// File: contracts/oracle/PhiatBackupPriceOracle.sol



// SPDX-License-Identifier: agpl-3.0
pragma solidity 0.7.6;

import {Ownable} from "../dependencies/openzeppelin/contracts/Ownable.sol";
import {SafeMath} from "../dependencies/openzeppelin/contracts/SafeMath.sol";

import {IPhiatBackupPriceOracle} from "../interfaces/IPhiatBackupPriceOracle.sol";
import {IPhiatPriceAggregator} from "../interfaces/IPhiatPriceAggregator.sol";

contract PhiatBackupPriceOracle is IPhiatBackupPriceOracle, Ownable {
    using SafeMath for uint256;

    mapping(address => uint256) private _prices;
    mapping(address => IPhiatPriceAggregator) private _assetsSources;
    mapping(address => bool) private _isKeeper;
    uint256 private _aggregatorWeightBps;

    event AssetSourceUpdated(address indexed asset, address indexed source);
    event AssetPriceUpdated(
        address indexed asset,
        uint256 price,
        uint256 timestamp
    );
    event KeeperUpdated(address indexed keeper, bool state);
    event AggregatorWeightUpdated(uint256 oldWeightBps, uint256 newWeightBps);

    constructor(
        address[] memory assets,
        address[] memory sources,
        address[] memory keepers,
        uint256 weightBps
    ) Ownable() {
        _setAssetsSources(assets, sources);
        for (uint256 i = 0; i < keepers.length; i++) {
            _isKeeper[keepers[i]] = true;
            emit KeeperUpdated(keepers[i], true);
        }
        _setAggregatorWeight(weightBps);
    }

    /**
     * @dev Throws if called by any account other than one of the keepers.
     */
    modifier onlyKeepers() {
        require(
            _isKeeper[_msgSender()],
            "PhiatBackupPriceOracle: caller is not one of the keepers"
        );
        _;
    }

    /// @notice External function called by the Phiat governance to set or replace sources of assets
    /// @param assets The addresses of the assets
    /// @param sources The address of the source of each asset
    function setAssetSources(
        address[] calldata assets,
        address[] calldata sources
    ) external onlyOwner {
        _setAssetsSources(assets, sources);
    }

    function setAggregatorWeight(uint256 weightBps) external onlyOwner {
        _setAggregatorWeight(weightBps);
    }

    function setKeeper(address keeper, bool state) external onlyOwner {
        _isKeeper[keeper] = state;
        emit KeeperUpdated(keeper, state);
    }

    function getAssetPrice(address asset)
        external
        view
        override
        returns (uint256)
    {
        if (_aggregatorWeightBps == 0 && _prices[asset] > 0) {
            return _prices[asset];
        } else {
            IPhiatPriceAggregator source = _assetsSources[asset];
            if (address(source) == address(0)) {
                return _prices[asset];
            }
            uint256 price = uint256(source.latestAnswer());
            if (price == 0) {
                return _prices[asset];
            } else if (_aggregatorWeightBps == 10000 || _prices[asset] == 0) {
                return price;
            } else {
                return
                    price
                        .mul(_aggregatorWeightBps)
                        .add(_prices[asset].mul(10000 - _aggregatorWeightBps))
                        .div(10000);
            }
        }
    }

    function setAssetPrice(address asset, uint256 price)
        external
        override
        onlyKeepers
    {
        _prices[asset] = price;
        emit AssetPriceUpdated(asset, price, block.timestamp);
    }

    /// @notice Internal function to set the sources for each asset
    /// @param assets The addresses of the assets
    /// @param sources The address of the source of each asset
    function _setAssetsSources(
        address[] memory assets,
        address[] memory sources
    ) internal {
        require(
            assets.length == sources.length,
            "PhiatBackupPriceOracle: inconsistent params length"
        );
        for (uint256 i = 0; i < assets.length; i++) {
            _assetsSources[assets[i]] = IPhiatPriceAggregator(sources[i]);
            emit AssetSourceUpdated(assets[i], sources[i]);
        }
    }

    /// @notice Internal function to set aggregator weight (in bps)
    /// @param weightBps New aggregator weight (in bps)
    function _setAggregatorWeight(uint256 weightBps) internal {
        require(
            weightBps <= 10000,
            "PhiatBackupPriceOracle: weight should be no higher than 10000 bps"
        );
        emit AggregatorWeightUpdated(_aggregatorWeightBps, weightBps);
        _aggregatorWeightBps = weightBps;
    }
}

// File: contracts/dependencies/openzeppelin/contracts/Ownable.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

import "./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 virtual 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: contracts/dependencies/openzeppelin/contracts/SafeMath.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

/**
 * @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, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryAdd(uint256 a, uint256 b)
        internal
        pure
        returns (bool, uint256)
    {
        uint256 c = a + b;
        if (c < a) return (false, 0);
        return (true, c);
    }

    /**
     * @dev Returns the substraction of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function trySub(uint256 a, uint256 b)
        internal
        pure
        returns (bool, uint256)
    {
        if (b > a) return (false, 0);
        return (true, a - b);
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryMul(uint256 a, uint256 b)
        internal
        pure
        returns (bool, 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 (true, 0);
        uint256 c = a * b;
        if (c / a != b) return (false, 0);
        return (true, c);
    }

    /**
     * @dev Returns the division of two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryDiv(uint256 a, uint256 b)
        internal
        pure
        returns (bool, uint256)
    {
        if (b == 0) return (false, 0);
        return (true, a / b);
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryMod(uint256 a, uint256 b)
        internal
        pure
        returns (bool, uint256)
    {
        if (b == 0) return (false, 0);
        return (true, a % b);
    }

    /**
     * @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) {
        require(b <= a, "SafeMath: subtraction overflow");
        return a - b;
    }

    /**
     * @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) {
        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, reverting 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) {
        require(b > 0, "SafeMath: division by zero");
        return a / b;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting 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) {
        require(b > 0, "SafeMath: modulo by zero");
        return a % b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {trySub}.
     *
     * 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);
        return a - b;
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryDiv}.
     *
     * 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);
        return a / b;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting with custom message when dividing by zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryMod}.
     *
     * 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;
    }
}

// File: contracts/interfaces/IPhiatBackupPriceOracle.sol



// SPDX-License-Identifier: agpl-3.0
pragma solidity 0.7.6;

/************
@title IPriceOracle interface
@notice Interface for the Aave price oracle.*/
interface IPhiatBackupPriceOracle {
    /***********
    @dev returns the asset price in ETH
     */
    function getAssetPrice(address asset) external view returns (uint256);

    /***********
    @dev sets the asset price, in wei
     */
    function setAssetPrice(address asset, uint256 price) external;
}

// File: contracts/interfaces/IPhiatPriceAggregator.sol



// SPDX-License-Identifier: agpl-3.0
pragma solidity 0.7.6;

interface IPhiatPriceAggregator {
    function decimals() external view returns (uint8);

    function latestAnswer() external view returns (int256);
}

// File: contracts/dependencies/openzeppelin/contracts/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;
    }
}