Feature/similar products

pom.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-starter-parent</artifactId>
+        <version>3.2.0</version>
+        <relativePath/>
+    </parent>
+
+    <groupId>com.zara</groupId>
+    <artifactId>similar-products-api</artifactId>
+    <version>1.0.0</version>
+    <packaging>jar</packaging>
+
+    <properties>
+        <java.version>17</java.version>
+        <maven.compiler.source>17</maven.compiler.source>
+        <maven.compiler.target>17</maven.compiler.target>
+        <testcontainers.version>1.19.3</testcontainers.version>
+        <archunit.version>1.2.1</archunit.version>
+    </properties>
+
+    <dependencies>
+        <!-- Spring Boot -->
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-webflux</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-validation</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-actuator</artifactId>
+        </dependency>
+
+        <!-- Testing -->
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>io.projectreactor</groupId>
+            <artifactId>reactor-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.testcontainers</groupId>
+            <artifactId>junit-jupiter</artifactId>
+            <version>${testcontainers.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.testcontainers</groupId>
+            <artifactId>mockserver</artifactId>
+            <version>${testcontainers.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>com.tngtech.archunit</groupId>
+            <artifactId>archunit-junit5</artifactId>
+            <version>${archunit.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.awaitility</groupId>
+            <artifactId>awaitility</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>com.squareup.okhttp3</groupId>
+            <artifactId>mockwebserver</artifactId>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-maven-plugin</artifactId>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-surefire-plugin</artifactId>
+                <configuration>
+                    <includes>
+                        <include>**/*Test.java</include>
+                        <include>**/*Tests.java</include>
+                    </includes>
+                </configuration>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-failsafe-plugin</artifactId>
+                <configuration>
+                    <includes>
+                        <include>**/*IT.java</include>
+                        <include>**/*IntegrationTest.java</include>
+                    </includes>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+</project>

src/main/java/com/zara/similarproducts/SimilarProductsApplication.java

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+package com.zara.similarproducts;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class SimilarProductsApplication {
+
+    public static void main(String[] args) {
+        SpringApplication.run(SimilarProductsApplication.class, args);
+    }
+}

src/main/java/com/zara/similarproducts/application/port/in/GetSimilarProductsUseCase.java

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+package com.zara.similarproducts.application.port.in;
+
+import com.zara.similarproducts.domain.model.ProductId;
+import com.zara.similarproducts.domain.model.SimilarProducts;
+import reactor.core.publisher.Mono;
+
+public interface GetSimilarProductsUseCase {
+
+    Mono<SimilarProducts> execute(ProductId productId);
+}

src/main/java/com/zara/similarproducts/application/port/out/ProductRepository.java

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+package com.zara.similarproducts.application.port.out;
+
+import com.zara.similarproducts.domain.model.Product;
+import com.zara.similarproducts.domain.model.ProductId;
+import reactor.core.publisher.Mono;
+
+public interface ProductRepository {
+
+    Mono<Product> findById(ProductId productId);
+}

src/main/java/com/zara/similarproducts/application/port/out/SimilarProductsRepository.java

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+package com.zara.similarproducts.application.port.out;
+
+import com.zara.similarproducts.domain.model.ProductId;
+import reactor.core.publisher.Flux;
+
+public interface SimilarProductsRepository {
+
+    Flux<ProductId> findSimilarProductIds(ProductId productId);
+}

src/main/java/com/zara/similarproducts/application/usecase/GetSimilarProductsUseCaseImpl.java

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+package com.zara.similarproducts.application.usecase;
+
+import com.zara.similarproducts.application.port.in.GetSimilarProductsUseCase;
+import com.zara.similarproducts.domain.model.ProductId;
+import com.zara.similarproducts.domain.model.SimilarProducts;
+import com.zara.similarproducts.domain.service.SimilarProductsDomainService;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.stereotype.Service;
+import reactor.core.publisher.Mono;
+
+import java.time.Duration;
+
+@Service
+public class GetSimilarProductsUseCaseImpl implements GetSimilarProductsUseCase {
+
+    private static final Logger logger = LoggerFactory.getLogger(GetSimilarProductsUseCaseImpl.class);
+    private static final Duration TIMEOUT = Duration.ofSeconds(10);
+
+    private final SimilarProductsDomainService domainService;
+
+    public GetSimilarProductsUseCaseImpl(SimilarProductsDomainService domainService) {
+        this.domainService = domainService;
+    }
+
+    @Override
+    public Mono<SimilarProducts> execute(ProductId productId) {
+        logger.info("Executing GetSimilarProducts use case for product: {}", productId.value());
+
+        return domainService.findSimilarProducts(productId)
+                .timeout(TIMEOUT)
+                .doOnSuccess(result -> logger.info("Found {} similar products for product: {}", 
+                    result.size(), productId.value()))
+                .doOnError(error -> logger.error("Error finding similar products for product: {}", 
+                    productId.value(), error));
+    }
+}

src/main/java/com/zara/similarproducts/domain/model/DomainException.java

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+package com.zara.similarproducts.domain.model;
+
+public abstract class DomainException extends RuntimeException {
+
+    protected DomainException(String message) {
+        super(message);
+    }
+
+    protected DomainException(String message, Throwable cause) {
+        super(message, cause);
+    }
+
+    public abstract String getErrorCode();
+}

src/main/java/com/zara/similarproducts/domain/model/ExternalServiceException.java

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+package com.zara.similarproducts.domain.model;
+
+public class ExternalServiceException extends DomainException {
+
+    private static final String ERROR_CODE = "EXTERNAL_SERVICE_ERROR";
+
+    public ExternalServiceException(String message) {
+        super(message);
+    }
+
+    public ExternalServiceException(String message, Throwable cause) {
+        super(message, cause);
+    }
+
+    @Override
+    public String getErrorCode() {
+        return ERROR_CODE;
+    }
+}

src/main/java/com/zara/similarproducts/domain/model/InvalidProductIdException.java

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+package com.zara.similarproducts.domain.model;
+
+public class InvalidProductIdException extends DomainException {
+
+    private static final String ERROR_CODE = "INVALID_PRODUCT_ID";
+    private final String productId;
+
+    public InvalidProductIdException(String productId) {
+        super("Invalid product ID format: " + productId);
+        this.productId = productId;
+    }
+
+    public String getProductId() {
+        return productId;
+    }
+
+    @Override
+    public String getErrorCode() {
+        return ERROR_CODE;
+    }
+}

src/main/java/com/zara/similarproducts/domain/model/Product.java

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+package com.zara.similarproducts.domain.model;
+
+import java.math.BigDecimal;
+import java.util.Objects;
+
+public record Product(
+        ProductId id,
+        String name,
+        BigDecimal price,
+        boolean availability
+) {
+
+    public Product {
+        Objects.requireNonNull(id, "Product ID cannot be null");
+        Objects.requireNonNull(name, "Product name cannot be null");
+        Objects.requireNonNull(price, "Product price cannot be null");
+
+        if (name.isBlank()) {
+            throw new IllegalArgumentException("Product name cannot be blank");
+        }
+        if (price.compareTo(BigDecimal.ZERO) < 0) {
+            throw new IllegalArgumentException("Product price cannot be negative");
+        }
+    }
+
+    public static Product of(ProductId id, String name, BigDecimal price, boolean availability) {
+        return new Product(id, name, price, availability);
+    }
+}

src/main/java/com/zara/similarproducts/domain/model/ProductId.java

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+package com.zara.similarproducts.domain.model;
+
+import java.util.Objects;
+
+public record ProductId(String value) {
+
+    public ProductId {
+        Objects.requireNonNull(value, "Product ID cannot be null");
+        if (value.isBlank()) {
+            throw new InvalidProductIdException(value);
+        }
+        if (!value.matches("^[0-9]+$")) {
+            throw new InvalidProductIdException(value);
+        }
+    }
+
+    public static ProductId of(String value) {
+        return new ProductId(value);
+    }
+}

src/main/java/com/zara/similarproducts/domain/model/ProductNotFoundException.java

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+package com.zara.similarproducts.domain.model;
+
+public class ProductNotFoundException extends DomainException {
+
+    private static final String ERROR_CODE = "PRODUCT_NOT_FOUND";
+    private final ProductId productId;
+
+    public ProductNotFoundException(ProductId productId) {
+        super("Product not found: " + productId.value());
+        this.productId = productId;
+    }
+
+    public ProductId getProductId() {
+        return productId;
+    }
+
+    @Override
+    public String getErrorCode() {
+        return ERROR_CODE;
+    }
+}

src/main/java/com/zara/similarproducts/domain/model/SimilarProducts.java

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+package com.zara.similarproducts.domain.model;
+
+import java.util.List;
+import java.util.Objects;
+
+public record SimilarProducts(List<Product> products) {
+
+    public SimilarProducts {
+        Objects.requireNonNull(products, "Products list cannot be null");
+    }
+
+    public static SimilarProducts of(List<Product> products) {
+        Objects.requireNonNull(products, "Products list cannot be null");
+        return new SimilarProducts(List.copyOf(products));
+    }
+
+    public static SimilarProducts empty() {
+        return new SimilarProducts(List.of());
+    }
+
+    public boolean isEmpty() {
+        return products.isEmpty();
+    }
+
+    public int size() {
+        return products.size();
+    }
+}