ETH Price: $2,535.01 (+0.11%)

Transaction Decoder

Block:
21538481 at Jan-02-2025 06:08:23 PM +UTC
Transaction Fee:
0.001582311699112774 ETH $4.01
Gas Used:
97,199 Gas / 16.279094426 Gwei

Emitted Events:

57 TetherToken.Transfer( from=[Receiver] TransparentUpgradeableProxy, to=0x953BB3438fe759dc3e33105847e06114Da51A879, value=700000000 )
58 TransparentUpgradeableProxy.0x302b3ebcd58d43753be6657117391b4a3b8dc310ae7054a9905486dd23241676( 0x302b3ebcd58d43753be6657117391b4a3b8dc310ae7054a9905486dd23241676, 0x00000000000000000000000000000000000000000000000000000000000001b2, 0x0000000000000000000000000000000000000000000000000000000000000024, 0x0000000000000000000000000000000000000000000000000000000000000001, 000000000000000000000000953bb3438fe759dc3e33105847e06114da51a879, 0000000000000000000000000000000000000000000000000000000029b92700 )

Account State Difference:

  Address   Before After State Difference Code
(Titan Builder)
13.468340424815491143 Eth13.468749846993340284 Eth0.000409422177849141
0x48d00540...c6012B831
2.362234069132331136 Eth
Nonce: 434
2.360651757433218362 Eth
Nonce: 435
0.001582311699112774
0xA4252F2A...2A37864AF
0xdAC17F95...13D831ec7

Execution Trace

TransparentUpgradeableProxy.08cb663a( )
  • Bridge.receiveApprove( srcChainId=36, srcAddress=0x36cAE7b6b0B68c4dDb2BBD3CDeE34fd56f948aAe, sequence=434, payload=0x00000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000029B92700000000000000000000000000953BB3438FE759DC3E33105847E06114DA51A879 )
    • TetherToken.transfer( _to=0x953BB3438fe759dc3e33105847e06114Da51A879, _value=700000000 )
      File 1 of 3: TransparentUpgradeableProxy
      // SPDX-License-Identifier: MIT
      // OpenZeppelin Contracts (last updated v4.9.0) (proxy/transparent/TransparentUpgradeableProxy.sol)
      pragma solidity ^0.8.0;
      import "../ERC1967/ERC1967Proxy.sol";
      /**
       * @dev Interface for {TransparentUpgradeableProxy}. In order to implement transparency, {TransparentUpgradeableProxy}
       * does not implement this interface directly, and some of its functions are implemented by an internal dispatch
       * mechanism. The compiler is unaware that these functions are implemented by {TransparentUpgradeableProxy} and will not
       * include them in the ABI so this interface must be used to interact with it.
       */
      interface ITransparentUpgradeableProxy is IERC1967 {
          function admin() external view returns (address);
          function implementation() external view returns (address);
          function changeAdmin(address) external;
          function upgradeTo(address) external;
          function upgradeToAndCall(address, bytes memory) external payable;
      }
      /**
       * @dev This contract implements a proxy that is upgradeable by an admin.
       *
       * To avoid https://medium.com/nomic-labs-blog/malicious-backdoors-in-ethereum-proxies-62629adf3357[proxy selector
       * clashing], which can potentially be used in an attack, this contract uses the
       * https://blog.openzeppelin.com/the-transparent-proxy-pattern/[transparent proxy pattern]. This pattern implies two
       * things that go hand in hand:
       *
       * 1. If any account other than the admin calls the proxy, the call will be forwarded to the implementation, even if
       * that call matches one of the admin functions exposed by the proxy itself.
       * 2. If the admin calls the proxy, it can access the admin functions, but its calls will never be forwarded to the
       * implementation. If the admin tries to call a function on the implementation it will fail with an error that says
       * "admin cannot fallback to proxy target".
       *
       * These properties mean that the admin account can only be used for admin actions like upgrading the proxy or changing
       * the admin, so it's best if it's a dedicated account that is not used for anything else. This will avoid headaches due
       * to sudden errors when trying to call a function from the proxy implementation.
       *
       * Our recommendation is for the dedicated account to be an instance of the {ProxyAdmin} contract. If set up this way,
       * you should think of the `ProxyAdmin` instance as the real administrative interface of your proxy.
       *
       * NOTE: The real interface of this proxy is that defined in `ITransparentUpgradeableProxy`. This contract does not
       * inherit from that interface, and instead the admin functions are implicitly implemented using a custom dispatch
       * mechanism in `_fallback`. Consequently, the compiler will not produce an ABI for this contract. This is necessary to
       * fully implement transparency without decoding reverts caused by selector clashes between the proxy and the
       * implementation.
       *
       * WARNING: It is not recommended to extend this contract to add additional external functions. If you do so, the compiler
       * will not check that there are no selector conflicts, due to the note above. A selector clash between any new function
       * and the functions declared in {ITransparentUpgradeableProxy} will be resolved in favor of the new one. This could
       * render the admin operations inaccessible, which could prevent upgradeability. Transparency may also be compromised.
       */
      contract TransparentUpgradeableProxy is ERC1967Proxy {
          /**
           * @dev Initializes an upgradeable proxy managed by `_admin`, backed by the implementation at `_logic`, and
           * optionally initialized with `_data` as explained in {ERC1967Proxy-constructor}.
           */
          constructor(address _logic, address admin_, bytes memory _data) payable ERC1967Proxy(_logic, _data) {
              _changeAdmin(admin_);
          }
          /**
           * @dev Modifier used internally that will delegate the call to the implementation unless the sender is the admin.
           *
           * CAUTION: This modifier is deprecated, as it could cause issues if the modified function has arguments, and the
           * implementation provides a function with the same selector.
           */
          modifier ifAdmin() {
              if (msg.sender == _getAdmin()) {
                  _;
              } else {
                  _fallback();
              }
          }
          /**
           * @dev If caller is the admin process the call internally, otherwise transparently fallback to the proxy behavior
           */
          function _fallback() internal virtual override {
              if (msg.sender == _getAdmin()) {
                  bytes memory ret;
                  bytes4 selector = msg.sig;
                  if (selector == ITransparentUpgradeableProxy.upgradeTo.selector) {
                      ret = _dispatchUpgradeTo();
                  } else if (selector == ITransparentUpgradeableProxy.upgradeToAndCall.selector) {
                      ret = _dispatchUpgradeToAndCall();
                  } else if (selector == ITransparentUpgradeableProxy.changeAdmin.selector) {
                      ret = _dispatchChangeAdmin();
                  } else if (selector == ITransparentUpgradeableProxy.admin.selector) {
                      ret = _dispatchAdmin();
                  } else if (selector == ITransparentUpgradeableProxy.implementation.selector) {
                      ret = _dispatchImplementation();
                  } else {
                      revert("TransparentUpgradeableProxy: admin cannot fallback to proxy target");
                  }
                  assembly {
                      return(add(ret, 0x20), mload(ret))
                  }
              } else {
                  super._fallback();
              }
          }
          /**
           * @dev Returns the current admin.
           *
           * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
           * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
           * `0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103`
           */
          function _dispatchAdmin() private returns (bytes memory) {
              _requireZeroValue();
              address admin = _getAdmin();
              return abi.encode(admin);
          }
          /**
           * @dev Returns the current implementation.
           *
           * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
           * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
           * `0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc`
           */
          function _dispatchImplementation() private returns (bytes memory) {
              _requireZeroValue();
              address implementation = _implementation();
              return abi.encode(implementation);
          }
          /**
           * @dev Changes the admin of the proxy.
           *
           * Emits an {AdminChanged} event.
           */
          function _dispatchChangeAdmin() private returns (bytes memory) {
              _requireZeroValue();
              address newAdmin = abi.decode(msg.data[4:], (address));
              _changeAdmin(newAdmin);
              return "";
          }
          /**
           * @dev Upgrade the implementation of the proxy.
           */
          function _dispatchUpgradeTo() private returns (bytes memory) {
              _requireZeroValue();
              address newImplementation = abi.decode(msg.data[4:], (address));
              _upgradeToAndCall(newImplementation, bytes(""), false);
              return "";
          }
          /**
           * @dev Upgrade the implementation of the proxy, and then call a function from the new implementation as specified
           * by `data`, which should be an encoded function call. This is useful to initialize new storage variables in the
           * proxied contract.
           */
          function _dispatchUpgradeToAndCall() private returns (bytes memory) {
              (address newImplementation, bytes memory data) = abi.decode(msg.data[4:], (address, bytes));
              _upgradeToAndCall(newImplementation, data, true);
              return "";
          }
          /**
           * @dev Returns the current admin.
           *
           * CAUTION: This function is deprecated. Use {ERC1967Upgrade-_getAdmin} instead.
           */
          function _admin() internal view virtual returns (address) {
              return _getAdmin();
          }
          /**
           * @dev To keep this contract fully transparent, all `ifAdmin` functions must be payable. This helper is here to
           * emulate some proxy functions being non-payable while still allowing value to pass through.
           */
          function _requireZeroValue() private {
              require(msg.value == 0);
          }
      }
      // SPDX-License-Identifier: MIT
      // OpenZeppelin Contracts (last updated v4.7.0) (proxy/ERC1967/ERC1967Proxy.sol)
      pragma solidity ^0.8.0;
      import "../Proxy.sol";
      import "./ERC1967Upgrade.sol";
      /**
       * @dev This contract implements an upgradeable proxy. It is upgradeable because calls are delegated to an
       * implementation address that can be changed. This address is stored in storage in the location specified by
       * https://eips.ethereum.org/EIPS/eip-1967[EIP1967], so that it doesn't conflict with the storage layout of the
       * implementation behind the proxy.
       */
      contract ERC1967Proxy is Proxy, ERC1967Upgrade {
          /**
           * @dev Initializes the upgradeable proxy with an initial implementation specified by `_logic`.
           *
           * If `_data` is nonempty, it's used as data in a delegate call to `_logic`. This will typically be an encoded
           * function call, and allows initializing the storage of the proxy like a Solidity constructor.
           */
          constructor(address _logic, bytes memory _data) payable {
              _upgradeToAndCall(_logic, _data, false);
          }
          /**
           * @dev Returns the current implementation address.
           */
          function _implementation() internal view virtual override returns (address impl) {
              return ERC1967Upgrade._getImplementation();
          }
      }
      // SPDX-License-Identifier: MIT
      // OpenZeppelin Contracts (last updated v4.6.0) (proxy/Proxy.sol)
      pragma solidity ^0.8.0;
      /**
       * @dev This abstract contract provides a fallback function that delegates all calls to another contract using the EVM
       * instruction `delegatecall`. We refer to the second contract as the _implementation_ behind the proxy, and it has to
       * be specified by overriding the virtual {_implementation} function.
       *
       * Additionally, delegation to the implementation can be triggered manually through the {_fallback} function, or to a
       * different contract through the {_delegate} function.
       *
       * The success and return data of the delegated call will be returned back to the caller of the proxy.
       */
      abstract contract Proxy {
          /**
           * @dev Delegates the current call to `implementation`.
           *
           * This function does not return to its internal call site, it will return directly to the external caller.
           */
          function _delegate(address implementation) internal virtual {
              assembly {
                  // Copy msg.data. We take full control of memory in this inline assembly
                  // block because it will not return to Solidity code. We overwrite the
                  // Solidity scratch pad at memory position 0.
                  calldatacopy(0, 0, calldatasize())
                  // Call the implementation.
                  // out and outsize are 0 because we don't know the size yet.
                  let result := delegatecall(gas(), implementation, 0, calldatasize(), 0, 0)
                  // Copy the returned data.
                  returndatacopy(0, 0, returndatasize())
                  switch result
                  // delegatecall returns 0 on error.
                  case 0 {
                      revert(0, returndatasize())
                  }
                  default {
                      return(0, returndatasize())
                  }
              }
          }
          /**
           * @dev This is a virtual function that should be overridden so it returns the address to which the fallback function
           * and {_fallback} should delegate.
           */
          function _implementation() internal view virtual returns (address);
          /**
           * @dev Delegates the current call to the address returned by `_implementation()`.
           *
           * This function does not return to its internal call site, it will return directly to the external caller.
           */
          function _fallback() internal virtual {
              _beforeFallback();
              _delegate(_implementation());
          }
          /**
           * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if no other
           * function in the contract matches the call data.
           */
          fallback() external payable virtual {
              _fallback();
          }
          /**
           * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if call data
           * is empty.
           */
          receive() external payable virtual {
              _fallback();
          }
          /**
           * @dev Hook that is called before falling back to the implementation. Can happen as part of a manual `_fallback`
           * call, or as part of the Solidity `fallback` or `receive` functions.
           *
           * If overridden should call `super._beforeFallback()`.
           */
          function _beforeFallback() internal virtual {}
      }
      // SPDX-License-Identifier: MIT
      // OpenZeppelin Contracts (last updated v4.9.0) (proxy/ERC1967/ERC1967Upgrade.sol)
      pragma solidity ^0.8.2;
      import "../beacon/IBeacon.sol";
      import "../../interfaces/IERC1967.sol";
      import "../../interfaces/draft-IERC1822.sol";
      import "../../utils/Address.sol";
      import "../../utils/StorageSlot.sol";
      /**
       * @dev This abstract contract provides getters and event emitting update functions for
       * https://eips.ethereum.org/EIPS/eip-1967[EIP1967] slots.
       *
       * _Available since v4.1._
       */
      abstract contract ERC1967Upgrade is IERC1967 {
          // This is the keccak-256 hash of "eip1967.proxy.rollback" subtracted by 1
          bytes32 private constant _ROLLBACK_SLOT = 0x4910fdfa16fed3260ed0e7147f7cc6da11a60208b5b9406d12a635614ffd9143;
          /**
           * @dev Storage slot with the address of the current implementation.
           * This is the keccak-256 hash of "eip1967.proxy.implementation" subtracted by 1, and is
           * validated in the constructor.
           */
          bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
          /**
           * @dev Returns the current implementation address.
           */
          function _getImplementation() internal view returns (address) {
              return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
          }
          /**
           * @dev Stores a new address in the EIP1967 implementation slot.
           */
          function _setImplementation(address newImplementation) private {
              require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
              StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
          }
          /**
           * @dev Perform implementation upgrade
           *
           * Emits an {Upgraded} event.
           */
          function _upgradeTo(address newImplementation) internal {
              _setImplementation(newImplementation);
              emit Upgraded(newImplementation);
          }
          /**
           * @dev Perform implementation upgrade with additional setup call.
           *
           * Emits an {Upgraded} event.
           */
          function _upgradeToAndCall(address newImplementation, bytes memory data, bool forceCall) internal {
              _upgradeTo(newImplementation);
              if (data.length > 0 || forceCall) {
                  Address.functionDelegateCall(newImplementation, data);
              }
          }
          /**
           * @dev Perform implementation upgrade with security checks for UUPS proxies, and additional setup call.
           *
           * Emits an {Upgraded} event.
           */
          function _upgradeToAndCallUUPS(address newImplementation, bytes memory data, bool forceCall) internal {
              // Upgrades from old implementations will perform a rollback test. This test requires the new
              // implementation to upgrade back to the old, non-ERC1822 compliant, implementation. Removing
              // this special case will break upgrade paths from old UUPS implementation to new ones.
              if (StorageSlot.getBooleanSlot(_ROLLBACK_SLOT).value) {
                  _setImplementation(newImplementation);
              } else {
                  try IERC1822Proxiable(newImplementation).proxiableUUID() returns (bytes32 slot) {
                      require(slot == _IMPLEMENTATION_SLOT, "ERC1967Upgrade: unsupported proxiableUUID");
                  } catch {
                      revert("ERC1967Upgrade: new implementation is not UUPS");
                  }
                  _upgradeToAndCall(newImplementation, data, forceCall);
              }
          }
          /**
           * @dev Storage slot with the admin of the contract.
           * This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is
           * validated in the constructor.
           */
          bytes32 internal constant _ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;
          /**
           * @dev Returns the current admin.
           */
          function _getAdmin() internal view returns (address) {
              return StorageSlot.getAddressSlot(_ADMIN_SLOT).value;
          }
          /**
           * @dev Stores a new address in the EIP1967 admin slot.
           */
          function _setAdmin(address newAdmin) private {
              require(newAdmin != address(0), "ERC1967: new admin is the zero address");
              StorageSlot.getAddressSlot(_ADMIN_SLOT).value = newAdmin;
          }
          /**
           * @dev Changes the admin of the proxy.
           *
           * Emits an {AdminChanged} event.
           */
          function _changeAdmin(address newAdmin) internal {
              emit AdminChanged(_getAdmin(), newAdmin);
              _setAdmin(newAdmin);
          }
          /**
           * @dev The storage slot of the UpgradeableBeacon contract which defines the implementation for this proxy.
           * This is bytes32(uint256(keccak256('eip1967.proxy.beacon')) - 1)) and is validated in the constructor.
           */
          bytes32 internal constant _BEACON_SLOT = 0xa3f0ad74e5423aebfd80d3ef4346578335a9a72aeaee59ff6cb3582b35133d50;
          /**
           * @dev Returns the current beacon.
           */
          function _getBeacon() internal view returns (address) {
              return StorageSlot.getAddressSlot(_BEACON_SLOT).value;
          }
          /**
           * @dev Stores a new beacon in the EIP1967 beacon slot.
           */
          function _setBeacon(address newBeacon) private {
              require(Address.isContract(newBeacon), "ERC1967: new beacon is not a contract");
              require(
                  Address.isContract(IBeacon(newBeacon).implementation()),
                  "ERC1967: beacon implementation is not a contract"
              );
              StorageSlot.getAddressSlot(_BEACON_SLOT).value = newBeacon;
          }
          /**
           * @dev Perform beacon upgrade with additional setup call. Note: This upgrades the address of the beacon, it does
           * not upgrade the implementation contained in the beacon (see {UpgradeableBeacon-_setImplementation} for that).
           *
           * Emits a {BeaconUpgraded} event.
           */
          function _upgradeBeaconToAndCall(address newBeacon, bytes memory data, bool forceCall) internal {
              _setBeacon(newBeacon);
              emit BeaconUpgraded(newBeacon);
              if (data.length > 0 || forceCall) {
                  Address.functionDelegateCall(IBeacon(newBeacon).implementation(), data);
              }
          }
      }
      // SPDX-License-Identifier: MIT
      // OpenZeppelin Contracts v4.4.1 (proxy/beacon/IBeacon.sol)
      pragma solidity ^0.8.0;
      /**
       * @dev This is the interface that {BeaconProxy} expects of its beacon.
       */
      interface IBeacon {
          /**
           * @dev Must return an address that can be used as a delegate call target.
           *
           * {BeaconProxy} will check that this address is a contract.
           */
          function implementation() external view returns (address);
      }
      // SPDX-License-Identifier: MIT
      // OpenZeppelin Contracts (last updated v4.9.0) (interfaces/IERC1967.sol)
      pragma solidity ^0.8.0;
      /**
       * @dev ERC-1967: Proxy Storage Slots. This interface contains the events defined in the ERC.
       *
       * _Available since v4.8.3._
       */
      interface IERC1967 {
          /**
           * @dev Emitted when the implementation is upgraded.
           */
          event Upgraded(address indexed implementation);
          /**
           * @dev Emitted when the admin account has changed.
           */
          event AdminChanged(address previousAdmin, address newAdmin);
          /**
           * @dev Emitted when the beacon is changed.
           */
          event BeaconUpgraded(address indexed beacon);
      }
      // SPDX-License-Identifier: MIT
      // OpenZeppelin Contracts (last updated v4.5.0) (interfaces/draft-IERC1822.sol)
      pragma solidity ^0.8.0;
      /**
       * @dev ERC1822: Universal Upgradeable Proxy Standard (UUPS) documents a method for upgradeability through a simplified
       * proxy whose upgrades are fully controlled by the current implementation.
       */
      interface IERC1822Proxiable {
          /**
           * @dev Returns the storage slot that the proxiable contract assumes is being used to store the implementation
           * address.
           *
           * IMPORTANT: A proxy pointing at a proxiable contract should not be considered proxiable itself, because this risks
           * bricking a proxy that upgrades to it, by delegating to itself until out of gas. Thus it is critical that this
           * function revert if invoked through a proxy.
           */
          function proxiableUUID() external view returns (bytes32);
      }
      // SPDX-License-Identifier: MIT
      // OpenZeppelin Contracts (last updated v4.9.0) (utils/Address.sol)
      pragma solidity ^0.8.1;
      /**
       * @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);
              }
          }
      }
      // SPDX-License-Identifier: MIT
      // OpenZeppelin Contracts (last updated v4.9.0) (utils/StorageSlot.sol)
      // This file was procedurally generated from scripts/generate/templates/StorageSlot.js.
      pragma solidity ^0.8.0;
      /**
       * @dev Library for reading and writing primitive types to specific storage slots.
       *
       * Storage slots are often used to avoid storage conflict when dealing with upgradeable contracts.
       * This library helps with reading and writing to such slots without the need for inline assembly.
       *
       * The functions in this library return Slot structs that contain a `value` member that can be used to read or write.
       *
       * Example usage to set ERC1967 implementation slot:
       * ```solidity
       * contract ERC1967 {
       *     bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
       *
       *     function _getImplementation() internal view returns (address) {
       *         return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
       *     }
       *
       *     function _setImplementation(address newImplementation) internal {
       *         require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
       *         StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
       *     }
       * }
       * ```
       *
       * _Available since v4.1 for `address`, `bool`, `bytes32`, `uint256`._
       * _Available since v4.9 for `string`, `bytes`._
       */
      library StorageSlot {
          struct AddressSlot {
              address value;
          }
          struct BooleanSlot {
              bool value;
          }
          struct Bytes32Slot {
              bytes32 value;
          }
          struct Uint256Slot {
              uint256 value;
          }
          struct StringSlot {
              string value;
          }
          struct BytesSlot {
              bytes value;
          }
          /**
           * @dev Returns an `AddressSlot` with member `value` located at `slot`.
           */
          function getAddressSlot(bytes32 slot) internal pure returns (AddressSlot storage r) {
              /// @solidity memory-safe-assembly
              assembly {
                  r.slot := slot
              }
          }
          /**
           * @dev Returns an `BooleanSlot` with member `value` located at `slot`.
           */
          function getBooleanSlot(bytes32 slot) internal pure returns (BooleanSlot storage r) {
              /// @solidity memory-safe-assembly
              assembly {
                  r.slot := slot
              }
          }
          /**
           * @dev Returns an `Bytes32Slot` with member `value` located at `slot`.
           */
          function getBytes32Slot(bytes32 slot) internal pure returns (Bytes32Slot storage r) {
              /// @solidity memory-safe-assembly
              assembly {
                  r.slot := slot
              }
          }
          /**
           * @dev Returns an `Uint256Slot` with member `value` located at `slot`.
           */
          function getUint256Slot(bytes32 slot) internal pure returns (Uint256Slot storage r) {
              /// @solidity memory-safe-assembly
              assembly {
                  r.slot := slot
              }
          }
          /**
           * @dev Returns an `StringSlot` with member `value` located at `slot`.
           */
          function getStringSlot(bytes32 slot) internal pure returns (StringSlot storage r) {
              /// @solidity memory-safe-assembly
              assembly {
                  r.slot := slot
              }
          }
          /**
           * @dev Returns an `StringSlot` representation of the string storage pointer `store`.
           */
          function getStringSlot(string storage store) internal pure returns (StringSlot storage r) {
              /// @solidity memory-safe-assembly
              assembly {
                  r.slot := store.slot
              }
          }
          /**
           * @dev Returns an `BytesSlot` with member `value` located at `slot`.
           */
          function getBytesSlot(bytes32 slot) internal pure returns (BytesSlot storage r) {
              /// @solidity memory-safe-assembly
              assembly {
                  r.slot := slot
              }
          }
          /**
           * @dev Returns an `BytesSlot` representation of the bytes storage pointer `store`.
           */
          function getBytesSlot(bytes storage store) internal pure returns (BytesSlot storage r) {
              /// @solidity memory-safe-assembly
              assembly {
                  r.slot := store.slot
              }
          }
      }
      

      File 2 of 3: TetherToken
      pragma solidity ^0.4.17;
      
      /**
       * @title SafeMath
       * @dev Math operations with safety checks that throw on error
       */
      library SafeMath {
          function mul(uint256 a, uint256 b) internal pure returns (uint256) {
              if (a == 0) {
                  return 0;
              }
              uint256 c = a * b;
              assert(c / a == b);
              return c;
          }
      
          function div(uint256 a, uint256 b) internal pure returns (uint256) {
              // assert(b > 0); // Solidity automatically throws when dividing by 0
              uint256 c = a / b;
              // assert(a == b * c + a % b); // There is no case in which this doesn't hold
              return c;
          }
      
          function sub(uint256 a, uint256 b) internal pure returns (uint256) {
              assert(b <= a);
              return a - b;
          }
      
          function add(uint256 a, uint256 b) internal pure returns (uint256) {
              uint256 c = a + b;
              assert(c >= a);
              return c;
          }
      }
      
      /**
       * @title Ownable
       * @dev The Ownable contract has an owner address, and provides basic authorization control
       * functions, this simplifies the implementation of "user permissions".
       */
      contract Ownable {
          address public owner;
      
          /**
            * @dev The Ownable constructor sets the original `owner` of the contract to the sender
            * account.
            */
          function Ownable() public {
              owner = msg.sender;
          }
      
          /**
            * @dev Throws if called by any account other than the owner.
            */
          modifier onlyOwner() {
              require(msg.sender == owner);
              _;
          }
      
          /**
          * @dev Allows the current owner to transfer control of the contract to a newOwner.
          * @param newOwner The address to transfer ownership to.
          */
          function transferOwnership(address newOwner) public onlyOwner {
              if (newOwner != address(0)) {
                  owner = newOwner;
              }
          }
      
      }
      
      /**
       * @title ERC20Basic
       * @dev Simpler version of ERC20 interface
       * @dev see https://github.com/ethereum/EIPs/issues/20
       */
      contract ERC20Basic {
          uint public _totalSupply;
          function totalSupply() public constant returns (uint);
          function balanceOf(address who) public constant returns (uint);
          function transfer(address to, uint value) public;
          event Transfer(address indexed from, address indexed to, uint value);
      }
      
      /**
       * @title ERC20 interface
       * @dev see https://github.com/ethereum/EIPs/issues/20
       */
      contract ERC20 is ERC20Basic {
          function allowance(address owner, address spender) public constant returns (uint);
          function transferFrom(address from, address to, uint value) public;
          function approve(address spender, uint value) public;
          event Approval(address indexed owner, address indexed spender, uint value);
      }
      
      /**
       * @title Basic token
       * @dev Basic version of StandardToken, with no allowances.
       */
      contract BasicToken is Ownable, ERC20Basic {
          using SafeMath for uint;
      
          mapping(address => uint) public balances;
      
          // additional variables for use if transaction fees ever became necessary
          uint public basisPointsRate = 0;
          uint public maximumFee = 0;
      
          /**
          * @dev Fix for the ERC20 short address attack.
          */
          modifier onlyPayloadSize(uint size) {
              require(!(msg.data.length < size + 4));
              _;
          }
      
          /**
          * @dev transfer token for a specified address
          * @param _to The address to transfer to.
          * @param _value The amount to be transferred.
          */
          function transfer(address _to, uint _value) public onlyPayloadSize(2 * 32) {
              uint fee = (_value.mul(basisPointsRate)).div(10000);
              if (fee > maximumFee) {
                  fee = maximumFee;
              }
              uint sendAmount = _value.sub(fee);
              balances[msg.sender] = balances[msg.sender].sub(_value);
              balances[_to] = balances[_to].add(sendAmount);
              if (fee > 0) {
                  balances[owner] = balances[owner].add(fee);
                  Transfer(msg.sender, owner, fee);
              }
              Transfer(msg.sender, _to, sendAmount);
          }
      
          /**
          * @dev Gets the balance of the specified address.
          * @param _owner The address to query the the balance of.
          * @return An uint representing the amount owned by the passed address.
          */
          function balanceOf(address _owner) public constant returns (uint balance) {
              return balances[_owner];
          }
      
      }
      
      /**
       * @title Standard ERC20 token
       *
       * @dev Implementation of the basic standard token.
       * @dev https://github.com/ethereum/EIPs/issues/20
       * @dev Based oncode by FirstBlood: https://github.com/Firstbloodio/token/blob/master/smart_contract/FirstBloodToken.sol
       */
      contract StandardToken is BasicToken, ERC20 {
      
          mapping (address => mapping (address => uint)) public allowed;
      
          uint public constant MAX_UINT = 2**256 - 1;
      
          /**
          * @dev Transfer tokens from one address to another
          * @param _from address The address which you want to send tokens from
          * @param _to address The address which you want to transfer to
          * @param _value uint the amount of tokens to be transferred
          */
          function transferFrom(address _from, address _to, uint _value) public onlyPayloadSize(3 * 32) {
              var _allowance = allowed[_from][msg.sender];
      
              // Check is not needed because sub(_allowance, _value) will already throw if this condition is not met
              // if (_value > _allowance) throw;
      
              uint fee = (_value.mul(basisPointsRate)).div(10000);
              if (fee > maximumFee) {
                  fee = maximumFee;
              }
              if (_allowance < MAX_UINT) {
                  allowed[_from][msg.sender] = _allowance.sub(_value);
              }
              uint sendAmount = _value.sub(fee);
              balances[_from] = balances[_from].sub(_value);
              balances[_to] = balances[_to].add(sendAmount);
              if (fee > 0) {
                  balances[owner] = balances[owner].add(fee);
                  Transfer(_from, owner, fee);
              }
              Transfer(_from, _to, sendAmount);
          }
      
          /**
          * @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
          * @param _spender The address which will spend the funds.
          * @param _value The amount of tokens to be spent.
          */
          function approve(address _spender, uint _value) public onlyPayloadSize(2 * 32) {
      
              // To change the approve amount you first have to reduce the addresses`
              //  allowance to zero by calling `approve(_spender, 0)` if it is not
              //  already 0 to mitigate the race condition described here:
              //  https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
              require(!((_value != 0) && (allowed[msg.sender][_spender] != 0)));
      
              allowed[msg.sender][_spender] = _value;
              Approval(msg.sender, _spender, _value);
          }
      
          /**
          * @dev Function to check the amount of tokens than an owner allowed to a spender.
          * @param _owner address The address which owns the funds.
          * @param _spender address The address which will spend the funds.
          * @return A uint specifying the amount of tokens still available for the spender.
          */
          function allowance(address _owner, address _spender) public constant returns (uint remaining) {
              return allowed[_owner][_spender];
          }
      
      }
      
      
      /**
       * @title Pausable
       * @dev Base contract which allows children to implement an emergency stop mechanism.
       */
      contract Pausable is Ownable {
        event Pause();
        event Unpause();
      
        bool public paused = false;
      
      
        /**
         * @dev Modifier to make a function callable only when the contract is not paused.
         */
        modifier whenNotPaused() {
          require(!paused);
          _;
        }
      
        /**
         * @dev Modifier to make a function callable only when the contract is paused.
         */
        modifier whenPaused() {
          require(paused);
          _;
        }
      
        /**
         * @dev called by the owner to pause, triggers stopped state
         */
        function pause() onlyOwner whenNotPaused public {
          paused = true;
          Pause();
        }
      
        /**
         * @dev called by the owner to unpause, returns to normal state
         */
        function unpause() onlyOwner whenPaused public {
          paused = false;
          Unpause();
        }
      }
      
      contract BlackList is Ownable, BasicToken {
      
          /////// Getters to allow the same blacklist to be used also by other contracts (including upgraded Tether) ///////
          function getBlackListStatus(address _maker) external constant returns (bool) {
              return isBlackListed[_maker];
          }
      
          function getOwner() external constant returns (address) {
              return owner;
          }
      
          mapping (address => bool) public isBlackListed;
          
          function addBlackList (address _evilUser) public onlyOwner {
              isBlackListed[_evilUser] = true;
              AddedBlackList(_evilUser);
          }
      
          function removeBlackList (address _clearedUser) public onlyOwner {
              isBlackListed[_clearedUser] = false;
              RemovedBlackList(_clearedUser);
          }
      
          function destroyBlackFunds (address _blackListedUser) public onlyOwner {
              require(isBlackListed[_blackListedUser]);
              uint dirtyFunds = balanceOf(_blackListedUser);
              balances[_blackListedUser] = 0;
              _totalSupply -= dirtyFunds;
              DestroyedBlackFunds(_blackListedUser, dirtyFunds);
          }
      
          event DestroyedBlackFunds(address _blackListedUser, uint _balance);
      
          event AddedBlackList(address _user);
      
          event RemovedBlackList(address _user);
      
      }
      
      contract UpgradedStandardToken is StandardToken{
          // those methods are called by the legacy contract
          // and they must ensure msg.sender to be the contract address
          function transferByLegacy(address from, address to, uint value) public;
          function transferFromByLegacy(address sender, address from, address spender, uint value) public;
          function approveByLegacy(address from, address spender, uint value) public;
      }
      
      contract TetherToken is Pausable, StandardToken, BlackList {
      
          string public name;
          string public symbol;
          uint public decimals;
          address public upgradedAddress;
          bool public deprecated;
      
          //  The contract can be initialized with a number of tokens
          //  All the tokens are deposited to the owner address
          //
          // @param _balance Initial supply of the contract
          // @param _name Token Name
          // @param _symbol Token symbol
          // @param _decimals Token decimals
          function TetherToken(uint _initialSupply, string _name, string _symbol, uint _decimals) public {
              _totalSupply = _initialSupply;
              name = _name;
              symbol = _symbol;
              decimals = _decimals;
              balances[owner] = _initialSupply;
              deprecated = false;
          }
      
          // Forward ERC20 methods to upgraded contract if this one is deprecated
          function transfer(address _to, uint _value) public whenNotPaused {
              require(!isBlackListed[msg.sender]);
              if (deprecated) {
                  return UpgradedStandardToken(upgradedAddress).transferByLegacy(msg.sender, _to, _value);
              } else {
                  return super.transfer(_to, _value);
              }
          }
      
          // Forward ERC20 methods to upgraded contract if this one is deprecated
          function transferFrom(address _from, address _to, uint _value) public whenNotPaused {
              require(!isBlackListed[_from]);
              if (deprecated) {
                  return UpgradedStandardToken(upgradedAddress).transferFromByLegacy(msg.sender, _from, _to, _value);
              } else {
                  return super.transferFrom(_from, _to, _value);
              }
          }
      
          // Forward ERC20 methods to upgraded contract if this one is deprecated
          function balanceOf(address who) public constant returns (uint) {
              if (deprecated) {
                  return UpgradedStandardToken(upgradedAddress).balanceOf(who);
              } else {
                  return super.balanceOf(who);
              }
          }
      
          // Forward ERC20 methods to upgraded contract if this one is deprecated
          function approve(address _spender, uint _value) public onlyPayloadSize(2 * 32) {
              if (deprecated) {
                  return UpgradedStandardToken(upgradedAddress).approveByLegacy(msg.sender, _spender, _value);
              } else {
                  return super.approve(_spender, _value);
              }
          }
      
          // Forward ERC20 methods to upgraded contract if this one is deprecated
          function allowance(address _owner, address _spender) public constant returns (uint remaining) {
              if (deprecated) {
                  return StandardToken(upgradedAddress).allowance(_owner, _spender);
              } else {
                  return super.allowance(_owner, _spender);
              }
          }
      
          // deprecate current contract in favour of a new one
          function deprecate(address _upgradedAddress) public onlyOwner {
              deprecated = true;
              upgradedAddress = _upgradedAddress;
              Deprecate(_upgradedAddress);
          }
      
          // deprecate current contract if favour of a new one
          function totalSupply() public constant returns (uint) {
              if (deprecated) {
                  return StandardToken(upgradedAddress).totalSupply();
              } else {
                  return _totalSupply;
              }
          }
      
          // Issue a new amount of tokens
          // these tokens are deposited into the owner address
          //
          // @param _amount Number of tokens to be issued
          function issue(uint amount) public onlyOwner {
              require(_totalSupply + amount > _totalSupply);
              require(balances[owner] + amount > balances[owner]);
      
              balances[owner] += amount;
              _totalSupply += amount;
              Issue(amount);
          }
      
          // Redeem tokens.
          // These tokens are withdrawn from the owner address
          // if the balance must be enough to cover the redeem
          // or the call will fail.
          // @param _amount Number of tokens to be issued
          function redeem(uint amount) public onlyOwner {
              require(_totalSupply >= amount);
              require(balances[owner] >= amount);
      
              _totalSupply -= amount;
              balances[owner] -= amount;
              Redeem(amount);
          }
      
          function setParams(uint newBasisPoints, uint newMaxFee) public onlyOwner {
              // Ensure transparency by hardcoding limit beyond which fees can never be added
              require(newBasisPoints < 20);
              require(newMaxFee < 50);
      
              basisPointsRate = newBasisPoints;
              maximumFee = newMaxFee.mul(10**decimals);
      
              Params(basisPointsRate, maximumFee);
          }
      
          // Called when new token are issued
          event Issue(uint amount);
      
          // Called when tokens are redeemed
          event Redeem(uint amount);
      
          // Called when contract is deprecated
          event Deprecate(address newAddress);
      
          // Called if contract ever adds fees
          event Params(uint feeBasisPoints, uint maxFee);
      }

      File 3 of 3: Bridge
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.8.0;
      import {Initializable} from "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
      import {ReentrancyGuardUpgradeable} from "@openzeppelin/contracts-upgradeable/security/ReentrancyGuardUpgradeable.sol";
      import {IERC20, SafeERC20} from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
      import {Address} from "@openzeppelin/contracts/utils/Address.sol";
      import "./interfaces/IZKBridgeReceiver.sol";
      import "./interfaces/IZKBridgeEndpoint.sol";
      import "./interfaces/IL1Bridge.sol";
      import {Pool} from "./Pool.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;
          // For two-step bridge management
          bool public pendingBridge;
          uint16 public pendingDstChainId;
          address public pendingBridgeAddress;
          //double check switch
          bool public doubleCheck;
          // messageHash -> isVerified, mapping of message isVerified
          mapping(bytes32 => bool) public verifiedMessages;
          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);
          event SetDoubleCheck(bool doubleCheck);
          /// @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: Invalid needDoubleCheck");
              doubleCheck = needDoubleCheck;
              emit SetDoubleCheck(needDoubleCheck);
          }
      }
      // SPDX-License-Identifier: MIT
      // OpenZeppelin Contracts (last updated v4.9.0) (proxy/utils/Initializable.sol)
      pragma solidity ^0.8.2;
      import "../../utils/AddressUpgradeable.sol";
      /**
       * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
       * behind a proxy. Since 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;
          }
      }
      // SPDX-License-Identifier: MIT
      // OpenZeppelin Contracts (last updated v4.9.0) (security/ReentrancyGuard.sol)
      pragma solidity ^0.8.0;
      import "../proxy/utils/Initializable.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;
      }
      // SPDX-License-Identifier: MIT
      // OpenZeppelin Contracts (last updated v4.9.3) (token/ERC20/utils/SafeERC20.sol)
      pragma solidity ^0.8.0;
      import "../IERC20.sol";
      import "../extensions/IERC20Permit.sol";
      import "../../../utils/Address.sol";
      /**
       * @title SafeERC20
       * @dev Wrappers around ERC20 operations that throw on failure (when the token
       * contract returns false). Tokens that return no value (and instead revert or
       * throw on failure) are also supported, non-reverting calls are assumed to be
       * successful.
       * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
       * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
       */
      library SafeERC20 {
          using Address for address;
          /**
           * @dev 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));
          }
      }
      // SPDX-License-Identifier: MIT
      // OpenZeppelin Contracts (last updated v4.9.0) (utils/Address.sol)
      pragma solidity ^0.8.1;
      /**
       * @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);
              }
          }
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.8.0;
      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;
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.8.0;
      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);
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.8.0;
      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);
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.8.0;
      import {ReentrancyGuardUpgradeable} from "@openzeppelin/contracts-upgradeable/security/ReentrancyGuardUpgradeable.sol";
      import {IERC20, SafeERC20} from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
      import {Address} from "@openzeppelin/contracts/utils/Address.sol";
      import {Admin} from "./Admin.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;
      }
      // SPDX-License-Identifier: MIT
      // OpenZeppelin Contracts (last updated v4.9.0) (utils/Address.sol)
      pragma solidity ^0.8.1;
      /**
       * @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);
              }
          }
      }
      // SPDX-License-Identifier: MIT
      // OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/IERC20.sol)
      pragma solidity ^0.8.0;
      /**
       * @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);
      }
      // SPDX-License-Identifier: MIT
      // OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/extensions/IERC20Permit.sol)
      pragma solidity ^0.8.0;
      /**
       * @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);
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.8.0;
      import {Initializable} from "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
      abstract contract Admin is Initializable {
          address public poolManager;
          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 pendingBridgeManager;
          address public pendingBridgeReviewer;
          address public approveManager;
          address public pendingApproveManager;
          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);
          }
          function initApproveManager(address newOwner) external onlyBridgeManager{
              require(approveManager == address(0), "Admin: already initialized");
              approveManager = newOwner;
          }
          /**
           * @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;
      }