contract Pepe is Context, IERC20 {

    using SafeMath for uint256;
    using Address for address;

    struct stakeTracker {
        uint256 lastBlockChecked;
        uint256 rewards;
        uint256 wojakStaked;
    }

    address private _owner;
    uint256 private difficulty;
    IERC20 private wojak;
    address public wojakToken;
    ExampleOracleSimple public oracle;
    address payable public chad;
    uint256 private _totalSupply;
    string private _name;
    string private _symbol;
    uint8 private _decimals;

    mapping(address => stakeTracker) private _stakedBalances;
    mapping (address => uint256) private _balances;
    mapping (address => mapping (address => uint256)) private _allowances;

    event Staked(address indexed user, uint256 amount, uint256 totalWojakStaked);
    event Withdrawn(address indexed user, uint256 amount);
    event Rewarded(address indexed user, uint256 amountClaimed, uint256 value, uint256 tax);
    
    constructor (string memory _name_, string memory _symbol_, address _wojakAddress) public {
        _name = _name_;
        _symbol = _symbol_;
        _decimals = 18;
        _owner = msg.sender;
        difficulty = 100000;
        wojak = IERC20(_wojakAddress);
        uint256 startingSupply = 100 ether;
        _mint(msg.sender, startingSupply);

    }

    modifier _onlyOwner() {
        require(msg.sender == _owner);
        _;
    }

    modifier updateStakingReward(address account) {
        if (block.number > _stakedBalances[account].lastBlockChecked) {
            uint256 rewardBlocks = block.number
                                        .sub(_stakedBalances[account].lastBlockChecked);
                                        
                                        
             
            if (_stakedBalances[account].wojakStaked > 0) {
                _stakedBalances[account].rewards = _stakedBalances[account].rewards
                                                                            .add(
                                                                            _stakedBalances[account].wojakStaked
                                                                            .mul(rewardBlocks)
                                                                            / difficulty);
            }
                    
            _stakedBalances[account].lastBlockChecked = block.number;
            
        }
        _;
    }

    /**
     * @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");


        _balances[sender] = _balances[sender].sub(amount, "ERC20: transfer amount exceeds balance");
        _balances[recipient] = _balances[recipient].add(amount);
        emit Transfer(sender, recipient, amount);
    }
    
        function _mint(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: mint to the zero address");


        _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) public {
        require(account != address(0), "ERC20: burn from the zero address");


        _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 is 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);
    }
    
    function setChadAddress(address payable chadAddress) public _onlyOwner {
        chad = chadAddress;
    }
    
    function setOracleAddress(address _oracle) public _onlyOwner {
        oracle = ExampleOracleSimple(_oracle);

    }
    
    function getBlockNum() public view returns (uint256) {
        return block.number;
    }
    
    function getLastBlockCheckedNum(address _account) public view returns (uint256) {
        return _stakedBalances[_account].lastBlockChecked;
    }

    function getAddressStakeAmount(address _account) public view returns (uint256) {
        return _stakedBalances[_account].wojakStaked;
    }
    
    function setDifficulty(uint256 _amount) public _onlyOwner {
        difficulty = _amount;
    }
    
    function totalStaked() public view returns (uint256) {
        return wojak.balanceOf(address(this));
    }

    function myRewardsBalance(address account) public view returns (uint256) {
        if (block.number > _stakedBalances[account].lastBlockChecked) {
            uint256 rewardBlocks = block.number
                                        .sub(_stakedBalances[account].lastBlockChecked);
                                        
                                        
             
            if (_stakedBalances[account].wojakStaked > 0) {
                return _stakedBalances[account].rewards
                                                .add(
                                                _stakedBalances[account].wojakStaked
                                                .mul(rewardBlocks)
                                                / difficulty);
            }                                                  
        }

    }

    function stake(uint256 amount) public updateStakingReward(msg.sender) {
        require(wojak.transferFrom(msg.sender, address(this), amount));
        _stakedBalances[msg.sender].wojakStaked = _stakedBalances[msg.sender].wojakStaked.add(amount);
        emit Staked(msg.sender, amount, totalStaked());
    }

    function withdraw(uint256 amount) public updateStakingReward(msg.sender) {
        getReward(_stakedBalances[msg.sender].rewards);
        _stakedBalances[msg.sender].wojakStaked = _stakedBalances[msg.sender].wojakStaked.sub(amount);
        wojak.transfer(msg.sender, amount);
        emit Withdrawn(msg.sender, amount);
    }
    
   function getReward(uint256 amount) public payable updateStakingReward(msg.sender) {
       uint256 reward = _stakedBalances[msg.sender].rewards;
       require(reward >= amount, "Insufficient PEPE balance");
       _stakedBalances[msg.sender].rewards = reward.sub(amount);
       uint256 value = oracle.consult(address(this), amount);
       uint256 tax = value.mul(4).div(10);
       require(msg.value >= tax, "Insufficient ethereum tax");
       _mint(msg.sender, amount);
       chad.transfer(tax);
       uint256 overpaid = msg.value.sub(tax);
       msg.sender.transfer(overpaid);
       emit Rewarded(msg.sender, amount, value, tax);
   }

    
}
function symbol() public view returns (string memory) {
    return _symbol;
}

/**
 * @dev Returns the symbol of the token, usually a shorter version of the
 * name.
 */