// File: contracts/Oracle/FXSOracleWrapper.sol



// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.6.11;

// ====================================================================
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// |    / _____________ __  __   / ____(_____  ____ _____  ________   |
// |   / /_  / ___/ __ `| |/_/  / /_  / / __ \/ __ `/ __ \/ ___/ _ \  |
// |  / __/ / /  / /_/ _>  <   / __/ / / / / / /_/ / / / / /__/  __/  |
// | /_/   /_/   \__,_/_/|_|  /_/   /_/_/ /_/\__,_/_/ /_/\___/\___/   |
// |                                                                  |
// ====================================================================
// ========================= FXSOracleWrapper =========================
// ====================================================================
// The Frax.sol contract needs an oracle with a specific ABI, so this is a
// 'middleman' one that lets it read Chainlink data.

// Frax Finance: https://github.com/FraxFinance

// Primary Author(s)
// Jason Huan: https://github.com/jasonhuan

// Reviewer(s) / Contributor(s)
// Travis Moore: https://github.com/FortisFortuna
// Sam Kazemian: https://github.com/samkazemian

import "../Math/SafeMath.sol";
import "./AggregatorV3Interface.sol";
import "../Staking/Owned.sol";

contract FXSOracleWrapper is Owned {
    using SafeMath for uint256;

    AggregatorV3Interface private priceFeedFXSUSD;
    AggregatorV3Interface private priceFeedETHUSD;

    uint256 public chainlink_fxs_usd_decimals;
    uint256 public chainlink_eth_usd_decimals;

    uint256 public PRICE_PRECISION = 1e6;
    address public timelock_address;

    /* ========== MODIFIERS ========== */

    modifier onlyByOwnGov() {
        require(msg.sender == owner || msg.sender == timelock_address, "Not owner or timelock");
        _;
    }

    /* ========== CONSTRUCTOR ========== */

    constructor (
        address _creator_address,
        address _timelock_address
    ) Owned(_creator_address) {
        timelock_address = _timelock_address;

        // FXS/USD
        priceFeedFXSUSD = AggregatorV3Interface(0x6Ebc52C8C1089be9eB3945C4350B68B8E4C2233f);
        chainlink_fxs_usd_decimals = priceFeedFXSUSD.decimals();

        // ETH/USD
        priceFeedETHUSD = AggregatorV3Interface(0x5f4eC3Df9cbd43714FE2740f5E3616155c5b8419);
        chainlink_eth_usd_decimals = priceFeedETHUSD.decimals();
    }

    /* ========== VIEWS ========== */

    function getFXSPrice() public view returns (uint256) {
        ( , int price, , , ) = priceFeedFXSUSD.latestRoundData();
        return uint256(price).mul(PRICE_PRECISION).div(10 ** chainlink_fxs_usd_decimals);
    }

    function getETHPrice() public view returns (uint256) {
        ( , int price, , , ) = priceFeedETHUSD.latestRoundData();
        return uint256(price).mul(PRICE_PRECISION).div(10 ** chainlink_eth_usd_decimals);
    }

    // Override the logic of the FXS-WETH Uniswap TWAP Oracle
    // Expected Parameters: weth address, uint256 1e6
    // Returns: FXS Chainlink price (with 1e6 precision)
    function consult(address token, uint amountIn) external view returns (uint amountOut) {
        // safety checks (replacing regular FXS-WETH oracle in FRAX.sol)
        require(token == 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2, "must use weth address");
        require(amountIn == 1e6, "must call with 1e6");

        // needs to return it inverted
        return getETHPrice().mul(PRICE_PRECISION).div(getFXSPrice());
    }

    /* ========== RESTRICTED FUNCTIONS ========== */

    function setChainlinkFXSUSDOracle(address _chainlink_fxs_usd_oracle) external onlyByOwnGov {
        priceFeedFXSUSD = AggregatorV3Interface(_chainlink_fxs_usd_oracle);
        chainlink_fxs_usd_decimals = priceFeedFXSUSD.decimals();
    }

    function setChainlinkETHUSDOracle(address _chainlink_eth_usd_oracle) external onlyByOwnGov {
        priceFeedETHUSD = AggregatorV3Interface(_chainlink_eth_usd_oracle);
        chainlink_eth_usd_decimals = priceFeedETHUSD.decimals();
    }
}
// File: contracts/Math/SafeMath.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.6.11;

/**
 * @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.
     *
     * _Available since v2.4.0._
     */
    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.
     *
     * _Available since v2.4.0._
     */
    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        // Solidity only automatically asserts when dividing by 0
        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.
     *
     * _Available since v2.4.0._
     */
    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b != 0, errorMessage);
        return a % b;
    }
}
// File: contracts/Oracle/AggregatorV3Interface.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0;

interface AggregatorV3Interface {

  function decimals() external view returns (uint8);
  function description() external view returns (string memory);
  function version() external view returns (uint256);

  // getRoundData and latestRoundData should both raise "No data present"
  // if they do not have data to report, instead of returning unset values
  // which could be misinterpreted as actual reported values.
  function getRoundData(uint80 _roundId)
    external
    view
    returns (
      uint80 roundId,
      int256 answer,
      uint256 startedAt,
      uint256 updatedAt,
      uint80 answeredInRound
    );
  function latestRoundData()
    external
    view
    returns (
      uint80 roundId,
      int256 answer,
      uint256 startedAt,
      uint256 updatedAt,
      uint80 answeredInRound
    );

}
// File: contracts/Staking/Owned.sol



// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.6.11;

// https://docs.synthetix.io/contracts/Owned
contract Owned {
    address public owner;
    address public nominatedOwner;

    constructor (address _owner) public {
        require(_owner != address(0), "Owner address cannot be 0");
        owner = _owner;
        emit OwnerChanged(address(0), _owner);
    }

    function nominateNewOwner(address _owner) external onlyOwner {
        nominatedOwner = _owner;
        emit OwnerNominated(_owner);
    }

    function acceptOwnership() external {
        require(msg.sender == nominatedOwner, "You must be nominated before you can accept ownership");
        emit OwnerChanged(owner, nominatedOwner);
        owner = nominatedOwner;
        nominatedOwner = address(0);
    }

    modifier onlyOwner {
        require(msg.sender == owner, "Only the contract owner may perform this action");
        _;
    }

    event OwnerNominated(address newOwner);
    event OwnerChanged(address oldOwner, address newOwner);
}