/**
 *Submitted for verification at Etherscan.io on 2021-06-12
 */

// SPDX-License-Identifier: AGPL-3.0-or-later
pragma solidity 0.7.5;

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;
    }
}

interface IERC20 {
    function decimals() external view returns (uint8);

    /**
     * @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
    );
}

library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies in extcodesize, which returns 0 for contracts in
        // construction, since the code is only stored at the end of the
        // constructor execution.

        uint256 size;
        // solhint-disable-next-line no-inline-assembly
        assembly {
            size := extcodesize(account)
        }
        return size > 0;
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(
            address(this).balance >= amount,
            "Address: insufficient balance"
        );

        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
        (bool success, ) = recipient.call{value: amount}("");
        require(
            success,
            "Address: unable to send value, recipient may have reverted"
        );
    }

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain`call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data)
        internal
        returns (bytes memory)
    {
        return functionCall(target, data, "Address: low-level call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return _functionCallWithValue(target, data, 0, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return
            functionCallWithValue(
                target,
                data,
                value,
                "Address: low-level call with value failed"
            );
    }

    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(
            address(this).balance >= value,
            "Address: insufficient balance for call"
        );
        require(isContract(target), "Address: call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.call{value: value}(
            data
        );
        return _verifyCallResult(success, returndata, errorMessage);
    }

    function _functionCallWithValue(
        address target,
        bytes memory data,
        uint256 weiValue,
        string memory errorMessage
    ) private returns (bytes memory) {
        require(isContract(target), "Address: call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.call{value: weiValue}(
            data
        );
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly

                // solhint-disable-next-line no-inline-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data)
        internal
        view
        returns (bytes memory)
    {
        return
            functionStaticCall(
                target,
                data,
                "Address: low-level static call failed"
            );
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.staticcall(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.3._
     */
    function functionDelegateCall(address target, bytes memory data)
        internal
        returns (bytes memory)
    {
        return
            functionDelegateCall(
                target,
                data,
                "Address: low-level delegate call failed"
            );
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.3._
     */
    function functionDelegateCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(isContract(target), "Address: delegate call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

    function _verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) private pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly

                // solhint-disable-next-line no-inline-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }

    function addressToString(address _address)
        internal
        pure
        returns (string memory)
    {
        bytes32 _bytes = bytes32(uint256(_address));
        bytes memory HEX = "0123456789abcdef";
        bytes memory _addr = new bytes(42);

        _addr[0] = "0";
        _addr[1] = "x";

        for (uint256 i = 0; i < 20; i++) {
            _addr[2 + i * 2] = HEX[uint8(_bytes[i + 12] >> 4)];
            _addr[3 + i * 2] = HEX[uint8(_bytes[i + 12] & 0x0f)];
        }

        return string(_addr);
    }
}

library SafeERC20 {
    using SafeMath for uint256;
    using Address for address;

    function safeTransfer(
        IERC20 token,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(
            token,
            abi.encodeWithSelector(token.transfer.selector, to, value)
        );
    }

    function safeTransferFrom(
        IERC20 token,
        address from,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(
            token,
            abi.encodeWithSelector(token.transferFrom.selector, from, to, value)
        );
    }

    /**
     * @dev Deprecated. This function has issues similar to the ones found in
     * {IERC20-approve}, and its usage is discouraged.
     *
     * Whenever possible, use {safeIncreaseAllowance} and
     * {safeDecreaseAllowance} instead.
     */
    function safeApprove(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        // solhint-disable-next-line max-line-length
        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 safeIncreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        uint256 newAllowance = token.allowance(address(this), spender).add(
            value
        );
        _callOptionalReturn(
            token,
            abi.encodeWithSelector(
                token.approve.selector,
                spender,
                newAllowance
            )
        );
    }

    function safeDecreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        uint256 newAllowance = token.allowance(address(this), spender).sub(
            value,
            "SafeERC20: decreased allowance below zero"
        );
        _callOptionalReturn(
            token,
            abi.encodeWithSelector(
                token.approve.selector,
                spender,
                newAllowance
            )
        );
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
        // the target address contains contract code and also asserts for success in the low-level call.

        bytes memory returndata = address(token).functionCall(
            data,
            "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"
            );
        }
    }
}

interface IOwnable {
    function manager() external view returns (address);

    function renounceManagement() external;

    function pushManagement(address newOwner_) external;

    function pullManagement() external;
}

contract Ownable is IOwnable {
    address internal _owner;
    address internal _newOwner;

    event OwnershipPushed(
        address indexed previousOwner,
        address indexed newOwner
    );
    event OwnershipPulled(
        address indexed previousOwner,
        address indexed newOwner
    );

    constructor() {
        _owner = msg.sender;
        emit OwnershipPushed(address(0), _owner);
    }

    function manager() public view override returns (address) {
        return _owner;
    }

    modifier onlyManager() {
        require(_owner == msg.sender, "Ownable: caller is not the owner");
        _;
    }

    function renounceManagement() public virtual override onlyManager {
        emit OwnershipPushed(_owner, address(0));
        _owner = address(0);
    }

    function pushManagement(address newOwner_)
        public
        virtual
        override
        onlyManager
    {
        require(
            newOwner_ != address(0),
            "Ownable: new owner is the zero address"
        );
        emit OwnershipPushed(_owner, newOwner_);
        _newOwner = newOwner_;
    }

    function pullManagement() public virtual override {
        require(msg.sender == _newOwner, "Ownable: must be new owner to pull");
        emit OwnershipPulled(_owner, _newOwner);
        _owner = _newOwner;
    }
}

interface IsASG {
    function rebase(uint256 asgProfit_, uint256 epoch_)
        external
        returns (uint256);

    function circulatingSupply() external view returns (uint256);

    function balanceOf(address who) external view returns (uint256);

    function gonsForBalance(uint256 amount) external view returns (uint256);

    function balanceForGons(uint256 gons) external view returns (uint256);

    function index() external view returns (uint256);
}

interface IWarmup {
    function retrieve(address staker_, uint256 amount_) external;
}

interface IDistributor {
    function distribute() external returns (bool);
}

contract AsgardStaking is Ownable {
    using SafeMath for uint256;
    using SafeERC20 for IERC20;

    address public immutable ASG;
    address public immutable sASG;

    struct Epoch {
        uint256 length;
        uint256 number;
        uint256 endBlock;
        uint256 distribute;
    }
    Epoch public epoch;

    address public distributor;

    address public locker;
    uint256 public totalBonus;

    address public warmupContract;
    uint256 public warmupPeriod;

    constructor(
        address _ASG,
        address _sASG,
        uint256 _epochLength,
        uint256 _firstEpochNumber,
        uint256 _firstEpochBlock
    ) {
        require(_ASG != address(0));
        ASG = _ASG;
        require(_sASG != address(0));
        sASG = _sASG;

        epoch = Epoch({
            length: _epochLength,
            number: _firstEpochNumber,
            endBlock: _firstEpochBlock,
            distribute: 0
        });
    }

    struct Claim {
        uint256 deposit;
        uint256 gons;
        uint256 expiry;
        bool lock; // prevents malicious delays
    }
    mapping(address => Claim) public warmupInfo;

    /**
        @notice stake ASG to enter warmup
        @param _amount uint
        @return bool
     */
    function stake(uint256 _amount, address _recipient)
        external
        returns (bool)
    {
        rebase();

        IERC20(ASG).safeTransferFrom(msg.sender, address(this), _amount);

        Claim memory info = warmupInfo[_recipient];
        require(!info.lock, "Deposits for account are locked");

        warmupInfo[_recipient] = Claim({
            deposit: info.deposit.add(_amount),
            gons: info.gons.add(IsASG(sASG).gonsForBalance(_amount)),
            expiry: epoch.number.add(warmupPeriod),
            lock: false
        });

        IERC20(sASG).safeTransfer(warmupContract, _amount);
        return true;
    }

    /**
        @notice retrieve sASG from warmup
        @param _recipient address
     */
    function claim(address _recipient) public {
        Claim memory info = warmupInfo[_recipient];
        if (epoch.number >= info.expiry && info.expiry != 0) {
            delete warmupInfo[_recipient];
            IWarmup(warmupContract).retrieve(
                _recipient,
                IsASG(sASG).balanceForGons(info.gons)
            );
        }
    }

    /**
        @notice forfeit sASG in warmup and retrieve ASG
     */
    function forfeit() external {
        Claim memory info = warmupInfo[msg.sender];
        delete warmupInfo[msg.sender];

        IWarmup(warmupContract).retrieve(
            address(this),
            IsASG(sASG).balanceForGons(info.gons)
        );
        IERC20(ASG).safeTransfer(msg.sender, info.deposit);
    }

    /**
        @notice prevent new deposits to address (protection from malicious activity)
     */
    function toggleDepositLock() external {
        warmupInfo[msg.sender].lock = !warmupInfo[msg.sender].lock;
    }

    /**
        @notice redeem sASG for ASG
        @param _amount uint
        @param _trigger bool
     */
    function unstake(uint256 _amount, bool _trigger) external {
        if (_trigger) {
            rebase();
        }
        IERC20(sASG).safeTransferFrom(msg.sender, address(this), _amount);
        IERC20(ASG).safeTransfer(msg.sender, _amount);
    }

    /**
        @notice returns the sASG index, which tracks rebase growth
        @return uint
     */
    function index() public view returns (uint256) {
        return IsASG(sASG).index();
    }

    /**
        @notice trigger rebase if epoch over
     */
    function rebase() public {
        if (epoch.endBlock <= block.number) {
            IsASG(sASG).rebase(epoch.distribute, epoch.number);

            epoch.endBlock = epoch.endBlock.add(epoch.length);
            epoch.number++;

            if (distributor != address(0)) {
                IDistributor(distributor).distribute();
            }

            uint256 balance = contractBalance();
            uint256 staked = IsASG(sASG).circulatingSupply();

            if (balance <= staked) {
                epoch.distribute = 0;
            } else {
                epoch.distribute = balance.sub(staked);
            }
        }
    }

    /**
        @notice returns contract ASG holdings, including bonuses provided
        @return uint
     */
    function contractBalance() public view returns (uint256) {
        return IERC20(ASG).balanceOf(address(this)).add(totalBonus);
    }

    /**
        @notice provide bonus to locked staking contract
        @param _amount uint
     */
    function giveLockBonus(uint256 _amount) external {
        require(msg.sender == locker);
        totalBonus = totalBonus.add(_amount);
        IERC20(sASG).safeTransfer(locker, _amount);
    }

    /**
        @notice reclaim bonus from locked staking contract
        @param _amount uint
     */
    function returnLockBonus(uint256 _amount) external {
        require(msg.sender == locker);
        totalBonus = totalBonus.sub(_amount);
        IERC20(sASG).safeTransferFrom(locker, address(this), _amount);
    }

    // enum CONTRACTS {
    //     DISTRIBUTOR,
    //     WARMUP,
    //     LOCKER
    // }

    enum CONTRACTS { DISTRIBUTOR, WARMUP, LOCKER }

    /**
        @notice sets the contract address for LP staking
        @param _contract address
     */
    function setContract( CONTRACTS _contract, address _address ) external onlyManager() {
        if( _contract == CONTRACTS.DISTRIBUTOR ) { // 0
            distributor = _address;
        } else if ( _contract == CONTRACTS.WARMUP ) { // 1
            require( warmupContract == address( 0 ), "Warmup cannot be set more than once" );
            warmupContract = _address;
        } else if ( _contract == CONTRACTS.LOCKER ) { // 2
            require( locker == address(0), "Locker cannot be set more than once" );
            locker = _address;
        }
    }

    /**
     * @notice set warmup period for new stakers
     * @param _warmupPeriod uint
     */
    function setWarmup(uint256 _warmupPeriod) external onlyManager {
        warmupPeriod = _warmupPeriod;
    }
}

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