// File: lib/communal/Address.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.6.11 <0.9.0;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize, which returns 0 for contracts in
        // construction, since the code is only stored at the end of the
        // constructor execution.

        uint256 size;
        // solhint-disable-next-line no-inline-assembly
        assembly { size := extcodesize(account) }
        return size > 0;
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
        (bool success, ) = recipient.call{ value: amount }("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain`call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
      return functionCall(target, data, "Address: low-level call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }

    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        require(isContract(target), "Address: call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.call{ value: value }(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data, string memory errorMessage) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.staticcall(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
        require(isContract(target), "Address: delegate call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

    function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns(bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly

                // solhint-disable-next-line no-inline-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}
// File: lib/communal/Context.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.6.11;

/*
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with GSN meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address payable) {
        return payable(msg.sender);
    }

    function _msgData() internal view virtual returns (bytes memory) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}
// File: lib/communal/IERC20.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.6.11;

import "./Context.sol";
import "./SafeMath.sol";

/**
 * @dev Interface of the ERC20 standard as defined in the EIP. Does not include
 * the optional functions; to access them see {ERC20Detailed}.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, uint256 amount) 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 `amount` 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 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);

    /**
     * @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);
}


// File: lib/communal/Owned.sol



// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.6.11;

// https://docs.synthetix.io/contracts/Owned
contract Owned {
    address public owner;
    address public nominatedOwner;

    constructor (address _owner) public {
        require(_owner != address(0), "Owner address cannot be 0");
        owner = _owner;
        emit OwnerChanged(address(0), _owner);
    }

    function nominateNewOwner(address _owner) external onlyOwner {
        nominatedOwner = _owner;
        emit OwnerNominated(_owner);
    }

    function acceptOwnership() external {
        require(msg.sender == nominatedOwner, "You must be nominated before you can accept ownership");
        emit OwnerChanged(owner, nominatedOwner);
        owner = nominatedOwner;
        nominatedOwner = address(0);
    }

    modifier onlyOwner {
        require(msg.sender == owner, "Only the contract owner may perform this action");
        _;
    }

    event OwnerNominated(address newOwner);
    event OwnerChanged(address oldOwner, address newOwner);
}
// File: lib/communal/SafeERC20.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.6.11;

import "./IERC20.sol";
import "./SafeMath.sol";
import "./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 SafeMath for uint256;
    using Address for address;

    function safeTransfer(IERC20 token, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }

    /**
     * @dev Deprecated. This function has issues similar to the ones found in
     * {IERC20-approve}, and its usage is discouraged.
     *
     * Whenever possible, use {safeIncreaseAllowance} and
     * {safeDecreaseAllowance} instead.
     */
    function safeApprove(IERC20 token, address spender, uint256 value) internal {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        // solhint-disable-next-line max-line-length
        require((value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }

    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 newAllowance = token.allowance(address(this), spender).add(value);
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 newAllowance = token.allowance(address(this), spender).sub(value, "SafeERC20: decreased allowance below zero");
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    /**
     * @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, "SafeERC20: low-level call failed");
        if (returndata.length > 0) { // Return data is optional
            // solhint-disable-next-line max-line-length
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}
// File: lib/communal/SafeMath.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.6.11;

/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");

        return c;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return sub(a, b, "SafeMath: subtraction overflow");
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     * - Subtraction cannot overflow.
     *
     * _Available since v2.4.0._
     */
    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        uint256 c = a - b;

        return c;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
        // benefit is lost if 'b' is also tested.
        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");

        return c;
    }

    /**
     * @dev Returns the integer division of two unsigned integers. Reverts on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return div(a, b, "SafeMath: division by zero");
    }

    /**
     * @dev Returns the integer division of two unsigned integers. Reverts with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     * - The divisor cannot be zero.
     *
     * _Available since v2.4.0._
     */
    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        // Solidity only automatically asserts when dividing by 0
        require(b > 0, errorMessage);
        uint256 c = a / b;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold

        return c;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return mod(a, b, "SafeMath: modulo by zero");
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts with custom message when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     * - The divisor cannot be zero.
     *
     * _Available since v2.4.0._
     */
    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b != 0, errorMessage);
        return a % b;
    }
}
// File: lib/communal/TransferHelper.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.6.11;

// helper methods for interacting with ERC20 tokens and sending ETH that do not consistently return true/false
library TransferHelper {
    function safeApprove(address token, address to, uint value) internal {
        // bytes4(keccak256(bytes('approve(address,uint256)')));
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(0x095ea7b3, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), 'TransferHelper: APPROVE_FAILED');
    }

    function safeTransfer(address token, address to, uint value) internal {
        // bytes4(keccak256(bytes('transfer(address,uint256)')));
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(0xa9059cbb, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), 'TransferHelper: TRANSFER_FAILED');
    }

    function safeTransferFrom(address token, address from, address to, uint value) internal {
        // bytes4(keccak256(bytes('transferFrom(address,address,uint256)')));
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(0x23b872dd, from, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), 'TransferHelper: TRANSFER_FROM_FAILED');
    }

    function safeTransferETH(address to, uint value) internal {
        (bool success,) = to.call{value:value}(new bytes(0));
        require(success, 'TransferHelper: ETH_TRANSFER_FAILED');
    }
}
// File: lib/openzeppelin/contracts/utils/introspection/IERC165.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)

pragma solidity ^0.8.0;

/**
 * @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);
}

// File: lib/solidity-examples/contracts/interfaces/IStargateReceiver.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.4;

interface IStargateReceiver {
    function sgReceive(
        uint16 _chainId,
        bytes memory _srcAddress,
        uint256 _nonce,
        address _token,
        uint256 amountLD,
        bytes memory payload
    ) external;
}

// File: lib/solidity-examples/contracts/token/oft/IOFTCore.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.5.0;

import "openzeppelin/contracts/utils/introspection/IERC165.sol";

/**
 * @dev Interface of the IOFT core standard
 */
interface IOFTCore is IERC165 {
    /**
     * @dev estimate send token `_tokenId` to (`_dstChainId`, `_toAddress`)
     * _dstChainId - L0 defined chain id to send tokens too
     * _toAddress - dynamic bytes array which contains the address to whom you are sending tokens to on the dstChain
     * _amount - amount of the tokens to transfer
     * _useZro - indicates to use zro to pay L0 fees
     * _adapterParam - flexible bytes array to indicate messaging adapter services in L0
     */
    function estimateSendFee(uint16 _dstChainId, bytes calldata _toAddress, uint _amount, bool _useZro, bytes calldata _adapterParams) external view returns (uint nativeFee, uint zroFee);

    /**
     * @dev send `_amount` amount of token to (`_dstChainId`, `_toAddress`) from `_from`
     * `_from` the owner of token
     * `_dstChainId` the destination chain identifier
     * `_toAddress` can be any size depending on the `dstChainId`.
     * `_amount` the quantity of tokens in wei
     * `_refundAddress` the address LayerZero refunds if too much message fee is sent
     * `_zroPaymentAddress` set to address(0x0) if not paying in ZRO (LayerZero Token)
     * `_adapterParams` is a flexible bytes array to indicate messaging adapter services
     */
    function sendFrom(address _from, uint16 _dstChainId, bytes calldata _toAddress, uint _amount, address payable _refundAddress, address _zroPaymentAddress, bytes calldata _adapterParams) external payable;

    /**
     * @dev returns the circulating amount of tokens on current chain
     */
    function circulatingSupply() external view returns (uint);

    /**
     * @dev returns the address of the ERC20 token
     */
    function token() external view returns (address);

    /**
     * @dev Emitted when `_amount` tokens are moved from the `_sender` to (`_dstChainId`, `_toAddress`)
     * `_nonce` is the outbound nonce
     */
    event SendToChain(uint16 indexed _dstChainId, address indexed _from, bytes _toAddress, uint _amount);

    /**
     * @dev Emitted when `_amount` tokens are received from `_srcChainId` into the `_toAddress` on the local chain.
     * `_nonce` is the inbound nonce.
     */
    event ReceiveFromChain(uint16 indexed _srcChainId, address indexed _to, uint _amount);

    event SetUseCustomAdapterParams(bool _useCustomAdapterParams);
}

// File: src/sgReceiver.sol



// SPDX-License-Identifier: No License
pragma solidity ^0.8.0;

import "layerzerolabs/contracts/interfaces/IStargateReceiver.sol";
import "layerzerolabs/contracts/token/oft/IOFTCore.sol";
import "communal/SafeERC20.sol";
import "communal/Owned.sol";
import "communal/TransferHelper.sol";


interface IunshethZap {
    function mint_with_usdt(uint256 amount, uint256 min_amount_unshethZap, uint256 unsheth_path) external;
}

interface IStargateRouter {
    function clearCachedSwap(uint16 _srcChainId, bytes calldata _srcAddress, uint256 nonce) external;
    function cachedSwapLookup(uint16 _srcChainId, bytes calldata _srcAddress, uint256 nonce) external view returns (address token, uint256 amountLD, address to, bytes memory payload);
}


contract USDTSGReceiver is IStargateReceiver, Owned {

    address public immutable stargateRouterAddress;
    address public unshethZapAddress;
    address public immutable usdtAddress;
    address public immutable unshethAddress;
    address public immutable proxyUnshethAddress;
    address public zroAddress = address(0);
    uint256 public unsheth_gas_cost;

    uint16 public srcChainId;

    mapping(uint256 => bool) public nonceHandled;

    //adapter params
    uint256 public adapter_version = 2;
    uint256 public adapter_gasLimit = 200000;
    uint256 public adapter_airdrop = 0;

    using SafeERC20 for IERC20;

    //to see chain ids and stargate router addresses, check out 
    //https://layerzero.gitbook.io/docs/technical-reference/mainnet/supported-chain-ids
    //https://stargateprotocol.gitbook.io/stargate/developers/contract-addresses/mainnet

    constructor(
        address _owner,  //address of the person deploying this
        address _proxyUnshethAddress, //address of the proxy unshETH deployed
        address _unshETHAddress, //address of unshETH token contract
        address _usdtAddress, //usdt address - 0xdac17f958d2ee523a2206206994597c13d831ec7
        address _stargateRouter, //0x8731d54E9D02c286767d56ac03e8037C07e01e98 as per https://stargateprotocol.gitbook.io/stargate/developers/contract-addresses/mainnet
        address _unshethZapAddress, //address of the unshETH Zap deployed
        uint16 _srcChainId //102 as per https://stargateprotocol.gitbook.io/stargate/developers/contract-addresses/mainnet
    ) Owned(_owner) {
        proxyUnshethAddress = _proxyUnshethAddress;
        stargateRouterAddress = _stargateRouter;
        unshethZapAddress = _unshethZapAddress;
        usdtAddress = _usdtAddress;
        unshethAddress = _unshETHAddress;
        unsheth_gas_cost = 0.01 ether;
        srcChainId = _srcChainId;
        
        //allow the unsheth zap to execute sendFrom for all USDT sent over
        TransferHelper.safeApprove(usdtAddress, unshethZapAddress, type(uint256).max);
        //allow the unsheth proxy to spend my unsheth
        TransferHelper.safeApprove(unshethAddress, proxyUnshethAddress, type(uint256).max);
    }

    //owner function to set the srcChainId and srcAddress
    function updateSrcChainId(uint16 _srcChainId) public onlyOwner{
        srcChainId = _srcChainId;
    }

    function updateAdapterParams(uint256 _version, uint256 _gasLimit, uint256 _airdrop) public onlyOwner {
        adapter_version = _version;
        adapter_gasLimit = _gasLimit;
        adapter_airdrop = _airdrop;
    }

    //owner function to set the zroAddress
    function updateZroAddress(address _zroAddress) public onlyOwner{
        zroAddress = _zroAddress;
    }

    //owner function to set the amount of eth to spend per unsheth transfer
    function set_unsheth_gas_cost(uint256 amount) public onlyOwner{
        unsheth_gas_cost = amount;
    }

    //sgReceive will receive USDT and then mint unshETH and send the unshETH back to the original sender
    function sgReceive(uint16 /*_chainId*/, bytes memory /*_srcAddress*/, uint /*_nonce*/, address _token, uint amountLD, bytes memory _payload) override external {
        require(msg.sender == address(stargateRouterAddress), "only stargate router can call sgReceive!");
        require(_token == usdtAddress, "only USDT can be sent to this contract!");
        require(unsheth_gas_cost <= address(this).balance, 'unsheth_gas_cost must be less than the eth balance in this contract');
        //Check the balance of USDT is above the amountLD
        require(amountLD <= IERC20(usdtAddress).balanceOf(address(this)), "Contract USDT balance is less than amountLD");
        //Extract the mint information
        (address userAddress, uint256 min_amount_unshethZap, uint256 unsheth_path) = abi.decode(_payload, (address, uint256, uint256));
        //Mint unsheth with usdt using the parameters bridged over
        uint256 unshethMinted = _mint_unsheth_with_usdt(amountLD, min_amount_unshethZap, unsheth_path);
        //Bridge the minted unsheth
        _bridge_unsheth(unshethMinted, unsheth_gas_cost, userAddress);
    }

    function _mint_unsheth_with_usdt(uint256 _usdtAmount, uint256 _minAmountOut, uint256 _pathId) internal returns (uint256 unshethMinted) {
        //get balance of unshETH before minting
        uint256 unshethBalBefore = IERC20(unshethAddress).balanceOf(address(this));
        //Mint unshETH to this contract address
        IunshethZap(unshethZapAddress).mint_with_usdt(_usdtAmount, _minAmountOut, _pathId);
        //get the new balance of unshETH
        uint256 unshethBal = IERC20(unshethAddress).balanceOf(address(this));
        //return unshethMinted = the difference in balances
        return (unshethBal - unshethBalBefore);
    }

    function _bridge_unsheth(uint256 _unshethAmount, uint256 _unsheth_gas_cost, address _userAddress) internal {
        IOFTCore(proxyUnshethAddress).sendFrom{value:_unsheth_gas_cost}(
            address(this), //current owner of the unsheth
            srcChainId, //chain Id where the proxy of the unsheth exists (this is set in the constructor)
            abi.encodePacked(_userAddress), //the address we want the unsheth to end up in
            _unshethAmount, //the amount of unsheth to send
            payable(address(this)), //the refund address if something goes wrong or excess
            zroAddress, //the ZRO Payment Address
            //Adapter params
            abi.encode( 
                adapter_version,
                adapter_gasLimit,
                adapter_airdrop,
                _userAddress
            ) 
        );
    }

    //function for user to rescue the usdt bridged over in case initial bridge txn fails
    function rescue_usdt(bytes memory srcAddress, uint256 nonce) external {
        //Ensure this nonce hasn't already been handled
        require(nonceHandled[nonce] == false, "Nonce has already been handled");
        (address _token, uint256 amountLD, address to, bytes memory _payload) = IStargateRouter(stargateRouterAddress).cachedSwapLookup(srcChainId, srcAddress, nonce);
        (address userAddress, , ) = abi.decode(_payload, (address, uint256, uint256));
        //Check parameters are reasonable
        require(to == address(this), "to is not sgreceiver contract address");
        require(_token == usdtAddress, "only USDT can be sent to this contract!");
        require(msg.sender == userAddress || msg.sender == owner, "only owner or user can rescue their usdt");
        require(amountLD > 0, "No tokens to rescue");
        require(amountLD <= IERC20(usdtAddress).balanceOf(address(this)), "Amount to rescue exceeds contract balance");
        TransferHelper.safeTransfer(usdtAddress, userAddress, amountLD);
        nonceHandled[nonce] = true;
    }

    //owner function to clear the cache with same params as before in case initial bridge txn fails. Gas is paid by team
    function retry_mint_clearCachedSwap(bytes memory srcAddress, uint256 nonce) external onlyOwner {
        IStargateRouter(stargateRouterAddress).clearCachedSwap(srcChainId, srcAddress, nonce);
        nonceHandled[nonce] = true;
    }

    //function for user to retry minting unsheth with usdt with new params in case initial bridge txn fails
    //front-end should suggest min_amount_unshethZap and unsheth_path based on optimal path to mint unsheth with usdt
    //front-end should also suggest msg.value which corresponds to gas cost of bridging unsheth to bnb
    function retry_mint_newParams(bytes memory srcAddress, uint256 nonce, uint256 min_amount_unshethZap, uint256 unsheth_path) external payable {
        //Ensure this nonce hasn't already been handled
        require(nonceHandled[nonce] == false, "Nonce has already been handled");
        //Extract the stargate cachedswap information with the given nonce
        (address _token, uint256 amountLD, address to, bytes memory _payload) = IStargateRouter(stargateRouterAddress).cachedSwapLookup(srcChainId, srcAddress, nonce);
        (address userAddress, , ) = abi.decode(_payload, (address, uint256, uint256));
        //Check parameters are reasonable
        require(to == address(this), "to is not sgreceiver contract address");
        require(_token == usdtAddress, "only USDT can be sent to this contract!");
        require(msg.sender == userAddress, "only user can retry mint");
        require(amountLD > 0, "No tokens to retry with");
        require(amountLD <= IERC20(usdtAddress).balanceOf(address(this)), "Amount to retry with exceeds contract balance");
        //Mint unsheth with usdt using the retry parameters
        uint256 unshethMinted = _mint_unsheth_with_usdt(amountLD, min_amount_unshethZap, unsheth_path);
        //Bridge the minted unsheth
        _bridge_unsheth(unshethMinted, msg.value, userAddress);
        nonceHandled[nonce] = true;
    }

    function updateUnshethZapAddress(address _unshethZapAddress) external onlyOwner {
        require(_unshethZapAddress != address(0), "Invalid address");
        //Remove approval of old unshETHZap Addresss
        TransferHelper.safeApprove(usdtAddress, unshethZapAddress, 0);

        //Set new unshETH Zap Address
        unshethZapAddress = _unshethZapAddress;

        //Approve new unshETHZap Address
        TransferHelper.safeApprove(usdtAddress, unshethZapAddress, type(uint256).max);
    }

    //owner function that sends the remaining eth back to the owner
    function rescue_eth() external onlyOwner{
        uint256 ethBal = address(this).balance;
        Address.sendValue(payable(owner), ethBal);
    }

    function emergency_rescue_usdt() external onlyOwner {
        uint256 usdtBal = IERC20(usdtAddress).balanceOf(address(this));
        TransferHelper.safeTransfer(usdtAddress, owner, usdtBal);
    }

    //Allow receiving eth to the contract
    receive() external payable {}
}