// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (metatx/ERC2771Context.sol)

pragma solidity ^0.8.1;

/**
 * @dev Context variant with ERC2771 support.
 */
// based on https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/metatx/ERC2771Context.sol
abstract contract ERC2771Context {
    address private immutable _trustedForwarder;

    constructor(address trustedForwarder) {
        _trustedForwarder = trustedForwarder;
    }

    function isTrustedForwarder(address forwarder)
        public
        view
        virtual
        returns (bool)
    {
        return forwarder == _trustedForwarder;
    }

    function _msgSender() internal view virtual returns (address sender) {
        if (isTrustedForwarder(msg.sender)) {
            // The assembly code is more direct than the Solidity version using `abi.decode`.
            /// @solidity memory-safe-assembly
            assembly {
                sender := shr(96, calldataload(sub(calldatasize(), 20)))
            }
        } else {
            return msg.sender;
        }
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        if (isTrustedForwarder(msg.sender)) {
            return msg.data[:msg.data.length - 20];
        } else {
            return msg.data;
        }
    }
}