Cryo Explorer Ethereum Mainnet

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

// solhint-disable-next-line interface-starts-with-i
interface AggregatorV3Interface {
  function decimals() external view returns (uint8);

  function description() external view returns (string memory);

  function version() external view returns (uint256);

  function getRoundData(
    uint80 _roundId
  ) external view returns (uint80 roundId, int256 answer, uint256 startedAt, uint256 updatedAt, uint80 answeredInRound);

  function latestRoundData()
    external
    view
    returns (uint80 roundId, int256 answer, uint256 startedAt, uint256 updatedAt, uint80 answeredInRound);
}

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

pragma solidity ^0.8.0;

import "../utils/ContextUpgradeable.sol";
import "../proxy/utils/Initializable.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 OwnableUpgradeable is Initializable, ContextUpgradeable {
    address private _owner;

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

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    function __Ownable_init() internal onlyInitializing {
        __Ownable_init_unchained();
    }

    function __Ownable_init_unchained() internal onlyInitializing {
        _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);
    }

    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[49] private __gap;
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (proxy/utils/Initializable.sol)

pragma solidity ^0.8.2;

import "../../utils/AddressUpgradeable.sol";

/**
 * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
 * behind a proxy. Since proxied contracts do not make use of a constructor, it's common to move constructor logic to an
 * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
 * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
 *
 * The initialization functions use a version number. Once a version number is used, it is consumed and cannot be
 * reused. This mechanism prevents re-execution of each "step" but allows the creation of new initialization steps in
 * case an upgrade adds a module that needs to be initialized.
 *
 * For example:
 *
 * [.hljs-theme-light.nopadding]
 * ```
 * contract MyToken is ERC20Upgradeable {
 *     function initialize() initializer public {
 *         __ERC20_init("MyToken", "MTK");
 *     }
 * }
 * contract MyTokenV2 is MyToken, ERC20PermitUpgradeable {
 *     function initializeV2() reinitializer(2) public {
 *         __ERC20Permit_init("MyToken");
 *     }
 * }
 * ```
 *
 * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
 * possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}.
 *
 * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
 * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
 *
 * [CAUTION]
 * ====
 * Avoid leaving a contract uninitialized.
 *
 * An uninitialized contract can be taken over by an attacker. This applies to both a proxy and its implementation
 * contract, which may impact the proxy. To prevent the implementation contract from being used, you should invoke
 * the {_disableInitializers} function in the constructor to automatically lock it when it is deployed:
 *
 * [.hljs-theme-light.nopadding]
 * ```
 * /// @custom:oz-upgrades-unsafe-allow constructor
 * constructor() {
 *     _disableInitializers();
 * }
 * ```
 * ====
 */
abstract contract Initializable {
    /**
     * @dev Indicates that the contract has been initialized.
     * @custom:oz-retyped-from bool
     */
    uint8 private _initialized;

    /**
     * @dev Indicates that the contract is in the process of being initialized.
     */
    bool private _initializing;

    /**
     * @dev Triggered when the contract has been initialized or reinitialized.
     */
    event Initialized(uint8 version);

    /**
     * @dev A modifier that defines a protected initializer function that can be invoked at most once. In its scope,
     * `onlyInitializing` functions can be used to initialize parent contracts. Equivalent to `reinitializer(1)`.
     */
    modifier initializer() {
        bool isTopLevelCall = !_initializing;
        require(
            (isTopLevelCall && _initialized < 1) || (!AddressUpgradeable.isContract(address(this)) && _initialized == 1),
            "Initializable: contract is already initialized"
        );
        _initialized = 1;
        if (isTopLevelCall) {
            _initializing = true;
        }
        _;
        if (isTopLevelCall) {
            _initializing = false;
            emit Initialized(1);
        }
    }

    /**
     * @dev A modifier that defines a protected reinitializer function that can be invoked at most once, and only if the
     * contract hasn't been initialized to a greater version before. In its scope, `onlyInitializing` functions can be
     * used to initialize parent contracts.
     *
     * `initializer` is equivalent to `reinitializer(1)`, so a reinitializer may be used after the original
     * initialization step. This is essential to configure modules that are added through upgrades and that require
     * initialization.
     *
     * Note that versions can jump in increments greater than 1; this implies that if multiple reinitializers coexist in
     * a contract, executing them in the right order is up to the developer or operator.
     */
    modifier reinitializer(uint8 version) {
        require(!_initializing && _initialized < version, "Initializable: contract is already initialized");
        _initialized = version;
        _initializing = true;
        _;
        _initializing = false;
        emit Initialized(version);
    }

    /**
     * @dev Modifier to protect an initialization function so that it can only be invoked by functions with the
     * {initializer} and {reinitializer} modifiers, directly or indirectly.
     */
    modifier onlyInitializing() {
        require(_initializing, "Initializable: contract is not initializing");
        _;
    }

    /**
     * @dev Locks the contract, preventing any future reinitialization. This cannot be part of an initializer call.
     * Calling this in the constructor of a contract will prevent that contract from being initialized or reinitialized
     * to any version. It is recommended to use this to lock implementation contracts that are designed to be called
     * through proxies.
     */
    function _disableInitializers() internal virtual {
        require(!_initializing, "Initializable: contract is initializing");
        if (_initialized < type(uint8).max) {
            _initialized = type(uint8).max;
            emit Initialized(type(uint8).max);
        }
    }
}

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

pragma solidity ^0.8.0;

import "../utils/ContextUpgradeable.sol";
import "../proxy/utils/Initializable.sol";

/**
 * @dev Contract module which allows children to implement an emergency stop
 * mechanism that can be triggered by an authorized account.
 *
 * This module is used through inheritance. It will make available the
 * modifiers `whenNotPaused` and `whenPaused`, which can be applied to
 * the functions of your contract. Note that they will not be pausable by
 * simply including this module, only once the modifiers are put in place.
 */
abstract contract PausableUpgradeable is Initializable, ContextUpgradeable {
    /**
     * @dev Emitted when the pause is triggered by `account`.
     */
    event Paused(address account);

    /**
     * @dev Emitted when the pause is lifted by `account`.
     */
    event Unpaused(address account);

    bool private _paused;

    /**
     * @dev Initializes the contract in unpaused state.
     */
    function __Pausable_init() internal onlyInitializing {
        __Pausable_init_unchained();
    }

    function __Pausable_init_unchained() internal onlyInitializing {
        _paused = false;
    }

    /**
     * @dev Modifier to make a function callable only when the contract is not paused.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    modifier whenNotPaused() {
        _requireNotPaused();
        _;
    }

    /**
     * @dev Modifier to make a function callable only when the contract is paused.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    modifier whenPaused() {
        _requirePaused();
        _;
    }

    /**
     * @dev Returns true if the contract is paused, and false otherwise.
     */
    function paused() public view virtual returns (bool) {
        return _paused;
    }

    /**
     * @dev Throws if the contract is paused.
     */
    function _requireNotPaused() internal view virtual {
        require(!paused(), "Pausable: paused");
    }

    /**
     * @dev Throws if the contract is not paused.
     */
    function _requirePaused() internal view virtual {
        require(paused(), "Pausable: not paused");
    }

    /**
     * @dev Triggers stopped state.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    function _pause() internal virtual whenNotPaused {
        _paused = true;
        emit Paused(_msgSender());
    }

    /**
     * @dev Returns to normal state.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    function _unpause() internal virtual whenPaused {
        _paused = false;
        emit Unpaused(_msgSender());
    }

    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[49] private __gap;
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (security/ReentrancyGuard.sol)

pragma solidity ^0.8.0;
import "../proxy/utils/Initializable.sol";

/**
 * @dev Contract module that helps prevent reentrant calls to a function.
 *
 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
 * available, which can be applied to functions to make sure there are no nested
 * (reentrant) calls to them.
 *
 * Note that because there is a single `nonReentrant` guard, functions marked as
 * `nonReentrant` may not call one another. This can be worked around by making
 * those functions `private`, and then adding `external` `nonReentrant` entry
 * points to them.
 *
 * TIP: If you would like to learn more about reentrancy and alternative ways
 * to protect against it, check out our blog post
 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
 */
abstract contract ReentrancyGuardUpgradeable is Initializable {
    // Booleans are more expensive than uint256 or any type that takes up a full
    // word because each write operation emits an extra SLOAD to first read the
    // slot's contents, replace the bits taken up by the boolean, and then write
    // back. This is the compiler's defense against contract upgrades and
    // pointer aliasing, and it cannot be disabled.

    // The values being non-zero value makes deployment a bit more expensive,
    // but in exchange the refund on every call to nonReentrant will be lower in
    // amount. Since refunds are capped to a percentage of the total
    // transaction's gas, it is best to keep them low in cases like this one, to
    // increase the likelihood of the full refund coming into effect.
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;

    uint256 private _status;

    function __ReentrancyGuard_init() internal onlyInitializing {
        __ReentrancyGuard_init_unchained();
    }

    function __ReentrancyGuard_init_unchained() internal onlyInitializing {
        _status = _NOT_ENTERED;
    }

    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and making it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        // On the first call to nonReentrant, _notEntered will be true
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");

        // Any calls to nonReentrant after this point will fail
        _status = _ENTERED;

        _;

        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _status = _NOT_ENTERED;
    }

    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[49] private __gap;
}

// 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 IERC20Upgradeable {
    /**
     * @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 (last updated v4.7.0) (utils/Address.sol)

pragma solidity ^0.8.1;

/**
 * @dev Collection of functions related to the address type
 */
library AddressUpgradeable {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     *
     * [IMPORTANT]
     * ====
     * You shouldn't rely on `isContract` to protect against flash loan attacks!
     *
     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
     * constructor.
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize/address.code.length, which returns 0
        // for contracts in construction, since the code is only stored at the end
        // of the constructor execution.

        return account.code.length > 0;
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain `call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCall(target, data, "Address: low-level call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }

    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        require(isContract(target), "Address: call to non-contract");

        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");

        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly
                /// @solidity memory-safe-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

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

pragma solidity ^0.8.0;
import "../proxy/utils/Initializable.sol";

/**
 * @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 ContextUpgradeable is Initializable {
    function __Context_init() internal onlyInitializing {
    }

    function __Context_init_unchained() internal onlyInitializing {
    }
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

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

    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[50] private __gap;
}

// SPDX-License-Identifier: MIT
pragma solidity 0.8.19;

interface IReferralRewards {
    function addReward(address referrer, uint256 ethAmount, uint256 usdtAmount) external payable;
}

// SPDX-License-Identifier: MIT
pragma solidity 0.8.19;

interface StakingManager {
    function depositByPresale(address _user, uint256 _amount) external;
}

//SPDX-License-Identifier: MIT
pragma solidity 0.8.19;

import "@openzeppelin/contracts-upgradeable/token/ERC20/IERC20Upgradeable.sol";
import "@openzeppelin/contracts-upgradeable/security/PausableUpgradeable.sol";
import "@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol";
import "@openzeppelin/contracts-upgradeable/security/ReentrancyGuardUpgradeable.sol";
import "@chainlink/contracts/src/v0.8/shared/interfaces/AggregatorV3Interface.sol";
import "./interfaces/IStakingManager.sol";
import "./interfaces/IReferralRewards.sol";


contract Presale is Initializable, ReentrancyGuardUpgradeable, OwnableUpgradeable, PausableUpgradeable {
  uint256 public totalTokensSold;
  uint256 public startTime;
  uint256 public endTime;
  address public saleToken;
  uint256 public baseDecimals;
  uint256 public maxTokensToBuy;
  uint256 public currentStep;
  uint256 public checkPoint;
  uint256 public usdRaised;
  uint256 public timeConstant;
  uint256 public totalBoughtAndStaked;
  uint256[][3] public rounds;
  uint256[] public prevCheckpoints;
  uint256[] public remainingTokensTracker;
  uint256[] public percentages;
  address[] public wallets;
  address public paymentWallet;
  bool public dynamicTimeFlag;
  bool public whitelistClaimOnly;
  bool public stakingWhitelistStatus;

  IERC20Upgradeable public USDTInterface;
  StakingManager public stakingManagerInterface;
  AggregatorV3Interface public priceFeed;

  mapping(address => uint256) public userDeposits;
  mapping(address => bool) public hasClaimed;
  mapping(address => bool) public isBlacklisted;
  mapping(address => bool) public isWhitelisted;

  uint256 public referralRewardPercentage;
  IReferralRewards public referralRewards;

  event SaleTimeSet(uint256 _start, uint256 _end, uint256 timestamp);
  event SaleTimeUpdated(bytes32 indexed key, uint256 prevValue, uint256 newValue, uint256 timestamp);
  event TokensBought(address indexed user, uint256 indexed tokensBought, address indexed purchaseToken, uint256 amountPaid, uint256 usdEq, uint256 timestamp);
  event TokensAdded(address indexed token, uint256 noOfTokens, uint256 timestamp);
  event TokensClaimed(address indexed user, uint256 amount, uint256 timestamp);
  event ClaimStartUpdated(uint256 prevValue, uint256 newValue, uint256 timestamp);
  event MaxTokensUpdated(uint256 prevValue, uint256 newValue, uint256 timestamp);
  event TokensBoughtAndStaked(address indexed user, uint256 indexed tokensBought, address indexed purchaseToken, uint256 amountPaid, uint256 usdEq, uint256 timestamp);
  event TokensClaimedAndStaked(address indexed user, uint256 amount, uint256 timestamp);

  /**
   * @dev To initialize the contract with price feed address
   */
  function initialize(address _priceFeed, address _usdtAddress) public initializer {
    __Ownable_init();  // Initialize owner
    priceFeed = AggregatorV3Interface(_priceFeed);
    USDTInterface = IERC20Upgradeable(_usdtAddress);
    baseDecimals = 1000000000000000000;
    referralRewardPercentage = 15; // Default 15%
  }

  /**
   * @dev To pause the presale
   */
  function pause() external onlyOwner {
    _pause();
  }

  /**
   * @dev To unpause the presale
   */
  function unpause() external onlyOwner {
    _unpause();
  }

  /**
   * @dev To calculate the price in USD for given amount of tokens.
   * @param _amount No of tokens
   */
  function calculatePrice(uint256 _amount) public view returns (uint256) {
    uint256 USDTAmount;
    uint256 total = checkPoint == 0 ? totalTokensSold : checkPoint;
    require(_amount <= maxTokensToBuy, "Amount exceeds max tokens to buy");
    if (_amount + total > rounds[0][currentStep] || block.timestamp >= rounds[2][currentStep]) {
      require(currentStep < (rounds[0].length - 1), "Wrong params");
      if (block.timestamp >= rounds[2][currentStep]) {
        require(rounds[0][currentStep] + _amount <= rounds[0][currentStep + 1], "Cant Purchase More in individual tx");
        USDTAmount = _amount * rounds[1][currentStep + 1];
      } else {
        uint256 tokenAmountForCurrentPrice = rounds[0][currentStep] - total;
        USDTAmount = tokenAmountForCurrentPrice * rounds[1][currentStep] + (_amount - tokenAmountForCurrentPrice) * rounds[1][currentStep + 1];
      }
    } else USDTAmount = _amount * rounds[1][currentStep];
    return USDTAmount;
  }

  /**
   * @dev To update the sale times
   * @param _startTime New start time
   * @param _endTime New end time
   */
  function changeSaleTimes(uint256 _startTime, uint256 _endTime) external onlyOwner {
    require(_startTime > 0 || _endTime > 0, "Invalid parameters");
    if (_startTime > 0) {
      require(block.timestamp < startTime, "Sale already started");
      require(block.timestamp < _startTime, "Sale time in past");
      uint256 prevValue = startTime;
      startTime = _startTime;
      emit SaleTimeUpdated(bytes32("START"), prevValue, _startTime, block.timestamp);
    }
    if (_endTime > 0) {
      require(_endTime > startTime, "Invalid endTime");
      uint256 prevValue = endTime;
      endTime = _endTime;
      emit SaleTimeUpdated(bytes32("END"), prevValue, _endTime, block.timestamp);
    }
  }

  /**
   * @dev To get latest ETH price in 10**18 format
   */
  function getLatestPrice() public view returns (uint256) {
      (, int256 price, , , ) = priceFeed.latestRoundData();
      price = price * (10 ** 10); // ETH/USD price with 18 decimals
      return uint256(price);
  }

  function setSplits(address[] memory _wallets, uint256[] memory _percentages) public onlyOwner {
    require(_wallets.length == _percentages.length, "Mismatched arrays");
    delete wallets;
    delete percentages;
    uint256 totalPercentage = 0;

    for (uint256 i = 0; i < _wallets.length; i++) {
      require(_percentages[i] > 0, "Percentage must be greater than 0");
      totalPercentage += _percentages[i];
      wallets.push(_wallets[i]);
      percentages.push(_percentages[i]);
    }

    require(totalPercentage == 100, "Total percentage must equal 100");
  }

  modifier checkSaleState(uint256 amount) {
    require(block.timestamp >= startTime && block.timestamp <= endTime, "Invalid time for buying");
    require(amount > 0, "Invalid sale amount");
    _;
  }

  /**
   * @dev To buy into a presale using USDT
   * @param amount No of tokens to buy
   * @param stake boolean flag for token staking
   * @param referrer referrer address
   */
  function buyWithUSDT(uint256 amount, bool stake, address referrer) external checkSaleState(amount) whenNotPaused nonReentrant returns (bool) {
    uint256 usdPrice = calculatePrice(amount);
    totalTokensSold += amount;
    uint256 price = usdPrice / (10 ** 12);
    if (checkPoint != 0) checkPoint += amount;
    uint256 total = totalTokensSold > checkPoint ? totalTokensSold : checkPoint;
    if (total > rounds[0][currentStep] || block.timestamp >= rounds[2][currentStep]) {
      if (block.timestamp >= rounds[2][currentStep]) {
        checkPoint = rounds[0][currentStep] + amount;
      }
      if (dynamicTimeFlag) {
        manageTimeDiff();
      }
      uint256 unsoldTokens = total > rounds[0][currentStep] ? 0 : rounds[0][currentStep] - total - amount;
      remainingTokensTracker.push(unsoldTokens);
      currentStep += 1;
    }
    if (stake) {
      if (stakingWhitelistStatus) {
        require(isWhitelisted[_msgSender()], "User not whitelisted for stake");
      }
      stakingManagerInterface.depositByPresale(_msgSender(), amount * baseDecimals);
      totalBoughtAndStaked += amount;
      emit TokensBoughtAndStaked(_msgSender(), amount, address(USDTInterface), price, usdPrice, block.timestamp);
    } else {
      userDeposits[_msgSender()] += (amount * baseDecimals);
      emit TokensBought(_msgSender(), amount, address(USDTInterface), price, usdPrice, block.timestamp);
    }

    usdRaised += usdPrice;
    uint256 ourAllowance = USDTInterface.allowance(_msgSender(), address(this));
    require(price <= ourAllowance, "Make sure to add enough allowance");
    // referral rewards
    if (referrer != address(0) && referrer != _msgSender() && address(referralRewards) != address(0)) {
        uint256 referralReward = (price * referralRewardPercentage) / 100;
        price -= referralReward; 
        require(
            USDTInterface.transferFrom(_msgSender(), address(referralRewards), referralReward),
            "USDT transfer to referral contract failed"
        );
        referralRewards.addReward(referrer, 0, referralReward);
    }
    splitUSDTValue(price);

    return true;
  }

  /**
   * @dev To buy into a presale using ETH
   * @param amount No of tokens to buy
   * @param stake boolean flag for token staking
   * @param referrer referrer address
   */
  function buyWithEth(uint256 amount, bool stake, address referrer) external payable checkSaleState(amount) whenNotPaused nonReentrant returns (bool) {
    uint256 usdPrice = calculatePrice(amount);
    uint256 ethAmount = (usdPrice * baseDecimals) / getLatestPrice();
    require(msg.value >= ethAmount, "Less payment");
    uint256 excess = msg.value - ethAmount;
    totalTokensSold += amount;
    if (checkPoint != 0) checkPoint += amount;
    uint256 total = totalTokensSold > checkPoint ? totalTokensSold : checkPoint;
    if (total > rounds[0][currentStep] || block.timestamp >= rounds[2][currentStep]) {
      if (block.timestamp >= rounds[2][currentStep]) {
        checkPoint = rounds[0][currentStep] + amount;
      }
      if (dynamicTimeFlag) {
        manageTimeDiff();
      }
      uint256 unsoldTokens = total > rounds[0][currentStep] ? 0 : rounds[0][currentStep] - total - amount;
      remainingTokensTracker.push(unsoldTokens);
      currentStep += 1;
    }
    if (stake) {
      if (stakingWhitelistStatus) {
        require(isWhitelisted[_msgSender()], "User not whitelisted for stake");
      }
      stakingManagerInterface.depositByPresale(_msgSender(), amount * baseDecimals);
      totalBoughtAndStaked += amount;
      emit TokensBoughtAndStaked(_msgSender(), amount, address(0), ethAmount, usdPrice, block.timestamp);
    } else {
      userDeposits[_msgSender()] += (amount * baseDecimals);
      emit TokensBought(_msgSender(), amount, address(0), ethAmount, usdPrice, block.timestamp);
    }
    usdRaised += usdPrice;
    // Handle referral rewards
    if (referrer != address(0) && referrer != _msgSender() && address(referralRewards) != address(0)) {
        uint256 referralReward = (ethAmount * referralRewardPercentage) / 100;
        ethAmount -= referralReward; // Deduct referral reward from total
        referralRewards.addReward{value: referralReward}(referrer, referralReward, 0);
    }
    splitETHValue(ethAmount);
    if (excess > 0) sendValue(payable(_msgSender()), excess);
    return true;
  }

  /**
   * @dev Helper funtion to get ETH price for given amount
   * @param amount No of tokens to buy
   */
  function ethBuyHelper(uint256 amount) external view returns (uint256 ethAmount) {
    uint256 usdPrice = calculatePrice(amount);
    ethAmount = (usdPrice * baseDecimals) / getLatestPrice();
  }

  /**
   * @dev Helper funtion to get USDT price for given amount
   * @param amount No of tokens to buy
   */
  function usdtBuyHelper(uint256 amount) external view returns (uint256 usdPrice) {
    usdPrice = calculatePrice(amount);
    usdPrice = usdPrice / (10 ** 12);
  }

  function sendValue(address payable recipient, uint256 amount) internal {
    require(address(this).balance >= amount, "Low balance");
    (bool success, ) = recipient.call{value: amount}("");
    require(success, "ETH Payment failed");
  }

  function splitETHValue(uint256 _amount) internal {
    if (wallets.length == 0) {
      require(paymentWallet != address(0), "Payment wallet not set");
      sendValue(payable(paymentWallet), _amount);
    } else {
      uint256 tempCalc;
      for (uint256 i = 0; i < wallets.length; i++) {
        uint256 amountToTransfer = (_amount * percentages[i]) / 100;
        sendValue(payable(wallets[i]), amountToTransfer);
        tempCalc += amountToTransfer;
      }
      if ((_amount - tempCalc) > 0) {
        sendValue(payable(wallets[wallets.length - 1]), _amount - tempCalc);
      }
    }
  }

  function splitUSDTValue(uint256 _amount) internal {
    if (wallets.length == 0) {
      require(paymentWallet != address(0), "Payment wallet not set");
      (bool success, ) = address(USDTInterface).call(abi.encodeWithSignature("transferFrom(address,address,uint256)", _msgSender(), paymentWallet, _amount));
      require(success, "Token payment failed");
    } else {
      uint256 tempCalc;
      for (uint256 i = 0; i < wallets.length; i++) {
        uint256 amountToTransfer = (_amount * percentages[i]) / 100;
        (bool success, ) = address(USDTInterface).call(abi.encodeWithSignature("transferFrom(address,address,uint256)", _msgSender(), wallets[i], amountToTransfer));
        require(success, "Token payment failed");
        tempCalc += amountToTransfer;
      }
      if ((_amount - tempCalc) > 0) {
        (bool success, ) = address(USDTInterface).call(abi.encodeWithSignature("transferFrom(address,address,uint256)", _msgSender(), wallets[wallets.length - 1], _amount - tempCalc));
        require(success, "Token payment failed");
      }
    }
  }

  /**
   * @dev To set the claim start time and sale token address by the owner
   * @param _startTime start time
   * @param _endTime start time
   * @param noOfTokens no of tokens to add to the contract
   * @param _saleToken sale toke address
   */
  function startClaim(uint256 _startTime, uint256 _endTime, uint256 noOfTokens, address _saleToken, address _stakingManagerAddress) external onlyOwner returns (bool) {
    require(_saleToken != address(0), "Zero token address");
    startTime = _startTime;
    endTime = _endTime;
    saleToken = _saleToken;
    whitelistClaimOnly = true;
    stakingManagerInterface = StakingManager(_stakingManagerAddress);
    IERC20Upgradeable(_saleToken).approve(_stakingManagerAddress, type(uint256).max);
    bool success = IERC20Upgradeable(_saleToken).transferFrom(_msgSender(), address(this), noOfTokens);
    require(success, "Token transfer failed");
    emit TokensAdded(_saleToken, noOfTokens, block.timestamp);
    return true;
  }

  /**
   * @dev To set status for claim whitelisting
   * @param _status bool value
   */
  function setStakingWhitelistStatus(bool _status) external onlyOwner {
    stakingWhitelistStatus = _status;
  }

  function changeMaxTokensToBuy(uint256 _maxTokensToBuy) external onlyOwner {
    require(_maxTokensToBuy > 0, "Zero max tokens to buy value");
    uint256 prevValue = maxTokensToBuy;
    maxTokensToBuy = _maxTokensToBuy;
    emit MaxTokensUpdated(prevValue, _maxTokensToBuy, block.timestamp);
  }

  function changeRoundsData(uint256[][3] memory _rounds) external onlyOwner {
    rounds = _rounds;
  }

  /**
    * @dev Set referral rewards contract
    */
  function setReferralRewardsContract(address _referralRewards) external onlyOwner {
      require(_referralRewards != address(0), "Invalid referral contract");
      referralRewards = IReferralRewards(_referralRewards);
  }

  /**
    * @dev Set referral reward percentage
    */
  function setReferralRewardPercentage(uint256 _percentage) external onlyOwner {
      require(_percentage <= 100, "Percentage cannot exceed 100");
      referralRewardPercentage = _percentage;
  }

  /**
   * @dev To add users to blacklist which restricts blacklisted users from claiming
   * @param _usersToBlacklist addresses of the users
   */
  function blacklistUsers(address[] calldata _usersToBlacklist) external onlyOwner {
    for (uint256 i = 0; i < _usersToBlacklist.length; i++) {
      isBlacklisted[_usersToBlacklist[i]] = true;
    }
  }

  /**
   * @dev To remove users from blacklist which restricts blacklisted users from claiming
   * @param _userToRemoveFromBlacklist addresses of the users
   */
  function removeFromBlacklist(address[] calldata _userToRemoveFromBlacklist) external onlyOwner {
    for (uint256 i = 0; i < _userToRemoveFromBlacklist.length; i++) {
      isBlacklisted[_userToRemoveFromBlacklist[i]] = false;
    }
  }

  /**
   * @dev To add users to whitelist which restricts users from claiming if claimWhitelistStatus is true
   * @param _usersToWhitelist addresses of the users
   */
  function whitelistUsers(address[] calldata _usersToWhitelist) external onlyOwner {
    for (uint256 i = 0; i < _usersToWhitelist.length; i++) {
      isWhitelisted[_usersToWhitelist[i]] = true;
    }
  }

  /**
   * @dev To remove users from whitelist which restricts users from claiming if claimWhitelistStatus is true
   * @param _userToRemoveFromWhitelist addresses of the users
   */
  function removeFromWhitelist(address[] calldata _userToRemoveFromWhitelist) external onlyOwner {
    for (uint256 i = 0; i < _userToRemoveFromWhitelist.length; i++) {
      isWhitelisted[_userToRemoveFromWhitelist[i]] = false;
    }
  }

  /**
   * @dev To set status for claim whitelisting
   * @param _status bool value
   */
  function setClaimWhitelistStatus(bool _status) external onlyOwner {
    whitelistClaimOnly = _status;
  }

  /**
   * @dev To set payment wallet address
   * @param _newPaymentWallet new payment wallet address
   */
  function changePaymentWallet(address _newPaymentWallet) external onlyOwner {
    require(_newPaymentWallet != address(0), "address cannot be zero");
    paymentWallet = _newPaymentWallet;
  }

  /**
   * @dev To manage time gap between two rounds
   */
  function manageTimeDiff() internal {
    for (uint256 i; i < rounds[2].length - currentStep; i++) {
      rounds[2][currentStep + i] = block.timestamp + i * timeConstant;
    }
  }

  /**
   * @dev To set time constant for manageTimeDiff()
   * @param _timeConstant time in <days>*24*60*60 format
   */
  function setTimeConstant(uint256 _timeConstant) external onlyOwner {
    timeConstant = _timeConstant;
  }

  /**
   * @dev To get array of round details at once
   * @param _no array index
   */
  function roundDetails(uint256 _no) external view returns (uint256[] memory) {
    return rounds[_no];
  }

  /**
   * @dev To increment the rounds from backend
   */
  function incrementCurrentStep() external onlyOwner {
      prevCheckpoints.push(checkPoint);
      if (dynamicTimeFlag) {
          manageTimeDiff();
      }
      if (checkPoint < rounds[0][currentStep]) {
          if (currentStep == 0) {
              remainingTokensTracker.push(rounds[0][currentStep] - totalTokensSold);
          } else {
              remainingTokensTracker.push(rounds[0][currentStep] - checkPoint);
          }
          checkPoint = rounds[0][currentStep];
      }
      currentStep++;
  }


  /**
   * @dev To change details of the round
   * @param _step round for which you want to change the details
   * @param _checkpoint token tracker amount
   */
  function setCurrentStep(uint256 _step, uint256 _checkpoint) external onlyOwner {
    currentStep = _step;
    checkPoint = _checkpoint;
  }

  /**
   * @dev To set time shift functionality on/off
   * @param _dynamicTimeFlag bool value
   */
  function setDynamicTimeFlag(bool _dynamicTimeFlag) external onlyOwner {
    dynamicTimeFlag = _dynamicTimeFlag;
  }

  /**
   * @dev     Function to return remainingTokenTracker Array
   */
  function trackRemainingTokens() external view returns (uint256[] memory) {
    return remainingTokensTracker;
  }

  /**
   * @dev     To update remainingTokensTracker Array
   * @param   _unsoldTokens  input parameters in uint256 array format
   */
  function setRemainingTokensArray(uint256[] memory _unsoldTokens) public onlyOwner {
    require(_unsoldTokens.length != 0, "cannot update invalid values");
    delete remainingTokensTracker;
    for (uint256 i = 0; i < _unsoldTokens.length; i++) {
      remainingTokensTracker.push(_unsoldTokens[i]);
    }
  }

  function withdrawRemainingTokens() external onlyOwner {
      require(block.timestamp > endTime, "Presale is still ongoing");
      uint256 remainingTokens = IERC20Upgradeable(saleToken).balanceOf(address(this));
      require(remainingTokens > 0, "No remaining tokens to withdraw");
      IERC20Upgradeable(saleToken).transfer(owner(), remainingTokens);
  }

  /**
   * @dev To claim tokens after claiming starts
   */
  function claim() external whenNotPaused returns (bool) {
    require(saleToken != address(0), "Sale token not added");
    require(!isBlacklisted[_msgSender()], "This Address is Blacklisted");
    if (whitelistClaimOnly) {
      require(isWhitelisted[_msgSender()], "User not whitelisted for claim");
    }
    require(block.timestamp >= endTime, "Claim has not started yet");
    require(!hasClaimed[_msgSender()], "Already claimed");
    hasClaimed[_msgSender()] = true;
    uint256 amount = userDeposits[_msgSender()];
    require(amount > 0, "Nothing to claim");
    delete userDeposits[_msgSender()];
    bool success = IERC20Upgradeable(saleToken).transfer(_msgSender(), amount);
    require(success, "Token transfer failed");
    emit TokensClaimed(_msgSender(), amount, block.timestamp);
    return true;
  }

  function claimAndStake() external whenNotPaused returns (bool) {
    require(saleToken != address(0), "Sale token not added");
    require(!isBlacklisted[_msgSender()], "This Address is Blacklisted");
    if (stakingWhitelistStatus) {
      require(isWhitelisted[_msgSender()], "User not whitelisted for stake");
    }
    uint256 amount = userDeposits[_msgSender()];
    require(amount > 0, "Nothing to stake");
    stakingManagerInterface.depositByPresale(_msgSender(), amount);
    delete userDeposits[_msgSender()];
    emit TokensClaimedAndStaked(_msgSender(), amount, block.timestamp);
    return true;
  }
}