// File: contracts/PhilanthropyToken.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import "./libs/Admin.sol";
import "./libs/Security.sol";
import "./libs/Utils.sol";
import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import "@openzeppelin/contracts/access/Ownable.sol";

contract PhilanthropyToken is ERC20, Ownable {
    using Admin for *;
    using Security for *;
    using Utils for *;

    uint256 public constant MAX_TOTAL_SUPPLY = 500 * 10 ** 6 * 10 ** 18; // Maximum total supply of 500 million tokens
    uint256 public constant MARKET_CAP = 10 * 10 ** 6 * 10 ** 18; // Default market cap of 10 million tokens

    uint256 public INVESTOR_ALLOCATION = 4 * 10 ** 6 * 10 ** 18; // 4 million tokens for investors
    uint256 public constant GENERAL_PUBLIC_ALLOCATION = 5 * 10 ** 6 * 10 ** 18; // 5 million tokens for the general public
    uint256 public CHARITY_ALLOCATION = 4 * 10 ** 6 * 10 ** 18; // 4 million tokens for charities
    uint256 public constant PRESALE_ALLOCATION = 5 * 10 ** 6 * 10 ** 18; // 5 million tokens for the presale
    uint256 public PRESALE_TOTAL_SOLD = 0; // the presale

    uint256 public constant INVESTOR_LOCK_PERIOD = 730 days; // 2 years Lock-up period for investors
    uint256 public constant PRESALE_LOCK_PERIOD = 365 days; // 1 year Lock-up period for presale
    uint256 public TOTAL_INITIAL_RELEASED = 0;
    uint256 public TOTAL_INVESTOR_CLAIMED = 0;
    uint256 public constant PRESALE_PRICE = 50 * 10 ** 15; // $0.50 in wei
    uint256 public constant TRANSACTION_THRESHOLD = 1 * 10 ** 6 * 10 ** 18; // 1m Transaction threshold for requiring a secret code

    uint256 public constant MIN_BALANCE_TO_INCREASE_SUPPLY = 2 * 10 ** 18; // 2 is min balance

    uint256 public presaleStartTime;
    // Mapping to track buyer purchase timestamps
    mapping(address => uint256) public lastPurchaseTimestamp;
    string private secretCode;

    mapping(address => bool) private admins;

    /**
     * Only admin modifier
     */
    modifier onlyAdmin() {
        require(admins[msg.sender] || msg.sender == owner(), "Not an admin");
        _;
    }

    /**
     * constructor
     */
    constructor() ERC20("PhilanthropyToken", "PTPH") {
        // Mint the initial supply to the contract owner
        _mint(address(this), MARKET_CAP);
        presaleStartTime = block.timestamp;

        // Transfer ownership to the contract deployer!
        // transferOwnership(msg.sender);
    }

    // Function to add or remove admins
    function setAdmin(address _admin, bool _status) external onlyAdmin {
        admins[_admin] = _status;
    }

    /**
     * Function to increase the market cap
     * @param amount uint256
     */
    function mint(uint256 amount) external onlyAdmin {
        uint256 currentSupply = totalSupply();
        require(
            currentSupply + amount <= MAX_TOTAL_SUPPLY,
            "Exceeds maximum total supply"
        );
        _mint(address(this), amount);
    }

    /**
     * Function to allow users to buy presale tokens
     * @param amount uint256
     */
    function buyPresaleTokens(uint256 amount) external payable {
        require(amount > 0, "Invalid purchase amount");
        require(
            block.timestamp >= presaleStartTime,
            "Presale has not started yet"
        );
        require(
            block.timestamp <= presaleStartTime + 182.5 days,
            "Presale has ended"
        );

        uint256 totalPrice = amount * PRESALE_PRICE;
        require(msg.value >= totalPrice, "Insufficient funds sent");

        // Calculate and check remaining presale allocation
        uint256 remainingPresaleAllocation = PRESALE_TOTAL_SOLD;
        require(
            amount <= remainingPresaleAllocation,
            "Not enough tokens available for purchase"
        );

        // Transfer tokens to the buyer
        _transfer(address(this), msg.sender, amount);

        // Update the buyer's last purchase timestamp
        lastPurchaseTimestamp[msg.sender] = block.timestamp;

        // Refund any excess funds sent
        if (msg.value > totalPrice) {
            payable(msg.sender).transfer(msg.value - totalPrice);
        }
        PRESALE_TOTAL_SOLD += amount;
    }

    /**
     * Function to distribute CHARITY_ALLOCATION to multiple addresses
     * @param recipients string<addresses>
     * @param amounts uint256
     */
    function initialRelease(
        address[] memory recipients,
        uint256[] memory amounts
    ) external onlyAdmin {
        require(
            recipients.length == amounts.length,
            "Array lengths do not match"
        );

        for (uint256 i = 0; i < recipients.length; i++) {
            address recipient = recipients[i];
            uint256 amount = amounts[i];

            require(recipient != address(0), "Invalid recipient address");
            require(amount > 0, "Invalid amount");

            TOTAL_INITIAL_RELEASED += amount;
            require(
                TOTAL_INITIAL_RELEASED <= CHARITY_ALLOCATION,
                "Total distribution exceeds CHARITY_ALLOCATION"
            );

            // Transfer tokens to the recipient
            _transfer(address(this), recipient, amount);
        }
    }

    /**
     * Function to distribute INVESTOR_ALLOCATION to multiple investors
     * @param investors address
     * @param amounts uint256
     */
    function claimInvestorTokens(
        address[] memory investors,
        uint256[] memory amounts
    ) external onlyAdmin {
        require(
            investors.length == amounts.length,
            "Array lengths do not match"
        );

        require(
            block.timestamp >= presaleStartTime + INVESTOR_LOCK_PERIOD,
            "Lock-up period not over"
        );

        for (uint256 i = 0; i < investors.length; i++) {
            address investor = investors[i];
            uint256 amount = amounts[i];

            require(investor != address(0), "Invalid investor address");
            require(amount > 0, "Invalid amount");

            TOTAL_INVESTOR_CLAIMED += amount;

            // Check if totalDistribution exceeds INVESTOR_ALLOCATION
            require(
                TOTAL_INVESTOR_CLAIMED <= INVESTOR_ALLOCATION,
                "Total distribution exceeds INVESTOR_ALLOCATION"
            );

            // Transfer tokens to the investor
            _transfer(address(this), investor, amount);
        }
    }

    // Function to set a secret code for transactions above the threshold
    function setSecretCode(string memory code) external onlyAdmin {
        secretCode = code;
    }

    /**
     * check secret code
     * @param code uint256
     */
    function checkSecretCode(string memory code) public view onlyOwner {
        require(
            keccak256(abi.encodePacked(code)) ==
                keccak256(abi.encodePacked(secretCode)),
            "Incorrect secret code"
        );
    }

    // Function to perform a transaction above the threshold with the correct secret code
    function transfer(
        address recipient,
        uint256 amount,
        string memory code
    ) external onlyAdmin {
        if (amount > TRANSACTION_THRESHOLD) {
            require(
                keccak256(abi.encodePacked(code)) ==
                    keccak256(abi.encodePacked(secretCode)),
                "Incorrect secret code"
            );
        }
        _transfer(address(this), recipient, amount);
    }

    function transferFrom(
        address recipient,
        uint256 amount,
        string memory code
    ) external {
        if (amount > TRANSACTION_THRESHOLD) {
            require(
                keccak256(abi.encodePacked(code)) ==
                    keccak256(abi.encodePacked(secretCode)),
                "Incorrect secret code"
            );
        }
        _transfer(msg.sender, recipient, amount);
    }

    /**
     * Function to automatically mint if the balance is below a certain threshold
     */
    function mintWhenNeedded() external onlyAdmin {
        uint256 currentBalance = balanceOf(address(this));
        if (currentBalance < MIN_BALANCE_TO_INCREASE_SUPPLY) {
            uint256 additionalSupply = MARKET_CAP;
            _mint(address(this), additionalSupply);
        }
    }

    // Custom burn function
    function burn(uint256 amount) public onlyAdmin {
        _burn(address(this), amount);
    }

    /**
     * Function to show available supply (minted balance) value
     * @return uint256
     */
    function getUnsudedSupplies() external view onlyAdmin returns (uint256) {
        return balanceOf(address(this));
    }

    /**
     * Function to show TOTAL_INITIAL_RELEASED value
     * @return uint256
     */
    function getTotalIInvestorAllocation()
        external
        view
        onlyAdmin
        returns (uint256)
    {
        return INVESTOR_ALLOCATION;
    }

    /**
     * Function to show TOTAL_INVESTOR_CLAIMED value
     * @return uint256
     */
    function getTotalInitialAllocation()
        external
        view
        onlyAdmin
        returns (uint256)
    {
        return CHARITY_ALLOCATION;
    }

    /**
     * Function to show TOTAL_INITIAL_RELEASED value
     * @return uint256
     */
    function getTotalInitialReleased()
        external
        view
        onlyAdmin
        returns (uint256)
    {
        return TOTAL_INITIAL_RELEASED;
    }

    /**
     * Function to show TOTAL_INVESTOR_CLAIMED value
     * @return uint256
     */
    function getTotalInvestorClaimed()
        external
        view
        onlyAdmin
        returns (uint256)
    {
        return TOTAL_INVESTOR_CLAIMED;
    }

    /**
     * Function to transfer tokens between TOTAL_INITIAL_RELEASED and TOTAL_INVESTOR_CLAIMED
     * @param amount uint256
     * @param fromInitialToInvestor boolean
     */
    function transferBetweenCategories(
        uint256 amount,
        bool fromInitialToInvestor
    ) external onlyAdmin {
        require(
            fromInitialToInvestor || TOTAL_INITIAL_RELEASED >= amount,
            "Insufficient tokens in INITIAL_RELEASED"
        );
        require(
            !fromInitialToInvestor || TOTAL_INVESTOR_CLAIMED >= amount,
            "Insufficient tokens in INVESTOR_CLAIMED"
        );

        if (fromInitialToInvestor) {
            CHARITY_ALLOCATION -= amount;
            INVESTOR_ALLOCATION += amount;
        } else {
            INVESTOR_ALLOCATION -= amount;
            CHARITY_ALLOCATION += amount;
        }

        _transfer(address(this), msg.sender, amount);
    }

    /**
     * Function to transfer tokens between TOTAL_INITIAL_RELEASED and TOTAL_INVESTOR_CLAIMED
     * @param amount uint256
     * @param fromInitialToInvestor boolean
     */
    function topupCategories(
        uint256 amount,
        bool fromInitialToInvestor
    ) external onlyAdmin {
        require(
            fromInitialToInvestor || CHARITY_ALLOCATION >= amount,
            "Insufficient tokens in INITIAL_RELEASED"
        );
        require(
            !fromInitialToInvestor || TOTAL_INVESTOR_CLAIMED >= amount,
            "Insufficient tokens in INVESTOR_CLAIMED"
        );

        if (fromInitialToInvestor) {
            CHARITY_ALLOCATION -= amount;
            INVESTOR_ALLOCATION += amount;
        } else {
            INVESTOR_ALLOCATION -= amount;
            CHARITY_ALLOCATION += amount;
        }

        // _transfer(address(this), msg.sender, amount);
    }

    // Function to perform a transaction above the threshold with an optional secret code
    function transferWithSecretCode(
        address recipient,
        uint256 amount,
        string memory code
    ) external {
        require(amount <= TRANSACTION_THRESHOLD, "Amount exceeds threshold");
        require(
            code.checkSecretCode(secretCode) || bytes(code).length == 0,
            "Incorrect secret code"
        );
        _transfer(msg.sender, recipient, amount);
    }

    /**
     * Function to top up CHARITY_ALLOCATION from the contract's available balance
     * @param amount uint256
     */
    function topUpCharityAllocation(uint256 amount) external onlyAdmin {
        uint256 availableBalance = balanceOf(address(this));
        require(amount <= availableBalance, "Exceeds available balance");
        CHARITY_ALLOCATION += amount;
        _transfer(address(this), address(this), amount);
    }

    /**
     * Function to top up INVESTOR_ALLOCATION from the contract's available balance
     * @param amount uint256
     */
    function topUpInvestorAllocation(uint256 amount) external onlyAdmin {
        uint256 availableBalance = balanceOf(address(this));
        require(amount <= availableBalance, "Exceeds available balance");
        INVESTOR_ALLOCATION += amount;
        _transfer(address(this), address(this), amount);
    }
}

// File: @openzeppelin/contracts/access/Ownable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (access/Ownable.sol)

pragma solidity ^0.8.0;

import "../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.
 */
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);
    }
}

// File: @openzeppelin/contracts/token/ERC20/ERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/ERC20.sol)

pragma solidity ^0.8.0;

import "./IERC20.sol";
import "./extensions/IERC20Metadata.sol";
import "../../utils/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 {}
}

// File: contracts/libs/Utils.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

library Utils {
    function topUpAllocation(uint256 availableBalance, uint256 amount, uint256 currentAllocation) internal pure returns (uint256) {
        require(amount <= availableBalance, "Exceeds available balance");
        return currentAllocation + amount;
    }
}

// File: contracts/libs/Security.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

library Security {
    function checkSecretCode(string memory providedCode, string storage storedCode) internal pure returns (bool) {
        return keccak256(abi.encodePacked(providedCode)) == keccak256(abi.encodePacked(storedCode));
    }
}

// File: contracts/libs/Admin.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

library Admin {
    function isOwnerOrAdmin(address owner, mapping(address => bool) storage admins, address account) internal view returns (bool) {
        return account == owner || admins[account];
    }
}

// File: @openzeppelin/contracts/utils/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: @openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol



// 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);
}

// File: @openzeppelin/contracts/token/ERC20/IERC20.sol



// 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);
}