//SPDX-License-Identifier: MIT

pragma solidity 0.8.19;
// File: @chainlink/contracts/src/v0.8/interfaces/AggregatorV3Interface.sol

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
    );
}

// File: @openzeppelin/contracts/security/ReentrancyGuard.sol


// OpenZeppelin Contracts (last updated v4.8.0) (security/ReentrancyGuard.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 ReentrancyGuard {
    // 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;

    constructor() {
        _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() {
        _nonReentrantBefore();
        _;
        _nonReentrantAfter();
    }

    function _nonReentrantBefore() private {
        // On the first call to nonReentrant, _status will be _NOT_ENTERED
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");

        // Any calls to nonReentrant after this point will fail
        _status = _ENTERED;
    }

    function _nonReentrantAfter() private {
        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _status = _NOT_ENTERED;
    }
}

// File: @openzeppelin/contracts/utils/math/SafeMath.sol


// OpenZeppelin Contracts (last updated v4.6.0) (utils/math/SafeMath.sol)



// CAUTION
// This version of SafeMath should only be used with Solidity 0.8 or later,
// because it relies on the compiler's built in overflow checks.

/**
 * @dev Wrappers over Solidity's arithmetic operations.
 *
 * NOTE: `SafeMath` is generally not needed starting with Solidity 0.8, since the compiler
 * now has built in overflow checking.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            uint256 c = a + b;
            if (c < a) return (false, 0);
            return (true, c);
        }
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b > a) return (false, 0);
            return (true, a - b);
        }
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
            // benefit is lost if 'b' is also tested.
            // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
            if (a == 0) return (true, 0);
            uint256 c = a * b;
            if (c / a != b) return (false, 0);
            return (true, c);
        }
    }

    /**
     * @dev Returns the division of two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a / b);
        }
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a % b);
        }
    }

    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        return a + b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return a - b;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        return a * b;
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator.
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return a / b;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return a % b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {trySub}.
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b <= a, errorMessage);
            return a - b;
        }
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a / b;
        }
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting with custom message when dividing by zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryMod}.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a % b;
        }
    }
}

// File: @openzeppelin/contracts/token/ERC20/IERC20.sol


// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)



/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);

    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `to`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address to, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `from` to `to` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) external returns (bool);
}

// File: @openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol


// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.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/interfaces/IERC20Metadata.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 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/access/Ownable.sol


// OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)



/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor() {
        _transferOwnership(_msgSender());
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        _checkOwner();
        _;
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if the sender is not the owner.
     */
    function _checkOwner() internal view virtual {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}

// File: contracts/OracleICO.sol


contract OracleICOUsdtEth is Context, ReentrancyGuard, Ownable {
    using SafeMath for uint256;

    struct User {
        uint256 totalBought;
        uint256 totalWithdrawn;
        uint256 contribution;
        uint256 lastWithdrawTime;
    }

    struct Sale {
        address wallet;
        uint256 usdtRate; //Price of 1 whole token in usdt
        uint256 usdtRaised;
        uint256 hardCap; //In usdt
        uint256 capPerWallet; //In usdt
        bool isActive;
    }

    mapping(uint8 => mapping(address => User)) public users;
    Sale[] public sales;

    IERC20Metadata public immutable token;
    // DAI/ETH in bsc mainnet
    AggregatorV3Interface internal constant USDT_ETH =
        AggregatorV3Interface(0xEe9F2375b4bdF6387aa8265dD4FB8F16512A1d46);// chainlink USDT_ETH price oracle;
    //USDT testnet     
    IERC20 internal constant USDT = IERC20(0xdAC17F958D2ee523a2206206994597C13D831ec7);    //USDT address

    uint8 public currentRound;

    event TokensPurchased(address indexed purchaser, uint256 value, uint256 amount, uint8 round);
    event Withdraw(uint256 tokensToSend, uint256 timestamp);

    modifier onlyActive(uint8 _round) {
        require(sales[_round].isActive, "Sale not active");
        _;
    }

    constructor(
         
        
    ) {
        sales.push(
            Sale({
                isActive: true,
                usdtRate: 2500,
                wallet: 0x93b72Ec24A6d90d3ce01616cA494e64802A7C8be, //owner
                hardCap: 75000 * 1e6, //75000 USDT
                capPerWallet: 2500 * 1e6, //2500 USDT
                usdtRaised: 0
            })
        );

        token = IERC20Metadata(0x345992CF0fb6Cf1dBaFEC87509a4395cBc4854D0); //token address
    }

    //_round : Round Id
    //_token : Address of token used to purchase (address(0) for eth)
    //_amount : Amount of token you want to purchase
    function buyTokens(
        uint8 _round,
        address _token,
        uint256 _amount
    ) public payable onlyActive(_round) nonReentrant {
        uint256 priceToken = getPriceInUSDT(_amount,_round);
        _preValidatePurchase(msg.sender, priceToken, currentRound);
        sales[_round].usdtRaised = sales[_round].usdtRaised.add(priceToken);
        users[_round][msg.sender].contribution = users[_round][msg.sender].contribution.add(priceToken);

        if(_token == address(USDT)){
            (bool success, ) = address(USDT).call(
            abi.encodeWithSignature(
                "transferFrom(address,address,uint256)",
                _msgSender(),
                sales[_round].wallet,
                priceToken
            )
        );
        require(success, "Token payment failed");
        } else if(_token == address(0)){
            uint256 priceInETH = convertUSDToETH(priceToken);
            require(msg.value >= priceInETH,"Not enough funds sent");
            (bool os,) = sales[_round].wallet.call{value: msg.value}("");
            require (os, "eth transfer failed");
        } else {
            revert("Invalid token for payment");
        }

        _deliverTokens(msg.sender, _amount, _round);
        emit TokensPurchased(msg.sender, priceToken, _amount, _round);
    }

    function _preValidatePurchase(
        address beneficiary,
        uint256 amount,
        uint8 round
    ) internal view {
        require(beneficiary != address(0), "Crowdsale: beneficiary is the zero address");
        require(amount != 0, "Crowdsale: amount is 0");
        require(
            users[round][beneficiary].contribution.add(amount) <= sales[round].capPerWallet,
            "Amoout exceeds user limit"
        );
        require(sales[round].usdtRaised.add(amount) <= sales[round].hardCap, "Amount exceeds round limit");
    }

    function _deliverTokens(
        address beneficiary,
        uint256 tokenAmount,
        uint8 round
    ) internal {
        users[round][beneficiary].totalBought = users[round][beneficiary].totalBought.add(tokenAmount);
    }

    function switchToNextRound(
        uint256 _usdtRate,
        address payable _wallet,
        uint256 _hardCap,
        uint256 _capPerWallet
    ) external onlyOwner {
        currentRound++;
        sales.push(
            Sale({
                isActive: true,
                usdtRate: _usdtRate,
                wallet: _wallet,
                hardCap: _hardCap * 1e6,
                capPerWallet: _capPerWallet * 1e6,
                usdtRaised: 0
            })
        );
    }

    function setRound(
        uint8 roundId,
        uint256 _usdtRate,
        address payable _wallet,
        uint256 _hardCap,
        uint256 _capPerWallet
    ) external onlyOwner onlyActive(roundId){
        Sale storage sale = sales[roundId];

        sale.usdtRate = _usdtRate;
        sale.wallet = _wallet;
        sale.hardCap = _hardCap * 1e6;
        sale.capPerWallet = _capPerWallet * 1e6;
    }

    function closeRound(uint8 _round) external onlyOwner {
        sales[_round].isActive = false;
    }

     function withdrawTokens(uint8 _round) public nonReentrant {
        require(!sales[_round].isActive, "Claim not unlocked yet");
        uint256 tokensToSend = users[_round][msg.sender].totalBought;
        require (tokensToSend - users[_round][msg.sender].totalWithdrawn > 0, "already claimed");
        users[_round][msg.sender].totalWithdrawn = tokensToSend;
        token.transfer(msg.sender, tokensToSend);
        users[_round][msg.sender].lastWithdrawTime = block.timestamp;
        emit Withdraw(tokensToSend, block.timestamp);
    }

    function getPriceInUSDT(uint256 tokenAmount, uint256 _round) public view returns (uint256 usdtAmount) {
        usdtAmount = (sales[_round].usdtRate * tokenAmount);
        return usdtAmount / 1e18;
    }

    function getPriceInETH(uint256 tokenAmount, uint256 _round) public view returns (uint256 ETHAmount) {
        uint256 usdtAmount = getPriceInUSDT(tokenAmount, _round);
        ETHAmount = convertUSDToETH(usdtAmount);
    }

    function convertUSDToETH(uint256 usdAmount) public view returns (uint256 ETHAmount) {
        (, int256 price, , , ) = USDT_ETH.latestRoundData();
        ETHAmount = (uint256(price) * usdAmount) / 10**6; //6 decimals for USDT
    }
}