pragma solidity ^0.6.0;

// SPDX-License-Identifier: MIT


/*
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with GSN meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
contract Context {
    // Empty internal constructor, to prevent people from mistakenly deploying
    // an instance of this contract, which should be used via inheritance.
    constructor  () public  { }
    // solhint-disable-previous-line no-empty-blocks

    function _msgSender() internal view returns (address payable) {
        return msg.sender;
    }

    function _msgData() internal view returns (bytes memory) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}



/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
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);
}


/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
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 () internal {
        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;
    }
}


/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
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;
    }
    
    
    
    /**
     * @dev Retuns the a%b.
     */
    
    
    function getPercentage(uint256 a, uint256 b) internal pure returns(uint256){
        
        uint256 value = (a * b)/100;
        return value;
    }
    
    /**
     * @dev Retuns the maximum of two integers
     */
    
    
    function getMax(uint256 a, uint256 b) internal pure returns(uint256){
        if(a>=b){
            return a;
        }
        else
        return b;
    }
    
    /**
     * @dev Retuns the minimum of two integers
     */
    
    
    function getMin(uint256 a, uint256 b) internal pure returns(uint256){
        if(a<=b){
            return a;
        }
        else
        return b;
    }
}


contract Stake is Ownable {
    
    
    IERC20 public tokenContract;
    
    using SafeMath for uint256;
    
    bool isContractOpen;
    uint256 deployTimestamp;
    
    struct User {
        address userAddress;
        uint256 referralBalance;
        bool    isPrivateInvestor;
    }
    
    struct UserStake {
        address userAddress;
        uint256 amount;
        uint256 startTimeStamp;
        uint256 lockTime; // 12 months or 24 months in seconds;
        uint8 lockChoice;
        uint256 redemptionAllowedAfter;
        uint256 lastRewardTimeStamp;
        uint256 interestClaimed;
        address refereeAddress;
        bool    stakeOpen;
    }
    
    struct UserLock {
        address userAddress;
        uint256 amount;
        uint256 startTimeStamp;
        uint256 lockChoice;
        uint256 lockTime;
        uint256 redemptionAllowedAfter;
        bool    lockStatus;
    }
    
    mapping (uint8=>uint256) lockTimes;
    mapping (address=>User) usersList;
    mapping (uint256=>UserStake) stakesList;
    mapping (uint256=>UserLock) locksList;
    mapping (address => uint256[]) userStakes;
    mapping (address=> uint256[]) userLocks;
    mapping (uint8=>uint256) interestRates;
    mapping (address=>uint256) userTotalStakeBalance;
    mapping (address=>uint256) userTotalLockBalance;

    
    uint256 stakeCount;
    uint256 lockCount;
    
    uint256 public totalTokensStaked;
    uint256 public totalTokensLocked;
    
    uint256 thrityDaysInSeconds;
    uint256 threeYearsInSeconds;
    uint256 thresHoldToMaintain;
    uint256 minStakeAmount;
    uint256 maxStakeAmount;
    
    bool emergencyWithdrwalEnabled;
    
    event InvestorListUpdated(address investorAddress,bool updateType);
    event ReferralClaimed(address indexed userAddress,uint256 amount);
    event ReferralAwarded(address indexed userAddress,uint256 amount);
    event RewardsClaimed(address indexed userAddress,uint256 amount);
    event Unstaked(address indexed userAddress,uint256 stakeId,uint256 amount);
    event StakeRedeemed(address indexed userAddress,uint256 stakeId,uint256 amount);
    event ContractStatusChanged(bool status,address indexed updatedBy);
    event LockCreated(address indexed userAddress,uint256 amount,uint256 lockId,address indexed createdBy);
    event StakeCreated(address indexed userAddress,uint256 amount,uint256 stakeId);
    event LockRdeeemed(uint256 lockId,address indexed userAddress,uint256 amount,address indexed txnBy);
    constructor(address _tokenContractAddress) public{
        
        tokenContract = IERC20(_tokenContractAddress);
        
        lockTimes[0] = 15552000; //need to replace with correct values later;
        lockTimes[1] = 31104000;
        lockTimes[2] = 62208000;
        
        interestRates[0] = 3;
        interestRates[1] = 4;
        interestRates[2] = 5;
        
        thrityDaysInSeconds =2592000;
        threeYearsInSeconds = 93312000;
        thresHoldToMaintain = 4000000*(10**18);
        minStakeAmount =1*(10**18);
        maxStakeAmount = 4000000*(10**18);
        isContractOpen = true;
        deployTimestamp = now;
        
        emergencyWithdrwalEnabled = false;
        
    }
    
    
    function updateContractStatus(bool _contractStatus) public onlyOwner{
        isContractOpen = _contractStatus;
        emit ContractStatusChanged(_contractStatus,msg.sender);
    }
    
    
    function enableEmergencyWithdrawl() public onlyOwner {
        emergencyWithdrwalEnabled = true;
    }
    
    /**
     * @dev updates a particular address as investor or not
     * 
     * Emits an {InvestorListUpdated} event indicating the update.
     *
     * Requirements:
     *
     * - `sender` must be admin.
     */
    
    function updateInvestorStatus(address _investorAddress,bool updateType) public onlyOwner {
        
        if(usersList[_investorAddress].userAddress == address(0)){
            usersList[_investorAddress] = User(_investorAddress,0,true);
        }
        usersList[_investorAddress].isPrivateInvestor = updateType;
        
        emit InvestorListUpdated(_investorAddress,updateType);
    }
    
    
    /**
     * @dev Transfers the referral balance amount to user
     * 
     * Emits an {ReferralClaimed} event indicating the update.
     *
     * Requirements:
     *
     * - `sender` must have referralBalance of more than 0.
     */
    function claimReferral() public {
        
        require(usersList[msg.sender].referralBalance > 0,'No referral balance');
        require(transferFunds(msg.sender,usersList[msg.sender].referralBalance));
        
        usersList[msg.sender].referralBalance = 0;
        
        emit ReferralClaimed(msg.sender,usersList[msg.sender].referralBalance);
    }
    
    
    function createStake(uint256 amount,uint8 lockChoice,address refereeAddress) public returns(uint256 stakeId){
        
        require(isContractOpen,'Staking is closed,please contact support');
        require(amount>minStakeAmount);
        require(amount<maxStakeAmount);
        
        if(usersList[msg.sender].userAddress == address(0)){
            usersList[msg.sender] = User(msg.sender,0,false);
        }
        
        require(tokenContract.transferFrom(msg.sender,address(this),amount),'Token tranfer to contract not completed');
        stakesList[stakeCount++] = UserStake(msg.sender,amount,now,lockTimes[lockChoice],lockChoice,now+lockTimes[lockChoice],now,0,refereeAddress,true);
        userStakes[msg.sender].push(stakeCount-1);
        userTotalStakeBalance[msg.sender] = userTotalStakeBalance[msg.sender].add(amount);
        totalTokensStaked = totalTokensStaked.add(amount);
        
        if(msg.sender != refereeAddress){
            awardReferral(refereeAddress,(amount*10)/100);
        }
        
        emit StakeCreated(msg.sender,amount,stakeCount-1);
        return stakeCount-1;
    }
    
    function createLock(address userAddress,uint256 amount,uint8 lockChoice) public returns(uint256 lockId){
        
        require(isContractOpen,'Contract is closed,please contact support');
        
        
        if(usersList[userAddress].userAddress == address(0)){
            usersList[userAddress] = User(userAddress,0,true);
        }else{
            usersList[userAddress].isPrivateInvestor = true;
        }
        
        require(tokenContract.transferFrom(msg.sender,address(this),amount),'Token tranfer to contract not completed');
        locksList[lockCount++] = UserLock(userAddress,amount,now,lockChoice,lockTimes[lockChoice],now+lockTimes[lockChoice],true);
        userLocks[userAddress].push(lockCount-1);
        userTotalLockBalance[userAddress] = userTotalLockBalance[userAddress].add(amount);
        totalTokensLocked = totalTokensLocked.add(amount);
        
        emit LockCreated(userAddress,amount,lockCount-1,msg.sender);
        return lockCount-1;
    }
    
    function unLock(uint256 _lockId) public returns(bool){
        
        require(locksList[_lockId].lockStatus,'This Lock status is not proper');
        require(msg.sender == owner() || now > locksList[_lockId].redemptionAllowedAfter);
        
        locksList[_lockId].lockStatus = false;
        require(transferFunds(locksList[_lockId].userAddress,locksList[_lockId].amount));
        totalTokensLocked = totalTokensLocked.sub(locksList[_lockId].amount);
        
        emit LockRdeeemed(_lockId,locksList[_lockId].userAddress,locksList[_lockId].amount,msg.sender);
        
    }
    
    function unStake(uint256 _stakeId) public returns (bool){
        
        require(stakesList[_stakeId].stakeOpen);
        require(!usersList[msg.sender].isPrivateInvestor);
        require(stakesList[_stakeId].userAddress == msg.sender);
        
        require(awardRewards(_stakeId));
        
        stakesList[_stakeId].stakeOpen = false;
        stakesList[_stakeId].lockTime = now;
        stakesList[_stakeId].redemptionAllowedAfter = stakesList[_stakeId].redemptionAllowedAfter.getMin(now +thrityDaysInSeconds);
        userTotalStakeBalance[msg.sender] = userTotalStakeBalance[msg.sender].sub(stakesList[_stakeId].amount);
        totalTokensStaked = totalTokensStaked.sub(stakesList[_stakeId].amount);
        emit Unstaked(stakesList[_stakeId].userAddress,_stakeId,stakesList[_stakeId].amount);
    }
    
    
    function redeem(uint256 _stakeId) public returns (bool){
        
        require(stakesList[_stakeId].userAddress == msg.sender);
    
        require(now>stakesList[_stakeId].redemptionAllowedAfter);
        
        if(stakesList[_stakeId].stakeOpen){
            require(awardRewards(_stakeId));
            userTotalStakeBalance[msg.sender] = userTotalStakeBalance[msg.sender].sub(stakesList[_stakeId].amount);
            totalTokensStaked = totalTokensStaked.sub(stakesList[_stakeId].amount);

        }
        
        stakesList[_stakeId].stakeOpen = false;
        
        require(transferFunds(stakesList[_stakeId].userAddress,stakesList[_stakeId].amount));
        
        emit StakeRedeemed(stakesList[_stakeId].userAddress,_stakeId,stakesList[_stakeId].amount);
    }
    
    function claimRewards(uint256 _stakeId) public returns (bool){
        require(stakesList[_stakeId].stakeOpen);
        require(stakesList[_stakeId].userAddress == msg.sender);
        require(now >stakesList[_stakeId].lastRewardTimeStamp+thrityDaysInSeconds);
        require(awardRewards(_stakeId));

    }
    
    
    function userDetails(address _userAddress) public view returns (uint256[] memory,uint256,bool,uint256,uint256){
        return(userStakes[_userAddress],usersList[_userAddress].referralBalance,usersList[_userAddress].isPrivateInvestor,userTotalStakeBalance[_userAddress],userTotalLockBalance[_userAddress]);   
    }
    
    function getUserLockList(address _userAddress) public view returns(uint256[] memory){
        return userLocks[_userAddress];
    }
    
    function getStakeDetails(uint256 _stakeId) public view returns(address userAddress,uint256 amount,uint256 startTimeStamp,uint256 lockChoice,uint256 lockTime,uint256 redemptionAllowedAfter,uint256 lastRewardTimeStamp,uint256 interestClaimed,address refereeAddress,bool stakeOpen){
        UserStake memory temp = stakesList[_stakeId];
        
        return (temp.userAddress,temp.amount,temp.startTimeStamp,temp.lockChoice,temp.lockTime,temp.redemptionAllowedAfter,temp.lastRewardTimeStamp,temp.interestClaimed,temp.refereeAddress,temp.stakeOpen);
    }
    
    function getLockDetails(uint256 _lockId) public view returns(address userAddress,uint256 amount,uint256 startTimeStamp,uint256 lockChoice,uint256 lockTime,uint256 redemptionAllowedAfter,bool lockStatus){
        UserLock memory temp = locksList[_lockId];
        
        return (temp.userAddress,temp.amount,temp.startTimeStamp,temp.lockChoice,temp.lockTime,temp.redemptionAllowedAfter,temp.lockStatus);
    }
    
    
    function getPendingInterestDetails(uint256 _stakeId) public view returns(uint256 amount){
        
        UserStake memory temp = stakesList[_stakeId];
        //require(temp.lastRewardTimeStamp<temp.redemptionAllowedAfter);
        uint256 monthDiff;
        if(now>stakesList[_stakeId].redemptionAllowedAfter){
            monthDiff = (now-stakesList[_stakeId].redemptionAllowedAfter)/thrityDaysInSeconds;   
        }
        uint256 interesMonths = (now-temp.lastRewardTimeStamp)/thrityDaysInSeconds-monthDiff;
        
        if(interesMonths>0){
            return (temp.amount*interesMonths*interestRates[temp.lockChoice])/100;
        }
        return 0;
        
    }
    
    
    function awardRewards(uint256 _stakeId) internal returns (bool){
        
        uint256 rewards = getPendingInterestDetails(_stakeId);
        if(rewards>0){
            stakesList[_stakeId].lastRewardTimeStamp = now;
            require(transferFunds(stakesList[_stakeId].userAddress,rewards));
            emit RewardsClaimed(stakesList[_stakeId].userAddress,rewards);
        }
        return true;
    }
    
    function awardReferral(address _refereeAddress,uint256 amount) internal returns (bool){
        
        if(_refereeAddress == address(this))
        return false;
        if(userTotalStakeBalance[_refereeAddress] <= 0)
        return false;
        
        usersList[_refereeAddress].referralBalance=usersList[_refereeAddress].referralBalance.add(amount);
        
        emit ReferralAwarded(_refereeAddress,amount);
        
    }
    function  transferFunds(address _transferTo,uint256 amount) internal returns (bool){
        
        require(tokenContract.balanceOf(address(this)) > amount,'Not enough balance in contract to make the transfer');
        require(tokenContract.transfer(_transferTo,amount));
        
        return true;
    }
    
    
    function redeemTokens(uint256 amount)public onlyOwner{
        
        uint256 tokenBalance = tokenContract.balanceOf(address(this));
        require(amount<=tokenBalance,"not enough balance");
        if(now>deployTimestamp+threeYearsInSeconds){
            require(tokenContract.transfer(msg.sender,amount));
        }else{
            require(amount<=(tokenBalance-thresHoldToMaintain),"not enough balance to maintian threshold");
            require(tokenContract.transfer(msg.sender,amount));

        }
    }
    
    
    function emergencyWithdraw(uint256 _stakeId) public {
        require(stakesList[_stakeId].userAddress == msg.sender);
        require(emergencyWithdrwalEnabled,"Emergency withdraw not enabled");
        require(stakesList[_stakeId].stakeOpen,"Stake status should be open");
        
        stakesList[_stakeId].stakeOpen = false;
        
        require(transferFunds(stakesList[_stakeId].userAddress,stakesList[_stakeId].amount));
        
        emit StakeRedeemed(stakesList[_stakeId].userAddress,_stakeId,stakesList[_stakeId].amount);
    }
    
    
    function withdrawAdditionalFunds(uint256 amount) public onlyOwner {
        
        uint256 tokenBalance = tokenContract.balanceOf(address(this));
        require(amount< tokenBalance.sub(totalTokensStaked));
        require(transferFunds(owner(),amount));
        
    }
    
    
    
    
    
}

{
  "compilationTarget": {
    "Stake.sol": "Stake"
  },
  "evmVersion": "istanbul",
  "libraries": {},
  "metadata": {
    "bytecodeHash": "ipfs"
  },
  "optimizer": {
    "enabled": true,
    "runs": 200
  },
  "remappings": []
}