creation_sourcecode: // SPDX-License-Identifier: MIT
  pragma solidity ^0.8.0 ^0.8.1 ^0.8.2;
  
  // lib/openzeppelin-contracts/contracts/token/ERC20/IERC20.sol
  
  // OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/IERC20.sol)
  
  /**
   * @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 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 `to`.
       *
       * Returns a boolean value indicating whether the operation succeeded.
       *
       * Emits a {Transfer} event.
       */
      function transfer(address to, 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 `from` to `to` 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 from, address to, uint256 amount) external returns (bool);
  }
  
  // lib/openzeppelin-contracts/contracts/token/ERC20/extensions/IERC20Permit.sol
  
  // OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/extensions/IERC20Permit.sol)
  
  /**
   * @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.
   */
  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].
       */
      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);
  }
  
  // lib/openzeppelin-contracts/contracts/utils/Address.sol
  
  // OpenZeppelin Contracts (last updated v4.9.0) (utils/Address.sol)
  
  /**
   * @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
       *
       * Furthermore, `isContract` will also return true if the target contract within
       * the same transaction is already scheduled for destruction by `SELFDESTRUCT`,
       * which only has an effect at the end of a transaction.
       * ====
       *
       * [IMPORTANT]
       * ====
       * You shouldn't rely on `isContract` to protect against flash loan attacks!
       *
       * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
       * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
       * constructor.
       * ====
       */
      function isContract(address account) internal view returns (bool) {
          // This method relies on extcodesize/address.code.length, which returns 0
          // for contracts in construction, since the code is only stored at the end
          // of the constructor execution.
  
          return account.code.length > 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://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/v0.8.0/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
       */
      function sendValue(address payable recipient, uint256 amount) internal {
          require(address(this).balance >= amount, "Address: insufficient balance");
  
          (bool success, ) = recipient.call{value: amount}("");
          require(success, "Address: unable to send value, recipient may have reverted");
      }
  
      /**
       * @dev Performs a Solidity function call using a low level `call`. A
       * plain `call` is an unsafe replacement for a function call: use this
       * function instead.
       *
       * If `target` reverts with a revert reason, it is bubbled up by this
       * function (like regular Solidity function calls).
       *
       * Returns the raw returned data. To convert to the expected return value,
       * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
       *
       * Requirements:
       *
       * - `target` must be a contract.
       * - calling `target` with `data` must not revert.
       *
       * _Available since v3.1._
       */
      function functionCall(address target, bytes memory data) internal returns (bytes memory) {
          return functionCallWithValue(target, data, 0, "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");
          (bool success, bytes memory returndata) = target.call{value: value}(data);
          return verifyCallResultFromTarget(target, 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) {
          (bool success, bytes memory returndata) = target.staticcall(data);
          return verifyCallResultFromTarget(target, 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) {
          (bool success, bytes memory returndata) = target.delegatecall(data);
          return verifyCallResultFromTarget(target, success, returndata, errorMessage);
      }
  
      /**
       * @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
       * the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
       *
       * _Available since v4.8._
       */
      function verifyCallResultFromTarget(
          address target,
          bool success,
          bytes memory returndata,
          string memory errorMessage
      ) internal view returns (bytes memory) {
          if (success) {
              if (returndata.length == 0) {
                  // only check isContract if the call was successful and the return data is empty
                  // otherwise we already know that it was a contract
                  require(isContract(target), "Address: call to non-contract");
              }
              return returndata;
          } else {
              _revert(returndata, errorMessage);
          }
      }
  
      /**
       * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
       * revert reason or using the provided one.
       *
       * _Available since v4.3._
       */
      function verifyCallResult(
          bool success,
          bytes memory returndata,
          string memory errorMessage
      ) internal pure returns (bytes memory) {
          if (success) {
              return returndata;
          } else {
              _revert(returndata, errorMessage);
          }
      }
  
      function _revert(bytes memory returndata, string memory errorMessage) 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(errorMessage);
          }
      }
  }
  
  // lib/openzeppelin-contracts-upgradeable/contracts/utils/AddressUpgradeable.sol
  
  // OpenZeppelin Contracts (last updated v4.9.0) (utils/Address.sol)
  
  /**
   * @dev Collection of functions related to the address type
   */
  library AddressUpgradeable {
      /**
       * @dev Returns true if `account` is a contract.
       *
       * [IMPORTANT]
       * ====
       * It is unsafe to assume that an address for which this function returns
       * false is an externally-owned account (EOA) and not a contract.
       *
       * Among others, `isContract` will return false for the following
       * types of addresses:
       *
       *  - an externally-owned account
       *  - a contract in construction
       *  - an address where a contract will be created
       *  - an address where a contract lived, but was destroyed
       *
       * Furthermore, `isContract` will also return true if the target contract within
       * the same transaction is already scheduled for destruction by `SELFDESTRUCT`,
       * which only has an effect at the end of a transaction.
       * ====
       *
       * [IMPORTANT]
       * ====
       * You shouldn't rely on `isContract` to protect against flash loan attacks!
       *
       * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
       * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
       * constructor.
       * ====
       */
      function isContract(address account) internal view returns (bool) {
          // This method relies on extcodesize/address.code.length, which returns 0
          // for contracts in construction, since the code is only stored at the end
          // of the constructor execution.
  
          return account.code.length > 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://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/v0.8.0/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
       */
      function sendValue(address payable recipient, uint256 amount) internal {
          require(address(this).balance >= amount, "Address: insufficient balance");
  
          (bool success, ) = recipient.call{value: amount}("");
          require(success, "Address: unable to send value, recipient may have reverted");
      }
  
      /**
       * @dev Performs a Solidity function call using a low level `call`. A
       * plain `call` is an unsafe replacement for a function call: use this
       * function instead.
       *
       * If `target` reverts with a revert reason, it is bubbled up by this
       * function (like regular Solidity function calls).
       *
       * Returns the raw returned data. To convert to the expected return value,
       * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
       *
       * Requirements:
       *
       * - `target` must be a contract.
       * - calling `target` with `data` must not revert.
       *
       * _Available since v3.1._
       */
      function functionCall(address target, bytes memory data) internal returns (bytes memory) {
          return functionCallWithValue(target, data, 0, "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");
          (bool success, bytes memory returndata) = target.call{value: value}(data);
          return verifyCallResultFromTarget(target, 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) {
          (bool success, bytes memory returndata) = target.staticcall(data);
          return verifyCallResultFromTarget(target, 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) {
          (bool success, bytes memory returndata) = target.delegatecall(data);
          return verifyCallResultFromTarget(target, success, returndata, errorMessage);
      }
  
      /**
       * @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
       * the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
       *
       * _Available since v4.8._
       */
      function verifyCallResultFromTarget(
          address target,
          bool success,
          bytes memory returndata,
          string memory errorMessage
      ) internal view returns (bytes memory) {
          if (success) {
              if (returndata.length == 0) {
                  // only check isContract if the call was successful and the return data is empty
                  // otherwise we already know that it was a contract
                  require(isContract(target), "Address: call to non-contract");
              }
              return returndata;
          } else {
              _revert(returndata, errorMessage);
          }
      }
  
      /**
       * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
       * revert reason or using the provided one.
       *
       * _Available since v4.3._
       */
      function verifyCallResult(
          bool success,
          bytes memory returndata,
          string memory errorMessage
      ) internal pure returns (bytes memory) {
          if (success) {
              return returndata;
          } else {
              _revert(returndata, errorMessage);
          }
      }
  
      function _revert(bytes memory returndata, string memory errorMessage) 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(errorMessage);
          }
      }
  }
  
  // src/interfaces/IL1Bridge.sol
  
  interface IL1Bridge {
      function transferETH(uint16 dstChainId_, uint256 amount_, address recipient_) external payable;
  
      function transferETHFromVault(uint16 dstChainId_, address recipient_) external payable;
  
      function transferERC20(uint16 dstChainId_, address l1Token_, uint256 amount_, address recipient_)
          external
          payable;
  
      function transferERC20FromVault(uint16 dstChainId_, address l1Token_, uint256 amount_, address recipient_)
          external;
  
      function fees(uint16 dstChainId_) external view returns (uint256);
  }
  
  // src/interfaces/IZKBridgeEndpoint.sol
  
  interface IZKBridgeEndpoint {
      function send(uint16 dstChainId, address dstAddress, bytes memory payload) external payable returns (uint64);
  
      function estimateFee(uint16 dstChainId) external view returns (uint256 fee);
  
      function chainId() external view returns (uint16);
  }
  
  // src/interfaces/IZKBridgeReceiver.sol
  
  interface IZKBridgeReceiver {
      // @notice ZKBridge endpoint will invoke this function to deliver the message on the destination
      // @param srcChainId - the source endpoint identifier
      // @param srcAddress - the source sending contract address from the source chain
      // @param sequence - the ordered message nonce
      // @param payload - the signed payload is the UA bytes has encoded to be sent
      function zkReceive(uint16 srcChainId, address srcAddress, uint64 sequence, bytes calldata payload) external;
  }
  
  // lib/openzeppelin-contracts-upgradeable/contracts/proxy/utils/Initializable.sol
  
  // OpenZeppelin Contracts (last updated v4.9.0) (proxy/utils/Initializable.sol)
  
  /**
   * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
   * behind a proxy. Since proxied contracts do not make use of a constructor, it's common to move constructor logic to an
   * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
   * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
   *
   * The initialization functions use a version number. Once a version number is used, it is consumed and cannot be
   * reused. This mechanism prevents re-execution of each "step" but allows the creation of new initialization steps in
   * case an upgrade adds a module that needs to be initialized.
   *
   * For example:
   *
   * [.hljs-theme-light.nopadding]
   * ```solidity
   * contract MyToken is ERC20Upgradeable {
   *     function initialize() initializer public {
   *         __ERC20_init("MyToken", "MTK");
   *     }
   * }
   *
   * contract MyTokenV2 is MyToken, ERC20PermitUpgradeable {
   *     function initializeV2() reinitializer(2) public {
   *         __ERC20Permit_init("MyToken");
   *     }
   * }
   * ```
   *
   * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
   * possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}.
   *
   * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
   * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
   *
   * [CAUTION]
   * ====
   * Avoid leaving a contract uninitialized.
   *
   * An uninitialized contract can be taken over by an attacker. This applies to both a proxy and its implementation
   * contract, which may impact the proxy. To prevent the implementation contract from being used, you should invoke
   * the {_disableInitializers} function in the constructor to automatically lock it when it is deployed:
   *
   * [.hljs-theme-light.nopadding]
   * ```
   * /// @custom:oz-upgrades-unsafe-allow constructor
   * constructor() {
   *     _disableInitializers();
   * }
   * ```
   * ====
   */
  abstract contract Initializable {
      /**
       * @dev Indicates that the contract has been initialized.
       * @custom:oz-retyped-from bool
       */
      uint8 private _initialized;
  
      /**
       * @dev Indicates that the contract is in the process of being initialized.
       */
      bool private _initializing;
  
      /**
       * @dev Triggered when the contract has been initialized or reinitialized.
       */
      event Initialized(uint8 version);
  
      /**
       * @dev A modifier that defines a protected initializer function that can be invoked at most once. In its scope,
       * `onlyInitializing` functions can be used to initialize parent contracts.
       *
       * Similar to `reinitializer(1)`, except that functions marked with `initializer` can be nested in the context of a
       * constructor.
       *
       * Emits an {Initialized} event.
       */
      modifier initializer() {
          bool isTopLevelCall = !_initializing;
          require(
              (isTopLevelCall && _initialized < 1) || (!AddressUpgradeable.isContract(address(this)) && _initialized == 1),
              "Initializable: contract is already initialized"
          );
          _initialized = 1;
          if (isTopLevelCall) {
              _initializing = true;
          }
          _;
          if (isTopLevelCall) {
              _initializing = false;
              emit Initialized(1);
          }
      }
  
      /**
       * @dev A modifier that defines a protected reinitializer function that can be invoked at most once, and only if the
       * contract hasn't been initialized to a greater version before. In its scope, `onlyInitializing` functions can be
       * used to initialize parent contracts.
       *
       * A reinitializer may be used after the original initialization step. This is essential to configure modules that
       * are added through upgrades and that require initialization.
       *
       * When `version` is 1, this modifier is similar to `initializer`, except that functions marked with `reinitializer`
       * cannot be nested. If one is invoked in the context of another, execution will revert.
       *
       * Note that versions can jump in increments greater than 1; this implies that if multiple reinitializers coexist in
       * a contract, executing them in the right order is up to the developer or operator.
       *
       * WARNING: setting the version to 255 will prevent any future reinitialization.
       *
       * Emits an {Initialized} event.
       */
      modifier reinitializer(uint8 version) {
          require(!_initializing && _initialized < version, "Initializable: contract is already initialized");
          _initialized = version;
          _initializing = true;
          _;
          _initializing = false;
          emit Initialized(version);
      }
  
      /**
       * @dev Modifier to protect an initialization function so that it can only be invoked by functions with the
       * {initializer} and {reinitializer} modifiers, directly or indirectly.
       */
      modifier onlyInitializing() {
          require(_initializing, "Initializable: contract is not initializing");
          _;
      }
  
      /**
       * @dev Locks the contract, preventing any future reinitialization. This cannot be part of an initializer call.
       * Calling this in the constructor of a contract will prevent that contract from being initialized or reinitialized
       * to any version. It is recommended to use this to lock implementation contracts that are designed to be called
       * through proxies.
       *
       * Emits an {Initialized} event the first time it is successfully executed.
       */
      function _disableInitializers() internal virtual {
          require(!_initializing, "Initializable: contract is initializing");
          if (_initialized != type(uint8).max) {
              _initialized = type(uint8).max;
              emit Initialized(type(uint8).max);
          }
      }
  
      /**
       * @dev Returns the highest version that has been initialized. See {reinitializer}.
       */
      function _getInitializedVersion() internal view returns (uint8) {
          return _initialized;
      }
  
      /**
       * @dev Returns `true` if the contract is currently initializing. See {onlyInitializing}.
       */
      function _isInitializing() internal view returns (bool) {
          return _initializing;
      }
  }
  
  // lib/openzeppelin-contracts-upgradeable/contracts/security/ReentrancyGuardUpgradeable.sol
  
  // OpenZeppelin Contracts (last updated v4.9.0) (security/ReentrancyGuard.sol)
  
  /**
   * @dev Contract module that helps prevent reentrant calls to a function.
   *
   * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
   * available, which can be applied to functions to make sure there are no nested
   * (reentrant) calls to them.
   *
   * Note that because there is a single `nonReentrant` guard, functions marked as
   * `nonReentrant` may not call one another. This can be worked around by making
   * those functions `private`, and then adding `external` `nonReentrant` entry
   * points to them.
   *
   * TIP: If you would like to learn more about reentrancy and alternative ways
   * to protect against it, check out our blog post
   * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
   */
  abstract contract ReentrancyGuardUpgradeable is Initializable {
      // Booleans are more expensive than uint256 or any type that takes up a full
      // word because each write operation emits an extra SLOAD to first read the
      // slot's contents, replace the bits taken up by the boolean, and then write
      // back. This is the compiler's defense against contract upgrades and
      // pointer aliasing, and it cannot be disabled.
  
      // The values being non-zero value makes deployment a bit more expensive,
      // but in exchange the refund on every call to nonReentrant will be lower in
      // amount. Since refunds are capped to a percentage of the total
      // transaction's gas, it is best to keep them low in cases like this one, to
      // increase the likelihood of the full refund coming into effect.
      uint256 private constant _NOT_ENTERED = 1;
      uint256 private constant _ENTERED = 2;
  
      uint256 private _status;
  
      function __ReentrancyGuard_init() internal onlyInitializing {
          __ReentrancyGuard_init_unchained();
      }
  
      function __ReentrancyGuard_init_unchained() internal onlyInitializing {
          _status = _NOT_ENTERED;
      }
  
      /**
       * @dev Prevents a contract from calling itself, directly or indirectly.
       * Calling a `nonReentrant` function from another `nonReentrant`
       * function is not supported. It is possible to prevent this from happening
       * by making the `nonReentrant` function external, and making it call a
       * `private` function that does the actual work.
       */
      modifier nonReentrant() {
          _nonReentrantBefore();
          _;
          _nonReentrantAfter();
      }
  
      function _nonReentrantBefore() private {
          // On the first call to nonReentrant, _status will be _NOT_ENTERED
          require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
  
          // Any calls to nonReentrant after this point will fail
          _status = _ENTERED;
      }
  
      function _nonReentrantAfter() private {
          // By storing the original value once again, a refund is triggered (see
          // https://eips.ethereum.org/EIPS/eip-2200)
          _status = _NOT_ENTERED;
      }
  
      /**
       * @dev Returns true if the reentrancy guard is currently set to "entered", which indicates there is a
       * `nonReentrant` function in the call stack.
       */
      function _reentrancyGuardEntered() internal view returns (bool) {
          return _status == _ENTERED;
      }
  
      /**
       * @dev This empty reserved space is put in place to allow future versions to add new
       * variables without shifting down storage in the inheritance chain.
       * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
       */
      uint256[49] private __gap;
  }
  
  // src/Admin.sol
  
  abstract contract Admin is Initializable {
      address public poolManager;
      address public approveManager;
      address public bridgeManager;
      address public bridgeReviewer; // When bridgeReviewer == bridgeManager, the reviewing step will be skipped.
  
      // Two-step ownership management design, similar to Ownable2Step in OpenZeppelin Contracts.
      address public pendingPoolManager;
      address public pendingApproveManager;
      address public pendingBridgeManager;
      address public pendingBridgeReviewer;
  
      event PoolManagerTransferStarted(address indexed previousOwner, address indexed newOwner);
      event PoolManagerTransferred(address indexed previousOwner, address indexed newOwner);
  
      event ApproveManagerTransferStarted(address indexed previousOwner, address indexed newOwner);
      event ApproveManagerTransferred(address indexed previousOwner, address indexed newOwner);
  
      event BridgeManagerTransferStarted(address indexed previousOwner, address indexed newOwner);
      event BridgeManagerTransferred(address indexed previousOwner, address indexed newOwner);
  
      event BridgeReviewerTransferStarted(address indexed previousOwner, address indexed newOwner);
      event BridgeReviewerTransferred(address indexed previousOwner, address indexed newOwner);
  
      function __Admin_init() internal onlyInitializing {
          poolManager = msg.sender;
          approveManager = msg.sender;
          bridgeManager = msg.sender;
          bridgeReviewer = msg.sender;
      }
  
      modifier onlyPoolManager() {
          require(msg.sender == poolManager, "Admin: caller is not poolManager");
          _;
      }
  
      modifier onlyApproveManager() {
          require(msg.sender == approveManager, "Admin: caller is not approveManager");
          _;
      }
  
      modifier onlyBridgeManager() {
          require(msg.sender == bridgeManager, "Admin: caller is not bridgeManager");
          _;
      }
  
      modifier onlyBridgeReviewer() {
          require(msg.sender == bridgeReviewer, "Admin: caller is not bridgeReviewer");
          _;
      }
  
      function transferPoolManager(address newOwner) external onlyPoolManager {
          pendingPoolManager = newOwner;
          emit PoolManagerTransferStarted(msg.sender, newOwner);
      }
  
      function acceptPoolManager() external {
          require(msg.sender == pendingPoolManager, "Admin: caller is not the new owner");
          delete pendingPoolManager;
          address oldOwner = poolManager;
          poolManager = msg.sender;
          emit PoolManagerTransferred(oldOwner, msg.sender);
      }
  
      function transferApproveManager(address newOwner) external onlyApproveManager {
          pendingApproveManager = newOwner;
          emit ApproveManagerTransferStarted(msg.sender, newOwner);
      }
  
      function acceptApproveManager() external {
          require(msg.sender == pendingApproveManager, "Admin: caller is not the new owner");
          delete pendingApproveManager;
          address oldOwner = approveManager;
          approveManager = msg.sender;
          emit ApproveManagerTransferred(oldOwner, msg.sender);
      }
  
      function transferBridgeManager(address newOwner) external onlyBridgeManager {
          pendingBridgeManager = newOwner;
          emit BridgeManagerTransferStarted(msg.sender, newOwner);
      }
  
      function acceptBridgeManager() external {
          require(msg.sender == pendingBridgeManager, "Admin: caller is not the new owner");
          delete pendingBridgeManager;
          address oldOwner = bridgeManager;
          bridgeManager = msg.sender;
          emit BridgeManagerTransferred(oldOwner, msg.sender);
      }
  
      function transferBridgeReviewer(address newOwner) external onlyBridgeReviewer {
          pendingBridgeReviewer = newOwner;
          emit BridgeReviewerTransferStarted(msg.sender, newOwner);
      }
  
      function acceptBridgeReviewer() external {
          require(msg.sender == pendingBridgeReviewer, "Admin: caller is not the new owner");
          delete pendingBridgeReviewer;
          address oldOwner = bridgeReviewer;
          bridgeReviewer = msg.sender;
          emit BridgeReviewerTransferred(oldOwner, msg.sender);
      }
  
      /**
       * @dev This empty reserved space is put in place to allow future versions to add new
       * variables without shifting down storage in the inheritance chain.
       * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
       */
      uint256[42] private __gap;
  }
  
  // lib/openzeppelin-contracts/contracts/token/ERC20/utils/SafeERC20.sol
  
  // OpenZeppelin Contracts (last updated v4.9.3) (token/ERC20/utils/SafeERC20.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 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.encodeWithSelector(token.transfer.selector, 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.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'
          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));
      }
  
      /**
       * @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);
          _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance + value));
      }
  
      /**
       * @dev Decrease the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
       * non-reverting calls are assumed to be successful.
       */
      function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
          unchecked {
              uint256 oldAllowance = token.allowance(address(this), spender);
              require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
              _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance - value));
          }
      }
  
      /**
       * @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.encodeWithSelector(token.approve.selector, spender, value);
  
          if (!_callOptionalReturnBool(token, approvalCall)) {
              _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, 0));
              _callOptionalReturn(token, approvalCall);
          }
      }
  
      /**
       * @dev Use a ERC-2612 signature to set the `owner` approval toward `spender` on `token`.
       * Revert on invalid signature.
       */
      function safePermit(
          IERC20Permit token,
          address owner,
          address spender,
          uint256 value,
          uint256 deadline,
          uint8 v,
          bytes32 r,
          bytes32 s
      ) internal {
          uint256 nonceBefore = token.nonces(owner);
          token.permit(owner, spender, value, deadline, v, r, s);
          uint256 nonceAfter = token.nonces(owner);
          require(nonceAfter == nonceBefore + 1, "SafeERC20: permit did not succeed");
      }
  
      /**
       * @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");
          require(returndata.length == 0 || abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
      }
  
      /**
       * @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.isContract(address(token));
      }
  }
  
  // src/Pool.sol
  
  abstract contract Pool is ReentrancyGuardUpgradeable, Admin {
      using SafeERC20 for IERC20;
  
      struct DstChainInfo {
          // Whether dstChain is enabled for this pool
          bool enabled;
          // Static fee when sending tokens to dstChain
          uint128 staticFee;
          // Numerator of dynamic fee, a fee proportionate to the transfer amount
          // Currently only supports native token pools
          uint64 dynamicFeeNum;
          // Limit of a single transfer
          uint256 maxTransferLimit;
      }
  
      uint256 public constant DYNAMIC_FEE_DEN = 1000000000; // denominator of dynamic fee
  
      struct PoolInfo {
          // Whether this pool is enabled
          bool enabled;
          // Should be (local decimals - shared decimals)
          // e.g. If local decimals is 18 and shared decimals is 6, this number should be 12
          // Local decimals is the decimals of the underlying ERC20 token
          // Shared decimals is the common decimals across all chains
          uint8 convertRateDecimals;
          // ERC20 token address. Should be address(0) for native token pool
          address token;
          // Token balance of this pool
          // This should be tracked via a variable because this contract also hold fees
          // Also, an attacker may force transfer tokens to this contract to reach maxLiquidity
          uint256 balance;
          // The liquidity of this pool when the remote pool is exhausted
          // Only works when there are two chains
          // When there are >= 3 chains, this does not work and should be set to type(uint256).max
          uint256 maxLiquidity;
      }
  
      // poolId -> dstChainId -> DstChainInfo
      mapping(uint256 => mapping(uint16 => DstChainInfo)) internal _dstChains;
  
      // Native token pool ID
      uint256 public immutable NATIVE_TOKEN_POOL_ID;
  
      // poolId -> PoolInfo
      // poolId needs to be the same across different chains for the same token
      mapping(uint256 => PoolInfo) internal _poolInfo;
  
      mapping(address => bool) public whitelists;
  
      event AddLiquidity(uint256 indexed poolId, uint256 amount);
      event RemoveLiquidity(uint256 indexed poolId, uint256 amount);
      event DstChainStatusChanged(uint256 indexed poolId, uint16 indexed dstChainId, bool indexed enabled);
      event NewMaxTransferLimit(uint256 indexed poolId, uint16 indexed dstChainId, uint256 maxTransferLimit);
      event NewMaxLiquidity(uint256 indexed poolId, uint256 maxLiquidity);
      event NewFee(uint256 indexed poolId, uint16 indexed dstChainId, uint256 staticFee, uint256 dynamicFeeNum);
      event ClaimedFees(address to, uint256 amount);
  
      constructor(uint256 NATIVE_TOKEN_POOL_ID_) {
          NATIVE_TOKEN_POOL_ID = NATIVE_TOKEN_POOL_ID_;
      }
  
      function poolInfo(uint256 poolId) public view returns (PoolInfo memory) {
          return _poolInfo[poolId];
      }
  
      function dstChains(uint256 poolId, uint16 dstChainId) public view returns (DstChainInfo memory) {
          return _dstChains[poolId][dstChainId];
      }
  
      function convertRate(uint256 poolId) public view returns (uint256) {
          return 10 ** _poolInfo[poolId].convertRateDecimals;
      }
  
      /// @dev ensure amount is a multiple of convertRate
      function _checkConvertRate(uint256 poolId, uint256 amount) internal view {
          require(amount % convertRate(poolId) == 0, "Pool: amount is not a multiple of convert rate");
      }
  
      function _checkPool(uint256 poolId) internal view {
          require(_poolInfo[poolId].enabled, "Pool: pool ID not enabled");
      }
  
      function _checkDstChain(uint256 poolId, uint16 dstChainId) internal view {
          _checkPool(poolId);
          require(_dstChains[poolId][dstChainId].enabled, "Pool: pool ID or dst chain ID not enabled");
      }
  
      function getFee(uint256 poolId, uint16 dstChainId, uint256 amount) public view returns (uint256) {
          return amount * _dstChains[poolId][dstChainId].dynamicFeeNum / DYNAMIC_FEE_DEN
              + _dstChains[poolId][dstChainId].staticFee;
      }
  
      /// @notice The main function for adding liquidity of ERC20 tokens
      function addLiquidity(uint256 poolId, uint256 amount) public onlyPoolManager nonReentrant {
          _checkPool(poolId);
          _checkConvertRate(poolId, amount);
          IERC20(_poolInfo[poolId].token).safeTransferFrom(msg.sender, address(this), amount);
          _poolInfo[poolId].balance += amount;
          emit AddLiquidity(poolId, amount);
      }
  
      /// @notice The main function for adding liquidity of native token
      function addLiquidityETH() public payable onlyPoolManager nonReentrant {
          uint256 poolId = NATIVE_TOKEN_POOL_ID;
          _checkPool(poolId);
          _checkConvertRate(poolId, msg.value);
          _poolInfo[poolId].balance += msg.value;
          emit AddLiquidity(poolId, msg.value);
      }
  
      /// @notice The main function for adding liquidity of ERC20 tokens without permission
      /// @dev When there are >= 3 chains, maxLiquidity is not enforced so everyone can add liquidity without any problem
      function addLiquidityPublic(uint256 poolId, uint256 amount) external nonReentrant {
          _checkPool(poolId);
          require(
              _poolInfo[poolId].maxLiquidity == type(uint256).max,
              "Pool: addLiquidityPublic only work when maxLiquidity is not limited"
          );
          _checkConvertRate(poolId, amount);
          IERC20(_poolInfo[poolId].token).safeTransferFrom(msg.sender, address(this), amount);
          _poolInfo[poolId].balance += amount;
          emit AddLiquidity(poolId, amount);
      }
  
      /// @notice The main function for adding liquidity of native token without permission
      /// @dev When there are >= 3 chains, maxLiquidity is not enforced so everyone can add liquidity without any problem
      function addLiquidityETHPublic() external payable nonReentrant {
          uint256 poolId = NATIVE_TOKEN_POOL_ID;
          _checkPool(poolId);
          require(
              _poolInfo[poolId].maxLiquidity == type(uint256).max,
              "Pool: addLiquidityPublic only work when maxLiquidity is not limited"
          );
          _checkConvertRate(poolId, msg.value);
          _poolInfo[poolId].balance += msg.value;
          emit AddLiquidity(poolId, msg.value);
      }
  
      /// @notice The main function for removing liquidity
      function removeLiquidity(uint256 poolId, uint256 amount) external onlyPoolManager nonReentrant {
          _checkPool(poolId);
          _checkConvertRate(poolId, amount);
          require(amount <= _poolInfo[poolId].balance);
          if (poolId == NATIVE_TOKEN_POOL_ID) {
              Address.sendValue(payable(msg.sender), amount);
          } else {
              IERC20(_poolInfo[poolId].token).safeTransfer(msg.sender, amount);
          }
          _poolInfo[poolId].balance -= amount;
          emit RemoveLiquidity(poolId, amount);
      }
  
      /// @notice Enable or disable a dstChain for a pool
      function setDstChain(uint256 poolId, uint16 dstChainId, bool enabled) external onlyPoolManager nonReentrant {
          _checkPool(poolId);
          require(_dstChains[poolId][dstChainId].enabled != enabled, "Pool: dst chain already enabled/disabled");
          _dstChains[poolId][dstChainId].enabled = enabled;
          emit DstChainStatusChanged(poolId, dstChainId, enabled);
      }
  
      /// @notice Set maxLiquidity. See the comments of PoolInfo.maxLiquidity
      function setMaxLiquidity(uint256 poolId, uint256 maxLiquidity) public onlyPoolManager nonReentrant {
          _checkPool(poolId);
          _poolInfo[poolId].maxLiquidity = maxLiquidity;
          emit NewMaxLiquidity(poolId, maxLiquidity);
      }
  
      /// @notice Adding liquidity and setting maxLiquidity in a single tx
      /// If you add liquidity first and then set maxLiquidity, the maxLiquidity may be reached between the two transactions, making the bridge unusable.
      /// If you raise maxLiquidity first and then add liquidity, a large number of users may use it between the two transactions, resulting in insufficient liquidity.
      /// Therefore, this function is provided to ensure atomicity.
      function addLiquidityAndSetMaxLiquidity(uint256 poolId, uint256 amount, uint256 maxLiquidity) external {
          addLiquidity(poolId, amount);
          setMaxLiquidity(poolId, maxLiquidity);
      }
  
      function addLiquidityETHAndSetMaxLiquidity(uint256 maxLiquidity) external payable {
          addLiquidityETH();
          setMaxLiquidity(NATIVE_TOKEN_POOL_ID, maxLiquidity);
      }
  
      function setMaxTransferLimit(uint256 poolId, uint16 dstChainId, uint256 maxTransferLimit)
          external
          onlyPoolManager
          nonReentrant
      {
          _checkDstChain(poolId, dstChainId);
          _dstChains[poolId][dstChainId].maxTransferLimit = maxTransferLimit;
          emit NewMaxTransferLimit(poolId, dstChainId, maxTransferLimit);
      }
  
      function setFee(uint256 poolId, uint16 dstChainId, uint256 staticFee, uint256 dynamicFeeNum)
          external
          onlyPoolManager
          nonReentrant
      {
          _checkDstChain(poolId, dstChainId);
  
          _dstChains[poolId][dstChainId].staticFee = uint128(staticFee);
          _dstChains[poolId][dstChainId].dynamicFeeNum = uint64(dynamicFeeNum);
          emit NewFee(poolId, dstChainId, staticFee, dynamicFeeNum);
      }
  
      function _deposit(uint256 poolId, uint16 dstChainId, uint256 amount) internal returns (uint256) {
          _checkDstChain(poolId, dstChainId);
          _checkConvertRate(poolId, amount);
          require(
              _poolInfo[poolId].balance + amount <= _poolInfo[poolId].maxLiquidity,
              "Pool: Insufficient liquidity on the target chain"
          );
          if (!whitelists[msg.sender]) {
              require(
                  amount <= _dstChains[poolId][dstChainId].maxTransferLimit,
                  "Pool: Exceeding the maximum limit of a single transfer"
              );
          }
  
          _poolInfo[poolId].balance += amount;
          return amount / convertRate(poolId);
      }
  
      function _withdraw(uint256 poolId, uint16 srcChainId, uint256 amountSD) internal returns (uint256) {
          _checkDstChain(poolId, srcChainId);
          uint256 amount = amountSD * convertRate(poolId);
          require(amount <= _poolInfo[poolId].balance, "Pool: Liquidity shortage");
          _poolInfo[poolId].balance -= amount;
          return amount;
      }
  
      function accumulatedFees() public view returns (uint256) {
          return address(this).balance - _poolInfo[NATIVE_TOKEN_POOL_ID].balance;
      }
  
      function claimFees() external onlyPoolManager nonReentrant {
          uint256 fee = accumulatedFees();
          Address.sendValue(payable(msg.sender), fee);
          emit ClaimedFees(msg.sender, fee);
      }
  
      /// @notice Create a new pool
      /// @param poolId is the new pool ID. It should be NATIVE_TOKEN_POOL_ID for native token and other values for ERC20 tokens
      /// poolId needs to be the same across different chains for the same token
      /// @param token ERC20 token address. Should be address(0) for native token pool
      /// @param convertRateDecimals Should be (local decimals - shared decimals). See the comments of PoolInfo.convertRateDecimals
      function createPool(uint256 poolId, address token, uint8 convertRateDecimals)
          external
          onlyBridgeManager
          nonReentrant
      {
          require(!_poolInfo[poolId].enabled, "Pool: pool already created");
          if (poolId == NATIVE_TOKEN_POOL_ID) {
              require(token == address(0), "Pool: native token pool should not have token address");
          } else {
              require(token != address(0), "Pool: token address should not be zero");
          }
          _poolInfo[poolId].enabled = true;
          _poolInfo[poolId].convertRateDecimals = convertRateDecimals;
          _poolInfo[poolId].token = token;
          _poolInfo[poolId].maxLiquidity = type(uint256).max;
      }
  
      function setWhitelist(address user_, bool enabled_) external onlyPoolManager {
          whitelists[user_] = enabled_;
      }
  
      /**
       * @dev This empty reserved space is put in place to allow future versions to add new
       * variables without shifting down storage in the inheritance chain.
       * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
       */
      uint256[47] private __gap;
  }
  
  // src/Bridge.sol
  
  contract Bridge is IZKBridgeReceiver, Initializable, ReentrancyGuardUpgradeable, Pool {
      using SafeERC20 for IERC20;
  
      IZKBridgeEndpoint public immutable zkBridgeEndpoint;
      IL1Bridge public immutable l1Bridge;
  
      // chainId -> bridge address, mapping of token bridge contracts on other chains
      mapping(uint16 => address) public bridgeLookup;
  
      // messageHash -> isVerified, mapping of message isVerified
      mapping(bytes32 => bool) public verifiedMessages;
  
      // For two-step bridge management
      bool public pendingBridge;
      uint16 public pendingDstChainId;
      address public pendingBridgeAddress;
      bool public doubleCheck;
  
      event TransferToken(
          uint64 indexed sequence,
          uint16 indexed dstChainId,
          uint256 indexed poolId,
          address sender,
          address recipient,
          uint256 amount
      );
  
      event ReceiveToken(
          uint64 indexed sequence, uint16 indexed srcChainId, uint256 indexed poolId, address recipient, uint256 amount
      );
  
      event ZkReceive(uint16 indexed srcChainId, address indexed srcAddress, uint64 indexed sequence, bytes payload);
  
      event NewPendingBridge(uint16 chainId, address bridge);
      event NewBridge(uint16 chainId, address bridge);
  
      /// @dev l1Bridge_ could be address(0) when Mux functions are not needed
      constructor(IZKBridgeEndpoint zkBridgeEndpoint_, IL1Bridge l1Bridge_, uint256 NATIVE_TOKEN_POOL_ID_)
          Pool(NATIVE_TOKEN_POOL_ID_)
      {
          require(address(zkBridgeEndpoint_) != address(0), "Bridge: zkBridgeEndpoint is the zero address");
          zkBridgeEndpoint = zkBridgeEndpoint_;
          l1Bridge = l1Bridge_;
      }
  
      function initialize() external initializer {
          __ReentrancyGuard_init();
          __Admin_init();
      }
  
      function estimateFee(uint256 poolId, uint16 dstChainId, uint256 amount) public view returns (uint256) {
          _checkDstChain(poolId, dstChainId);
          uint256 uaFee = getFee(poolId, dstChainId, amount);
          uint256 zkBridgeFee = zkBridgeEndpoint.estimateFee(dstChainId);
          return uaFee + zkBridgeFee;
      }
  
      function _transfer(uint16 dstChainId, uint256 poolId, uint256 amount, address recipient, uint256 fee)
          internal
          returns (uint256)
      {
          address dstBridge = bridgeLookup[dstChainId];
          require(dstBridge != address(0), "Bridge: dstChainId does not exist");
  
          uint256 uaFee = getFee(poolId, dstChainId, amount);
          uint256 zkBridgeFee = zkBridgeEndpoint.estimateFee(dstChainId);
          require(fee >= uaFee + zkBridgeFee, "Bridge: Insufficient Fee");
  
          uint256 amountSD = _deposit(poolId, dstChainId, amount);
  
          bytes memory payload = abi.encode(poolId, amountSD, recipient);
          uint64 sequence = zkBridgeEndpoint.send{value: zkBridgeFee}(dstChainId, dstBridge, payload);
  
          emit TransferToken(sequence, dstChainId, poolId, msg.sender, recipient, amountSD);
  
          // Returns the actual amount of fees used
          return uaFee + zkBridgeFee;
      }
  
      /// @notice The main function for sending native token through bridge
      function transferETH(uint16 dstChainId, uint256 amount, address recipient) external payable nonReentrant {
          require(msg.value >= amount, "Bridge: Insufficient ETH");
          _transfer(dstChainId, NATIVE_TOKEN_POOL_ID, amount, recipient, msg.value - amount);
      }
  
      /// @notice The main function for sending ERC20 tokens through bridge
      function transferToken(uint16 dstChainId, uint256 poolId, uint256 amount, address recipient)
          external
          payable
          nonReentrant
      {
          require(poolId != NATIVE_TOKEN_POOL_ID, "Bridge: Can't transfer token using native token pool ID");
          IERC20(_poolInfo[poolId].token).safeTransferFrom(msg.sender, address(this), amount);
          _transfer(dstChainId, poolId, amount, recipient, msg.value);
      }
  
      /// @notice The main function for receiving verify message. Should only be called by zkBridge
      function zkReceive(uint16 srcChainId, address srcAddress, uint64 sequence, bytes calldata payload)
          external
          nonReentrant
      {
          require(msg.sender == address(zkBridgeEndpoint), "Bridge: Not from zkBridgeEndpoint");
  
          if (doubleCheck) {
              bytes32 hash = _getVerifyMsgHash(srcChainId, srcAddress, sequence, payload);
              verifiedMessages[hash] = true;
              emit ZkReceive(srcChainId, srcAddress, sequence, payload);
          } else {
              _doReceive(srcChainId, srcAddress, sequence, payload);
          }
      }
  
      /// @notice The main function for receiving tokens. Should only be called by approveManager
      function receiveApprove(uint16 srcChainId, address srcAddress, uint64 sequence, bytes calldata payload)
          external
          onlyApproveManager
          nonReentrant
      {
          bytes32 hash = _getVerifyMsgHash(srcChainId, srcAddress, sequence, payload);
          require(verifiedMessages[hash], "Bridge: Message not verified");
          delete verifiedMessages[hash];
          _doReceive(srcChainId, srcAddress, sequence, payload);
      }
  
      function _doReceive(uint16 srcChainId, address srcAddress, uint64 sequence, bytes calldata payload) internal {
          require(srcAddress != address(0) && srcAddress == bridgeLookup[srcChainId], "Bridge: Invalid emitter");
  
          (uint256 poolId, uint256 amountSD, address recipient) = abi.decode(payload, (uint256, uint256, address));
  
          uint256 amount = _withdraw(poolId, srcChainId, amountSD);
  
          if (poolId == NATIVE_TOKEN_POOL_ID) {
              Address.sendValue(payable(recipient), amount);
          } else {
              IERC20(_poolInfo[poolId].token).safeTransfer(recipient, amount);
          }
          emit ReceiveToken(sequence, srcChainId, poolId, recipient, amountSD);
      }
  
      function _getVerifyMsgHash(uint16 srcChainId, address srcAddress, uint64 sequence, bytes calldata payload)
          internal
          pure
          returns (bytes32)
      {
          return keccak256(abi.encodePacked(srcChainId, srcAddress, sequence, payload));
      }
  
      /// @notice Sending native token through bridge, fallback to l1bridge when limits are triggered
      function transferETHMux(uint16 dstChainId, uint256 amount, address recipient) external payable nonReentrant {
          require(address(l1Bridge) != address(0), "Bridge: l1Bridge not available");
          uint256 refundAmount;
          if (
              _poolInfo[NATIVE_TOKEN_POOL_ID].balance + amount <= _poolInfo[NATIVE_TOKEN_POOL_ID].maxLiquidity
                  && amount <= _dstChains[NATIVE_TOKEN_POOL_ID][dstChainId].maxTransferLimit
          ) {
              require(msg.value >= amount, "Bridge: Insufficient ETH");
              uint256 fee = _transfer(dstChainId, NATIVE_TOKEN_POOL_ID, amount, recipient, msg.value - amount);
              refundAmount = msg.value - amount - fee;
          } else {
              uint256 fee = l1Bridge.fees(dstChainId);
              require(msg.value >= amount + fee, "Bridge: Insufficient ETH");
              l1Bridge.transferETH{value: amount + fee}(dstChainId, amount, recipient);
              refundAmount = msg.value - amount - fee;
          }
  
          if (refundAmount > 0) {
              Address.sendValue(payable(msg.sender), refundAmount);
          }
      }
  
      /// @notice Sending ERC20 tokens through bridge, fallback to l1bridge when limits are triggered
      function transferTokenMux(uint16 dstChainId, uint256 poolId, uint256 amount, address recipient)
          external
          payable
          nonReentrant
      {
          require(address(l1Bridge) != address(0), "Bridge: l1Bridge not available");
          require(poolId != NATIVE_TOKEN_POOL_ID, "Bridge: Can't transfer token using native token pool ID");
          address token = _poolInfo[poolId].token;
          require(token != address(0), "Bridge: pool not found");
          IERC20(token).safeTransferFrom(msg.sender, address(this), amount);
          uint256 refundAmount;
          if (
              _poolInfo[poolId].balance + amount <= _poolInfo[poolId].maxLiquidity
                  && amount <= _dstChains[poolId][dstChainId].maxTransferLimit
          ) {
              uint256 fee = _transfer(dstChainId, poolId, amount, recipient, msg.value);
              refundAmount = msg.value - fee;
          } else {
              uint256 fee = l1Bridge.fees(dstChainId);
              require(msg.value >= fee, "Bridge: Insufficient fee");
              IERC20(token).safeApprove(address(l1Bridge), amount);
              l1Bridge.transferERC20{value: fee}(dstChainId, token, amount, recipient);
              IERC20(token).safeApprove(address(l1Bridge), 0);
              refundAmount = msg.value - fee;
          }
  
          if (refundAmount > 0) {
              Address.sendValue(payable(msg.sender), refundAmount);
          }
      }
  
      function estimateFeeMux(uint256 poolId, uint16 dstChainId, uint256 amount) external view returns (uint256) {
          require(address(l1Bridge) != address(0), "Bridge: l1Bridge not available");
          uint256 fee = estimateFee(poolId, dstChainId, amount);
          uint256 l1Fee = l1Bridge.fees(dstChainId);
          return fee > l1Fee ? fee : l1Fee;
      }
  
      /// @notice adding a new dstChain bridge address
      /// @param bridge could be address(0) when deleting a bridge
      function setBridge(uint16 dstChainId, address bridge) external onlyBridgeManager nonReentrant {
          if (bridgeManager != bridgeReviewer) {
              // Two-step bridge management needed
              pendingDstChainId = dstChainId;
              pendingBridgeAddress = bridge;
              pendingBridge = true;
              emit NewPendingBridge(dstChainId, bridge);
          } else {
              // bridgeManager is the same as bridgeReviewer, two-step bridge management not needed
              bridgeLookup[dstChainId] = bridge;
              if (pendingBridge) {
                  pendingBridge = false;
              }
              emit NewBridge(dstChainId, bridge);
          }
      }
  
      /// @notice approve a new dstChain bridge address
      /// @dev The dstChainId and bridge params are required to prevent front-running attacks
      function approveSetBridge(uint16 dstChainId, address bridge) external onlyBridgeReviewer nonReentrant {
          require(pendingBridge, "Bridge: no pending bridge");
          require(
              dstChainId == pendingDstChainId && bridge == pendingBridgeAddress,
              "Bridge: dstChainId or bridge does not match"
          );
          bridgeLookup[dstChainId] = bridge;
          pendingBridge = false;
          emit NewBridge(dstChainId, bridge);
      }
  
      function setDoubleCheck(bool needDoubleCheck) external onlyApproveManager nonReentrant {
          require(doubleCheck != needDoubleCheck, "Bridge: dstChainId or bridge does not match");
          doubleCheck = needDoubleCheck;
      }
  }