feat(inqcust): translate INQCUST to Java

.github/workflows/ci.yml

@@ -11,7 +11,8 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 30
     env:
-      COCKROACH_URL: jdbc:postgresql://localhost:26257/cbsa?sslmode=disable
+      CBSA_TESTS_USE_LOCAL_COCKROACH: "true"
+      COCKROACH_URL: jdbc:postgresql://localhost:26257/cbsa_test?sslmode=disable
       COCKROACH_USER: root
       COCKROACH_PASSWORD: ""
     steps:
@@ -54,7 +55,7 @@ jobs:
             sleep 1
           done
           cockroach sql --insecure --host=localhost:26257 \
-            -e "CREATE DATABASE IF NOT EXISTS cbsa"
+            -e "CREATE DATABASE IF NOT EXISTS cbsa_test"
 
       - name: Build and verify
         run: ./mvnw -B -ntp verify

src/main/java/com/augment/cbsa/CbsaApplication.java

@@ -1,11 +1,19 @@
 package com.augment.cbsa;
 
+import com.augment.cbsa.service.RandomCustomerNumberGenerator;
+import java.util.concurrent.ThreadLocalRandom;
+import org.springframework.context.annotation.Bean;
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 
 @SpringBootApplication
 public class CbsaApplication {
 
+    @Bean
+    RandomCustomerNumberGenerator randomCustomerNumberGenerator() {
+        return highestCustomerNumber -> ThreadLocalRandom.current().nextLong(1, highestCustomerNumber + 1);
+    }
+
     public static void main(String[] args) {
         SpringApplication.run(CbsaApplication.class, args);
     }

src/main/java/com/augment/cbsa/domain/CustomerDetails.java

@@ -0,0 +1,26 @@
+package com.augment.cbsa.domain;
+
+import java.time.LocalDate;
+import java.util.Objects;
+
+public record CustomerDetails(
+        String sortcode,
+        long customerNumber,
+        String name,
+        String address,
+        LocalDate dateOfBirth,
+        int creditScore,
+        LocalDate csReviewDate
+) {
+
+    public CustomerDetails {
+        Objects.requireNonNull(sortcode, "sortcode must not be null");
+        Objects.requireNonNull(name, "name must not be null");
+        Objects.requireNonNull(address, "address must not be null");
+        Objects.requireNonNull(dateOfBirth, "dateOfBirth must not be null");
+
+        if (creditScore < 0 || creditScore > 999) {
+            throw new IllegalArgumentException("creditScore must be between 0 and 999");
+        }
+    }
+}

src/main/java/com/augment/cbsa/domain/InqcustRequest.java

@@ -0,0 +1,4 @@
+package com.augment.cbsa.domain;
+
+public record InqcustRequest(long customerNumber) {
+}

src/main/java/com/augment/cbsa/domain/InqcustResult.java

@@ -0,0 +1,45 @@
+package com.augment.cbsa.domain;
+
+import java.util.Objects;
+
+public record InqcustResult(
+        boolean inquirySuccess,
+        String failCode,
+        long customerNumber,
+        CustomerDetails customer,
+        String message
+) {
+
+    public InqcustResult {
+        Objects.requireNonNull(failCode, "failCode must not be null");
+
+        if (inquirySuccess && customer == null) {
+            throw new IllegalArgumentException("Successful results must include a customer");
+        }
+
+        if (!inquirySuccess && customer != null) {
+            throw new IllegalArgumentException("Failure results must not include a customer");
+        }
+
+        if (!inquirySuccess && (message == null || message.isBlank())) {
+            throw new IllegalArgumentException("Failure results must include a non-blank message");
+        }
+    }
+
+    public static InqcustResult success(CustomerDetails customer) {
+        Objects.requireNonNull(customer, "customer must not be null");
+        return new InqcustResult(true, "0", customer.customerNumber(), customer, null);
+    }
+
+    public static InqcustResult failure(String failCode, long customerNumber, String message) {
+        return new InqcustResult(false, failCode, customerNumber, null, message);
+    }
+
+    public boolean isNotFoundFailure() {
+        return !inquirySuccess && "1".equals(failCode);
+    }
+
+    public boolean isRandomRetryExhaustedFailure() {
+        return !inquirySuccess && "R".equals(failCode);
+    }
+}

src/main/java/com/augment/cbsa/error/CbsaAbendException.java

@@ -0,0 +1,22 @@
+package com.augment.cbsa.error;
+
+import java.util.Objects;
+
+public class CbsaAbendException extends RuntimeException {
+
+    private final String abendCode;
+
+    public CbsaAbendException(String abendCode, String message) {
+        super(message);
+        this.abendCode = Objects.requireNonNull(abendCode, "abendCode must not be null");
+    }
+
+    public CbsaAbendException(String abendCode, String message, Throwable cause) {
+        super(message, cause);
+        this.abendCode = Objects.requireNonNull(abendCode, "abendCode must not be null");
+    }
+
+    public String getAbendCode() {
+        return abendCode;
+    }
+}

src/main/java/com/augment/cbsa/error/CbsaExceptionHandler.java

@@ -0,0 +1,54 @@
+package com.augment.cbsa.error;
+
+import jakarta.validation.ConstraintViolationException;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ProblemDetail;
+import org.springframework.http.ResponseEntity;
+import org.springframework.validation.BindException;
+import org.springframework.web.bind.MethodArgumentNotValidException;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.bind.annotation.RestControllerAdvice;
+import org.springframework.web.method.annotation.HandlerMethodValidationException;
+
+@RestControllerAdvice
+public class CbsaExceptionHandler {
+
+    private static final Logger logger = LoggerFactory.getLogger(CbsaExceptionHandler.class);
+
+    @ExceptionHandler({
+            MethodArgumentNotValidException.class,
+            BindException.class,
+            HandlerMethodValidationException.class,
+            ConstraintViolationException.class
+    })
+    public ResponseEntity<ProblemDetail> handleValidation(Exception exception) {
+        ProblemDetail problemDetail = ProblemDetail.forStatus(HttpStatus.BAD_REQUEST);
+        problemDetail.setTitle("Validation failed");
+        problemDetail.setDetail("Request validation failed.");
+        return ResponseEntity.badRequest().body(problemDetail);
+    }
+
+    @ExceptionHandler(CbsaAbendException.class)
+    public ResponseEntity<ProblemDetail> handleAbend(CbsaAbendException exception) {
+        logger.error("CBSA abend while processing request [abendCode={}]", exception.getAbendCode(), exception);
+
+        ProblemDetail problemDetail = ProblemDetail.forStatus(HttpStatus.INTERNAL_SERVER_ERROR);
+        problemDetail.setTitle("CBSA abend");
+        problemDetail.setDetail("Service abend");
+        problemDetail.setProperty("abendCode", exception.getAbendCode());
+        return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body(problemDetail);
+    }
+
+    @ExceptionHandler(Exception.class)
+    public ResponseEntity<ProblemDetail> handleUnexpected(Exception exception) {
+        logger.error("Unhandled exception while processing request", exception);
+
+        ProblemDetail problemDetail = ProblemDetail.forStatus(HttpStatus.INTERNAL_SERVER_ERROR);
+        problemDetail.setTitle("Unexpected error");
+        problemDetail.setDetail("Internal server error");
+        problemDetail.setProperty("abendCode", "UNEX");
+        return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body(problemDetail);
+    }
+}

src/main/java/com/augment/cbsa/error/CbsaFailureResponse.java

@@ -0,0 +1,11 @@
+package com.augment.cbsa.error;
+
+import java.util.Objects;
+
+public record CbsaFailureResponse(String failCode, String message) {
+
+    public CbsaFailureResponse {
+        Objects.requireNonNull(failCode, "failCode must not be null");
+        Objects.requireNonNull(message, "message must not be null");
+    }
+}

src/main/java/com/augment/cbsa/repository/CustomerRepository.java

@@ -0,0 +1,46 @@
+package com.augment.cbsa.repository;
+
+import com.augment.cbsa.domain.CustomerDetails;
+import com.augment.cbsa.jooq.tables.records.CustomerRecord;
+import java.util.Optional;
+import org.jooq.DSLContext;
+import org.springframework.stereotype.Repository;
+
+import static com.augment.cbsa.jooq.Tables.CUSTOMER;
+
+@Repository
+public class CustomerRepository {
+
+    private final DSLContext dsl;
+
+    public CustomerRepository(DSLContext dsl) {
+        this.dsl = dsl;
+    }
+
+    public Optional<CustomerDetails> findBySortcodeAndCustomerNumber(String sortcode, long customerNumber) {
+        return dsl.selectFrom(CUSTOMER)
+                .where(CUSTOMER.SORTCODE.eq(sortcode))
+                .and(CUSTOMER.CUSTOMER_NUMBER.eq(customerNumber))
+                .fetchOptional(this::toDomain);
+    }
+
+    public Optional<CustomerDetails> findLastBySortcode(String sortcode) {
+        return dsl.selectFrom(CUSTOMER)
+                .where(CUSTOMER.SORTCODE.eq(sortcode))
+                .orderBy(CUSTOMER.CUSTOMER_NUMBER.desc())
+                .limit(1)
+                .fetchOptional(this::toDomain);
+    }
+
+    private CustomerDetails toDomain(CustomerRecord record) {
+        return new CustomerDetails(
+                record.getSortcode(),
+                record.getCustomerNumber(),
+                record.getName(),
+                record.getAddress(),
+                record.getDateOfBirth(),
+                record.getCreditScore() == null ? 0 : record.getCreditScore(),
+                record.getCsReviewDate()
+        );
+    }
+}

src/main/java/com/augment/cbsa/service/InqcustService.java

@@ -0,0 +1,92 @@
+package com.augment.cbsa.service;
+
+import com.augment.cbsa.domain.CustomerDetails;
+import com.augment.cbsa.domain.InqcustRequest;
+import com.augment.cbsa.domain.InqcustResult;
+import com.augment.cbsa.error.CbsaAbendException;
+import com.augment.cbsa.repository.CustomerRepository;
+import java.util.Objects;
+import java.util.Optional;
+import org.jooq.exception.DataAccessException;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.stereotype.Service;
+
+@Service
+public class InqcustService {
+
+    private static final String ABEND_CODE = "CVR1";
+    private static final String NO_CUSTOMERS_EXIST_MESSAGE = "No customers exist.";
+    private static final String NOT_FOUND_CODE = "1";
+    private static final String RANDOM_RETRY_EXHAUSTED_CODE = "R";
+    private static final long RANDOM_CUSTOMER_NUMBER = 0L;
+    private static final long LAST_CUSTOMER_NUMBER = 9_999_999_999L;
+    private static final int RANDOM_RETRY_LIMIT = 1000;
+
+    private final CustomerRepository customerRepository;
+    private final RandomCustomerNumberGenerator randomCustomerNumberGenerator;
+    private final String sortcode;
+
+    public InqcustService(
+            CustomerRepository customerRepository,
+            @Value("${cbsa.sortcode}") String sortcode,
+            RandomCustomerNumberGenerator randomCustomerNumberGenerator
+    ) {
+        this.customerRepository = customerRepository;
+        this.sortcode = sortcode;
+        this.randomCustomerNumberGenerator = randomCustomerNumberGenerator;
+    }
+
+    public InqcustResult inquire(InqcustRequest request) {
+        Objects.requireNonNull(request, "request must not be null");
+
+        try {
+            long customerNumber = request.customerNumber();
+
+            if (customerNumber == RANDOM_CUSTOMER_NUMBER) {
+                return findRandomCustomer();
+            }
+
+            if (customerNumber == LAST_CUSTOMER_NUMBER) {
+                return customerRepository.findLastBySortcode(sortcode)
+                        .map(InqcustResult::success)
+                        .orElseGet(() -> InqcustResult.failure(
+                                NOT_FOUND_CODE,
+                                customerNumber,
+                                NO_CUSTOMERS_EXIST_MESSAGE
+                        ));
+            }
+
+            return customerRepository.findBySortcodeAndCustomerNumber(sortcode, customerNumber)
+                    .map(InqcustResult::success)
+                    .orElseGet(() -> InqcustResult.failure(
+                            NOT_FOUND_CODE,
+                            customerNumber,
+                            "Customer number %d was not found.".formatted(customerNumber)
+                    ));
+        } catch (DataAccessException exception) {
+            throw new CbsaAbendException(ABEND_CODE, "INQCUST failed to read the customer data.", exception);
+        }
+    }
+
+    private InqcustResult findRandomCustomer() {
+        Optional<CustomerDetails> lastCustomer = customerRepository.findLastBySortcode(sortcode);
+        if (lastCustomer.isEmpty() || lastCustomer.get().customerNumber() < 1) {
+            return InqcustResult.failure(NOT_FOUND_CODE, RANDOM_CUSTOMER_NUMBER, NO_CUSTOMERS_EXIST_MESSAGE);
+        }
+
+        long highestCustomerNumber = lastCustomer.get().customerNumber();
+        for (int attempt = 0; attempt < RANDOM_RETRY_LIMIT; attempt++) {
+            long candidate = randomCustomerNumberGenerator.nextCustomerNumber(highestCustomerNumber);
+            Optional<CustomerDetails> customer = customerRepository.findBySortcodeAndCustomerNumber(sortcode, candidate);
+            if (customer.isPresent()) {
+                return InqcustResult.success(customer.get());
+            }
+        }
+
+        return InqcustResult.failure(
+                RANDOM_RETRY_EXHAUSTED_CODE,
+                RANDOM_CUSTOMER_NUMBER,
+                "Unable to find a random customer after exhausting retry attempts."
+        );
+    }
+}

src/main/java/com/augment/cbsa/service/RandomCustomerNumberGenerator.java

@@ -0,0 +1,7 @@
+package com.augment.cbsa.service;
+
+@FunctionalInterface
+public interface RandomCustomerNumberGenerator {
+
+    long nextCustomerNumber(long highestCustomerNumber);
+}