contract EthTeleportAgent is Ownable, Initializable {
    using SafeERC20 for IERC20;
    using Address for address;

    mapping(uint256/*fromChainId*/ => mapping(uint256/*fromChainTeleportId*/ => bool/*finished*/)) public finishedTeleports;
    mapping(uint256/*original chain id*/ => mapping(address/*original token address*/ => address/*wrapped token address*/)) public originalToWrappedTokens;
    mapping(address/*wrapped token address*/ => OriginalToken) public wrappedToOriginalTokens;
    
    address public signOwner;
    address public feeOwner;
    address public wrappedTokenImplementation;
    address public wrappedTokenAdmin;
    
    uint256 public teleportIdGenerator;
    uint256 public teleportFee;
    
    string private constant ERROR_ALREADY_EXECUTED = "already executed";
    string private constant ERROR_MINT_FAILED = "mint failed";
    
    event SetSignOwner(
        address indexed oldValue,
        address indexed newValue);
        
    event SetFeeOwner(
        address indexed oldValue,
        address indexed newValue);
        
    event SetTeleportFee(
        uint256 oldValue,
        uint256 newValue);
        
    event SetWrappedTokenAdmin(
        address indexed oldValue,
        address indexed newValue);
    
    event WrappedTokenCreated(
        address indexed sponsor,
        uint256 originalTokenChainId,
        address indexed originalTokenAddr,
        address indexed wrappedTokenAddr,
        string name,
        string symbol,
        uint8 decimals);

    event TeleportStarted(
        uint256 teleportId,
        address indexed sender,
        uint256 originalTokenChainId,
        address indexed originalTokenAddr,
        address indexed tokenAddr,
        uint256 amount,
        uint256 toChainId,
        address recipient,
        uint256 feeAmount);

    event TeleportFinished(
        address indexed recipient,
        uint256 fromChainId,
        uint256 fromChainTeleportId,
        uint256 originalTokenChainId,
        address indexed originalTokenAddr,
        address indexed tokenAddr,
        uint256 amount);
        
    event TeleportCancelStarted(
        uint256 fromChainId,
        uint256 fromChainTeleportId);
        
    event TeleportCancelFinished(
        uint256 teleportId,
        address tokenAddr,
        uint256 amount,
        address recipient);

    function initialize(
        address payable _ownerAddr,
        address _signOwner,
        address _feeOwner,
        uint256 _teleportFee,
        address _wrappedTokenImpl,
        address _wrappedTokenAdmin) external virtual initializer {
            
        _ensureNotZeroAddress(_ownerAddr);
        _ensureNotZeroAddress(_signOwner);
        _ensureNotZeroAddress(_feeOwner);
        _ensureNotZeroAddress(_wrappedTokenImpl);

        initializeOwnable(_ownerAddr);

        signOwner = _signOwner;
        emit SetSignOwner(address(0), _signOwner);
        
        feeOwner = _feeOwner;
        emit SetFeeOwner(address(0), _feeOwner);
        
        teleportFee = _teleportFee;
        emit SetTeleportFee(0, _teleportFee);
        
        wrappedTokenImplementation = _wrappedTokenImpl;
        
        wrappedTokenAdmin = _wrappedTokenAdmin;
        emit SetWrappedTokenAdmin(address(0), _wrappedTokenAdmin);
    }
    
    function setSignOwner(address _signOwner) onlyOwner external {
        _ensureNotZeroAddress(_signOwner);
        require(signOwner != _signOwner, ERROR_ALREADY_EXECUTED);
        emit SetSignOwner(signOwner, _signOwner);
        signOwner = _signOwner;
    }
    
    function setFeeOwner(address _feeOwner) onlyOwner external {
        _ensureNotZeroAddress(_feeOwner);
        require(feeOwner != _feeOwner, ERROR_ALREADY_EXECUTED);
        emit SetFeeOwner(feeOwner, _feeOwner);
        feeOwner = _feeOwner;
    }

    function setTeleportFee(uint256 _teleportFee) onlyOwner external {
        require(teleportFee != _teleportFee, ERROR_ALREADY_EXECUTED);
        emit SetTeleportFee(teleportFee, _teleportFee);
        teleportFee = _teleportFee;
    }
    
    function setWrappedTokenAdmin(address _wrappedTokenAdmin) onlyOwner external {
        _ensureNotZeroAddress(_wrappedTokenAdmin);
        require(wrappedTokenAdmin != _wrappedTokenAdmin, ERROR_ALREADY_EXECUTED);
        emit SetWrappedTokenAdmin(wrappedTokenAdmin, _wrappedTokenAdmin);
        wrappedTokenAdmin = _wrappedTokenAdmin;
    }
    
    /**
     * @dev This function is called by the oracle to create wrapped token in present chain.
     * Wrapped token will represent the original token from another chain.
     * This function is optional but it will reduce the cost of the first {teleportFinish} function call
     * for given token pair.
     */
    function createWrappedToken(
        uint256 _originalTokenChainId,
        address _originalTokenAddr,
        string calldata _name,
        string calldata _symbol,
        uint8 _decimals) onlyOwner external {
        
        _createWrappedToken(
            _originalTokenChainId,
            _originalTokenAddr,
            _name,
            _symbol,
            _decimals);
    }
    
    /**
     * @dev This function is called by the user to create wrapped token in present chain.
     * Wrapped token will represent the original token from another chain.
     * This function is optional but it will reduce the cost of the first {teleportFinish} function call
     * for given token pair.
     * All parameters of this function are signed with oracle private key. The signature is passed in
     * {_signature} parameter.
     */
    function createWrappedToken(
        uint256 _originalTokenChainId,
        address _originalTokenAddr,
        string calldata _name,
        string calldata _symbol,
        uint8 _decimals,
        bytes calldata _signature) external {
        
        string memory message = string(abi.encodePacked(
            _toAsciiString(_msgSender()), ";",
            _uintToString(_originalTokenChainId), ";",
            _toAsciiString(_originalTokenAddr), ";",
            _name, ";",
            _symbol, ";",
            _uintToString(_decimals)));
            
        _verify(message, _signature);
        
        _createWrappedToken(
            _originalTokenChainId,
            _originalTokenAddr,
            _name,
            _symbol,
            _decimals);
    }
    
    function _createWrappedToken(
        uint256 _originalTokenChainId,
        address _originalTokenAddr,
        string memory _name,
        string memory _symbol,
        uint8 _decimals) private returns (address) {
            
        _ensureNotZeroAddress(_originalTokenAddr);
        require(block.chainid != _originalTokenChainId, "can't create wrapped token in original chain");
        require(originalToWrappedTokens[_originalTokenChainId][_originalTokenAddr] == address(0), "already created");
        
        address msgSender = _msgSender();

        address wrappedToken = _deployMinimalProxy(wrappedTokenImplementation);
        IWrappedToken(wrappedToken).initialize(_name, _symbol, _decimals, address(this), wrappedTokenAdmin);
        
        originalToWrappedTokens[_originalTokenChainId][_originalTokenAddr] = wrappedToken;
        wrappedToOriginalTokens[wrappedToken] = OriginalToken({chainId: _originalTokenChainId, addr: _originalTokenAddr});
        
        emit WrappedTokenCreated(
            msgSender,
            _originalTokenChainId,
            _originalTokenAddr,
            wrappedToken,
            _name,
            _symbol,
            _decimals);
            
        return wrappedToken;
    }
    

    /**
     * @dev Anyone can call this function to start the token teleportation process.
     * It either freezes the {_tokenAddr} tokens on the bridge or burns them and emits a signal to the oracle.
     */
    function teleportStart(address _tokenAddr, uint256 _amount, uint256 _toChainId, address _recipient) payable external {
        _ensureNotZeroAddress(_tokenAddr);
        _ensureNotZeroAddress(_recipient);
        require(_amount > 0, "zero amount");
        require(msg.value >= teleportFee, "fee mismatch");

        if (msg.value != 0) {
            (bool sent, ) = feeOwner.call{value: msg.value}("");
            require(sent, "fee send failed");
        }
        
        address msgSender = _msgSender();
        
        OriginalToken storage originalToken = wrappedToOriginalTokens[_tokenAddr];
        
        if (originalToken.addr == address(0)) { // teleportable token {_tokenAddr} is original token
            IERC20(_tokenAddr).safeTransferFrom(msgSender, address(this), _amount);
        
            emit TeleportStarted(
                ++teleportIdGenerator,
                msgSender,
                block.chainid,
                _tokenAddr,
                _tokenAddr,
                _amount,
                _toChainId,
                _recipient,
                msg.value);
            
            return;
        }
        
        // teleportable token {_tokenAddr} is wrapped token
            
        require(IWrappedToken(_tokenAddr).burnFrom(msgSender, _amount), "burn failed");
        
        emit TeleportStarted(
            ++teleportIdGenerator,
            msgSender,
            originalToken.chainId,
            originalToken.addr,
            _tokenAddr,
            _amount,
            _toChainId,
            _recipient,
            msg.value);
    }
    
    /**
     * @dev This function is called by the oracle to finish the token teleportation process.
     * The required admount of tokens is minted or unfreezed to {_toAddress} address in present chain.
     */
    function teleportFinish(
        uint256 _fromChainId,
        uint256 _fromChainTeleportId,
        uint256 _originalTokenChainId,
        address _originalTokenAddr,
        string memory _name,
        string memory _symbol,
        uint8 _decimals,
        address _recipient,
        uint256 _amount) onlyOwner external {
            
        _teleportFinish(
            _fromChainId,
            _fromChainTeleportId,
            _originalTokenChainId,
            _originalTokenAddr,
            _name,
            _symbol,
            _decimals,
            _recipient,
            _amount);
    }
    
    /**
     * @dev This function is called by the user to finish the token teleportation process.
     * All parameters of this function are signed with oracle private key. The signature is passed in
     * {_signature} parameter.
     * The required admount of tokens is minted or unfreezed to {_toAddress} address in present chain.
     */
    function teleportFinish(
        uint256 _fromChainId,
        uint256 _fromChainTeleportId,
        uint256 _originalTokenChainId,
        address _originalTokenAddr,
        string memory _name,
        string memory _symbol,
        uint8 _decimals,
        uint256 _amount,
        bytes memory _signature) external {
        
        address recipient = _msgSender();
        
        string memory message = string(abi.encodePacked(
            _toAsciiString(recipient), ";",
            _uintToString(_fromChainId), ";",
            _uintToString(_fromChainTeleportId), ";",
            _uintToString(_originalTokenChainId), ";",
            _toAsciiString(_originalTokenAddr), ";",
            _name, ";",
            _symbol, ";",
            _uintToString(_decimals), ";",
            _uintToString(_amount)));
            
        _verify(message, _signature);
        
        _teleportFinish(
            _fromChainId,
            _fromChainTeleportId,
            _originalTokenChainId,
            _originalTokenAddr,
            _name,
            _symbol,
            _decimals,
            recipient,
            _amount);
    }
    
    function _teleportFinish(
        uint256 _fromChainId,
        uint256 _fromChainTeleportId,
        uint256 _originalTokenChainId,
        address _originalTokenAddr,
        string memory _name,
        string memory _symbol,
        uint8 _decimals,
        address _recipient,
        uint256 _amount) private {
            
        _ensureNotZeroAddress(_originalTokenAddr);
        _ensureNotZeroAddress(_recipient);
            
        require(!finishedTeleports[_fromChainId][_fromChainTeleportId], ERROR_ALREADY_EXECUTED);
        finishedTeleports[_fromChainId][_fromChainTeleportId] = true;
            
        address tokenAddr;
    
        if (_originalTokenChainId == block.chainid) {
            IERC20(_originalTokenAddr).safeTransfer(_recipient, _amount);
            tokenAddr = _originalTokenAddr;
        } else {
            tokenAddr = originalToWrappedTokens[_originalTokenChainId][_originalTokenAddr];
            
            if (tokenAddr == address(0)) {
                tokenAddr = _createWrappedToken(
                    _originalTokenChainId,
                    _originalTokenAddr,
                    _name,
                    _symbol,
                    _decimals);
            }
            
            require(IWrappedToken(tokenAddr).mintTo(_recipient, _amount), ERROR_MINT_FAILED);
        }
        
        emit TeleportFinished(
            _recipient,
            _fromChainId,
            _fromChainTeleportId,
            _originalTokenChainId,
            _originalTokenAddr,
            tokenAddr,
            _amount);
    }
    
    function teleportCancelStart(uint256 _fromChainId, uint256 _fromChainTeleportId) onlyOwner external {
        require(!finishedTeleports[_fromChainId][_fromChainTeleportId], ERROR_ALREADY_EXECUTED);
        finishedTeleports[_fromChainId][_fromChainTeleportId] = true;
        
        emit TeleportCancelStarted(_fromChainId, _fromChainTeleportId);
    }
    
    function teleportCancelFinish(
        uint256 _teleportId,
        address _tokenAddr,
        uint256 _amount,
        address _recipient) onlyOwner external {
            
        OriginalToken storage originalToken = wrappedToOriginalTokens[_tokenAddr];
        
        if (originalToken.addr == address(0)) { // {_tokenAddr} is original token
            IERC20(_tokenAddr).safeTransfer(_recipient, _amount);
        } else { // {_tokenAddr} is wrapped token
            require(IWrappedToken(_tokenAddr).mintTo(_recipient, _amount), ERROR_MINT_FAILED);
        }

        emit TeleportCancelFinished(_teleportId, _tokenAddr, _amount, _recipient);
    }

    function _deployMinimalProxy(address _logic) private returns (address proxy) {
        // Adapted from https://github.com/optionality/clone-factory/blob/32782f82dfc5a00d103a7e61a17a5dedbd1e8e9d/contracts/CloneFactory.sol
        bytes20 targetBytes = bytes20(_logic);
        assembly {
            let clone := mload(0x40)
            mstore(clone, 0x3d602d80600a3d3981f3363d3d373d3d3d363d73000000000000000000000000)
            mstore(add(clone, 0x14), targetBytes)
            mstore(add(clone, 0x28), 0x5af43d82803e903d91602b57fd5bf30000000000000000000000000000000000)
            proxy := create(0, clone, 0x37)
        }
    }
    
    function _verify(string memory _message, bytes memory _sig) private view {
        bytes32 messageHash = keccak256(abi.encodePacked("\x19Ethereum Signed Message:\n32", keccak256(abi.encodePacked(_message))));
        address messageSigner = _recover(messageHash, _sig);

        require(messageSigner == signOwner, "verification failed");
    }

    function _recover(bytes32 _hash, bytes memory _sig) private pure returns (address) {
        bytes32 r;
        bytes32 s;
        uint8 v;

        require(_sig.length == 65, "_recover: invalid sig size");

        assembly {
            r := mload(add(_sig, 32))
            s := mload(add(_sig, 64))
            v := byte(0, mload(add(_sig, 96)))
        }

        if (v < 27) {
            v += 27;
        }

        require(v == 27 || v == 28, "_recover: invalid sig");

        return ecrecover(_hash, v, r, s);
    }

    function _uintToString(uint _i) private pure returns (string memory) {
        if (_i == 0) {
            return "0";
        }
        uint j = _i;
        uint len;
        while (j != 0) {
            len++;
            j /= 10;
        }
        bytes memory bstr = new bytes(len);
        uint k = len;
        while (_i != 0) {
            k = k - 1;
            uint8 temp = (48 + uint8(_i - _i / 10 * 10));
            bytes1 b1 = bytes1(temp);
            bstr[k] = b1;
            _i /= 10;
        }
        return string(bstr);
    }

    function _toAsciiString(address _addr) private pure returns (string memory) {
        bytes memory s = new bytes(40);
        for (uint i = 0; i < 20; i++) {
            bytes1 b = bytes1(uint8(uint(uint160(_addr)) / (2 ** (8 * (19 - i)))));
            bytes1 hi = bytes1(uint8(b) / 16);
            bytes1 lo = bytes1(uint8(b) - 16 * uint8(hi));
            s[2 * i] = _char(hi);
            s[2 * i + 1] = _char(lo);
        }
        return string(s);
    }

    function _char(bytes1 value) private pure returns (bytes1) {
        return (uint8(value) < 10) ? bytes1(uint8(value) + 0x30) : bytes1(uint8(value) + 0x57);
    }
    
    function _ensureNotZeroAddress(address _address) private pure {
        require(_address != address(0), "zero address");
    }
}
function createWrappedToken(
    uint256 _originalTokenChainId,
    address _originalTokenAddr,
    string calldata _name,
    string calldata _symbol,
    uint8 _decimals,
    bytes calldata _signature) external {
        
    string memory message = string(abi.encodePacked(
        _toAsciiString(_msgSender()), ";",
        _uintToString(_originalTokenChainId), ";",
        _toAsciiString(_originalTokenAddr), ";",
        _name, ";",
        _symbol, ";",
        _uintToString(_decimals)));
            
    _verify(message, _signature);
        
    _createWrappedToken(
        _originalTokenChainId,
        _originalTokenAddr,
        _name,
        _symbol,
        _decimals);
}

/**
 * @dev This function is called by the user to create wrapped token in present chain.
 * Wrapped token will represent the original token from another chain.
 * This function is optional but it will reduce the cost of the first {teleportFinish} function call
 * for given token pair.
 * All parameters of this function are signed with oracle private key. The signature is passed in
 * {_signature} parameter.
 */