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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)

pragma solidity ^0.8.0;

import "../utils/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() {
        _transferOwnership(_msgSender());
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        _checkOwner();
        _;
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if the sender is not the owner.
     */
    function _checkOwner() internal view virtual {
        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);
    }
}

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



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

pragma solidity ^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 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) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}

// File: contracts/CrossChainRateProvider.sol



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

import {Ownable} from "@openzeppelin/contracts/access/Ownable.sol";

import {ILayerZeroEndpoint} from "./interfaces/ILayerZeroEndpoint.sol";
import {IWstETH} from "./interfaces/IWstETH.sol";

/// @title Cross chain rate provider
/// @author witherblock
/// @notice Provides a rate to a receiver contract on a different chain than the one this contract is deployed on
/// @dev Powered using LayerZero
contract CrossChainRateProvider is Ownable {
    /// @notice Last rate updated on the receiver. Not guaranteed as updates can be dropped.
    uint256 public rate;

    /// @notice Last time rate was updated.
    uint256 public lastUpdated;

    /// @notice Destination chainId
    uint16 public dstChainId;

    /// @notice LayerZero endpoint address.
    address public layerZeroEndpoint;

    /// @notice Rate Reciever address address.
    address public rateReceiver;

    /// @notice Emitted when rate is updated
    /// @param newRate the rate that was updated
    event RateUpdated(uint256 newRate);

    /// @notice Emitted when LayerZero Endpoint is updated
    /// @param newLayerZeroEndpoint the LayerZero Endpoint address that was updated
    event LayerZeroEndpointUpdated(address newLayerZeroEndpoint);

    /// @notice Emitted when RateReceiver is updated
    /// @param newRateReceiver the RateReceiver address that was updated
    event RateReceiverUpdated(address newRateReceiver);

    /// @notice Emitted when the destination chainId is updated
    /// @param newDstChainId the destination chainId that was updated
    event DstChainIdUpdated(uint16 newDstChainId);

    /// @notice Updates the LayerZero Endpoint address
    /// @dev Can only be called by owner
    /// @param _layerZeroEndpoint the new layer zero endpoint address
    function updateLayerZeroEndpoint(
        address _layerZeroEndpoint
    ) external onlyOwner {
        layerZeroEndpoint = _layerZeroEndpoint;

        emit LayerZeroEndpointUpdated(_layerZeroEndpoint);
    }

    /// @notice Updates the RateReceiver address
    /// @dev Can only be called by owner
    /// @param _rateReceiver the new rate receiver address
    function updateRateReceiver(address _rateReceiver) external onlyOwner {
        rateReceiver = _rateReceiver;

        emit RateReceiverUpdated(_rateReceiver);
    }

    /// @notice Updates the destination chainId
    /// @dev Can only be called by owner
    /// @param _dstChainId the destination chainId
    function updateDstChainId(uint16 _dstChainId) external onlyOwner {
        dstChainId = _dstChainId;

        emit DstChainIdUpdated(_dstChainId);
    }

    /// @notice Updates rate in this contract and on the receiver
    function updateRate() external payable {
        uint256 latestRate = getLatestRate();

        bytes memory remoteAndLocalAddresses = abi.encodePacked(
            rateReceiver,
            address(this)
        );

        rate = latestRate;

        lastUpdated = block.timestamp;

        bytes memory _payload = abi.encode(latestRate);

        ILayerZeroEndpoint(layerZeroEndpoint).send{value: msg.value}(
            dstChainId,
            remoteAndLocalAddresses,
            _payload,
            payable(msg.sender),
            address(0x0),
            bytes("")
        );

        emit RateUpdated(rate);
    }

    /// @notice Returns the latest rate from wstETH contract
    function getLatestRate() public view returns (uint256) {
        return
            IWstETH(0x7f39C581F595B53c5cb19bD0b3f8dA6c935E2Ca0).stEthPerToken();
    }
}

// File: contracts/interfaces/ILayerZeroEndpoint.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.5.0;

import "./ILayerZeroUserApplicationConfig.sol";

interface ILayerZeroEndpoint is ILayerZeroUserApplicationConfig {
    // @notice send a LayerZero message to the specified address at a LayerZero endpoint.
    // @param _dstChainId - the destination chain identifier
    // @param _destination - the address on destination chain (in bytes). address length/format may vary by chains
    // @param _payload - a custom bytes payload to send to the destination contract
    // @param _refundAddress - if the source transaction is cheaper than the amount of value passed, refund the additional amount to this address
    // @param _zroPaymentAddress - the address of the ZRO token holder who would pay for the transaction
    // @param _adapterParams - parameters for custom functionality. e.g. receive airdropped native gas from the relayer on destination
    function send(
        uint16 _dstChainId,
        bytes calldata _destination,
        bytes calldata _payload,
        address payable _refundAddress,
        address _zroPaymentAddress,
        bytes calldata _adapterParams
    ) external payable;

    // @notice used by the messaging library to publish verified payload
    // @param _srcChainId - the source chain identifier
    // @param _srcAddress - the source contract (as bytes) at the source chain
    // @param _dstAddress - the address on destination chain
    // @param _nonce - the unbound message ordering nonce
    // @param _gasLimit - the gas limit for external contract execution
    // @param _payload - verified payload to send to the destination contract
    function receivePayload(
        uint16 _srcChainId,
        bytes calldata _srcAddress,
        address _dstAddress,
        uint64 _nonce,
        uint _gasLimit,
        bytes calldata _payload
    ) external;

    // @notice get the inboundNonce of a lzApp from a source chain which could be EVM or non-EVM chain
    // @param _srcChainId - the source chain identifier
    // @param _srcAddress - the source chain contract address
    function getInboundNonce(
        uint16 _srcChainId,
        bytes calldata _srcAddress
    ) external view returns (uint64);

    // @notice get the outboundNonce from this source chain which, consequently, is always an EVM
    // @param _srcAddress - the source chain contract address
    function getOutboundNonce(
        uint16 _dstChainId,
        address _srcAddress
    ) external view returns (uint64);

    // @notice gets a quote in source native gas, for the amount that send() requires to pay for message delivery
    // @param _dstChainId - the destination chain identifier
    // @param _userApplication - the user app address on this EVM chain
    // @param _payload - the custom message to send over LayerZero
    // @param _payInZRO - if false, user app pays the protocol fee in native token
    // @param _adapterParam - parameters for the adapter service, e.g. send some dust native token to dstChain
    function estimateFees(
        uint16 _dstChainId,
        address _userApplication,
        bytes calldata _payload,
        bool _payInZRO,
        bytes calldata _adapterParam
    ) external view returns (uint nativeFee, uint zroFee);

    // @notice get this Endpoint's immutable source identifier
    function getChainId() external view returns (uint16);

    // @notice the interface to retry failed message on this Endpoint destination
    // @param _srcChainId - the source chain identifier
    // @param _srcAddress - the source chain contract address
    // @param _payload - the payload to be retried
    function retryPayload(
        uint16 _srcChainId,
        bytes calldata _srcAddress,
        bytes calldata _payload
    ) external;

    // @notice query if any STORED payload (message blocking) at the endpoint.
    // @param _srcChainId - the source chain identifier
    // @param _srcAddress - the source chain contract address
    function hasStoredPayload(
        uint16 _srcChainId,
        bytes calldata _srcAddress
    ) external view returns (bool);

    // @notice query if the _libraryAddress is valid for sending msgs.
    // @param _userApplication - the user app address on this EVM chain
    function getSendLibraryAddress(
        address _userApplication
    ) external view returns (address);

    // @notice query if the _libraryAddress is valid for receiving msgs.
    // @param _userApplication - the user app address on this EVM chain
    function getReceiveLibraryAddress(
        address _userApplication
    ) external view returns (address);

    // @notice query if the non-reentrancy guard for send() is on
    // @return true if the guard is on. false otherwise
    function isSendingPayload() external view returns (bool);

    // @notice query if the non-reentrancy guard for receive() is on
    // @return true if the guard is on. false otherwise
    function isReceivingPayload() external view returns (bool);

    // @notice get the configuration of the LayerZero messaging library of the specified version
    // @param _version - messaging library version
    // @param _chainId - the chainId for the pending config change
    // @param _userApplication - the contract address of the user application
    // @param _configType - type of configuration. every messaging library has its own convention.
    function getConfig(
        uint16 _version,
        uint16 _chainId,
        address _userApplication,
        uint _configType
    ) external view returns (bytes memory);

    // @notice get the send() LayerZero messaging library version
    // @param _userApplication - the contract address of the user application
    function getSendVersion(
        address _userApplication
    ) external view returns (uint16);

    // @notice get the lzReceive() LayerZero messaging library version
    // @param _userApplication - the contract address of the user application
    function getReceiveVersion(
        address _userApplication
    ) external view returns (uint16);
}

// File: contracts/interfaces/ILayerZeroUserApplicationConfig.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.5.0;

interface ILayerZeroUserApplicationConfig {
    // @notice set the configuration of the LayerZero messaging library of the specified version
    // @param _version - messaging library version
    // @param _chainId - the chainId for the pending config change
    // @param _configType - type of configuration. every messaging library has its own convention.
    // @param _config - configuration in the bytes. can encode arbitrary content.
    function setConfig(
        uint16 _version,
        uint16 _chainId,
        uint _configType,
        bytes calldata _config
    ) external;

    // @notice set the send() LayerZero messaging library version to _version
    // @param _version - new messaging library version
    function setSendVersion(uint16 _version) external;

    // @notice set the lzReceive() LayerZero messaging library version to _version
    // @param _version - new messaging library version
    function setReceiveVersion(uint16 _version) external;

    // @notice Only when the UA needs to resume the message flow in blocking mode and clear the stored payload
    // @param _srcChainId - the chainId of the source chain
    // @param _srcAddress - the contract address of the source contract at the source chain
    function forceResumeReceive(
        uint16 _srcChainId,
        bytes calldata _srcAddress
    ) external;
}

// File: contracts/interfaces/IWstETH.sol



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

interface IWstETH {
    function stEthPerToken() external view returns (uint);
}