contract ProxyAdmin is OpenZeppelinUpgradesOwnable {
  
  /**
   * @dev Returns the current implementation of a proxy.
   * This is needed because only the proxy admin can query it.
   * @return The address of the current implementation of the proxy.
   */
  function getProxyImplementation(AdminUpgradeabilityProxy proxy) public view returns (address) {
    // We need to manually run the static call since the getter cannot be flagged as view
    // bytes4(keccak256("implementation()")) == 0x5c60da1b
    (bool success, bytes memory returndata) = address(proxy).staticcall(hex"5c60da1b");
    require(success);
    return abi.decode(returndata, (address));
  }

  /**
   * @dev Returns the admin of a proxy. Only the admin can query it.
   * @return The address of the current admin of the proxy.
   */
  function getProxyAdmin(AdminUpgradeabilityProxy proxy) public view returns (address) {
    // We need to manually run the static call since the getter cannot be flagged as view
    // bytes4(keccak256("admin()")) == 0xf851a440
    (bool success, bytes memory returndata) = address(proxy).staticcall(hex"f851a440");
    require(success);
    return abi.decode(returndata, (address));
  }

  /**
   * @dev Changes the admin of a proxy.
   * @param proxy Proxy to change admin.
   * @param newAdmin Address to transfer proxy administration to.
   */
  function changeProxyAdmin(AdminUpgradeabilityProxy proxy, address newAdmin) public onlyOwner {
    proxy.changeAdmin(newAdmin);
  }

  /**
   * @dev Upgrades a proxy to the newest implementation of a contract.
   * @param proxy Proxy to be upgraded.
   * @param implementation the address of the Implementation.
   */
  function upgrade(AdminUpgradeabilityProxy proxy, address implementation) public onlyOwner {
    proxy.upgradeTo(implementation);
  }

  /**
   * @dev Upgrades a proxy to the newest implementation of a contract and forwards a function call to it.
   * This is useful to initialize the proxied contract.
   * @param proxy Proxy to be upgraded.
   * @param implementation Address of the Implementation.
   * @param data Data to send as msg.data in the low level call.
   * It should include the signature and the parameters of the function to be called, as described in
   * https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#function-selector-and-argument-encoding.
   */
  function upgradeAndCall(AdminUpgradeabilityProxy proxy, address implementation, bytes memory data) payable public onlyOwner {
    proxy.upgradeToAndCall.value(msg.value)(implementation, data);
  }
}
/**
 * @title ProxyAdmin
 * @dev This contract is the admin of a proxy, and is in charge
 * of upgrading it as well as transferring it to another admin.
 */
function changeProxyAdmin(AdminUpgradeabilityProxy proxy, address newAdmin) public onlyOwner {
  proxy.changeAdmin(newAdmin);
}

/**
 * @dev Changes the admin of a proxy.
 * @param proxy Proxy to change admin.
 * @param newAdmin Address to transfer proxy administration to.
 */