// File: contracts/protocol/ReserveOracle.sol



// SPDX-License-Identifier: agpl-3.0
pragma solidity 0.8.4;

import "@chainlink/contracts/src/v0.8/interfaces/AggregatorV3Interface.sol";
import {OwnableUpgradeable} from "@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol";
import {Initializable} from "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
import {IReserveOracleGetter} from "../interfaces/IReserveOracleGetter.sol";
import {BlockContext} from "../utils/BlockContext.sol";

contract ReserveOracle is IReserveOracleGetter, OwnableUpgradeable, BlockContext {
  uint256 private constant TOKEN_DIGIT = 10**18;

  event AggregatorAdded(address currencyKey, address aggregator);
  event AggregatorRemoved(address currencyKey, address aggregator);

  // key by currency symbol, eg USDT
  mapping(address => AggregatorV3Interface) public priceFeedMap;
  address[] public priceFeedKeys;

  address public weth;

  function initialize(address _weth) public initializer {
    __Ownable_init();
    weth = _weth;
  }

  function setAggregators(address[] calldata _priceFeedKeys, address[] calldata _aggregators) external onlyOwner {
    require(_priceFeedKeys.length == _aggregators.length, "ReserveOracle: INCONSISTENT_PARAMS_LENGTH");
    for (uint256 i = 0; i < _priceFeedKeys.length; i++) {
      _addAggregator(_priceFeedKeys[i], _aggregators[i]);
    }
  }

  function addAggregator(address _priceFeedKey, address _aggregator) external onlyOwner {
    _addAggregator(_priceFeedKey, _aggregator);
  }

  function _addAggregator(address _priceFeedKey, address _aggregator) internal {
    requireNonEmptyAddress(_priceFeedKey);
    requireNonEmptyAddress(_aggregator);
    if (address(priceFeedMap[_priceFeedKey]) == address(0)) {
      priceFeedKeys.push(_priceFeedKey);
    }
    priceFeedMap[_priceFeedKey] = AggregatorV3Interface(_aggregator);
    emit AggregatorAdded(_priceFeedKey, address(_aggregator));
  }

  function removeAggregator(address _priceFeedKey) external onlyOwner {
    address aggregator = address(priceFeedMap[_priceFeedKey]);
    requireNonEmptyAddress(aggregator);
    delete priceFeedMap[_priceFeedKey];

    uint256 length = priceFeedKeys.length;
    for (uint256 i = 0; i < length; i++) {
      if (priceFeedKeys[i] == _priceFeedKey) {
        // if the removal item is the last one, just `pop`
        if (i != length - 1) {
          priceFeedKeys[i] = priceFeedKeys[length - 1];
        }
        priceFeedKeys.pop();
        emit AggregatorRemoved(_priceFeedKey, aggregator);
        break;
      }
    }
  }

  function getAggregator(address _priceFeedKey) public view returns (AggregatorV3Interface) {
    return priceFeedMap[_priceFeedKey];
  }

  function getAssetPrice(address _priceFeedKey) external view override returns (uint256) {
    if (_priceFeedKey == weth) {
      return 1 ether;
    }
    require(isExistedKey(_priceFeedKey), "ReserveOracle: key not existed");
    AggregatorV3Interface aggregator = getAggregator(_priceFeedKey);

    (, int256 _price, , , ) = aggregator.latestRoundData();
    require(_price >= 0, "ReserveOracle: negative answer");
    uint8 decimals = aggregator.decimals();

    return formatDecimals(uint256(_price), decimals);
  }

  function getLatestTimestamp(address _priceFeedKey) public view returns (uint256) {
    AggregatorV3Interface aggregator = getAggregator(_priceFeedKey);
    requireNonEmptyAddress(address(aggregator));

    (, , , uint256 timestamp, ) = aggregator.latestRoundData();

    return timestamp;
  }

  function getTwapPrice(address _priceFeedKey, uint256 _interval) external view override returns (uint256) {
    require(isExistedKey(_priceFeedKey), "ReserveOracle: key not existed");
    require(_interval != 0, "ReserveOracle: interval can't be 0");

    AggregatorV3Interface aggregator = getAggregator(_priceFeedKey);
    (uint80 roundId, int256 _price, , uint256 timestamp, ) = aggregator.latestRoundData();
    require(_price >= 0, "ReserveOracle: negative answer");
    uint8 decimals = aggregator.decimals();

    uint256 latestPrice = formatDecimals(uint256(_price), decimals);

    require(roundId >= 0, "ReserveOracle: Not enough history");
    uint256 latestTimestamp = timestamp;
    uint256 baseTimestamp = _blockTimestamp() - _interval;
    // if latest updated timestamp is earlier than target timestamp, return the latest price.
    if (latestTimestamp < baseTimestamp || roundId == 0) {
      return latestPrice;
    }

    // rounds are like snapshots, latestRound means the latest price snapshot. follow chainlink naming
    uint256 cumulativeTime = _blockTimestamp() - latestTimestamp;
    uint256 previousTimestamp = latestTimestamp;
    uint256 weightedPrice = latestPrice * cumulativeTime;
    while (true) {
      if (roundId == 0) {
        // if cumulative time is less than requested interval, return current twap price
        return weightedPrice / cumulativeTime;
      }

      roundId = roundId - 1;
      // get current round timestamp and price
      (, int256 _priceTemp, , uint256 currentTimestamp, ) = aggregator.getRoundData(roundId);
      require(_priceTemp >= 0, "ReserveOracle: negative answer");

      uint256 price = formatDecimals(uint256(_priceTemp), decimals);

      // check if current round timestamp is earlier than target timestamp
      if (currentTimestamp <= baseTimestamp) {
        // weighted time period will be (target timestamp - previous timestamp). For example,
        // now is 1000, _interval is 100, then target timestamp is 900. If timestamp of current round is 970,
        // and timestamp of NEXT round is 880, then the weighted time period will be (970 - 900) = 70,
        // instead of (970 - 880)
        weightedPrice = weightedPrice + (price * (previousTimestamp - baseTimestamp));
        break;
      }

      uint256 timeFraction = previousTimestamp - currentTimestamp;
      weightedPrice = weightedPrice + (price * timeFraction);
      cumulativeTime = cumulativeTime + timeFraction;
      previousTimestamp = currentTimestamp;
    }
    return weightedPrice / _interval;
  }

  function isExistedKey(address _priceFeedKey) private view returns (bool) {
    uint256 length = priceFeedKeys.length;
    for (uint256 i = 0; i < length; i++) {
      if (priceFeedKeys[i] == _priceFeedKey) {
        return true;
      }
    }
    return false;
  }

  function requireNonEmptyAddress(address _addr) internal pure {
    require(_addr != address(0), "ReserveOracle: empty address");
  }

  function formatDecimals(uint256 _price, uint8 _decimals) internal pure returns (uint256) {
    return (_price * TOKEN_DIGIT) / (10**uint256(_decimals));
  }

  function getPriceFeedLength() public view returns (uint256 length) {
    return priceFeedKeys.length;
  }
}

// File: @chainlink/contracts/src/v0.8/interfaces/AggregatorV3Interface.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

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: @openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (access/Ownable.sol)

pragma solidity ^0.8.0;

import "../utils/ContextUpgradeable.sol";
import "../proxy/utils/Initializable.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 OwnableUpgradeable is Initializable, ContextUpgradeable {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    function __Ownable_init() internal onlyInitializing {
        __Context_init_unchained();
        __Ownable_init_unchained();
    }

    function __Ownable_init_unchained() internal onlyInitializing {
        _transferOwnership(_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 {
        _transferOwnership(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");
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
    uint256[49] private __gap;
}

// File: @openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (proxy/utils/Initializable.sol)

pragma solidity ^0.8.0;

import "../../utils/AddressUpgradeable.sol";

/**
 * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
 * behind a proxy. Since a proxied contract can't have a constructor, it's common to move constructor logic to an
 * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
 * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
 *
 * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
 * possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}.
 *
 * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
 * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
 *
 * [CAUTION]
 * ====
 * Avoid leaving a contract uninitialized.
 *
 * An uninitialized contract can be taken over by an attacker. This applies to both a proxy and its implementation
 * contract, which may impact the proxy. To initialize the implementation contract, you can either invoke the
 * initializer manually, or you can include a constructor to automatically mark it as initialized when it is deployed:
 *
 * [.hljs-theme-light.nopadding]
 * ```
 * /// @custom:oz-upgrades-unsafe-allow constructor
 * constructor() initializer {}
 * ```
 * ====
 */
abstract contract Initializable {
    /**
     * @dev Indicates that the contract has been initialized.
     */
    bool private _initialized;

    /**
     * @dev Indicates that the contract is in the process of being initialized.
     */
    bool private _initializing;

    /**
     * @dev Modifier to protect an initializer function from being invoked twice.
     */
    modifier initializer() {
        // If the contract is initializing we ignore whether _initialized is set in order to support multiple
        // inheritance patterns, but we only do this in the context of a constructor, because in other contexts the
        // contract may have been reentered.
        require(_initializing ? _isConstructor() : !_initialized, "Initializable: contract is already initialized");

        bool isTopLevelCall = !_initializing;
        if (isTopLevelCall) {
            _initializing = true;
            _initialized = true;
        }

        _;

        if (isTopLevelCall) {
            _initializing = false;
        }
    }

    /**
     * @dev Modifier to protect an initialization function so that it can only be invoked by functions with the
     * {initializer} modifier, directly or indirectly.
     */
    modifier onlyInitializing() {
        require(_initializing, "Initializable: contract is not initializing");
        _;
    }

    function _isConstructor() private view returns (bool) {
        return !AddressUpgradeable.isContract(address(this));
    }
}

// File: contracts/interfaces/IReserveOracleGetter.sol



// SPDX-License-Identifier: agpl-3.0
pragma solidity 0.8.4;

/************
@title IReserveOracleGetter interface
@notice Interface for getting Reserve price oracle.*/
interface IReserveOracleGetter {
  /* CAUTION: Price uint is ETH based (WEI, 18 decimals) */
  /***********
    @dev returns the asset price in ETH
     */
  function getAssetPrice(address asset) external view returns (uint256);

  // get twap price depending on _period
  function getTwapPrice(address _priceFeedKey, uint256 _interval) external view returns (uint256);
}

// File: contracts/utils/BlockContext.sol



// SPDX-License-Identifier: agpl-3.0
pragma solidity 0.8.4;

// wrap block.xxx functions for testing
// only support timestamp and number so far
abstract contract BlockContext {
  //◥◤◥◤◥◤◥◤◥◤◥◤◥◤◥◤ add state variables below ◥◤◥◤◥◤◥◤◥◤◥◤◥◤◥◤//

  //◢◣◢◣◢◣◢◣◢◣◢◣◢◣◢◣ add state variables above ◢◣◢◣◢◣◢◣◢◣◢◣◢◣◢◣//
  uint256[50] private __gap;

  function _blockTimestamp() internal view virtual returns (uint256) {
    return block.timestamp;
  }

  function _blockNumber() internal view virtual returns (uint256) {
    return block.number;
  }
}

// File: @openzeppelin/contracts-upgradeable/utils/ContextUpgradeable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)

pragma solidity ^0.8.0;
import "../proxy/utils/Initializable.sol";

/**
 * @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 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 ContextUpgradeable is Initializable {
    function __Context_init() internal onlyInitializing {
        __Context_init_unchained();
    }

    function __Context_init_unchained() internal onlyInitializing {
    }
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
    uint256[50] private __gap;
}

// File: @openzeppelin/contracts-upgradeable/utils/AddressUpgradeable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Address.sol)

pragma solidity ^0.8.0;

/**
 * @dev Collection of functions related to the address type
 */
library AddressUpgradeable {
    /**
     * @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 on extcodesize, which returns 0 for contracts in
        // construction, since the code is only stored at the end of the
        // constructor execution.

        uint256 size;
        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");

        (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");

        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResult(success, returndata, 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");

        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal 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

                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}