <= 7 days, "DividendTracker: Claim wait time must be between 1 minute and 7 days");

    claimWait = newClaimWait;

    emit ClaimWaitUpdated(newClaimWait);
  }

  function getNumberOfTokenHolders() external view returns (uint256) {
    return tokenHoldersMap.keys.length;
  }

  function getAccountData(address _account) public view returns (
      address account,
      int256 index,
      int256 iterationsUntilProcessed,
      uint256 withdrawableDividends,
      uint256 totalDividends,
      uint256 lastClaimTime,
      uint256 nextClaimTime,
      uint256 secondsUntilAutoClaimAvailable
    )
  {
    account = _account;
    index = tokenHoldersMap.getIndexOfKey(account);
    iterationsUntilProcessed = -1;

    if (index >= 0) {
      if (uint256(index) > lastProcessedIndex) {
        iterationsUntilProcessed = index - int256(lastProcessedIndex);
      } else {
        uint256 processesUntilEndOfArray = tokenHoldersMap.keys.length > lastProcessedIndex ? tokenHoldersMap.keys.length - lastProcessedIndex : 0;
        iterationsUntilProcessed = index + int256(processesUntilEndOfArray);
      }
    }

    withdrawableDividends = withdrawableDividendOf(account);
    totalDividends = accumulativeDividendOf(account);
    lastClaimTime = lastClaimTimes[account];
    nextClaimTime = lastClaimTime > 0 ? lastClaimTime + claimWait : 0;
    secondsUntilAutoClaimAvailable = nextClaimTime > block.timestamp ? nextClaimTime - block.timestamp : 0;
  }

  function getAccountDataAtIndex(uint256 index) public view returns (
      address,
      int256,
      int256,
      uint256,
      uint256,
      uint256,
      uint256,
      uint256
    )
  {
    if (index >= tokenHoldersMap.size()) return (address(0), -1, -1, 0, 0, 0, 0, 0);

    address account = tokenHoldersMap.getKeyAtIndex(index);

    return getAccountData(account);
  }

  function claim(address account) public onlyOwner returns (bool) {
    uint256 amount = _withdrawDividend(account);

    if (amount > 0) {
      lastClaimTimes[account] = block.timestamp;
      return true;
    }
    return false;
  }

  function _canAutoClaim(uint256 lastClaimTime) private view returns (bool) {
    if (block.timestamp < lastClaimTime) return false;
    
    return block.timestamp - lastClaimTime >= claimWait;
  }

  function setBalance(address account, uint256 newBalance) public onlyOwner {
    if (!isExcludedFromDividends[account]) {

      if (newBalance >= minimumTokenBalanceForDividends) {
        _setBalance(account, newBalance);
        tokenHoldersMap.set(account, newBalance);
      } else {
        _setBalance(account, 0);
        tokenHoldersMap.remove(account);
      }

    }
  }

  function process(uint256 gas) external onlyOwner returns(uint256 iterations, uint256 claims) {
    uint256 numberOfTokenHolders = tokenHoldersMap.keys.length;

    if (numberOfTokenHolders == 0) return (0, 0);

    uint256 _lastProcessedIndex = lastProcessedIndex;
    uint256 gasUsed = 0;
    uint256 gasLeft = gasleft();

    iterations = 0;
    claims = 0;

    while (gasUsed < gas && iterations < numberOfTokenHolders) {
      _lastProcessedIndex++;

      if (_lastProcessedIndex >= tokenHoldersMap.keys.length) _lastProcessedIndex = 0;

      address account = tokenHoldersMap.keys[_lastProcessedIndex];

      if (_canAutoClaim(lastClaimTimes[account])) {
        if (claim(account)) {
          claims++;
        }
      }

      iterations++;

      uint256 newGasLeft = gasleft();

      if (gasLeft > newGasLeft) gasUsed = gasUsed + (gasLeft - newGasLeft);

      gasLeft = newGasLeft;
    }

    lastProcessedIndex = _lastProcessedIndex;

    emit ProcessedDividendTracker(iterations, claims);
  }
}

abstract contract DividendTrackerFunctions is Ownable {
  DividendTracker public dividendTracker;

  uint256 public gasForProcessing;

  event DeployedDividendTracker(address indexed dividendTracker);
  event GasForProcessingUpdated(uint256 gasForProcessing);

  function _deployDividendTracker(uint256 claimWait, uint256 minimumTokenBalance) internal {
    dividendTracker = new DividendTracker(claimWait, minimumTokenBalance);

    emit DeployedDividendTracker(address(dividendTracker));
  }

  function gasForProcessingSetup(uint256 _gasForProcessing) public onlyOwner {
    require(_gasForProcessing >= 200_000 && _gasForProcessing <= 500_000, "DividendTracker: gasForProcessing must be between 200k and 500k units");
    
    gasForProcessing = _gasForProcessing;

    emit GasForProcessingUpdated(_gasForProcessing);
  }

  function claimWaitSetup(uint256 claimWait) external onlyOwner {
    dividendTracker.claimWaitSetup(claimWait);
  }

  function _excludeFromDividends(address account, bool isExcluded) internal virtual;

  function isExcludedFromDividends(address account) public view returns (bool) {
    return dividendTracker.isExcludedFromDividends(account);
  }

  function claim() external returns(bool) {
    return dividendTracker.claim(msg.sender);
  }
  
  function getClaimWait() external view returns (uint256) {
    return dividendTracker.claimWait();
  }

  function getTotalDividendsDistributed() external view returns (uint256) {
    return dividendTracker.totalDividendsDistributed();
  }

  function withdrawableDividendOf(address account) public view returns (uint256) {
    return dividendTracker.withdrawableDividendOf(account);
  }

  function dividendTokenBalanceOf(address account) public view returns (uint256) {
    return dividendTracker.balanceOf(account);
  }

  function dividendTokenTotalSupply() public view returns (uint256) {
    return dividendTracker.totalSupply();
  }

  function getAccountDividendsInfo(address account) external view returns (
      address,
      int256,
      int256,
      uint256,
      uint256,
      uint256,
      uint256,
      uint256
    ) {
    return dividendTracker.getAccountData(account);
  }

  function getAccountDividendsInfoAtIndex(uint256 index) external view returns (
      address,
      int256,
      int256,
      uint256,
      uint256,
      uint256,
      uint256,
      uint256
    ) {
    return dividendTracker.getAccountDataAtIndex(index);
  }

  function getLastProcessedIndex() external view returns (uint256) {
    return dividendTracker.lastProcessedIndex();
  }

  function getNumberOfDividendTokenHolders() public view returns (uint256) {
    return dividendTracker.getNumberOfTokenHolders();
  }

  function process(uint256 gas) external returns(uint256 iterations, uint256 claims) {
    return dividendTracker.process(gas);
  }
}

// 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: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/ERC20.sol)

pragma solidity ^0.8.0;

import "./IERC20.sol";
import "./IERC20Metadata.sol";
import "./Context.sol";

/**
 * @dev Implementation of the {IERC20} interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using {_mint}.
 * For a generic mechanism see {ERC20PresetMinterPauser}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.openzeppelin.com/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * The default value of {decimals} is 18. To change this, you should override
 * this function so it returns a different value.
 *
 * We have followed general OpenZeppelin Contracts guidelines: functions revert
 * instead returning `false` on failure. This behavior is nonetheless
 * conventional and does not conflict with the expectations of ERC20
 * applications.
 *
 * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
 * This allows applications to reconstruct the allowance for all accounts just
 * by listening to said events. Other implementations of the EIP may not emit
 * these events, as it isn't required by the specification.
 *
 * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
 * functions have been added to mitigate the well-known issues around setting
 * allowances. See {IERC20-approve}.
 */
contract ERC20 is Context, IERC20, IERC20Metadata {
    mapping(address => uint256) private _balances;

    mapping(address => mapping(address => uint256)) private _allowances;

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;

    /**
     * @dev Sets the values for {name} and {symbol}.
     *
     * All two of these values are immutable: they can only be set once during
     * construction.
     */
    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }

    /**
     * @dev Returns the name of the token.
     */
    function name() public view virtual override returns (string memory) {
        return _name;
    }

    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }

    /**
     * @dev Returns the number of decimals used to get its user representation.
     * For example, if `decimals` equals `2`, a balance of `505` tokens should
     * be displayed to a user as `5.05` (`505 / 10 ** 2`).
     *
     * Tokens usually opt for a value of 18, imitating the relationship between
     * Ether and Wei. This is the default value returned by this function, unless
     * it's overridden.
     *
     * NOTE: This information is only used for _display_ purposes: it in
     * no way affects any of the arithmetic of the contract, including
     * {IERC20-balanceOf} and {IERC20-transfer}.
     */
    function decimals() public view virtual override returns (uint8) {
        return 18;
    }

    /**
     * @dev See {IERC20-totalSupply}.
     */
    function totalSupply() public view virtual override returns (uint256) {
        return _totalSupply;
    }

    /**
     * @dev See {IERC20-balanceOf}.
     */
    function balanceOf(address account) public view virtual override returns (uint256) {
        return _balances[account];
    }

    /**
     * @dev See {IERC20-transfer}.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - the caller must have a balance of at least `amount`.
     */
    function transfer(address to, uint256 amount) public virtual override returns (bool) {
        address owner = _msgSender();
        _transfer(owner, to, amount);
        return true;
    }

    /**
     * @dev See {IERC20-allowance}.
     */
    function allowance(address owner, address spender) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }

    /**
     * @dev See {IERC20-approve}.
     *
     * NOTE: If `amount` is the maximum `uint256`, the allowance is not updated on
     * `transferFrom`. This is semantically equivalent to an infinite approval.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, amount);
        return true;
    }

    /**
     * @dev See {IERC20-transferFrom}.
     *
     * Emits an {Approval} event indicating the updated allowance. This is not
     * required by the EIP. See the note at the beginning of {ERC20}.
     *
     * NOTE: Does not update the allowance if the current allowance
     * is the maximum `uint256`.
     *
     * Requirements:
     *
     * - `from` and `to` cannot be the zero address.
     * - `from` must have a balance of at least `amount`.
     * - the caller must have allowance for ``from``'s tokens of at least
     * `amount`.
     */
    function transferFrom(address from, address to, uint256 amount) public virtual override returns (bool) {
        address spender = _msgSender();
        _spendAllowance(from, spender, amount);
        _transfer(from, to, amount);
        return true;
    }

    /**
     * @dev Atomically increases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, allowance(owner, spender) + addedValue);
        return true;
    }

    /**
     * @dev Atomically decreases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `spender` must have allowance for the caller of at least
     * `subtractedValue`.
     */
    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
        address owner = _msgSender();
        uint256 currentAllowance = allowance(owner, spender);
        require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
        unchecked {
            _approve(owner, spender, currentAllowance - subtractedValue);
        }

        return true;
    }

    /**
     * @dev Moves `amount` of tokens from `from` to `to`.
     *
     * This internal function is equivalent to {transfer}, and can be used to
     * e.g. implement automatic token fees, slashing mechanisms, etc.
     *
     * Emits a {Transfer} event.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `from` must have a balance of at least `amount`.
     */
    function _transfer(address from, address to, uint256 amount) internal virtual {
        require(from != address(0), "ERC20: transfer from the zero address");
        require(to != address(0), "ERC20: transfer to the zero address");

        _beforeTokenTransfer(from, to, amount);

        uint256 fromBalance = _balances[from];
        require(fromBalance >= amount, "ERC20: transfer amount exceeds balance");
        unchecked {
            _balances[from] = fromBalance - amount;
            // Overflow not possible: the sum of all balances is capped by totalSupply, and the sum is preserved by
            // decrementing then incrementing.
            _balances[to] += amount;
        }

        emit Transfer(from, to, amount);

        _afterTokenTransfer(from, to, amount);
    }

    /** @dev Creates `amount` tokens and assigns them to `account`, increasing
     * the total supply.
     *
     * Emits a {Transfer} event with `from` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     */
    function _mint(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: mint to the zero address");

        _beforeTokenTransfer(address(0), account, amount);

        _totalSupply += amount;
        unchecked {
            // Overflow not possible: balance + amount is at most totalSupply + amount, which is checked above.
            _balances[account] += amount;
        }
        emit Transfer(address(0), account, amount);

        _afterTokenTransfer(address(0), account, amount);
    }

    /**
     * @dev Destroys `amount` tokens from `account`, reducing the
     * total supply.
     *
     * Emits a {Transfer} event with `to` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     * - `account` must have at least `amount` tokens.
     */
    function _burn(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: burn from the zero address");

        _beforeTokenTransfer(account, address(0), amount);

        uint256 accountBalance = _balances[account];
        require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
        unchecked {
            _balances[account] = accountBalance - amount;
            // Overflow not possible: amount <= accountBalance <= totalSupply.
            _totalSupply -= amount;
        }

        emit Transfer(account, address(0), amount);

        _afterTokenTransfer(account, address(0), amount);
    }

    /**
     * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
     *
     * This internal function is equivalent to `approve`, and can be used to
     * e.g. set automatic allowances for certain subsystems, etc.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `owner` cannot be the zero address.
     * - `spender` cannot be the zero address.
     */
    function _approve(address owner, address spender, uint256 amount) internal virtual {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }

    /**
     * @dev Updates `owner` s allowance for `spender` based on spent `amount`.
     *
     * Does not update the allowance amount in case of infinite allowance.
     * Revert if not enough allowance is available.
     *
     * Might emit an {Approval} event.
     */
    function _spendAllowance(address owner, address spender, uint256 amount) internal virtual {
        uint256 currentAllowance = allowance(owner, spender);
        if (currentAllowance != type(uint256).max) {
            require(currentAllowance >= amount, "ERC20: insufficient allowance");
            unchecked {
                _approve(owner, spender, currentAllowance - amount);
            }
        }
    }

    /**
     * @dev Hook that is called before any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * will be transferred to `to`.
     * - when `from` is zero, `amount` tokens will be minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual {}

    /**
     * @dev Hook that is called after any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * has been transferred to `to`.
     * - when `from` is zero, `amount` tokens have been minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens have been burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _afterTokenTransfer(address from, address to, uint256 amount) internal virtual {}
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (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);
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)

pragma solidity ^0.8.0;

import "./IERC20.sol";

/**
 * @dev Interface for the optional metadata functions from the ERC20 standard.
 *
 * _Available since v4.1._
 */
interface IERC20Metadata is IERC20 {
    /**
     * @dev Returns the name of the token.
     */
    function name() external view returns (string memory);

    /**
     * @dev Returns the symbol of the token.
     */
    function symbol() external view returns (string memory);

    /**
     * @dev Returns the decimals places of the token.
     */
    function decimals() external view returns (uint8);
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (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. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby disabling 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);
    }
}

{
  "compilationTarget": {
    "CoinDividendTracker.sol": "DividendTracker"
  },
  "evmVersion": "paris",
  "libraries": {
    "CoinDividendTracker.sol:IterableMapping": "0x31ee4a53bd2c1c339662dffb973017ef81a6bad5"
  },
  "metadata": {
    "bytecodeHash": "ipfs"
  },
  "optimizer": {
    "enabled": true,
    "runs": 200
  },
  "remappings": []
}