added inventory service to check if product and sufficient quantity is...

added inventory service to check if product and sufficient quantity is available before placing the order

inventory-service/pom.xml

+<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.nisum</groupId>
+        <artifactId>ordering-app</artifactId>
+        <version>1.0-SNAPSHOT</version>
+    </parent>
+
+    <artifactId>inventory-service</artifactId>
+    <packaging>jar</packaging>
+
+    <name>inventory-service</name>
+    <url>http://maven.apache.org</url>
+
+    <properties>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    </properties>
+
+    <dependencies>
+        <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-webflux -->
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-webflux</artifactId>
+            <version>3.4.0</version>
+        </dependency>
+        <!-- https://mvnrepository.com/artifact/org.projectlombok/lombok -->
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <version>1.18.12</version>
+            <scope>provided</scope>
+        </dependency>
+        <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-data-mongodb-reactive -->
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-data-mongodb-reactive</artifactId>
+            <version>3.4.0</version>
+        </dependency>
+        <dependency>
+            <groupId>org.slf4j</groupId>
+            <artifactId>slf4j-api</artifactId>
+            <version>2.0.16</version>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+            <version>3.4.1</version>
+        </dependency>
+        <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-logging -->
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-logging</artifactId>
+            <version>3.4.2</version>
+        </dependency>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>3.8.1</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+</project>

inventory-service/src/main/java/org/nisum/InventoryServiceApplication.java

+package org.nisum;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+/**
+ * Hello world!
+ *
+ */
+@SpringBootApplication
+public class InventoryServiceApplication
+{
+    public static void main( String[] args )
+    {
+        SpringApplication.run(InventoryServiceApplication.class);
+    }
+}

inventory-service/src/main/java/org/nisum/controller/InventoryController.java

+package org.nisum.controller;
+
+import org.nisum.model.Inventory;
+import org.nisum.service.InventoryService;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.*;
+import reactor.core.publisher.Mono;
+
+@RestController
+@RequestMapping("/inventory")
+public class InventoryController {
+
+    @Autowired
+    private InventoryService inventoryService;
+
+    @PostMapping("/create")
+    public Mono<Inventory> AddProductToInventory(@RequestBody Inventory inventory){
+        return inventoryService.createInventory(inventory);
+    }
+
+    @GetMapping("/check/{productId}/{quantity}")
+    public ResponseEntity<Boolean> checkProductAvailability(@PathVariable("productId") String productId, @PathVariable("quantity") int quantity){
+        return inventoryService.checkProductAvailability(productId,quantity);
+    }
+
+
+}

inventory-service/src/main/java/org/nisum/model/Inventory.java

+package org.nisum.model;
+
+
+import lombok.Data;
+import org.springframework.data.annotation.Id;
+import org.springframework.data.mongodb.core.mapping.Document;
+
+import java.time.LocalDateTime;
+
+@Data
+@Document(collection = "inventory")
+public class Inventory {
+    @Id
+    private String id;
+    private String productId;
+    private boolean inStock;
+    private int quantity;
+    private LocalDateTime timeStamp;
+}

inventory-service/src/main/java/org/nisum/repository/InventoryRepository.java

+package org.nisum.repository;
+
+import org.nisum.model.Inventory;
+import org.springframework.data.mongodb.repository.ReactiveMongoRepository;
+import org.springframework.stereotype.Repository;
+
+import java.util.Optional;
+
+@Repository
+public interface InventoryRepository extends ReactiveMongoRepository<Inventory,String> {
+    Optional<Inventory> findByProductId(String productId);
+}

inventory-service/src/main/java/org/nisum/service/InventoryService.java

+package org.nisum.service;
+
+import org.nisum.model.Inventory;
+import org.nisum.repository.InventoryRepository;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.http.ResponseEntity;
+import org.springframework.stereotype.Service;
+import reactor.core.publisher.Mono;
+
+import java.time.LocalDateTime;
+import java.util.Optional;
+
+@Service
+public class InventoryService {
+
+    @Autowired
+    private InventoryRepository inventoryRepository;
+
+    public static final Logger log = LoggerFactory.getLogger(InventoryService.class);
+    public Mono<Inventory> createInventory(Inventory inventory) {
+        inventory.setTimeStamp(LocalDateTime.now());
+        inventory.setInStock(true);
+        return inventoryRepository.save(inventory).doOnSuccess(inventory1 -> {
+            log.info("product with product id: "+inventory1.getProductId() + " added successfully to the inventory");
+        });
+    }
+
+    public ResponseEntity<Boolean> checkProductAvailability(String productId, int requiredQuantity){
+        Inventory inventory = inventoryRepository.findByProductId(productId).orElse(null);
+
+        if(inventory != null){
+            if(inventory.getQuantity() >= requiredQuantity){
+                return ResponseEntity.ok(true);
+            }else{
+                return ResponseEntity.ok(false);
+            }
+        }else {
+            return ResponseEntity.ok(false);
+        }
+    }
+}

inventory-service/src/main/resources/application.yml

+server:
+  port: 8082
+spring:
+  data:
+    mongodb:
+      uri: mongodb://localhost:27017/inventory_db
\ No newline at end of file

inventory-service/src/test/java/org/nisum/InventoryServiceApplicationTest.java

+package org.nisum;
+
+import junit.framework.Test;
+import junit.framework.TestCase;
+import junit.framework.TestSuite;
+
+/**
+ * Unit test for simple App.
+ */
+public class InventoryServiceApplicationTest
+    extends TestCase
+{
+    /**
+     * Create the test case
+     *
+     * @param testName name of the test case
+     */
+    public InventoryServiceApplicationTest(String testName )
+    {
+        super( testName );
+    }
+
+    /**
+     * @return the suite of tests being tested
+     */
+    public static Test suite()
+    {
+        return new TestSuite( InventoryServiceApplicationTest.class );
+    }
+
+    /**
+     * Rigourous Test :-)
+     */
+    public void testApp()
+    {
+        assertTrue( true );
+    }
+}

order-service/src/main/java/org/nisum/config/WebClientConfig.java

+package org.nisum.config;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.web.reactive.function.client.WebClient;
+
+@Configuration
+public class WebClientConfig {
+
+    @Bean
+    public WebClient.Builder webClientBuilder(){
+        return WebClient.builder();
+    }
+}

order-service/src/main/java/org/nisum/controller/OrderController.java

@@ -18,10 +18,15 @@ public class OrderController {
     }
 
 //    @PostMapping("/createOrder")
-//    public Mono<Order> createOrder(@RequestBody Order order){
+//    public Mono<String> createOrder(@RequestBody Order order){
 //        return orderService.createOrder(order);
 //    }
 
+    @PostMapping("/place")
+    public Mono<String> placeOrder(@RequestParam(name = "productId") String productId, @RequestParam(name = "quantity") int quantity){
+        return orderService.placeOrder(productId,quantity);
+    }
+
 //    @GetMapping("/{id}")
 //    public Mono<Order> getOrderById(@PathVariable String id){
 //        return orderService.getOrderById(id);

order-service/src/main/java/org/nisum/service/OrderService.java

@@ -14,6 +14,7 @@ import org.springframework.data.domain.Sort;
 import org.springframework.data.mongodb.core.ReactiveMongoTemplate;
 import org.springframework.kafka.core.KafkaTemplate;
 import org.springframework.stereotype.Service;
+import org.springframework.web.reactive.function.client.WebClient;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 
@@ -27,26 +28,50 @@ public class OrderService {
 
     @Autowired
     private OrderRepository orderRepository;
-    @Autowired
-    private ReactiveMongoTemplate reactiveMongoTemplate;
 //    private final KafkaTemplate<String,String> kafkaTemplate;
 
+    private final WebClient webClient;
 
+    @Autowired
+    public OrderService(WebClient.Builder webClientBuilder) {
+        this.webClient = webClientBuilder.baseUrl("http://localhost:8082/inventory").build();
+    }
 
-//    public Mono<Order> createOrder(Order order){
-//
-//        if(order.getProductId() == null){
-//            return Mono.error(new OrderNotFoundException("Order Id cannot be null"));
-//        }
-//        order.setStatus("Placed");
-//        order.setTimeStamp(LocalDateTime.now());
-//        return orderRepository.save(order).doOnSuccess(
-//                order1 -> kafkaTemplate
-//                        .send("order-status-topic",
-//                                "Order with product id: " + order1.getProductId()
-//                                +" is placed successfully" ));
-//
-//    }
+    public Mono<String> placeOrder(String productId, int quantity){
+        return checkProductAvailability(productId, quantity)
+                .flatMap(isAvailable -> {
+                    if(isAvailable){
+                        return createOrder(productId,quantity);
+                    }
+                    return Mono.just("Product is out of stock or insufficient quantity.");
+                });
+
+    }
+
+    private Mono<Boolean> checkProductAvailability(String productId, int quantity){
+        return webClient.get()
+                .uri("/check/{productId}/{quantity}")
+                .retrieve()
+                .bodyToMono(Boolean.class);
+    }
+
+
+
+    private Mono<String> createOrder(String productId, int quantity){
+        Order order = new Order();
+        if(productId == null){
+            log.error("product id cannot be null");
+        }
+        order.setStatus("Placed");
+        order.setTimeStamp(LocalDateTime.now());
+        order.setProductId(productId);
+        order.setQuantity(quantity);
+        orderRepository.save(order).doOnSuccess(order1 -> {
+            log.info("order with order id: " + order1.getId() + " placed successfully");
+        });
+        return Mono.just("Order placed successfully for product " + order.getProductId());
+
+    }
 
     public Flux<Order> getAllOrders(int page, int size) {
         Pageable pageable = PageRequest.of(page,size);

pom.xml

@@ -12,6 +12,7 @@
   <modules>
     <module>notification-service</module>
     <module>order-service</module>
+    <module>inventory-service</module>
   </modules>
 
   <properties>