Magento – How to update customer address using custom Api in magento2

I have created custom API to update customer address using customer id or address id.

Below code I used to implement it.

[Vendor]/[Module]/etc/webapi.xml

<route url="/V1/address/createUpdate" method="POST">
    <service class="[Vendor]\[Module]\Api\CustomAddressInterface" method="addressUpdate"/>
    <resources>
        <resource ref="anonymous"/>
    </resources>
</route>

[Vendor]/[Module]/Api/CustomAddressInterface.php

 <?php
  namespace [Vendor]\[Module]\Api;

  interface CustomAddressInterface
 {
/**
 * Returns greeting message to user
 *
 * @api
 * @param string $name Users name.
 * @return string Greeting message with users name.
 */
public function name($name);

/**
 * POST for attribute api
 * @param mixed $param
 * @return array
 */

 public function addressUpdate($params);

}

[Vendo]/[Module]/Model/Address.php

namespace [Vendor]\[Module]\Model;
use [Vendor]\[Module]\Api\CustomAddressInterface;
use Magento\Store\Model\StoreManagerInterface;

class Address implements CustomAddressInterface
{   
protected $_storeManager;
protected $addressFactory;
protected $addressRepository;
protected $customerRepository;
protected $_customer; 
public function __construct(
    \Magento\Framework\ObjectManagerInterface $objectManager,
    \Magento\Store\Model\StoreManagerInterface $storeManager,
    \Magento\Customer\Model\AddressFactory $addressFactory,
    \Magento\Customer\Api\AddressRepositoryInterface $addressRepository,
    \Magento\Customer\Api\CustomerRepositoryInterface $customerRepository,
    \Magento\Customer\Model\Customer $customer
) {
    $this->_objectManager = $objectManager;
    $this->_storeManager = $storeManager;
    $this->_addressFactory = $addressFactory;
    $this->addressRepository = $addressRepository;
    $this->customerRepository = $customerRepository;
    $this->_customer = $customer;
}

/**
 * Returns greeting message to user
 *
 * @api
 * @param string $name Users name.
 * @return string Greeting message with users name.
 */
public function name($name) {
    return "Hello, " . $name;
}

public function addressUpdate($params) {

   public function addressUpdate($params) {
    //return 'Response: ' . json_encode($params);   
    $resultArr = array();
    $paramArr = array();
    $result =  json_encode($params);
    $resultSet = json_decode($result,true);

    $EntType = $resultSet['Entity_Type'];
    $customerId = $resultSet['Entity_Attributes']['CustomerId'];
    $AddressId = $resultSet['Entity_Attributes']['AddressId'];

    if(empty($customerId)){
        $resultArr['result'] = "Failed";
        $resultArr['message'] = "customerId shouldn't be empty!!!";
        $paramArr['Magento_ID'] = "";
        $paramArr['NAV_ID'] = "";
        $resultArr['parameters'] = $paramArr;
        echo json_encode($resultArr,JSON_PRETTY_PRINT);
        die;
    }else{  
        $address1 = $resultSet['Entity_Attributes']['Address'];         
        $address2 = $resultSet['Entity_Attributes']['Address2'];
        $City = $resultSet['Entity_Attributes']['City'];
        $County = $resultSet['Entity_Attributes']['County'];
        $PostCode = $resultSet['Entity_Attributes']['PostCode'];
        $PhoneNo = $resultSet['Entity_Attributes']['PhoneNo'];
        $Contact = $resultSet['Entity_Attributes']['Contact'];
        $MagentoDefault = $resultSet['Entity_Attributes']['MagentoDefault'];
        $Initials = $resultSet['Entity_Attributes']['Initials'];
        $FirstName = $resultSet['Entity_Attributes']['FirstName'];
        $Surname = $resultSet['Entity_Attributes']['Surname'];
        try{
            if(isset($AddressId) && $AddressId !=''){
                $address = $this->addressRepository->getById($AddressId);
                $address->setFirstname($FirstName);
                $address->setLastname($Surname);
                $address->setCountryId('GB');
                $address->setPostcode($PostCode);
                $address->setCity($City);
                $address->setPrefix($Initials);
                $address->setTelephone($PhoneNo);
                $this->addressRepository->save($address);
                $resultArr['message'] = "customer Address saved Sucessfully!!!";
                $paramArr['Address_Id'] = $addressId;
                $paramArr['NAV_ID'] = "";
                $resultArr['parameters'] = $paramArr;
                echo json_encode($resultArr,JSON_PRETTY_PRINT);
                die;
            }else{
                $customerObj = $this->_customer->load($customerId);
                $customerAddress = array();
                foreach($customerObj->getAddresses() as $address)
                {
                    $customerAddress[] = $address->toArray();
                }
                $addressId = $customerAddress[0]["entity_id"];
                if(isset($addressId) && $addressId != '' ){
                    $address = $this->addressRepository->getById($addressId);
                    $address->setFirstname($FirstName);
                    $address->setLastname($Surname);
                    $address->setCountryId('GB');
                    $address->setPostcode($PostCode);
                    $address->setCity($City);
                    $address->setPrefix($Initials);
                    $address->setTelephone($PhoneNo);
                    $this->addressRepository->save($address);
                    $resultArr['message'] = "customer Address saved Sucessfully!!!";
                    $paramArr['Address_Id'] = $addressId;
                    $paramArr['NAV_ID'] = "";
                    $resultArr['parameters'] = $paramArr;
                    echo json_encode($resultArr,JSON_PRETTY_PRINT);
                    die;
                }else{
                    $address = $this->_addressFactory->create();//->setStreet(Street)                   

                    $address->setCustomerId($customerId)
                        ->setFirstname($FirstName)
                        ->setLastname($Surname)
                        ->setCountryId('GB')
                        ->setPostcode($PostCode)
                        ->setCity($City)
                        ->setRegion($County)
                        ->setPrefix($Initials)
                        ->setStreet($address2)
                        ->setTelephone($PhoneNo)                    
                        ->setIsDefaultBilling('1')
                        ->setIsDefaultShipping('1')
                        ->setSaveInAddressBook('1');
                        $address->save();

                        $resultArr['message'] = "customer Address saved Sucessfully!!!";
                        $paramArr['Address_Id'] = $address->getId();
                        $paramArr['NAV_ID'] = "";
                        $resultArr['parameters'] = $paramArr;
                        echo json_encode($resultArr,JSON_PRETTY_PRINT);
                        die;
                    }                   

            }
        }
        catch(\Exception $e){
                $resultArr['result'] = "Failed";
                $resultArr['message'] = $e->getMessage();
                $paramArr['Magento_ID'] = '';
                $paramArr['NAV_ID'] = '';
                $resultArr['parameters'] = $paramArr;
        } 

        echo json_encode($resultArr,JSON_PRETTY_PRINT);
        die;
    }
}
}

I need to update customer address using customerId or addressId, How this can be done? if address id not exist i am trying to get addresId from customerId and updating else i am creating new address for customer.

Here is my request json.

{
 "params": {
"Entity_Type": "Address",
"Entity_Attributes": {
  "Name": "test",
  "CustomerId": "46897",
  "AddressId":"0",
  "Address": "test",
  "Address2": "test",
  "City": "Craigavon",
  "County": "test",
  "PostCode": "BT65 5BE",
  "PhoneNo": "656565656565",
  "FirstName": "test",
  "Surname": "test"
   }
 }
}