CustomerRepo.kt

import software.amazon.awssdk.services.dynamodb.DynamoDbAsyncClient
import software.amazon.awssdk.services.dynamodb.model.*
import java.util.concurrent.CompletableFuture

class CustomerRepo(private val client: DynamoDbAsyncClient,
                   private val customerTableName: String) {

    fun saveCustomer(customer: CustomerPersist): CompletableFuture<PutItemResponse> {
        val putItemRequest = PutItemRequest.builder()
            .item(
                mapOf(
                    "customerId" to AttributeValue.builder().s(customer.customerId).build(),
                    "emailAddress" to AttributeValue.builder().s(customer.emailAddress).build(),
                    "firstName" to AttributeValue.builder().s(customer.firstName).build(),
                    "lastName" to AttributeValue.builder().s(customer.lastName).build()
                )
            )
            .tableName(customerTableName)
            .build()

        return client.putItem(putItemRequest)
    }

    fun retrieveCustomer(customerId: String): CustomerPersist {
        val getItemRequest = GetItemRequest.builder()
            .key(mapOf("customerId" to AttributeValue.builder().s(customerId).build()))
            .tableName(customerTableName)
            .build()

        return client.getItem(getItemRequest).get()
            .let { getItemResponse: GetItemResponse ->
                CustomerPersist(
                    customerId,
                    (getItemResponse.item()["emailAddress"] ?: error("emailAddress N/A")).s(),
                    (getItemResponse.item()["firstName"] ?: error("firstName N/A")).s(),
                    (getItemResponse.item()["lastName"] ?: error("lastName N/A")).s())
            }
    }
}