//Orenda Protocol - Multichain DeFi & Insurance Services
//www.or-protocol.io
//SPDX-License-Identifier: MIT
pragma solidity ^0.6.12;

abstract contract Context {
    function _msgSender() internal view virtual returns (address payable) {
        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;
    }
}

interface IERC20 {
    /**
     * @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 `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, 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 `sender` to `recipient` 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 sender, address recipient, uint256 amount) external returns (bool);

    /**
     * @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);
}


library SafeMath {
    /**
     * @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) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");

        return c;
    }

    /**
     * @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 sub(a, b, "SafeMath: subtraction overflow");
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        uint256 c = a - b;

        return c;
    }

    /**
     * @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) {
        // 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 0;
        }

        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");

        return c;
    }

    /**
     * @dev Returns the integer division of two unsigned integers. Reverts 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) internal pure returns (uint256) {
        return div(a, b, "SafeMath: division by zero");
    }

    /**
     * @dev Returns the integer division of two unsigned integers. Reverts 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) {
        require(b > 0, errorMessage);
        uint256 c = a / b;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold

        return c;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts 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 mod(a, b, "SafeMath: modulo by zero");
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts with custom message 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, string memory errorMessage) internal pure returns (uint256) {
        require(b != 0, errorMessage);
        return a % b;
    }
}

contract ERC20 is Context, IERC20 {
    using SafeMath for uint256;
    using SafeERC20 for IERC20;

    mapping (address => uint256) private _balances;

    mapping (address => mapping (address => uint256)) private _allowances;

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;
    uint8 private _decimals;

    /**
     * @dev Sets the values for {name} and {symbol}, initializes {decimals} with
     * a default value of 18.
     *
     * To select a different value for {decimals}, use {_setupDecimals}.
     *
     * All three of these values are immutable: they can only be set once during
     * construction.
     */
    constructor (string memory name, string memory symbol) public {
        _name = name;
        _symbol = symbol;
        _decimals = 18;
    }

    /**
     * @dev Returns the name of the token.
     */
    function name() public view returns (string memory) {
        return _name;
    }

    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view 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 value {ERC20} uses, unless {_setupDecimals} is
     * called.
     *
     * 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 returns (uint8) {
        return _decimals;
    }

    /**
     * @dev See {IERC20-totalSupply}.
     */
    function totalSupply() public view override returns (uint256) {
        return _totalSupply;
    }

    /**
     * @dev See {IERC20-balanceOf}.
     */
    function balanceOf(address account) public view override returns (uint256) {
        return _balances[account];
    }

    /**
     * @dev See {IERC20-transfer}.
     *
     * Requirements:
     *
     * - `recipient` cannot be the zero address.
     * - the caller must have a balance of at least `amount`.
     */
    function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
        _transfer(_msgSender(), recipient, amount);
        return true;
    }

    /**
     * @dev See {IERC20-allowance}.
     */
    function allowance(address owner, address spender) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }

    /**
     * @dev See {IERC20-approve}.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        _approve(_msgSender(), spender, amount);
        return true;
    }

    /**
     * @dev See {IERC20-transferFrom}.
     *
     * Emits an {Approval} event indicating the updated allowance. This is not
     * required by the EIP. See the note at the beginning of {ERC20}.
     *
     * Requirements:
     *
     * - `sender` and `recipient` cannot be the zero address.
     * - `sender` must have a balance of at least `amount`.
     * - the caller must have allowance for ``sender``'s tokens of at least
     * `amount`.
     */
    function transferFrom(address sender, address recipient, uint256 amount) public virtual override returns (bool) {
        _transfer(sender, recipient, amount);
        _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance"));
        return true;
    }

    /**
     * @dev Atomically increases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));
        return true;
    }

    /**
     * @dev Atomically decreases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `spender` must have allowance for the caller of at least
     * `subtractedValue`.
     */
    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "ERC20: decreased allowance below zero"));
        return true;
    }

    /**
     * @dev Moves tokens `amount` from `sender` to `recipient`.
     *
     * This is internal function is equivalent to {transfer}, and can be used to
     * e.g. implement automatic token fees, slashing mechanisms, etc.
     *
     * Emits a {Transfer} event.
     *
     * Requirements:
     *
     * - `sender` cannot be the zero address.
     * - `recipient` cannot be the zero address.
     * - `sender` must have a balance of at least `amount`.
     */
    function _transfer(address sender, address recipient, uint256 amount) internal virtual {
        require(sender != address(0), "ERC20: transfer from the zero address");
        require(recipient != address(0), "ERC20: transfer to the zero address");

        _beforeTokenTransfer(sender, recipient, amount);

        _balances[sender] = _balances[sender].sub(amount, "ERC20: transfer amount exceeds balance");
        _balances[recipient] = _balances[recipient].add(amount);
        emit Transfer(sender, recipient, amount);
    }

    /** @dev Creates `amount` tokens and assigns them to `account`, increasing
     * the total supply.
     *
     * Emits a {Transfer} event with `from` set to the zero address.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     */
    function _mint(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: mint to the zero address");

        _beforeTokenTransfer(address(0), account, amount);

        _totalSupply = _totalSupply.add(amount);
        _balances[account] = _balances[account].add(amount);
        emit Transfer(address(0), account, amount);
    }

    /**
     * @dev Destroys `amount` tokens from `account`, reducing the
     * total supply.
     *
     * Emits a {Transfer} event with `to` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     * - `account` must have at least `amount` tokens.
     */
    function _burn(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: burn from the zero address");

        _beforeTokenTransfer(account, address(0), amount);

        _balances[account] = _balances[account].sub(amount, "ERC20: burn amount exceeds balance");
        _totalSupply = _totalSupply.sub(amount);
        emit Transfer(account, address(0), amount);
    }

    /**
     * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
     *
     * This internal function is equivalent to `approve`, and can be used to
     * e.g. set automatic allowances for certain subsystems, etc.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `owner` cannot be the zero address.
     * - `spender` cannot be the zero address.
     */
    function _approve(address owner, address spender, uint256 amount) internal virtual {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }

    /**
     * @dev Sets {decimals} to a value other than the default one of 18.
     *
     * WARNING: This function should only be called from the constructor. Most
     * applications that interact with token contracts will not expect
     * {decimals} to ever change, and may work incorrectly if it does.
     */
    function _setupDecimals(uint8 decimals_) internal {
        _decimals = decimals_;
    }

    /**
     * @dev Hook that is called before any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * will be to transferred to `to`.
     * - when `from` is zero, `amount` tokens will be minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual { }
}


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 () public{
        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), msgSender);
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        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 {
        emit OwnershipTransferred(_owner, address(0));
        _owner = 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");
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}

contract OrexTokenCore is ERC20("Orenda Protocol", "OREX"), Ownable {
    using SafeMath for uint256;

    address internal _taxer;
    address internal _pool;
    address internal _devfund;
    address internal _daofund;
    uint internal _taxTime;
    uint internal constant _taxRate = 2; //2 percent
    bool internal _lock = true;
    mapping (address => bool) internal _taxWhitelist;
    mapping (address => bool) internal _plan4Whitelist;
    mapping (address => bool) internal _plan5Whitelist;
    mapping (address => bool) internal _unlockWhitelist;

    function transfer(address recipient, uint256 amount) public override returns (bool) {
        require(msg.sender == owner() || _unlockWhitelist[msg.sender] || !_lock, "Transfer is locking");

        uint256 taxAmount = amount.mul(_taxRate).div(100);
        if (_taxWhitelist[msg.sender] == true || _taxTime > block.timestamp) {
            taxAmount = 0;
        }
        uint256 transferAmount = amount.sub(taxAmount);
        require(balanceOf(msg.sender) >= amount, "insufficient balance.");
        super.transfer(recipient, transferAmount);

        if (taxAmount != 0) {
            super.transfer(_pool, taxAmount.div(2));
            super.transfer(_devfund, taxAmount.div(4));
            super.transfer(_daofund, taxAmount.div(4));
        }
        return true;
    }

    function transferFrom(address sender, address recipient, uint256 amount) public override returns (bool) {
        require(sender == owner() || _unlockWhitelist[msg.sender] || !_lock, "TransferFrom is locking");

        uint256 taxAmount = amount.mul(_taxRate).div(100);
        if (_taxWhitelist[sender] == true || _taxTime > block.timestamp ) {
            taxAmount = 0;
        }
        uint256 transferAmount = amount.sub(taxAmount);
        require(balanceOf(sender) >= amount, "insufficient balance.");
        super.transferFrom(sender, recipient, transferAmount);
        if (taxAmount != 0) {
            super.transfer(_pool, taxAmount.div(2));
            super.transfer(_devfund, taxAmount.div(4));
            super.transfer(_daofund, taxAmount.div(4));
        }
        return true;
    }
}


contract OrexToken is OrexTokenCore {
    
    event Taxer(address indexed account);

    constructor() public{
        _mint(owner(), 1000000000000000000000000);
        _taxer = owner();
        _pool = address(0x401d6C6fFC28db4c43C0b52E7AF1F8A607576842);
        _devfund = address(0xE58A34f524eEBb396C124B28EE2f41Cf0b77E362);
        _daofund = address(0xE2C707559f0cbB82Ca9bC078E5B6c7522FF1d314);
        _taxTime = block.timestamp + 30 days;
    }

    function burn(uint amount) public {
        require(amount > 0);
        require(balanceOf(msg.sender) >= amount);
        _burn(msg.sender, amount);
    }

    modifier onlyTaxer() {
        require(msg.sender == _taxer, "Only for taxer.");
        _;
    }

    function setTaxer(address account) public onlyTaxer {
        _taxer = account;
        emit Taxer(_taxer);
    }


    function addToTaxWhitelist(address account) public onlyTaxer {
        _taxWhitelist[account] = true;
    }

    function removeFromTaxWhitelist(address account) public onlyTaxer {
        _taxWhitelist[account] = false;
    }
    
    function addToPlan4Whitelist(address account) public onlyOwner {
        _plan4Whitelist[account] = true;
    }

    function removeFromPlan4Whitelist(address account) public onlyOwner {
        _plan4Whitelist[account] = false;
    }
    
    function addToPlan5Whitelist(address account) public onlyOwner {
        _plan5Whitelist[account] = true;
    }

    function removeFromPlan5Whitelist(address account) public onlyOwner {
        _plan5Whitelist[account] = false;
    }
    
    function addToUnlockWhitelist(address account) public onlyOwner {
        _unlockWhitelist[account] = true;
    }

    function removeFromUnlockWhitelist(address account) public onlyOwner {
        _unlockWhitelist[account] = false;
    }

    function taxer() public view returns(address) {
        return _taxer;
    }

    function pool() public view returns(address) {
        return _pool;
    }

    function devfund() public view returns(address) {
        return _devfund;
    }

    function daofund() public view returns(address) {
        return _daofund;
    }

    function taxRate() public view returns(uint256) {
        return _taxRate;
    }

    function isInTaxWhitelist(address account) public view returns(bool) {
        return _taxWhitelist[account];
    }
    
    function isInPlan4Whitelist(address account) public view returns(bool) {
        return _plan4Whitelist[account];
    }
    
    function isInPlan5Whitelist(address account) public view returns(bool) {
        return _plan5Whitelist[account];
    }
    
    function isInUnlockWhitelist(address account) public view returns(bool) {
        return _unlockWhitelist[account];
    }

    function unlock() public onlyOwner {
        _lock = false;
    }

    function getLockStatus() view public returns(bool) {
        return _lock;
    }


}

library Address {

    function isContract(address account) internal view returns (bool) {
        // According to EIP-1052, 0x0 is the value returned for not-yet created accounts
        // and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned
        // for accounts without code, i.e. `keccak256('')`
        bytes32 codehash;
        bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;
        // solhint-disable-next-line no-inline-assembly
        assembly { codehash := extcodehash(account) }
        return (codehash != accountHash && codehash != 0x0);
    }

    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
        (bool success, ) = recipient.call{ value: amount }("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
      return functionCall(target, data, "Address: low-level call failed");
    }

    function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
        return _functionCallWithValue(target, data, 0, errorMessage);
    }

    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");
    }

    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");
        return _functionCallWithValue(target, data, value, errorMessage);
    }

    function _functionCallWithValue(address target, bytes memory data, uint256 weiValue, string memory errorMessage) private returns (bytes memory) {
        require(isContract(target), "Address: call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.call{ value: weiValue }(data);
        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

                // solhint-disable-next-line no-inline-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

library SafeERC20 {
    using SafeMath for uint256;
    using Address for address;

    function safeTransfer(IERC20 token, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }

    function safeApprove(IERC20 token, address spender, uint256 value) internal {
        require((value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }

    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 newAllowance = token.allowance(address(this), spender).add(value);
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 newAllowance = token.allowance(address(this), spender).sub(value, "SafeERC20: decreased allowance below zero");
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
        if (returndata.length > 0) { // Return data is optional
            // solhint-disable-next-line max-line-length
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}



contract Staking is Ownable {

    using SafeMath for uint256;
    using SafeERC20 for OrexToken;
    using Address for address;

    OrexToken public token;
    
    // annual yield period
    uint256 private constant DURATION = 365 days;
    uint256 private constant MINIMUM_AMOUNT = 1e18;
    //uint256 public _poolAmount = 0;
    bool public haveStarted = false;
    //uint256 public _totalTokenBalance;
    
    uint256 public _plan1RewardLimit = 70000e18;
    uint256 public _plan2RewardLimit = 55000e18;
    uint256 public _plan3RewardLimit = 45000e18;
    uint256 public _plan4RewardLimit = 60000e18;
    uint256 public _plan5RewardLimit = 20000e18;
    uint256 public _plan1RewardAmount = 0;
    uint256 public _plan2RewardAmount = 0;
    uint256 public _plan3RewardAmount = 0;
    uint256 public _plan4RewardAmount = 0;
    uint256 public _plan5RewardAmount = 0;

    mapping(address => uint256) private _stakerTokenBalance;
    mapping(address => uint256) public _stakerRewardRate;
    mapping(address => uint256) public _stakerStakingPlan;
    mapping(address => uint256) public _stakerWithdrawFeeRate;
    mapping(address => uint256) public _stakerStakingTime;
    mapping(address => uint256) public _stakerTokenRewardsClaimed;

    event Stake(address indexed from, uint amount);
    event Withdraw(address indexed to, uint amount);
    event Claim(address indexed to, uint amount);
    event StartStaking(bool haveStarted);

    constructor(address _token) public{
        token = OrexToken(_token);
    }


    function stake(uint plan, uint amount) public shouldStarted {
        
        require(_stakerStakingPlan[msg.sender] == 0, "Withdraw your current plan.");
        require(!address(msg.sender).isContract(), "Please use your individual account.");
        require(amount >= MINIMUM_AMOUNT, "Should stake at least 1 Token.");
        
        _stakerStakingTime[msg.sender] = block.timestamp;
        _stakerStakingPlan[msg.sender] = plan;

        updateRewards(msg.sender);
        
        token.safeTransferFrom(msg.sender, address(this), amount);
       // _totalTokenBalance = _totalTokenBalance.add(amount);
        _stakerTokenBalance[msg.sender] = _stakerTokenBalance[msg.sender].add(amount);
        
        emit Stake(msg.sender, amount);
    }

    function withdraw(uint amount) public shouldStarted {
        
        require(amount <= _stakerTokenBalance[msg.sender] && _stakerTokenBalance[msg.sender] > 0, "Bad withdraw.");
        
        if(_stakerStakingPlan[msg.sender] == 4 || _stakerStakingPlan[msg.sender] == 5){
            require(block.timestamp >= _stakerStakingTime[msg.sender] + 30 days, "Early withdrawal available after 30 days");
        }
        
        claim();
        
        _stakerTokenBalance[msg.sender] = _stakerTokenBalance[msg.sender].sub(amount);
        _stakerTokenRewardsClaimed[msg.sender] = 0;
        _stakerStakingPlan[msg.sender] = 0;


        if(_stakerWithdrawFeeRate[msg.sender] > 0){
            uint256 _burnedAmount = amount.mul(_stakerWithdrawFeeRate[msg.sender]).div(100);
            amount = amount.sub(_burnedAmount);
            token.burn(_burnedAmount);
        }
        
        token.safeTransfer(msg.sender, amount);
        
        emit Withdraw(msg.sender, amount);
    }
    
    // Withdraw without caring about rewards. EMERGENCY ONLY.
    function emergencyWithdraw(uint amount) public shouldStarted {
        require(amount <= _stakerTokenBalance[msg.sender] && _stakerTokenBalance[msg.sender] > 0, "Bad withdraw.");
        
        if(_stakerStakingPlan[msg.sender] == 4 || _stakerStakingPlan[msg.sender] == 5){
            require(block.timestamp >= _stakerStakingTime[msg.sender] + 30 days, "Early withdrawal available after 30 days");
        }
        
        updateRewards(msg.sender);
        
        _stakerTokenBalance[msg.sender] = _stakerTokenBalance[msg.sender].sub(amount);
        _stakerTokenRewardsClaimed[msg.sender] = 0;
        _stakerStakingPlan[msg.sender] = 0;


        if(_stakerWithdrawFeeRate[msg.sender] > 0){
            uint256 _burnedAmount = amount.mul(_stakerWithdrawFeeRate[msg.sender]).div(100);
            amount = amount.sub(_burnedAmount);
            token.burn(_burnedAmount);
        }
        
        token.safeTransfer(msg.sender, amount);
        
        emit Withdraw(msg.sender, amount);
    }

    function claim() public shouldStarted {
        
        uint pending = getTotalRewardsAmount(msg.sender);
        
        updateRewards(msg.sender);

        if(pending > 0 && token.balanceOf(address(this)) > 0){

            if(_stakerStakingPlan[msg.sender] == 1){
                
            require(_plan1RewardLimit >= _plan1RewardAmount, "Reward Limit 70,000 Tokens");
             _plan1RewardAmount = _plan1RewardAmount.add(pending);
          
        } else if(_stakerStakingPlan[msg.sender] == 2){

            require(_plan2RewardLimit >= _plan2RewardAmount, "Reward Limit 55,000 Tokens");
             _plan2RewardAmount = _plan2RewardAmount.add(pending);
            
        } else if(_stakerStakingPlan[msg.sender] == 3){
    
           require(_plan3RewardLimit >= _plan3RewardAmount, "Reward Limit 45,000 Tokens");
            _plan3RewardAmount = _plan3RewardAmount.add(pending);
            
        } else if(_stakerStakingPlan[msg.sender] == 4){

           require(_plan4RewardLimit >= _plan4RewardAmount, "Reward Limit 60,000 Tokens");
            _plan4RewardAmount = _plan4RewardAmount.add(pending);
           
            
        } else if(_stakerStakingPlan[msg.sender] == 5){

           require(_plan5RewardLimit >= _plan5RewardAmount, "Reward Limit 20,000 Tokens");
           _plan5RewardAmount = _plan5RewardAmount.add(pending);
            
        }
        
        token.safeTransfer(msg.sender, getTotalRewardsAmount(msg.sender));
        
       
        _stakerTokenRewardsClaimed[msg.sender] = _stakerTokenRewardsClaimed[msg.sender].add(pending);
        
        
        emit Claim(msg.sender, pending);

        }
        
        
    }

    modifier shouldStarted() {
        require(haveStarted == true, "Have not started.");
        _;
    }

    function getRewardsAmountPerSeconds(address account) public view returns(uint256) {
        return balanceOf(account).mul(_stakerRewardRate[msg.sender]).div(100)
                .div(DURATION);
    }
    
    function balanceOf(address account) public view returns(uint256) {
        return _stakerTokenBalance[account];
    }
    
    function getTotalRewardsAmount(address account) public view returns (uint256) {
   
        return block.timestamp.sub(_stakerStakingTime[account]).mul(getRewardsAmountPerSeconds(account)).sub(_stakerTokenRewardsClaimed[account]);
    }


    function updateRewards(address account) internal {
        
        if(_stakerStakingPlan[msg.sender] == 1){

            _stakerRewardRate[msg.sender] = 40;

            if(block.timestamp < _stakerStakingTime[msg.sender] + 60 days){
                 _stakerWithdrawFeeRate[msg.sender] = 6;
            } else {
                _stakerWithdrawFeeRate[msg.sender] = 0;
            }

        } else if(_stakerStakingPlan[msg.sender] == 2){

            _stakerRewardRate[msg.sender] = 69;

            if(block.timestamp < _stakerStakingTime[msg.sender] + 120 days){
                 _stakerWithdrawFeeRate[msg.sender] = 12;
            } else {
                _stakerWithdrawFeeRate[msg.sender] = 0;
            }
            
        } else if(_stakerStakingPlan[msg.sender] == 3){

            _stakerRewardRate[msg.sender] = 81;

            if(block.timestamp < _stakerStakingTime[msg.sender] + 240 days){
                 _stakerWithdrawFeeRate[msg.sender] = 24;
            } else {
                _stakerWithdrawFeeRate[msg.sender] = 0;
            }
            
        } else if(_stakerStakingPlan[msg.sender] == 4 &&  token.isInPlan4Whitelist(msg.sender)){

            _stakerRewardRate[msg.sender] = 75;
            _stakerWithdrawFeeRate[msg.sender] = 0;
            
            
        } else if(_stakerStakingPlan[msg.sender] == 5 &&  token.isInPlan5Whitelist(msg.sender) ){

            _stakerRewardRate[msg.sender] = 40;
            _stakerWithdrawFeeRate[msg.sender] = 0;
            
        }

        
    }

    function startStaking() external onlyOwner {
        updateRewards(address(0));
        haveStarted = true;
        emit StartStaking(haveStarted);
    }


}