pragma solidity 0.5.11; // optimization runs: 200, evm version: petersburg


interface DharmaKeyRingFactoryV1Interface {
  // Fires an event when a new key ring is deployed and initialized.
  event KeyRingDeployed(address keyRing, address userSigningKey);

  function newKeyRing(
    address userSigningKey
  ) external returns (address keyRing);

  function newKeyRingAndAdditionalKey(
    address userSigningKey,
    address additionalSigningKey,
    bytes calldata signature
  ) external returns (address keyRing);

  function newKeyRingAndDaiWithdrawal(
    address userSigningKey,
    address smartWallet,
    uint256 amount,
    address recipient,
    uint256 minimumActionGas,
    bytes calldata userSignature,
    bytes calldata dharmaSignature
  ) external returns (address keyRing, bool withdrawalSuccess);

  function newKeyRingAndUSDCWithdrawal(
    address userSigningKey,
    address smartWallet,
    uint256 amount,
    address recipient,
    uint256 minimumActionGas,
    bytes calldata userSignature,
    bytes calldata dharmaSignature
  ) external returns (address keyRing, bool withdrawalSuccess);

   function getNextKeyRing(
    address userSigningKey
  ) external view returns (address keyRing);
}


interface DharmaKeyRingInitializer {
  function initialize(
    uint128 adminThreshold,
    uint128 executorThreshold,
    address[] calldata keys,
    uint8[] calldata keyTypes
  ) external; // selector: 0x30fc201f
}



interface DharmaKeyRingImplementationV0Interface {
  enum AdminActionType {
    AddStandardKey,
    RemoveStandardKey,
    SetStandardThreshold,
    AddAdminKey,
    RemoveAdminKey,
    SetAdminThreshold,
    AddDualKey,
    RemoveDualKey,
    SetDualThreshold
  }

  function takeAdminAction(
    AdminActionType adminActionType, uint160 argument, bytes calldata signatures
  ) external;
}


interface DharmaSmartWalletImplementationV0Interface {
  function withdrawDai(
    uint256 amount,
    address recipient,
    uint256 minimumActionGas,
    bytes calldata userSignature,
    bytes calldata dharmaSignature
  ) external returns (bool ok);

  function withdrawUSDC(
    uint256 amount,
    address recipient,
    uint256 minimumActionGas,
    bytes calldata userSignature,
    bytes calldata dharmaSignature
  ) external returns (bool ok);
}


/**
 * @title KeyRingUpgradeBeaconProxyV1
 * @author 0age
 * @notice This contract delegates all logic, including initialization, to a key
 * ring implementation contract specified by a hard-coded "upgrade beacon". Note
 * that this implementation can be reduced in size by stripping out the metadata
 * hash, or even more significantly by using a minimal upgrade beacon proxy
 * implemented using raw EVM opcodes.
 */
contract KeyRingUpgradeBeaconProxyV1 {
  // Set upgrade beacon address as a constant (i.e. not in contract storage).
  address private constant _KEY_RING_UPGRADE_BEACON = address(
    0x0000000000BDA2152794ac8c76B2dc86cbA57cad
  );

  /**
   * @notice In the constructor, perform initialization via delegatecall to the
   * implementation set on the key ring upgrade beacon, supplying initialization
   * calldata as a constructor argument. The deployment will revert and pass
   * along the revert reason if the initialization delegatecall reverts.
   * @param initializationCalldata Calldata to supply when performing the
   * initialization delegatecall.
   */
  constructor(bytes memory initializationCalldata) public payable {
    // Delegatecall into the implementation, supplying initialization calldata.
    (bool ok, ) = _implementation().delegatecall(initializationCalldata);
    
    // Revert and include revert data if delegatecall to implementation reverts.
    if (!ok) {
      assembly {
        returndatacopy(0, 0, returndatasize)
        revert(0, returndatasize)
      }
    }
  }

  /**
   * @notice In the fallback, delegate execution to the implementation set on
   * the key ring upgrade beacon.
   */
  function () external payable {
    // Delegate execution to implementation contract provided by upgrade beacon.
    _delegate(_implementation());
  }

  /**
   * @notice Private view function to get the current implementation from the
   * key ring upgrade beacon. This is accomplished via a staticcall to the key
   * ring upgrade beacon with no data, and the beacon will return an abi-encoded
   * implementation address.
   * @return implementation Address of the implementation.
   */
  function _implementation() private view returns (address implementation) {
    // Get the current implementation address from the upgrade beacon.
    (bool ok, bytes memory returnData) = _KEY_RING_UPGRADE_BEACON.staticcall("");
    
    // Revert and pass along revert message if call to upgrade beacon reverts.
    require(ok, string(returnData));

    // Set the implementation to the address returned from the upgrade beacon.
    implementation = abi.decode(returnData, (address));
  }

  /**
   * @notice Private function that delegates execution to an implementation
   * contract. This is a low level function that doesn't return to its internal
   * call site. It will return whatever is returned by the implementation to the
   * external caller, reverting and returning the revert data if implementation
   * reverts.
   * @param implementation Address to delegate.
   */
  function _delegate(address implementation) private {
    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)

      // Delegatecall to the implementation, supplying calldata and gas.
      // Out and outsize are set to zero - instead, use the return buffer.
      let result := delegatecall(gas, implementation, 0, calldatasize, 0, 0)

      // Copy the returned data from the return buffer.
      returndatacopy(0, 0, returndatasize)

      switch result
      // Delegatecall returns 0 on error.
      case 0 { revert(0, returndatasize) }
      default { return(0, returndatasize) }
    }
  }
}


/**
 * @title DharmaKeyRingFactoryV1
 * @author 0age
 * @notice This contract deploys new Dharma Key Ring instances as "Upgrade
 * Beacon" proxies that reference a shared implementation contract specified by
 * the Dharma Key Ring Upgrade Beacon contract. It also supplies methods for
 * performing additional operations post-deployment, including setting a second
 * signing key on the keyring and making a withdrawal from the associated smart
 * wallet. Note that the batch operations may fail, or be applied to the wrong
 * keyring, if another caller frontruns them by deploying a keyring to the
 * intended address first. If this becomes an issue, a future version of this
 * factory can remedy this by passing the target deployment address as an
 * additional argument and checking for existence of a contract at that address.
 */
contract DharmaKeyRingFactoryV1 is DharmaKeyRingFactoryV1Interface {
  // Use DharmaKeyRing initialize selector to construct initialization calldata.
  bytes4 private constant _INITIALIZE_SELECTOR = bytes4(0x30fc201f);

  /**
   * @notice In the constructor, ensure that the initialize selector constant is
   * correct.
   */
  constructor() public {
    DharmaKeyRingInitializer initializer;
    require(
      initializer.initialize.selector == _INITIALIZE_SELECTOR,
      "Incorrect initializer selector supplied."
    );
  }

  /**
   * @notice Deploy a new key ring contract using the provided user signing key.
   * @param userSigningKey address The user signing key, supplied as a
   * constructor argument.
   * @return The address of the new key ring.
   */
  function newKeyRing(
    address userSigningKey
  ) external returns (address keyRing) {
    // Deploy and initialize a keyring instance and emit a corresponding event.
    keyRing = _deployNewKeyRing(userSigningKey);
  }

  /**
   * @notice Deploy a new key ring contract using the provided user signing key
   * and immediately add a second signing key to the key ring.
   * @param userSigningKey address The user signing key, supplied as a
   * constructor argument.
   * @param additionalSigningKey address The second user signing key, supplied
   * as an argument to `takeAdminAction` on the newly-deployed keyring.
   * @param signature bytes A signature approving the addition of the second key
   * that has been signed by the first key.
   * @return The address of the new key ring.
   */
  function newKeyRingAndAdditionalKey(
    address userSigningKey,
    address additionalSigningKey,
    bytes calldata signature
  ) external returns (address keyRing) {
    // Deploy and initialize a keyring instance and emit a corresponding event.
    keyRing = _deployNewKeyRing(userSigningKey);

    // Set the additional key on the newly-deployed keyring.
    DharmaKeyRingImplementationV0Interface(keyRing).takeAdminAction(
      DharmaKeyRingImplementationV0Interface.AdminActionType.AddDualKey,
      uint160(additionalSigningKey),
      signature
    );
  }

  /**
   * @notice Deploy a new key ring contract using the provided user signing key
   * and immediately make a Dai withdrawal from the supplied smart wallet.
   * @param userSigningKey address The user signing key, supplied as a
   * constructor argument.
   * @param smartWallet address The smart wallet to make the withdrawal from and
   * that has the keyring to be deployed set as its user singing address.
   * @param amount uint256 The amount of Dai to withdraw.
   * @param recipient address The account to transfer the withdrawn Dai to.
   * @param minimumActionGas uint256 The minimum amount of gas that must be
   * provided to the call to the smart wallet - be aware that additional gas
   * must still be included to account for the cost of overhead incurred up
   * until the start of the function call.
   * @param userSignature bytes A signature that resolves to userSigningKey set
   * on the keyring and resolved using ERC1271. A unique hash returned from
   * `getCustomActionID` on the smart wallet is prefixed and hashed to create
   * the message hash for the signature.
   * @param dharmaSignature bytes A signature that resolves to the public key
   * returned for the smart wallet from the Dharma Key Registry. A unique hash
   * returned from `getCustomActionID` on the smart wallet is prefixed and
   * hashed to create the signed message.
   * @return The address of the new key ring and the success status of the
   * withdrawal.
   */
  function newKeyRingAndDaiWithdrawal(
    address userSigningKey,
    address smartWallet,
    uint256 amount,
    address recipient,
    uint256 minimumActionGas,
    bytes calldata userSignature,
    bytes calldata dharmaSignature
  ) external returns (address keyRing, bool withdrawalSuccess) {
    // Deploy and initialize a keyring instance and emit a corresponding event.
    keyRing = _deployNewKeyRing(userSigningKey);

    // Attempt to withdraw Dai from the provided smart wallet.
    withdrawalSuccess = DharmaSmartWalletImplementationV0Interface(
      smartWallet
    ).withdrawDai(
      amount, recipient, minimumActionGas, userSignature, dharmaSignature
    );
  }

  /**
   * @notice Deploy a new key ring contract using the provided user signing key
   * and immediately make a USDC withdrawal from the supplied smart wallet.
   * @param userSigningKey address The user signing key, supplied as a
   * constructor argument.
   * @param smartWallet address The smart wallet to make the withdrawal from and
   * that has the keyring to be deployed set as its user singing address.
   * @param amount uint256 The amount of USDC to withdraw.
   * @param recipient address The account to transfer the withdrawn USDC to.
   * @param minimumActionGas uint256 The minimum amount of gas that must be
   * provided to the call to the smart wallet - be aware that additional gas
   * must still be included to account for the cost of overhead incurred up
   * until the start of the function call.
   * @param userSignature bytes A signature that resolves to userSigningKey set
   * on the keyring and resolved using ERC1271. A unique hash returned from
   * `getCustomActionID` on the smart wallet is prefixed and hashed to create
   * the message hash for the signature.
   * @param dharmaSignature bytes A signature that resolves to the public key
   * returned for the smart wallet from the Dharma Key Registry. A unique hash
   * returned from `getCustomActionID` on the smart wallet is prefixed and
   * hashed to create the signed message.
   * @return The address of the new key ring and the success status of the
   * withdrawal.
   */
  function newKeyRingAndUSDCWithdrawal(
    address userSigningKey,
    address smartWallet,
    uint256 amount,
    address recipient,
    uint256 minimumActionGas,
    bytes calldata userSignature,
    bytes calldata dharmaSignature
  ) external returns (address keyRing, bool withdrawalSuccess) {
    // Deploy and initialize a keyring instance and emit a corresponding event.
    keyRing = _deployNewKeyRing(userSigningKey);

    // Attempt to withdraw USDC from the provided smart wallet.
    withdrawalSuccess = DharmaSmartWalletImplementationV0Interface(
      smartWallet
    ).withdrawUSDC(
      amount, recipient, minimumActionGas, userSignature, dharmaSignature
    );
  }

  /**
   * @notice View function to find the address of the next key ring address that
   * will be deployed for a given user signing key. Note that a new value will
   * be returned if a particular user signing key has been used before.
   * @param userSigningKey address The user signing key, supplied as a
   * constructor argument.
   * @return The future address of the next key ring.
   */
  function getNextKeyRing(
    address userSigningKey
  ) external view returns (address keyRing) {
    // Ensure that a user signing key has been provided.
    require(userSigningKey != address(0), "No user signing key supplied.");

    // Get initialization calldata using the initial user signing key.
    bytes memory initializationCalldata = _constructInitializationCalldata(
      userSigningKey
    );
    
    // Determine the user's key ring address based on the user signing key.
    keyRing = _computeNextAddress(initializationCalldata);
  }

  /**
   * @notice Internal function to deploy a new key ring contract using the
   * provided user signing key.
   * @param userSigningKey address The user signing key, supplied as a
   * constructor argument during deployment.
   * @return The address of the new key ring.
   */
  function _deployNewKeyRing(
    address userSigningKey
  ) internal returns (address keyRing) {
    // Get initialization calldata using the initial user signing key.
    bytes memory initializationCalldata = _constructInitializationCalldata(
      userSigningKey
    );
    
    // Deploy and initialize new user key ring as an Upgrade Beacon proxy.
    keyRing = _deployUpgradeBeaconProxyInstance(initializationCalldata);

    // Emit an event to signal the creation of the new key ring contract.
    emit KeyRingDeployed(keyRing, userSigningKey);
  }

  /**
   * @notice Private function to deploy an upgrade beacon proxy via `CREATE2`.
   * @param initializationCalldata bytes The calldata that will be supplied to
   * the `DELEGATECALL` from the deployed contract to the implementation set on
   * the upgrade beacon during contract creation.
   * @return The address of the newly-deployed upgrade beacon proxy.
   */
  function _deployUpgradeBeaconProxyInstance(
    bytes memory initializationCalldata
  ) private returns (address upgradeBeaconProxyInstance) {
    // Place creation code and constructor args of new proxy instance in memory.
    bytes memory initCode = abi.encodePacked(
      type(KeyRingUpgradeBeaconProxyV1).creationCode,
      abi.encode(initializationCalldata)
    );

    // Get salt to use during deployment using the supplied initialization code.
    (uint256 salt, ) = _getSaltAndTarget(initCode);

    // Deploy the new upgrade beacon proxy contract using `CREATE2`.
    assembly {
      let encoded_data := add(0x20, initCode) // load initialization code.
      let encoded_size := mload(initCode)     // load the init code's length.
      upgradeBeaconProxyInstance := create2(  // call `CREATE2` w/ 4 arguments.
        callvalue,                            // forward any supplied endowment.
        encoded_data,                         // pass in initialization code.
        encoded_size,                         // pass in init code's length.
        salt                                  // pass in the salt value.
      )

      // Pass along failure message and revert if contract deployment fails.
      if iszero(upgradeBeaconProxyInstance) {
        returndatacopy(0, 0, returndatasize)
        revert(0, returndatasize)
      }
    }
  }

  function _constructInitializationCalldata(
    address userSigningKey
  ) internal pure returns (bytes memory initializationCalldata) {
    address[] memory keys = new address[](1);
    keys[0] = userSigningKey;

    uint8[] memory keyTypes = new uint8[](1);
    keyTypes[0] = uint8(3); // Dual key type

    // Get initialization calldata from initialize selector & arguments.
    initializationCalldata = abi.encodeWithSelector(
      _INITIALIZE_SELECTOR, 1, 1, keys, keyTypes
    );
  }

  /**
   * @notice Private view function for finding the address of the next upgrade
   * beacon proxy that will be deployed, given a particular initialization
   * calldata payload.
   * @param initializationCalldata bytes The calldata that will be supplied to
   * the `DELEGATECALL` from the deployed contract to the implementation set on
   * the upgrade beacon during contract creation.
   * @return The address of the next upgrade beacon proxy contract with the
   * given initialization calldata.
   */
  function _computeNextAddress(
    bytes memory initializationCalldata
  ) private view returns (address target) {
    // Place creation code and constructor args of the proxy instance in memory.
    bytes memory initCode = abi.encodePacked(
      type(KeyRingUpgradeBeaconProxyV1).creationCode,
      abi.encode(initializationCalldata)
    );

    // Get target address using the constructed initialization code.
    (, target) = _getSaltAndTarget(initCode);
  }

  /**
   * @notice Private function for determining the salt and the target deployment
   * address for the next deployed contract (using `CREATE2`) based on the
   * contract creation code.
   */
  function _getSaltAndTarget(
    bytes memory initCode
  ) private view returns (uint256 nonce, address target) {
    // Get the keccak256 hash of the init code for address derivation.
    bytes32 initCodeHash = keccak256(initCode);

    // Set the initial nonce to be provided when constructing the salt.
    nonce = 0;
    
    // Declare variable for code size of derived address.
    uint256 codeSize;

    // Loop until an contract deployment address with no code has been found.
    while (true) {
      target = address(            // derive the target deployment address.
        uint160(                   // downcast to match the address type.
          uint256(                 // cast to uint to truncate upper digits.
            keccak256(             // compute CREATE2 hash using 4 inputs.
              abi.encodePacked(    // pack all inputs to the hash together.
                bytes1(0xff),      // pass in the control character.
                address(this),     // pass in the address of this contract.
                nonce,              // pass in the salt from above.
                initCodeHash       // pass in hash of contract creation code.
              )
            )
          )
        )
      );

      // Determine if a contract is already deployed to the target address.
      assembly { codeSize := extcodesize(target) }

      // Exit the loop if no contract is deployed to the target address.
      if (codeSize == 0) {
        break;
      }

      // Otherwise, increment the nonce and derive a new salt.
      nonce++;
    }
  }
}