// File: /contracts/FixedRateNmxSupplier.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.7.0 <0.8.0;

import "./NmxSupplier.sol";
import "./RecoverableByOwner.sol";

contract FixedRateNmxSupplier is NmxSupplier, RecoverableByOwner {
    address immutable nmx;
    address immutable stakingRouter;
    uint128 public nmxPerSecond;
    uint40 public fromTime;

    modifier onlyStakingRouter() {
        require(stakingRouter == msg.sender, "FixedRateNmxSupplier: caller is not the staking router");
        _;
    }

    constructor(address _nmx, address _stakingRouter) {
        nmx = _nmx;
        stakingRouter = _stakingRouter;
    }

    function updateRate(uint128 _nmxPerSecond) onlyOwner external {
        updateRate(_nmxPerSecond, uint40(block.timestamp));
    }

    function updateRate(uint128 _nmxPerSecond, uint40 _fromTime) onlyOwner public {
        nmxPerSecond = _nmxPerSecond;
        fromTime = _fromTime;
    }

    function supplyNmx(uint40 maxTime) onlyStakingRouter external override returns (uint256) {
        uint128 _nmxPerSecond = nmxPerSecond;
        if (_nmxPerSecond == 0) return 0;
        if (uint40(block.timestamp) < maxTime) maxTime = uint40(block.timestamp);
        uint40 _fromTime = fromTime;
        if (_fromTime >= maxTime) return 0;
        uint40 secondsPassed = maxTime - _fromTime;
        uint256 amount = _nmxPerSecond * secondsPassed;
        uint256 balance = IERC20(nmx).balanceOf(address(this));
        if (balance < amount) amount = balance;
        if (amount > 0) {
            bool transferred = IERC20(nmx).transfer(msg.sender, amount);
            require(transferred, "FixedRateNmxSupplier: NMX_FAILED_TRANSFER");
            fromTime = maxTime;
        }
        return amount;
    }

}
// File: /contracts/RecoverableByOwner.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.7.0 <0.8.0;

import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";

/**
 @dev The contract is intendent to help recovering arbitrary ERC20 tokens and ETH accidentally transferred to the contract address
 */
abstract contract RecoverableByOwner is Ownable {
    function getRecoverableAmount(address tokenAddress)
        internal
        view
        virtual
        returns (uint256)
    {
        if (tokenAddress == address(0)) return address(this).balance;
        else return IERC20(tokenAddress).balanceOf(address(this));
    }

    /**
     @param tokenAddress ERC20 token's address to recover or address(0) to recover ETH
     @param amount to recover from contract's address
     @param to address to receive tokens from the contract
     */
    function recoverFunds(
        address tokenAddress,
        uint256 amount,
        address to
    ) external onlyOwner {
        uint256 recoverableAmount = getRecoverableAmount(tokenAddress);
        require(
            amount <= recoverableAmount,
            "RecoverableByOwner: RECOVERABLE_AMOUNT_NOT_ENOUGH"
        );
        if (tokenAddress == address(0)) recoverEth(amount, to);
        else recoverErc20(tokenAddress, amount, to);
    }

    function recoverEth(uint256 amount, address to) private {
        address payable toPayable = payable(to);
        toPayable.transfer(amount);
    }

    function recoverErc20(
        address tokenAddress,
        uint256 amount,
        address to
    ) private {
        // bytes4(keccak256(bytes('transfer(address,uint256)')));
        (bool success, bytes memory data) = tokenAddress.call(abi.encodeWithSelector(0xa9059cbb, to, amount));
        require(success && (data.length == 0 || abi.decode(data, (bool))), 'RecoverableByOwner: TRANSFER_FAILED');
    }
}

// File: /contracts/NmxSupplier.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.7.0 <0.8.0;

/**
 * @dev Interface to got minted Nmx.
 */
interface NmxSupplier {
    /**
      @dev if caller is owner of any mint pool it will be supplied with Nmx based on the schedule and time passed from the moment
      when the method was invoked by the same mint pool owner last time
      @param maxTime the upper limit of the time to make calculations
    */
    function supplyNmx(uint40 maxTime) external returns (uint256);
}

// File: @openzeppelin/contracts/token/ERC20/IERC20.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

/**
 * @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);
}

// File: @openzeppelin/contracts/access/Ownable.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

import "../GSN/Context.sol";
/**
 * @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.
 */
abstract 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;
    }
}

// File: @openzeppelin/contracts/GSN/Context.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

/*
 * @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.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address payable) {
        return msg.sender;
    }

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