// Contract: MetaCore
// Target function: function disburse(uint256 amount) internal
pragma solidity ^0.6.0;
// SPDX-License-Identifier: UNLICENSED

/**
 * @title SafeMath
 * @dev Math operations with safety checks that throw on error
 *
*/
 
library SafeMath {
  function mul(uint256 a, uint256 b) internal pure returns (uint256) {
    if (a == 0) {
      return 0;
    }
    uint256 c = a * b;
    assert(c / a == b);
    return c;
  }

  function div(uint256 a, uint256 b) internal pure returns (uint256) {
    // assert(b > 0); // Solidity automatically throws when dividing by 0
    uint256 c = a / b;
    // assert(a == b * c + a % b); // There is no case in which this doesn't hold
    return c;
  }

  function sub(uint256 a, uint256 b) internal pure returns (uint256) {
    assert(b <= a);
    return a - b;
  }

  function add(uint256 a, uint256 b) internal pure returns (uint256) {
    uint256 c = a + b;
    assert(c >= a);
    return c;
  }
 
  function ceil(uint a, uint m) internal pure returns (uint r) {
    return (a + m - 1) / m * m;
  }
}

// ----------------------------------------------------------------------------
// ERC Token Standard #20 Interface
// https://github.com/ethereum/EIPs/blob/master/EIPS/eip-20-token-standard.md
// ----------------------------------------------------------------------------
abstract contract ERC20Interface {
    function totalSupply() public virtual view returns (uint);
    function balanceOf(address tokenOwner) public virtual view returns (uint256 balance);
    function allowance(address tokenOwner, address spender) public virtual view returns (uint256 remaining);
    function transfer(address to, uint256 tokens) public virtual returns (bool success);
    function approve(address spender, uint256 tokens) public virtual returns (bool success);
    function transferFrom(address from, address to, uint256 tokens) public virtual returns (bool success);

    event Transfer(address indexed from, address indexed to, uint256 tokens);
    event Approval(address indexed tokenOwner, address indexed spender, uint256 tokens);
}

// ----------------------------------------------------------------------------
// ERC Token Standard #20 Interface
// ----------------------------------------------------------------------------
interface IERC20 {
    function transfer(address to, uint256 tokens) external returns (bool success);
    function transferFrom(address from, address to, uint256 tokens) external returns (bool success);
}

// ----------------------------------------------------------------------------
// Owned contract
// ----------------------------------------------------------------------------
contract Owned {
    address payable public owner;

    event OwnershipTransferred(address indexed _from, address indexed _to);

    constructor() public {
        owner = msg.sender;
    }

    modifier onlyOwner {
        require(msg.sender == owner);
        _;
    }

    function transferOwnership(address payable _newOwner) public onlyOwner {
        owner = _newOwner;
        emit OwnershipTransferred(msg.sender, _newOwner);
    }
}

// ----------------------------------------------------------------------------
// 'MCORE' token AND staking contract

// Symbol      : MCORE
// Name        : MetaCore
// Total supply: 7000 (7 thousands)
// Decimals    : 18


// ----------------------------------------------------------------------------
// ERC20 Token, with the addition of symbol, name and decimals and assisted
// token transfers
// ----------------------------------------------------------------------------
contract MetaCore is ERC20Interface, Owned {
    using SafeMath for uint256;
   
    string public symbol = "MCORE";
    string public  name = "MetaCore";
    uint256 public decimals = 18;
    
    uint256 _totalSupply = 7e3 * 10 ** (decimals);
    
    uint256 deployTime;
    uint256 private totalDividentPoints;
    uint256 pointMultiplier = 1000000000000000000;
    uint256 public stakedCoins;
    
    uint256 public totalRewardsClaimed;
    
    address uniSwapAddress = 0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D;
    address MCORE_WETH_POOL_ADDRESS = address(0);
    address devs;
    address communityFund;
    
    struct  Account {
        uint256 balance;
        uint256 lastDividentPoints;
        uint256 timeInvest;
        uint256 lastClaimed;
        uint256 rewardsClaimed;
        uint256 totalStakes;
        uint256 pending;
    }

    mapping(address => Account) accounts;
    mapping(address => uint256) balances;
    mapping(address => mapping(address => uint256)) allowed;
   
    // ------------------------------------------------------------------------
    // Constructor
    // ------------------------------------------------------------------------
    constructor() public {
        
        owner = 0xcC3d0B03DCC7C2d4f7C71E4DAFDb1C40A4829Df5;
        devs =  0x81B794fad3BC654C8662614e83750E3541591fE5;
        communityFund = 0x9F2742e7427E26DeC6beD359F0B4b5bff6A41bB3;
        
        balances[communityFund] =  totalSupply(); // 7000
        emit Transfer(address(0), communityFund, totalSupply());
        
        deployTime = block.timestamp;
    }

    function setLpsAddress(address _MCORE_WETH_POOL_ADDRESS) external onlyOwner{
        require(_MCORE_WETH_POOL_ADDRESS != address(0), "Pool address cannot be zero");
        require(MCORE_WETH_POOL_ADDRESS == address(0), "Pool address already set");
        MCORE_WETH_POOL_ADDRESS = _MCORE_WETH_POOL_ADDRESS;
    }
    
    // ------------------------------------------------------------------------
    // Stake the 'MCORE-WETH Lp' tokens to earn reward in 'MCORE'tokens
    // ------------------------------------------------------------------------
    
    function STAKE(uint256 _tokens) external returns(bool){
        require(IERC20(MCORE_WETH_POOL_ADDRESS).transferFrom(msg.sender, address(this), _tokens), "Insufficient Tokens!");

        stakedCoins = stakedCoins.add(_tokens); // MCORE_WETH Lp
        
        uint256 owing = dividendsOwing(msg.sender); // MCORE tokens
        
        if(owing > 0) { // checks previous pending rewards
            accounts[msg.sender].pending = owing;
        }
        
        accounts[msg.sender].balance = accounts[msg.sender].balance.add(_tokens); // MCORE_WETH Lp
        accounts[msg.sender].lastDividentPoints = totalDividentPoints;            // MCORE tokens
        accounts[msg.sender].timeInvest = now;
        accounts[msg.sender].lastClaimed = now;
        accounts[msg.sender].totalStakes = accounts[msg.sender].totalStakes.add(_tokens); // MCORE_WETH Lp
        
        return true;
    }
    
    // ------------------------------------------------------------------------
    // Gives the tokens in MCORE - ready to claim
    // ------------------------------------------------------------------------
    function pendingReward(address _user) external view returns(uint256 MCORE){
        uint256 owing = dividendsOwing(_user);
        return owing;
    }
    
    // ------------------------------------------------------------------------
    // internal function used when MCORE tokens reward is claimed
    // ------------------------------------------------------------------------
    function updateDividend(address investor) internal returns(uint256){
        uint256 owing = dividendsOwing(investor);       // MCORE tokens
        if (owing > 0){
            accounts[investor].lastDividentPoints = totalDividentPoints; 
        }
        return owing;
    }
    
    // ------------------------------------------------------------------------
    // Gives the MCORE_WETH Lp tokens actively staked by the user
    // ------------------------------------------------------------------------
    function activeStake(address _user) external view returns (uint256){
        return accounts[_user].balance;
    }
    
    // ------------------------------------------------------------------------
    // Gives the MCORE_WETH Lp tokens staked by the user till the current date
    // ------------------------------------------------------------------------
    function totalStakesTillToday(address _user) external view returns (uint256){
        return accounts[_user].totalStakes;
    }
   
    // ------------------------------------------------------------------------
    // Used to stop the staking and get back MCORE_WETH Lp Tokens
    // ------------------------------------------------------------------------
    function UNSTAKE() external returns (bool){
        require(stakedCoins > 0);   // MCORE_WETH Lp 
        require(accounts[msg.sender].balance > 0); // MCORE_WETH Lp 
        
        uint256 owing = dividendsOwing(msg.sender); // MCORE tokens
        
        if(owing > 0) { // checks previous pending rewards
            accounts[msg.sender].pending = owing;
        }
        
        stakedCoins = stakedCoins.sub(accounts[msg.sender].balance); // MCORE_WETH Lp 
       
        require(IERC20(MCORE_WETH_POOL_ADDRESS).transfer(msg.sender, accounts[msg.sender].balance)); // sends the lp tokens back from the contract to the investor
       
        accounts[msg.sender].balance = 0; // reset the balance of the investor
        
        return true;
    }