// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (utils/Address.sol)

pragma solidity ^0.8.20;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev The ETH balance of the account is not enough to perform the operation.
     */
    error AddressInsufficientBalance(address account);

    /**
     * @dev There's no code at `target` (it is not a contract).
     */
    error AddressEmptyCode(address target);

    /**
     * @dev A call to an address target failed. The target may have reverted.
     */
    error FailedInnerCall();

    /**
     * @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://consensys.net/diligence/blog/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/v0.8.20/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        if (address(this).balance < amount) {
            revert AddressInsufficientBalance(address(this));
        }

        (bool success, ) = recipient.call{value: amount}("");
        if (!success) {
            revert FailedInnerCall();
        }
    }

    /**
     * @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 or custom error, it is bubbled
     * up by this function (like regular Solidity function calls). However, if
     * the call reverted with no returned reason, this function reverts with a
     * {FailedInnerCall} error.
     *
     * 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.
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0);
    }

    /**
     * @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`.
     */
    function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
        if (address(this).balance < value) {
            revert AddressInsufficientBalance(address(this));
        }
        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResultFromTarget(target, success, returndata);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResultFromTarget(target, success, returndata);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResultFromTarget(target, success, returndata);
    }

    /**
     * @dev Tool to verify that a low level call to smart-contract was successful, and reverts if the target
     * was not a contract or bubbling up the revert reason (falling back to {FailedInnerCall}) in case of an
     * unsuccessful call.
     */
    function verifyCallResultFromTarget(
        address target,
        bool success,
        bytes memory returndata
    ) internal view returns (bytes memory) {
        if (!success) {
            _revert(returndata);
        } else {
            // only check if target is a contract if the call was successful and the return data is empty
            // otherwise we already know that it was a contract
            if (returndata.length == 0 && target.code.length == 0) {
                revert AddressEmptyCode(target);
            }
            return returndata;
        }
    }

    /**
     * @dev Tool to verify that a low level call was successful, and reverts if it wasn't, either by bubbling the
     * revert reason or with a default {FailedInnerCall} error.
     */
    function verifyCallResult(bool success, bytes memory returndata) internal pure returns (bytes memory) {
        if (!success) {
            _revert(returndata);
        } else {
            return returndata;
        }
    }

    /**
     * @dev Reverts with returndata if present. Otherwise reverts with {FailedInnerCall}.
     */
    function _revert(bytes memory returndata) private pure {
        // 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
            /// @solidity memory-safe-assembly
            assembly {
                let returndata_size := mload(returndata)
                revert(add(32, returndata), returndata_size)
            }
        } else {
            revert FailedInnerCall();
        }
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.1) (utils/Context.sol)

pragma solidity ^0.8.20;

/**
 * @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;
    }

    function _contextSuffixLength() internal view virtual returns (uint256) {
        return 0;
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (utils/introspection/IERC165.sol)

pragma solidity ^0.8.20;

/**
 * @dev Interface of the ERC165 standard, as defined in the
 * https://eips.ethereum.org/EIPS/eip-165[EIP].
 *
 * Implementers can declare support of contract interfaces, which can then be
 * queried by others ({ERC165Checker}).
 *
 * For an implementation, see {ERC165}.
 */
interface IERC165 {
    /**
     * @dev Returns true if this contract implements the interface defined by
     * `interfaceId`. See the corresponding
     * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
     * to learn more about how these ids are created.
     *
     * This function call must use less than 30 000 gas.
     */
    function supportsInterface(bytes4 interfaceId) external view returns (bool);
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.20;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @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);

    /**
     * @dev Returns the value of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the value of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves a `value` amount of tokens from the caller's account to `to`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address to, uint256 value) 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 a `value` amount of tokens 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 value) external returns (bool);

    /**
     * @dev Moves a `value` amount of tokens from `from` to `to` using the
     * allowance mechanism. `value` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(address from, address to, uint256 value) external returns (bool);
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/extensions/IERC20Permit.sol)

pragma solidity ^0.8.20;

/**
 * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
 * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
 *
 * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
 * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't
 * need to send a transaction, and thus is not required to hold Ether at all.
 *
 * ==== Security Considerations
 *
 * There are two important considerations concerning the use of `permit`. The first is that a valid permit signature
 * expresses an allowance, and it should not be assumed to convey additional meaning. In particular, it should not be
 * considered as an intention to spend the allowance in any specific way. The second is that because permits have
 * built-in replay protection and can be submitted by anyone, they can be frontrun. A protocol that uses permits should
 * take this into consideration and allow a `permit` call to fail. Combining these two aspects, a pattern that may be
 * generally recommended is:
 *
 * ```solidity
 * function doThingWithPermit(..., uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s) public {
 *     try token.permit(msg.sender, address(this), value, deadline, v, r, s) {} catch {}
 *     doThing(..., value);
 * }
 *
 * function doThing(..., uint256 value) public {
 *     token.safeTransferFrom(msg.sender, address(this), value);
 *     ...
 * }
 * ```
 *
 * Observe that: 1) `msg.sender` is used as the owner, leaving no ambiguity as to the signer intent, and 2) the use of
 * `try/catch` allows the permit to fail and makes the code tolerant to frontrunning. (See also
 * {SafeERC20-safeTransferFrom}).
 *
 * Additionally, note that smart contract wallets (such as Argent or Safe) are not able to produce permit signatures, so
 * contracts should have entry points that don't rely on permit.
 */
interface IERC20Permit {
    /**
     * @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,
     * given ``owner``'s signed approval.
     *
     * IMPORTANT: The same issues {IERC20-approve} has related to transaction
     * ordering also apply here.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `deadline` must be a timestamp in the future.
     * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
     * over the EIP712-formatted function arguments.
     * - the signature must use ``owner``'s current nonce (see {nonces}).
     *
     * For more information on the signature format, see the
     * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
     * section].
     *
     * CAUTION: See Security Considerations above.
     */
    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;

    /**
     * @dev Returns the current nonce for `owner`. This value must be
     * included whenever a signature is generated for {permit}.
     *
     * Every successful call to {permit} increases ``owner``'s nonce by one. This
     * prevents a signature from being used multiple times.
     */
    function nonces(address owner) external view returns (uint256);

    /**
     * @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.
     */
    // solhint-disable-next-line func-name-mixedcase
    function DOMAIN_SEPARATOR() external view returns (bytes32);
}

// SPDX-License-Identifier: MIT

pragma solidity >=0.8.0;

import { Origin } from "./ILayerZeroEndpointV2.sol";

interface ILayerZeroReceiver {
    function allowInitializePath(Origin calldata _origin) external view returns (bool);

    function nextNonce(uint32 _eid, bytes32 _sender) external view returns (uint64);

    function lzReceive(
        Origin calldata _origin,
        bytes32 _guid,
        bytes calldata _message,
        address _executor,
        bytes calldata _extraData
    ) external payable;
}

// SPDX-License-Identifier: MIT

pragma solidity >=0.8.0;

interface IMessagingChannel {
    event InboundNonceSkipped(uint32 srcEid, bytes32 sender, address receiver, uint64 nonce);
    event PacketNilified(uint32 srcEid, bytes32 sender, address receiver, uint64 nonce, bytes32 payloadHash);
    event PacketBurnt(uint32 srcEid, bytes32 sender, address receiver, uint64 nonce, bytes32 payloadHash);

    function eid() external view returns (uint32);

    // this is an emergency function if a message cannot be verified for some reasons
    // required to provide _nextNonce to avoid race condition
    function skip(address _oapp, uint32 _srcEid, bytes32 _sender, uint64 _nonce) external;

    function nilify(address _oapp, uint32 _srcEid, bytes32 _sender, uint64 _nonce, bytes32 _payloadHash) external;

    function burn(address _oapp, uint32 _srcEid, bytes32 _sender, uint64 _nonce, bytes32 _payloadHash) external;

    function nextGuid(address _sender, uint32 _dstEid, bytes32 _receiver) external view returns (bytes32);

    function inboundNonce(address _receiver, uint32 _srcEid, bytes32 _sender) external view returns (uint64);

    function outboundNonce(address _sender, uint32 _dstEid, bytes32 _receiver) external view returns (uint64);

    function inboundPayloadHash(
        address _receiver,
        uint32 _srcEid,
        bytes32 _sender,
        uint64 _nonce
    ) external view returns (bytes32);

    function lazyInboundNonce(address _receiver, uint32 _srcEid, bytes32 _sender) external view returns (uint64);
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.20;

import { ILayerZeroEndpointV2 } from "@layerzerolabs/lz-evm-protocol-v2/contracts/interfaces/ILayerZeroEndpointV2.sol";

/**
 * @title IOAppCore
 */
interface IOAppCore {
    // Custom error messages
    error OnlyPeer(uint32 eid, bytes32 sender);
    error NoPeer(uint32 eid);
    error InvalidEndpointCall();
    error InvalidDelegate();

    // Event emitted when a peer (OApp) is set for a corresponding endpoint
    event PeerSet(uint32 eid, bytes32 peer);

    /**
     * @notice Retrieves the OApp version information.
     * @return senderVersion The version of the OAppSender.sol contract.
     * @return receiverVersion The version of the OAppReceiver.sol contract.
     */
    function oAppVersion() external view returns (uint64 senderVersion, uint64 receiverVersion);

    /**
     * @notice Retrieves the LayerZero endpoint associated with the OApp.
     * @return iEndpoint The LayerZero endpoint as an interface.
     */
    function endpoint() external view returns (ILayerZeroEndpointV2 iEndpoint);

    /**
     * @notice Retrieves the peer (OApp) associated with a corresponding endpoint.
     * @param _eid The endpoint ID.
     * @return peer The peer address (OApp instance) associated with the corresponding endpoint.
     */
    function peers(uint32 _eid) external view returns (bytes32 peer);

    /**
     * @notice Sets the peer address (OApp instance) for a corresponding endpoint.
     * @param _eid The endpoint ID.
     * @param _peer The address of the peer to be associated with the corresponding endpoint.
     */
    function setPeer(uint32 _eid, bytes32 _peer) external;

    /**
     * @notice Sets the delegate address for the OApp Core.
     * @param _delegate The address of the delegate to be set.
     */
    function setDelegate(address _delegate) external;
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.20;

/**
 * @title IOAppMsgInspector
 * @dev Interface for the OApp Message Inspector, allowing examination of message and options contents.
 */
interface IOAppMsgInspector {
    // Custom error message for inspection failure
    error InspectionFailed(bytes message, bytes options);

    /**
     * @notice Allows the inspector to examine LayerZero message contents and optionally throw a revert if invalid.
     * @param _message The message payload to be inspected.
     * @param _options Additional options or parameters for inspection.
     * @return valid A boolean indicating whether the inspection passed (true) or failed (false).
     *
     * @dev Optionally done as a revert, OR use the boolean provided to handle the failure.
     */
    function inspect(bytes calldata _message, bytes calldata _options) external view returns (bool valid);
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

import { ILayerZeroReceiver, Origin } from "@layerzerolabs/lz-evm-protocol-v2/contracts/interfaces/ILayerZeroReceiver.sol";

interface IOAppReceiver is ILayerZeroReceiver {
    /**
     * @notice Indicates whether an address is an approved composeMsg sender to the Endpoint.
     * @param _origin The origin information containing the source endpoint and sender address.
     *  - srcEid: The source chain endpoint ID.
     *  - sender: The sender address on the src chain.
     *  - nonce: The nonce of the message.
     * @param _message The lzReceive payload.
     * @param _sender The sender address.
     * @return isSender Is a valid sender.
     *
     * @dev Applications can optionally choose to implement a separate composeMsg sender that is NOT the bridging layer.
     * @dev The default sender IS the OAppReceiver implementer.
     */
    function isComposeMsgSender(
        Origin calldata _origin,
        bytes calldata _message,
        address _sender
    ) external view returns (bool isSender);
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.20;

import { MessagingReceipt, MessagingFee } from "@layerzerolabs/oapp-evm/contracts/oapp/OAppSender.sol";

/**
 * @dev Struct representing token parameters for the OFT send() operation.
 */
struct SendParam {
    uint32 dstEid; // Destination endpoint ID.
    bytes32 to; // Recipient address.
    uint256 amountLD; // Amount to send in local decimals.
    uint256 minAmountLD; // Minimum amount to send in local decimals.
    bytes extraOptions; // Additional options supplied by the caller to be used in the LayerZero message.
    bytes composeMsg; // The composed message for the send() operation.
    bytes oftCmd; // The OFT command to be executed, unused in default OFT implementations.
}

/**
 * @dev Struct representing OFT limit information.
 * @dev These amounts can change dynamically and are up the specific oft implementation.
 */
struct OFTLimit {
    uint256 minAmountLD; // Minimum amount in local decimals that can be sent to the recipient.
    uint256 maxAmountLD; // Maximum amount in local decimals that can be sent to the recipient.
}

/**
 * @dev Struct representing OFT receipt information.
 */
struct OFTReceipt {
    uint256 amountSentLD; // Amount of tokens ACTUALLY debited from the sender in local decimals.
    // @dev In non-default implementations, the amountReceivedLD COULD differ from this value.
    uint256 amountReceivedLD; // Amount of tokens to be received on the remote side.
}

/**
 * @dev Struct representing OFT fee details.
 * @dev Future proof mechanism to provide a standardized way to communicate fees to things like a UI.
 */
struct OFTFeeDetail {
    int256 feeAmountLD; // Amount of the fee in local decimals.
    string description; // Description of the fee.
}

/**
 * @title IOFT
 * @dev Interface for the OftChain (OFT) token.
 * @dev Does not inherit ERC20 to accommodate usage by OFTAdapter as well.
 * @dev This specific interface ID is '0x02e49c2c'.
 */
interface IOFT {
    // Custom error messages
    error InvalidLocalDecimals();
    error SlippageExceeded(uint256 amountLD, uint256 minAmountLD);

    // Events
    event OFTSent(
        bytes32 indexed guid, // GUID of the OFT message.
        uint32 dstEid, // Destination Endpoint ID.
        address indexed fromAddress, // Address of the sender on the src chain.
        uint256 amountSentLD, // Amount of tokens sent in local decimals.
        uint256 amountReceivedLD // Amount of tokens received in local decimals.
    );
    event OFTReceived(
        bytes32 indexed guid, // GUID of the OFT message.
        uint32 srcEid, // Source Endpoint ID.
        address indexed toAddress, // Address of the recipient on the dst chain.
        uint256 amountReceivedLD // Amount of tokens received in local decimals.
    );

    /**
     * @notice Retrieves interfaceID and the version of the OFT.
     * @return interfaceId The interface ID.
     * @return version The version.
     *
     * @dev interfaceId: This specific interface ID is '0x02e49c2c'.
     * @dev version: Indicates a cross-chain compatible msg encoding with other OFTs.
     * @dev If a new feature is added to the OFT cross-chain msg encoding, the version will be incremented.
     * ie. localOFT version(x,1) CAN send messages to remoteOFT version(x,1)
     */
    function oftVersion() external view returns (bytes4 interfaceId, uint64 version);

    /**
     * @notice Retrieves the address of the token associated with the OFT.
     * @return token The address of the ERC20 token implementation.
     */
    function token() external view returns (address);

    /**
     * @notice Indicates whether the OFT contract requires approval of the 'token()' to send.
     * @return requiresApproval Needs approval of the underlying token implementation.
     *
     * @dev Allows things like wallet implementers to determine integration requirements,
     * without understanding the underlying token implementation.
     */
    function approvalRequired() external view returns (bool);

    /**
     * @notice Retrieves the shared decimals of the OFT.
     * @return sharedDecimals The shared decimals of the OFT.
     */
    function sharedDecimals() external view returns (uint8);

    /**
     * @notice Provides a quote for OFT-related operations.
     * @param _sendParam The parameters for the send operation.
     * @return limit The OFT limit information.
     * @return oftFeeDetails The details of OFT fees.
     * @return receipt The OFT receipt information.
     */
    function quoteOFT(
        SendParam calldata _sendParam
    ) external view returns (OFTLimit memory, OFTFeeDetail[] memory oftFeeDetails, OFTReceipt memory);

    /**
     * @notice Provides a quote for the send() operation.
     * @param _sendParam The parameters for the send() operation.
     * @param _payInLzToken Flag indicating whether the caller is paying in the LZ token.
     * @return fee The calculated LayerZero messaging fee from the send() operation.
     *
     * @dev MessagingFee: LayerZero msg fee
     *  - nativeFee: The native fee.
     *  - lzTokenFee: The lzToken fee.
     */
    function quoteSend(SendParam calldata _sendParam, bool _payInLzToken) external view returns (MessagingFee memory);

    /**
     * @notice Executes the send() operation.
     * @param _sendParam The parameters for the send operation.
     * @param _fee The fee information supplied by the caller.
     *      - nativeFee: The native fee.
     *      - lzTokenFee: The lzToken fee.
     * @param _refundAddress The address to receive any excess funds from fees etc. on the src.
     * @return receipt The LayerZero messaging receipt from the send() operation.
     * @return oftReceipt The OFT receipt information.
     *
     * @dev MessagingReceipt: LayerZero msg receipt
     *  - guid: The unique identifier for the sent message.
     *  - nonce: The nonce of the sent message.
     *  - fee: The LayerZero fee incurred for the message.
     */
    function send(
        SendParam calldata _sendParam,
        MessagingFee calldata _fee,
        address _refundAddress
    ) external payable returns (MessagingReceipt memory, OFTReceipt memory);
}

// SPDX-License-Identifier: LZBL-1.2
pragma solidity ^0.8.22;

import { Ownable } from "@openzeppelin/contracts/access/Ownable.sol";
import { IERC20, SafeERC20 } from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";

import { OFTAdapter } from "@layerzerolabs/oft-evm/contracts/OFTAdapter.sol";
import { RateLimiter } from "./RateLimiter.sol";

/**
 * @title L1OFTAdapter
 * @dev L1OFTAdapter is a lock-and-unlock OFTAdapter with rate limiting functionality.
 */
contract L1OFTAdapter is OFTAdapter, RateLimiter {
    using SafeERC20 for IERC20;

    constructor(
        address _token,
        address _lzEndpoint,
        address _delegate
    ) OFTAdapter(_token, _lzEndpoint, _delegate) Ownable(_delegate) {}

    /**
     * @notice Sets the Rate Limit.
     * @param _rateLimitConfigs A `RateLimitConfig` struct representing the rate limit configuration.
     * - `dstEid`: The destination endpoint id.
     * - `limit`: This represents the maximum allowed amount within a given window.
     * - `window`: Defines the duration of the rate limiting window.
     */
    function setRateLimits(RateLimiter.RateLimitConfig[] memory _rateLimitConfigs) external virtual onlyOwner {
        _setRateLimits(_rateLimitConfigs);
    }

    /**
     * @dev Locks tokens from the sender's specified balance in this contract.
     * @param _from The address to debit from.
     * @param _amountLD The amount of tokens to send in local decimals.
     * @param _minAmountLD The minimum amount to send in local decimals.
     * @param _dstEid The destination chain ID.
     * @return amountSentLD The amount sent in local decimals.
     * @return amountReceivedLD The amount received in local decimals on the remote.
     *
     * @dev msg.sender will need to approve this _amountLD of tokens to be locked inside of the contract.
     * @dev WARNING: The default OFTAdapter implementation assumes LOSSLESS transfers, ie. 1 token in, 1 token out.
     * IF the 'innerToken' applies something like a transfer fee, the default will NOT work...
     * a pre/post balance check will need to be done to calculate the amountReceivedLD.
     */
    function _debit(
        address _from,
        uint256 _amountLD,
        uint256 _minAmountLD,
        uint32 _dstEid
    ) internal virtual override returns (uint256 amountSentLD, uint256 amountReceivedLD) {
        (amountSentLD, amountReceivedLD) = _debitView(_amountLD, _minAmountLD, _dstEid);
        _outflow(_dstEid, amountReceivedLD);
        // @dev Lock tokens by moving them into this contract from the caller.
        innerToken.safeTransferFrom(_from, address(this), amountSentLD);
    }

    /**
     * @dev Credits tokens to the specified address.
     * @param _to The address to credit the tokens to.
     * @param _amountLD The amount of tokens to credit in local decimals.
     * @dev _srcEid The source chain ID.
     * @return amountReceivedLD The amount of tokens ACTUALLY received in local decimals.
     *
     * @dev WARNING: The default OFTAdapter implementation assumes LOSSLESS transfers, ie. 1 token in, 1 token out.
     * IF the 'innerToken' applies something like a transfer fee, the default will NOT work...
     * a pre/post balance check will need to be done to calculate the amountReceivedLD.
     */
    function _credit(
        address _to,
        uint256 _amountLD,
        uint32 _srcEid
    ) internal virtual override returns (uint256 amountReceivedLD) {
        _inflow(_srcEid, _amountLD);
        // @dev Unlock the tokens and transfer to the recipient.
        innerToken.safeTransfer(_to, _amountLD);
        // @dev In the case of NON-default OFTAdapter, the amountLD MIGHT not be == amountReceivedLD.
        return _amountLD;
    }
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.20;

// @dev Import the 'MessagingFee' and 'MessagingReceipt' so it's exposed to OApp implementers
// solhint-disable-next-line no-unused-import
import { OAppSender, MessagingFee, MessagingReceipt } from "./OAppSender.sol";
// @dev Import the 'Origin' so it's exposed to OApp implementers
// solhint-disable-next-line no-unused-import
import { OAppReceiver, Origin } from "./OAppReceiver.sol";
import { OAppCore } from "./OAppCore.sol";

/**
 * @title OApp
 * @dev Abstract contract serving as the base for OApp implementation, combining OAppSender and OAppReceiver functionality.
 */
abstract contract OApp is OAppSender, OAppReceiver {
    /**
     * @dev Constructor to initialize the OApp with the provided endpoint and owner.
     * @param _endpoint The address of the LOCAL LayerZero endpoint.
     * @param _delegate The delegate capable of making OApp configurations inside of the endpoint.
     */
    constructor(address _endpoint, address _delegate) OAppCore(_endpoint, _delegate) {}

    /**
     * @notice Retrieves the OApp version information.
     * @return senderVersion The version of the OAppSender.sol implementation.
     * @return receiverVersion The version of the OAppReceiver.sol implementation.
     */
    function oAppVersion()
        public
        pure
        virtual
        override(OAppSender, OAppReceiver)
        returns (uint64 senderVersion, uint64 receiverVersion)
    {
        return (SENDER_VERSION, RECEIVER_VERSION);
    }
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.20;

import { Ownable } from "@openzeppelin/contracts/access/Ownable.sol";
import { IOAppCore, ILayerZeroEndpointV2 } from "./interfaces/IOAppCore.sol";

/**
 * @title OAppCore
 * @dev Abstract contract implementing the IOAppCore interface with basic OApp configurations.
 */
abstract contract OAppCore is IOAppCore, Ownable {
    // The LayerZero endpoint associated with the given OApp
    ILayerZeroEndpointV2 public immutable endpoint;

    // Mapping to store peers associated with corresponding endpoints
    mapping(uint32 eid => bytes32 peer) public peers;

    /**
     * @dev Constructor to initialize the OAppCore with the provided endpoint and delegate.
     * @param _endpoint The address of the LOCAL Layer Zero endpoint.
     * @param _delegate The delegate capable of making OApp configurations inside of the endpoint.
     *
     * @dev The delegate typically should be set as the owner of the contract.
     */
    constructor(address _endpoint, address _delegate) {
        endpoint = ILayerZeroEndpointV2(_endpoint);

        if (_delegate == address(0)) revert InvalidDelegate();
        endpoint.setDelegate(_delegate);
    }

    /**
     * @notice Sets the peer address (OApp instance) for a corresponding endpoint.
     * @param _eid The endpoint ID.
     * @param _peer The address of the peer to be associated with the corresponding endpoint.
     *
     * @dev Only the owner/admin of the OApp can call this function.
     * @dev Indicates that the peer is trusted to send LayerZero messages to this OApp.
     * @dev Set this to bytes32(0) to remove the peer address.
     * @dev Peer is a bytes32 to accommodate non-evm chains.
     */
    function setPeer(uint32 _eid, bytes32 _peer) public virtual onlyOwner {
        _setPeer(_eid, _peer);
    }

    /**
     * @notice Sets the peer address (OApp instance) for a corresponding endpoint.
     * @param _eid The endpoint ID.
     * @param _peer The address of the peer to be associated with the corresponding endpoint.
     *
     * @dev Indicates that the peer is trusted to send LayerZero messages to this OApp.
     * @dev Set this to bytes32(0) to remove the peer address.
     * @dev Peer is a bytes32 to accommodate non-evm chains.
     */
    function _setPeer(uint32 _eid, bytes32 _peer) internal virtual {
        peers[_eid] = _peer;
        emit PeerSet(_eid, _peer);
    }

    /**
     * @notice Internal function to get the peer address associated with a specific endpoint; reverts if NOT set.
     * ie. the peer is set to bytes32(0).
     * @param _eid The endpoint ID.
     * @return peer The address of the peer associated with the specified endpoint.
     */
    function _getPeerOrRevert(uint32 _eid) internal view virtual returns (bytes32) {
        bytes32 peer = peers[_eid];
        if (peer == bytes32(0)) revert NoPeer(_eid);
        return peer;
    }

    /**
     * @notice Sets the delegate address for the OApp.
     * @param _delegate The address of the delegate to be set.
     *
     * @dev Only the owner/admin of the OApp can call this function.
     * @dev Provides the ability for a delegate to set configs, on behalf of the OApp, directly on the Endpoint contract.
     */
    function setDelegate(address _delegate) public onlyOwner {
        endpoint.setDelegate(_delegate);
    }
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.20;

import { Ownable } from "@openzeppelin/contracts/access/Ownable.sol";
import { IPreCrime } from "./interfaces/IPreCrime.sol";
import { IOAppPreCrimeSimulator, InboundPacket, Origin } from "./interfaces/IOAppPreCrimeSimulator.sol";

/**
 * @title OAppPreCrimeSimulator
 * @dev Abstract contract serving as the base for preCrime simulation functionality in an OApp.
 */
abstract contract OAppPreCrimeSimulator is IOAppPreCrimeSimulator, Ownable {
    // The address of the preCrime implementation.
    address public preCrime;

    /**
     * @dev Retrieves the address of the OApp contract.
     * @return The address of the OApp contract.
     *
     * @dev The simulator contract is the base contract for the OApp by default.
     * @dev If the simulator is a separate contract, override this function.
     */
    function oApp() external view virtual returns (address) {
        return address(this);
    }

    /**
     * @dev Sets the preCrime contract address.
     * @param _preCrime The address of the preCrime contract.
     */
    function setPreCrime(address _preCrime) public virtual onlyOwner {
        preCrime = _preCrime;
        emit PreCrimeSet(_preCrime);
    }

    /**
     * @dev Interface for pre-crime simulations. Always reverts at the end with the simulation results.
     * @param _packets An array of InboundPacket objects representing received packets to be delivered.
     *
     * @dev WARNING: MUST revert at the end with the simulation results.
     * @dev Gives the preCrime implementation the ability to mock sending packets to the lzReceive function,
     * WITHOUT actually executing them.
     */
    function lzReceiveAndRevert(InboundPacket[] calldata _packets) public payable virtual {
        for (uint256 i = 0; i < _packets.length; i++) {
            InboundPacket calldata packet = _packets[i];

            // Ignore packets that are not from trusted peers.
            if (!isPeer(packet.origin.srcEid, packet.origin.sender)) continue;

            // @dev Because a verifier is calling this function, it doesnt have access to executor params:
            //  - address _executor
            //  - bytes calldata _extraData
            // preCrime will NOT work for OApps that rely on these two parameters inside of their _lzReceive().
            // They are instead stubbed to default values, address(0) and bytes("")
            // @dev Calling this.lzReceiveSimulate removes ability for assembly return 0 callstack exit,
            // which would cause the revert to be ignored.
            this.lzReceiveSimulate{ value: packet.value }(
                packet.origin,
                packet.guid,
                packet.message,
                packet.executor,
                packet.extraData
            );
        }

        // @dev Revert with the simulation results. msg.sender must implement IPreCrime.buildSimulationResult().
        revert SimulationResult(IPreCrime(msg.sender).buildSimulationResult());
    }

    /**
     * @dev Is effectively an internal function because msg.sender must be address(this).
     * Allows resetting the call stack for 'internal' calls.
     * @param _origin The origin information containing the source endpoint and sender address.
     *  - srcEid: The source chain endpoint ID.
     *  - sender: The sender address on the src chain.
     *  - nonce: The nonce of the message.
     * @param _guid The unique identifier of the packet.
     * @param _message The message payload of the packet.
     * @param _executor The executor address for the packet.
     * @param _extraData Additional data for the packet.
     */
    function lzReceiveSimulate(
        Origin calldata _origin,
        bytes32 _guid,
        bytes calldata _message,
        address _executor,
        bytes calldata _extraData
    ) external payable virtual {
        // @dev Ensure ONLY can be called 'internally'.
        if (msg.sender != address(this)) revert OnlySelf();
        _lzReceiveSimulate(_origin, _guid, _message, _executor, _extraData);
    }

    /**
     * @dev Internal function to handle the OAppPreCrimeSimulator simulated receive.
     * @param _origin The origin information.
     *  - srcEid: The source chain endpoint ID.
     *  - sender: The sender address from the src chain.
     *  - nonce: The nonce of the LayerZero message.
     * @param _guid The GUID of the LayerZero message.
     * @param _message The LayerZero message.
     * @param _executor The address of the off-chain executor.
     * @param _extraData Arbitrary data passed by the msg executor.
     *
     * @dev Enables the preCrime simulator to mock sending lzReceive() messages,
     * routes the msg down from the OAppPreCrimeSimulator, and back up to the OAppReceiver.
     */
    function _lzReceiveSimulate(
        Origin calldata _origin,
        bytes32 _guid,
        bytes calldata _message,
        address _executor,
        bytes calldata _extraData
    ) internal virtual;

    /**
     * @dev checks if the specified peer is considered 'trusted' by the OApp.
     * @param _eid The endpoint Id to check.
     * @param _peer The peer to check.
     * @return Whether the peer passed is considered 'trusted' by the OApp.
     */
    function isPeer(uint32 _eid, bytes32 _peer) public view virtual returns (bool);
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.20;

import { SafeERC20, IERC20 } from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import { MessagingParams, MessagingFee, MessagingReceipt } from "@layerzerolabs/lz-evm-protocol-v2/contracts/interfaces/ILayerZeroEndpointV2.sol";
import { OAppCore } from "./OAppCore.sol";

/**
 * @title OAppSender
 * @dev Abstract contract implementing the OAppSender functionality for sending messages to a LayerZero endpoint.
 */
abstract contract OAppSender is OAppCore {
    using SafeERC20 for IERC20;

    // Custom error messages
    error NotEnoughNative(uint256 msgValue);
    error LzTokenUnavailable();

    // @dev The version of the OAppSender implementation.
    // @dev Version is bumped when changes are made to this contract.
    uint64 internal constant SENDER_VERSION = 1;

    /**
     * @notice Retrieves the OApp version information.
     * @return senderVersion The version of the OAppSender.sol contract.
     * @return receiverVersion The version of the OAppReceiver.sol contract.
     *
     * @dev Providing 0 as the default for OAppReceiver version. Indicates that the OAppReceiver is not implemented.
     * ie. this is a SEND only OApp.
     * @dev If the OApp uses both OAppSender and OAppReceiver, then this needs to be override returning the correct versions
     */
    function oAppVersion() public view virtual returns (uint64 senderVersion, uint64 receiverVersion) {
        return (SENDER_VERSION, 0);
    }

    /**
     * @dev Internal function to interact with the LayerZero EndpointV2.quote() for fee calculation.
     * @param _dstEid The destination endpoint ID.
     * @param _message The message payload.
     * @param _options Additional options for the message.
     * @param _payInLzToken Flag indicating whether to pay the fee in LZ tokens.
     * @return fee The calculated MessagingFee for the message.
     *      - nativeFee: The native fee for the message.
     *      - lzTokenFee: The LZ token fee for the message.
     */
    function _quote(
        uint32 _dstEid,
        bytes memory _message,
        bytes memory _options,
        bool _payInLzToken
    ) internal view virtual returns (MessagingFee memory fee) {
        return
            endpoint.quote(
                MessagingParams(_dstEid, _getPeerOrRevert(_dstEid), _message, _options, _payInLzToken),
                address(this)
            );
    }

    /**
     * @dev Internal function to interact with the LayerZero EndpointV2.send() for sending a message.
     * @param _dstEid The destination endpoint ID.
     * @param _message The message payload.
     * @param _options Additional options for the message.
     * @param _fee The calculated LayerZero fee for the message.
     *      - nativeFee: The native fee.
     *      - lzTokenFee: The lzToken fee.
     * @param _refundAddress The address to receive any excess fee values sent to the endpoint.
     * @return receipt The receipt for the sent message.
     *      - guid: The unique identifier for the sent message.
     *      - nonce: The nonce of the sent message.
     *      - fee: The LayerZero fee incurred for the message.
     */
    function _lzSend(
        uint32 _dstEid,
        bytes memory _message,
        bytes memory _options,
        MessagingFee memory _fee,
        address _refundAddress
    ) internal virtual returns (MessagingReceipt memory receipt) {
        // @dev Push corresponding fees to the endpoint, any excess is sent back to the _refundAddress from the endpoint.
        uint256 messageValue = _payNative(_fee.nativeFee);
        if (_fee.lzTokenFee > 0) _payLzToken(_fee.lzTokenFee);

        return
            // solhint-disable-next-line check-send-result
            endpoint.send{ value: messageValue }(
                MessagingParams(_dstEid, _getPeerOrRevert(_dstEid), _message, _options, _fee.lzTokenFee > 0),
                _refundAddress
            );
    }

    /**
     * @dev Internal function to pay the native fee associated with the message.
     * @param _nativeFee The native fee to be paid.
     * @return nativeFee The amount of native currency paid.
     *
     * @dev If the OApp needs to initiate MULTIPLE LayerZero messages in a single transaction,
     * this will need to be overridden because msg.value would contain multiple lzFees.
     * @dev Should be overridden in the event the LayerZero endpoint requires a different native currency.
     * @dev Some EVMs use an ERC20 as a method for paying transactions/gasFees.
     * @dev The endpoint is EITHER/OR, ie. it will NOT support both types of native payment at a time.
     */
    function _payNative(uint256 _nativeFee) internal virtual returns (uint256 nativeFee) {
        if (msg.value != _nativeFee) revert NotEnoughNative(msg.value);
        return _nativeFee;
    }

    /**
     * @dev Internal function to pay the LZ token fee associated with the message.
     * @param _lzTokenFee The LZ token fee to be paid.
     *
     * @dev If the caller is trying to pay in the specified lzToken, then the lzTokenFee is passed to the endpoint.
     * @dev Any excess sent, is passed back to the specified _refundAddress in the _lzSend().
     */
    function _payLzToken(uint256 _lzTokenFee) internal virtual {
        // @dev Cannot cache the token because it is not immutable in the endpoint.
        address lzToken = endpoint.lzToken();
        if (lzToken == address(0)) revert LzTokenUnavailable();

        // Pay LZ token fee by sending tokens to the endpoint.
        IERC20(lzToken).safeTransferFrom(msg.sender, address(endpoint), _lzTokenFee);
    }
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.20;

library OFTComposeMsgCodec {
    // Offset constants for decoding composed messages
    uint8 private constant NONCE_OFFSET = 8;
    uint8 private constant SRC_EID_OFFSET = 12;
    uint8 private constant AMOUNT_LD_OFFSET = 44;
    uint8 private constant COMPOSE_FROM_OFFSET = 76;

    /**
     * @dev Encodes a OFT composed message.
     * @param _nonce The nonce value.
     * @param _srcEid The source endpoint ID.
     * @param _amountLD The amount in local decimals.
     * @param _composeMsg The composed message.
     * @return _msg The encoded Composed message.
     */
    function encode(
        uint64 _nonce,
        uint32 _srcEid,
        uint256 _amountLD,
        bytes memory _composeMsg // 0x[composeFrom][composeMsg]
    ) internal pure returns (bytes memory _msg) {
        _msg = abi.encodePacked(_nonce, _srcEid, _amountLD, _composeMsg);
    }

    /**
     * @dev Retrieves the nonce for the composed message.
     * @param _msg The message.
     * @return The nonce value.
     */
    function nonce(bytes calldata _msg) internal pure returns (uint64) {
        return uint64(bytes8(_msg[:NONCE_OFFSET]));
    }

    /**
     * @dev Retrieves the source endpoint ID for the composed message.
     * @param _msg The message.
     * @return The source endpoint ID.
     */
    function srcEid(bytes calldata _msg) internal pure returns (uint32) {
        return uint32(bytes4(_msg[NONCE_OFFSET:SRC_EID_OFFSET]));
    }

    /**
     * @dev Retrieves the amount in local decimals from the composed message.
     * @param _msg The message.
     * @return The amount in local decimals.
     */
    function amountLD(bytes calldata _msg) internal pure returns (uint256) {
        return uint256(bytes32(_msg[SRC_EID_OFFSET:AMOUNT_LD_OFFSET]));
    }

    /**
     * @dev Retrieves the composeFrom value from the composed message.
     * @param _msg The message.
     * @return The composeFrom value.
     */
    function composeFrom(bytes calldata _msg) internal pure returns (bytes32) {
        return bytes32(_msg[AMOUNT_LD_OFFSET:COMPOSE_FROM_OFFSET]);
    }

    /**
     * @dev Retrieves the composed message.
     * @param _msg The message.
     * @return The composed message.
     */
    function composeMsg(bytes calldata _msg) internal pure returns (bytes memory) {
        return _msg[COMPOSE_FROM_OFFSET:];
    }

    /**
     * @dev Converts an address to bytes32.
     * @param _addr The address to convert.
     * @return The bytes32 representation of the address.
     */
    function addressToBytes32(address _addr) internal pure returns (bytes32) {
        return bytes32(uint256(uint160(_addr)));
    }

    /**
     * @dev Converts bytes32 to an address.
     * @param _b The bytes32 value to convert.
     * @return The address representation of bytes32.
     */
    function bytes32ToAddress(bytes32 _b) internal pure returns (address) {
        return address(uint160(uint256(_b)));
    }
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.20;

import { OApp, Origin } from "@layerzerolabs/oapp-evm/contracts/oapp/OApp.sol";
import { OAppOptionsType3 } from "@layerzerolabs/oapp-evm/contracts/oapp/libs/OAppOptionsType3.sol";
import { IOAppMsgInspector } from "@layerzerolabs/oapp-evm/contracts/oapp/interfaces/IOAppMsgInspector.sol";

import { OAppPreCrimeSimulator } from "@layerzerolabs/oapp-evm/contracts/precrime/OAppPreCrimeSimulator.sol";

import { IOFT, SendParam, OFTLimit, OFTReceipt, OFTFeeDetail, MessagingReceipt, MessagingFee } from "./interfaces/IOFT.sol";
import { OFTMsgCodec } from "./libs/OFTMsgCodec.sol";
import { OFTComposeMsgCodec } from "./libs/OFTComposeMsgCodec.sol";

/**
 * @title OFTCore
 * @dev Abstract contract for the OftChain (OFT) token.
 */
abstract contract OFTCore is IOFT, OApp, OAppPreCrimeSimulator, OAppOptionsType3 {
    using OFTMsgCodec for bytes;
    using OFTMsgCodec for bytes32;

    // @notice Provides a conversion rate when swapping between denominations of SD and LD
    //      - shareDecimals == SD == shared Decimals
    //      - localDecimals == LD == local decimals
    // @dev Considers that tokens have different decimal amounts on various chains.
    // @dev eg.
    //  For a token
    //      - locally with 4 decimals --> 1.2345 => uint(12345)
    //      - remotely with 2 decimals --> 1.23 => uint(123)
    //      - The conversion rate would be 10 ** (4 - 2) = 100
    //  @dev If you want to send 1.2345 -> (uint 12345), you CANNOT represent that value on the remote,
    //  you can only display 1.23 -> uint(123).
    //  @dev To preserve the dust that would otherwise be lost on that conversion,
    //  we need to unify a denomination that can be represented on ALL chains inside of the OFT mesh
    uint256 public immutable decimalConversionRate;

    // @notice Msg types that are used to identify the various OFT operations.
    // @dev This can be extended in child contracts for non-default oft operations
    // @dev These values are used in things like combineOptions() in OAppOptionsType3.sol.
    uint16 public constant SEND = 1;
    uint16 public constant SEND_AND_CALL = 2;

    // Address of an optional contract to inspect both 'message' and 'options'
    address public msgInspector;
    event MsgInspectorSet(address inspector);

    /**
     * @dev Constructor.
     * @param _localDecimals The decimals of the token on the local chain (this chain).
     * @param _endpoint The address of the LayerZero endpoint.
     * @param _delegate The delegate capable of making OApp configurations inside of the endpoint.
     */
    constructor(uint8 _localDecimals, address _endpoint, address _delegate) OApp(_endpoint, _delegate) {
        if (_localDecimals < sharedDecimals()) revert InvalidLocalDecimals();
        decimalConversionRate = 10 ** (_localDecimals - sharedDecimals());
    }

    /**
     * @notice Retrieves interfaceID and the version of the OFT.
     * @return interfaceId The interface ID.
     * @return version The version.
     *
     * @dev interfaceId: This specific interface ID is '0x02e49c2c'.
     * @dev version: Indicates a cross-chain compatible msg encoding with other OFTs.
     * @dev If a new feature is added to the OFT cross-chain msg encoding, the version will be incremented.
     * ie. localOFT version(x,1) CAN send messages to remoteOFT version(x,1)
     */
    function oftVersion() external pure virtual returns (bytes4 interfaceId, uint64 version) {
        return (type(IOFT).interfaceId, 1);
    }

    /**
     * @dev Retrieves the shared decimals of the OFT.
     * @return The shared decimals of the OFT.
     *
     * @dev Sets an implicit cap on the amount of tokens, over uint64.max() will need some sort of outbound cap / totalSupply cap
     * Lowest common decimal denominator between chains.
     * Defaults to 6 decimal places to provide up to 18,446,744,073,709.551615 units (max uint64).
     * For tokens exceeding this totalSupply(), they will need to override the sharedDecimals function with something smaller.
     * ie. 4 sharedDecimals would be 1,844,674,407,370,955.1615
     */
    function sharedDecimals() public view virtual returns (uint8) {
        return 6;
    }

    /**
     * @dev Sets the message inspector address for the OFT.
     * @param _msgInspector The address of the message inspector.
     *
     * @dev This is an optional contract that can be used to inspect both 'message' and 'options'.
     * @dev Set it to address(0) to disable it, or set it to a contract address to enable it.
     */
    function setMsgInspector(address _msgInspector) public virtual onlyOwner {
        msgInspector = _msgInspector;
        emit MsgInspectorSet(_msgInspector);
    }

    /**
     * @notice Provides a quote for OFT-related operations.
     * @param _sendParam The parameters for the send operation.
     * @return oftLimit The OFT limit information.
     * @return oftFeeDetails The details of OFT fees.
     * @return oftReceipt The OFT receipt information.
     */
    function quoteOFT(
        SendParam calldata _sendParam
    )
        external
        view
        virtual
        returns (OFTLimit memory oftLimit, OFTFeeDetail[] memory oftFeeDetails, OFTReceipt memory oftReceipt)
    {
        uint256 minAmountLD = 0; // Unused in the default implementation.
        uint256 maxAmountLD = type(uint64).max; // Unused in the default implementation.
        oftLimit = OFTLimit(minAmountLD, maxAmountLD);

        // Unused in the default implementation; reserved for future complex fee details.
        oftFeeDetails = new OFTFeeDetail[](0);

        // @dev This is the same as the send() operation, but without the actual send.
        // - amountSentLD is the amount in local decimals that would be sent from the sender.
        // - amountReceivedLD is the amount in local decimals that will be credited to the recipient on the remote OFT instance.
        // @dev The amountSentLD MIGHT not equal the amount the user actually receives. HOWEVER, the default does.
        (uint256 amountSentLD, uint256 amountReceivedLD) = _debitView(
            _sendParam.amountLD,
            _sendParam.minAmountLD,
            _sendParam.dstEid
        );
        oftReceipt = OFTReceipt(amountSentLD, amountReceivedLD);
    }

    /**
     * @notice Provides a quote for the send() operation.
     * @param _sendParam The parameters for the send() operation.
     * @param _payInLzToken Flag indicating whether the caller is paying in the LZ token.
     * @return msgFee The calculated LayerZero messaging fee from the send() operation.
     *
     * @dev MessagingFee: LayerZero msg fee
     *  - nativeFee: The native fee.
     *  - lzTokenFee: The lzToken fee.
     */
    function quoteSend(
        SendParam calldata _sendParam,
        bool _payInLzToken
    ) external view virtual returns (MessagingFee memory msgFee) {
        // @dev mock the amount to receive, this is the same operation used in the send().
        // The quote is as similar as possible to the actual send() operation.
        (, uint256 amountReceivedLD) = _debitView(_sendParam.amountLD, _sendParam.minAmountLD, _sendParam.dstEid);

        // @dev Builds the options and OFT message to quote in the endpoint.
        (bytes memory message, bytes memory options) = _buildMsgAndOptions(_sendParam, amountReceivedLD);

        // @dev Calculates the LayerZero fee for the send() operation.
        return _quote(_sendParam.dstEid, message, options, _payInLzToken);
    }

    /**
     * @dev Executes the send operation.
     * @param _sendParam The parameters for the send operation.
     * @param _fee The calculated fee for the send() operation.
     *      - nativeFee: The native fee.
     *      - lzTokenFee: The lzToken fee.
     * @param _refundAddress The address to receive any excess funds.
     * @return msgReceipt The receipt for the send operation.
     * @return oftReceipt The OFT receipt information.
     *
     * @dev MessagingReceipt: LayerZero msg receipt
     *  - guid: The unique identifier for the sent message.
     *  - nonce: The nonce of the sent message.
     *  - fee: The LayerZero fee incurred for the message.
     */
    function send(
        SendParam calldata _sendParam,
        MessagingFee calldata _fee,
        address _refundAddress
    ) external payable virtual returns (MessagingReceipt memory msgReceipt, OFTReceipt memory oftReceipt) {
        // @dev Applies the token transfers regarding this send() operation.
        // - amountSentLD is the amount in local decimals that was ACTUALLY sent/debited from the sender.
        // - amountReceivedLD is the amount in local decimals that will be received/credited to the recipient on the remote OFT instance.
        (uint256 amountSentLD, uint256 amountReceivedLD) = _debit(
            msg.sender,
            _sendParam.amountLD,
            _sendParam.minAmountLD,
            _sendParam.dstEid
        );

        // @dev Builds the options and OFT message to quote in the endpoint.
        (bytes memory message, bytes memory options) = _buildMsgAndOptions(_sendParam, amountReceivedLD);

        // @dev Sends the message to the LayerZero endpoint and returns the LayerZero msg receipt.
        msgReceipt = _lzSend(_sendParam.dstEid, message, options, _fee, _refundAddress);
        // @dev Formulate the OFT receipt.
        oftReceipt = OFTReceipt(amountSentLD, amountReceivedLD);

        emit OFTSent(msgReceipt.guid, _sendParam.dstEid, msg.sender, amountSentLD, amountReceivedLD);
    }

    /**
     * @dev Internal function to build the message and options.
     * @param _sendParam The parameters for the send() operation.
     * @param _amountLD The amount in local decimals.
     * @return message The encoded message.
     * @return options The encoded options.
     */
    function _buildMsgAndOptions(
        SendParam calldata _sendParam,
        uint256 _amountLD
    ) internal view virtual returns (bytes memory message, bytes memory options) {
        bool hasCompose;
        // @dev This generated message has the msg.sender encoded into the payload so the remote knows who the caller is.
        (message, hasCompose) = OFTMsgCodec.encode(
            _sendParam.to,
            _toSD(_amountLD),
            // @dev Must be include a non empty bytes if you want to compose, EVEN if you dont need it on the remote.
            // EVEN if you dont require an arbitrary payload to be sent... eg. '0x01'
            _sendParam.composeMsg
        );
        // @dev Change the msg type depending if its composed or not.
        uint16 msgType = hasCompose ? SEND_AND_CALL : SEND;
        // @dev Combine the callers _extraOptions with the enforced options via the OAppOptionsType3.
        options = combineOptions(_sendParam.dstEid, msgType, _sendParam.extraOptions);

        // @dev Optionally inspect the message and options depending if the OApp owner has set a msg inspector.
        // @dev If it fails inspection, needs to revert in the implementation. ie. does not rely on return boolean
        address inspector = msgInspector; // caches the msgInspector to avoid potential double storage read
        if (inspector != address(0)) IOAppMsgInspector(inspector).inspect(message, options);
    }

    /**
     * @dev Internal function to handle the receive on the LayerZero endpoint.
     * @param _origin The origin information.
     *  - srcEid: The source chain endpoint ID.
     *  - sender: The sender address from the src chain.
     *  - nonce: The nonce of the LayerZero message.
     * @param _guid The unique identifier for the received LayerZero message.
     * @param _message The encoded message.
     * @dev _executor The address of the executor.
     * @dev _extraData Additional data.
     */
    function _lzReceive(
        Origin calldata _origin,
        bytes32 _guid,
        bytes calldata _message,
        address /*_executor*/, // @dev unused in the default implementation.
        bytes calldata /*_extraData*/ // @dev unused in the default implementation.
    ) internal virtual override {
        // @dev The src sending chain doesnt know the address length on this chain (potentially non-evm)
        // Thus everything is bytes32() encoded in flight.
        address toAddress = _message.sendTo().bytes32ToAddress();
        // @dev Credit the amountLD to the recipient and return the ACTUAL amount the recipient received in local decimals
        uint256 amountReceivedLD = _credit(toAddress, _toLD(_message.amountSD()), _origin.srcEid);

        if (_message.isComposed()) {
            // @dev Proprietary composeMsg format for the OFT.
            bytes memory composeMsg = OFTComposeMsgCodec.encode(
                _origin.nonce,
                _origin.srcEid,
                amountReceivedLD,
                _message.composeMsg()
            );

            // @dev Stores the lzCompose payload that will be executed in a separate tx.
            // Standardizes functionality for executing arbitrary contract invocation on some non-evm chains.
            // @dev The off-chain executor will listen and process the msg based on the src-chain-callers compose options passed.
            // @dev The index is used when a OApp needs to compose multiple msgs on lzReceive.
            // For default OFT implementation there is only 1 compose msg per lzReceive, thus its always 0.
            endpoint.sendCompose(toAddress, _guid, 0 /* the index of the composed message*/, composeMsg);
        }

        emit OFTReceived(_guid, _origin.srcEid, toAddress, amountReceivedLD);
    }

    /**
     * @dev Internal function to handle the OAppPreCrimeSimulator simulated receive.
     * @param _origin The origin information.
     *  - srcEid: The source chain endpoint ID.
     *  - sender: The sender address from the src chain.
     *  - nonce: The nonce of the LayerZero message.
     * @param _guid The unique identifier for the received LayerZero message.
     * @param _message The LayerZero message.
     * @param _executor The address of the off-chain executor.
     * @param _extraData Arbitrary data passed by the msg executor.
     *
     * @dev Enables the preCrime simulator to mock sending lzReceive() messages,
     * routes the msg down from the OAppPreCrimeSimulator, and back up to the OAppReceiver.
     */
    function _lzReceiveSimulate(
        Origin calldata _origin,
        bytes32 _guid,
        bytes calldata _message,
        address _executor,
        bytes calldata _extraData
    ) internal virtual override {
        _lzReceive(_origin, _guid, _message, _executor, _extraData);
    }

    /**
     * @dev Check if the peer is considered 'trusted' by the OApp.
     * @param _eid The endpoint ID to check.
     * @param _peer The peer to check.
     * @return Whether the peer passed is considered 'trusted' by the OApp.
     *
     * @dev Enables OAppPreCrimeSimulator to check whether a potential Inbound Packet is from a trusted source.
     */
    function isPeer(uint32 _eid, bytes32 _peer) public view virtual override returns (bool) {
        return peers[_eid] == _peer;
    }

    /**
     * @dev Internal function to remove dust from the given local decimal amount.
     * @param _amountLD The amount in local decimals.
     * @return amountLD The amount after removing dust.
     *
     * @dev Prevents the loss of dust when moving amounts between chains with different decimals.
     * @dev eg. uint(123) with a conversion rate of 100 becomes uint(100).
     */
    function _removeDust(uint256 _amountLD) internal view virtual returns (uint256 amountLD) {
        return (_amountLD / decimalConversionRate) * decimalConversionRate;
    }

    /**
     * @dev Internal function to convert an amount from shared decimals into local decimals.
     * @param _amountSD The amount in shared decimals.
     * @return amountLD The amount in local decimals.
     */
    function _toLD(uint64 _amountSD) internal view virtual returns (uint256 amountLD) {
        return _amountSD * decimalConversionRate;
    }

    /**
     * @dev Internal function to convert an amount from local decimals into shared decimals.
     * @param _amountLD The amount in local decimals.
     * @return amountSD The amount in shared decimals.
     */
    function _toSD(uint256 _amountLD) internal view virtual returns (uint64 amountSD) {
        return uint64(_amountLD / decimalConversionRate);
    }

    /**
     * @dev Internal function to mock the amount mutation from a OFT debit() operation.
     * @param _amountLD The amount to send in local decimals.
     * @param _minAmountLD The minimum amount to send in local decimals.
     * @dev _dstEid The destination endpoint ID.
     * @return amountSentLD The amount sent, in local decimals.
     * @return amountReceivedLD The amount to be received on the remote chain, in local decimals.
     *
     * @dev This is where things like fees would be calculated and deducted from the amount to be received on the remote.
     */
    function _debitView(
        uint256 _amountLD,
        uint256 _minAmountLD,
        uint32 /*_dstEid*/
    ) internal view virtual returns (uint256 amountSentLD, uint256 amountReceivedLD) {
        // @dev Remove the dust so nothing is lost on the conversion between chains with different decimals for the token.
        amountSentLD = _removeDust(_amountLD);
        // @dev The amount to send is the same as amount received in the default implementation.
        amountReceivedLD = amountSentLD;

        // @dev Check for slippage.
        if (amountReceivedLD < _minAmountLD) {
            revert SlippageExceeded(amountReceivedLD, _minAmountLD);
        }
    }

    /**
     * @dev Internal function to perform a debit operation.
     * @param _from The address to debit.
     * @param _amountLD The amount to send in local decimals.
     * @param _minAmountLD The minimum amount to send in local decimals.
     * @param _dstEid The destination endpoint ID.
     * @return amountSentLD The amount sent in local decimals.
     * @return amountReceivedLD The amount received in local decimals on the remote.
     *
     * @dev Defined here but are intended to be overriden depending on the OFT implementation.
     * @dev Depending on OFT implementation the _amountLD could differ from the amountReceivedLD.
     */
    function _debit(
        address _from,
        uint256 _amountLD,
        uint256 _minAmountLD,
        uint32 _dstEid
    ) internal virtual returns (uint256 amountSentLD, uint256 amountReceivedLD);

    /**
     * @dev Internal function to perform a credit operation.
     * @param _to The address to credit.
     * @param _amountLD The amount to credit in local decimals.
     * @param _srcEid The source endpoint ID.
     * @return amountReceivedLD The amount ACTUALLY received in local decimals.
     *
     * @dev Defined here but are intended to be overriden depending on the OFT implementation.
     * @dev Depending on OFT implementation the _amountLD could differ from the amountReceivedLD.
     */
    function _credit(
        address _to,
        uint256 _amountLD,
        uint32 _srcEid
    ) internal virtual returns (uint256 amountReceivedLD);
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.20;

library OFTMsgCodec {
    // Offset constants for encoding and decoding OFT messages
    uint8 private constant SEND_TO_OFFSET = 32;
    uint8 private constant SEND_AMOUNT_SD_OFFSET = 40;

    /**
     * @dev Encodes an OFT LayerZero message.
     * @param _sendTo The recipient address.
     * @param _amountShared The amount in shared decimals.
     * @param _composeMsg The composed message.
     * @return _msg The encoded message.
     * @return hasCompose A boolean indicating whether the message has a composed payload.
     */
    function encode(
        bytes32 _sendTo,
        uint64 _amountShared,
        bytes memory _composeMsg
    ) internal view returns (bytes memory _msg, bool hasCompose) {
        hasCompose = _composeMsg.length > 0;
        // @dev Remote chains will want to know the composed function caller ie. msg.sender on the src.
        _msg = hasCompose
            ? abi.encodePacked(_sendTo, _amountShared, addressToBytes32(msg.sender), _composeMsg)
            : abi.encodePacked(_sendTo, _amountShared);
    }

    /**
     * @dev Checks if the OFT message is composed.
     * @param _msg The OFT message.
     * @return A boolean indicating whether the message is composed.
     */
    function isComposed(bytes calldata _msg) internal pure returns (bool) {
        return _msg.length > SEND_AMOUNT_SD_OFFSET;
    }

    /**
     * @dev Retrieves the recipient address from the OFT message.
     * @param _msg The OFT message.
     * @return The recipient address.
     */
    function sendTo(bytes calldata _msg) internal pure returns (bytes32) {
        return bytes32(_msg[:SEND_TO_OFFSET]);
    }

    /**
     * @dev Retrieves the amount in shared decimals from the OFT message.
     * @param _msg The OFT message.
     * @return The amount in shared decimals.
     */
    function amountSD(bytes calldata _msg) internal pure returns (uint64) {
        return uint64(bytes8(_msg[SEND_TO_OFFSET:SEND_AMOUNT_SD_OFFSET]));
    }

    /**
     * @dev Retrieves the composed message from the OFT message.
     * @param _msg The OFT message.
     * @return The composed message.
     */
    function composeMsg(bytes calldata _msg) internal pure returns (bytes memory) {
        return _msg[SEND_AMOUNT_SD_OFFSET:];
    }

    /**
     * @dev Converts an address to bytes32.
     * @param _addr The address to convert.
     * @return The bytes32 representation of the address.
     */
    function addressToBytes32(address _addr) internal pure returns (bytes32) {
        return bytes32(uint256(uint160(_addr)));
    }

    /**
     * @dev Converts bytes32 to an address.
     * @param _b The bytes32 value to convert.
     * @return The address representation of bytes32.
     */
    function bytes32ToAddress(bytes32 _b) internal pure returns (address) {
        return address(uint160(uint256(_b)));
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/utils/SafeERC20.sol)

pragma solidity ^0.8.20;

import {IERC20} from "../IERC20.sol";
import {IERC20Permit} from "../extensions/IERC20Permit.sol";
import {Address} from "../../../utils/Address.sol";

/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    using Address for address;

    /**
     * @dev An operation with an ERC20 token failed.
     */
    error SafeERC20FailedOperation(address token);

    /**
     * @dev Indicates a failed `decreaseAllowance` request.
     */
    error SafeERC20FailedDecreaseAllowance(address spender, uint256 currentAllowance, uint256 requestedDecrease);

    /**
     * @dev Transfer `value` amount of `token` from the calling contract to `to`. If `token` returns no value,
     * non-reverting calls are assumed to be successful.
     */
    function safeTransfer(IERC20 token, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeCall(token.transfer, (to, value)));
    }

    /**
     * @dev Transfer `value` amount of `token` from `from` to `to`, spending the approval given by `from` to the
     * calling contract. If `token` returns no value, non-reverting calls are assumed to be successful.
     */
    function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeCall(token.transferFrom, (from, to, value)));
    }

    /**
     * @dev Increase the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful.
     */
    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 oldAllowance = token.allowance(address(this), spender);
        forceApprove(token, spender, oldAllowance + value);
    }

    /**
     * @dev Decrease the calling contract's allowance toward `spender` by `requestedDecrease`. If `token` returns no
     * value, non-reverting calls are assumed to be successful.
     */
    function safeDecreaseAllowance(IERC20 token, address spender, uint256 requestedDecrease) internal {
        unchecked {
            uint256 currentAllowance = token.allowance(address(this), spender);
            if (currentAllowance < requestedDecrease) {
                revert SafeERC20FailedDecreaseAllowance(spender, currentAllowance, requestedDecrease);
            }
            forceApprove(token, spender, currentAllowance - requestedDecrease);
        }
    }

    /**
     * @dev Set the calling contract's allowance toward `spender` to `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful. Meant to be used with tokens that require the approval
     * to be set to zero before setting it to a non-zero value, such as USDT.
     */
    function forceApprove(IERC20 token, address spender, uint256 value) internal {
        bytes memory approvalCall = abi.encodeCall(token.approve, (spender, value));

        if (!_callOptionalReturnBool(token, approvalCall)) {
            _callOptionalReturn(token, abi.encodeCall(token.approve, (spender, 0)));
            _callOptionalReturn(token, approvalCall);
        }
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We use {Address-functionCall} to perform this call, which verifies that
        // the target address contains contract code and also asserts for success in the low-level call.

        bytes memory returndata = address(token).functionCall(data);
        if (returndata.length != 0 && !abi.decode(returndata, (bool))) {
            revert SafeERC20FailedOperation(address(token));
        }
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     *
     * This is a variant of {_callOptionalReturn} that silents catches all reverts and returns a bool instead.
     */
    function _callOptionalReturnBool(IERC20 token, bytes memory data) private returns (bool) {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We cannot use {Address-functionCall} here since this should return false
        // and not revert is the subcall reverts.

        (bool success, bytes memory returndata) = address(token).call(data);
        return success && (returndata.length == 0 || abi.decode(returndata, (bool))) && address(token).code.length > 0;
    }
}