feat: adding promo code and checkout logic and tests

pom.xml

@@ -55,6 +55,11 @@
             <version>2.8.5</version>
         </dependency>
 
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-amqp</artifactId>
+        </dependency>
+
         <!-- Logging -->
         <dependency>
             <groupId>net.logstash.logback</groupId>
@@ -87,7 +92,7 @@
         <dependency>
             <groupId>org.mockito</groupId>
             <artifactId>mockito-core</artifactId>
-            <version>5.5.0</version>
+            <version>5.12.0</version>
             <scope>test</scope>
         </dependency>
         <!-- Mockito JUnit 5 Extension -->

src/main/java/cart/config/RabbitMQConfig.java

@@ -0,0 +1,50 @@
+package cart.config;
+
+//import org.springframework.amqp.core.Binding;
+//import org.springframework.amqp.core.BindingBuilder;
+//import org.springframework.amqp.core.Queue;
+import org.springframework.amqp.core.TopicExchange;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+public class RabbitMQConfig {
+
+    @Value("${rabbitmq.exchange.name}")
+    private String exchangeName;
+
+    @Value("${rabbitmq.routing.key.checkout}")
+    private String checkoutRoutingKey;
+
+    // Define the exchange (e.g., a Topic Exchange)
+    @Bean
+    TopicExchange cartEventsExchange() {
+        return new TopicExchange(exchangeName);
+    }
+
+    // Note: The Cart Service *produces* messages. The *consumer* (Order Service)
+    // would typically define the Queue and the Binding. However, defining the
+    // exchange here is good practice for the producer.
+    // If the Cart service also needed to *consume* events (e.g., order confirmations),
+    // you would define Queues and Bindings here as well.
+
+    /* Example Consumer setup (would be in Order Service):
+    @Value("${rabbitmq.queue.name.order}") // e.g., q.order.checkout
+    private String orderQueueName;
+
+    @Bean
+    Queue orderQueue() {
+        return new Queue(orderQueueName, true); // durable=true
+    }
+
+    @Bean
+    Binding orderBinding(Queue orderQueue, TopicExchange cartEventsExchange) {
+        return BindingBuilder.bind(orderQueue).to(cartEventsExchange).with(checkoutRoutingKey);
+    }
+    */
+
+    // You might also need a MessageConverter bean (e.g., Jackson2JsonMessageConverter)
+    // if you haven't configured one globally, to ensure your CheckoutEvent object
+    // is serialized correctly (usually auto-configured by Spring Boot).
+}

src/main/java/cart/controller/CartController.java

@@ -238,4 +238,45 @@ public ResponseEntity<Cart> checkoutCart(
                     + "communicating with Order Service");
         }
     }
+
+    @Operation(summary = "Apply a promo code to the cart")
+    @ApiResponses(value = {
+            @ApiResponse(responseCode = "200",
+                    description = "Promo code applied successfully"),
+            @ApiResponse(responseCode = "400",
+                    description = "Invalid or expired promo code"),
+            @ApiResponse(responseCode = "404",
+                    description = "Active cart not found")
+    })
+    @PostMapping("/{customerId}/promo/{promoCode}")
+    public ResponseEntity<Cart> applyPromoCode(
+            @PathVariable("customerId") final String customerId,
+            @PathVariable("promoCode") final String promoCode) {
+        log.debug("Entering applyPromoCode endpoint with "
+                + "customerId: {}, promoCode: {}",
+                customerId, promoCode);
+        Cart updatedCart = cartService.applyPromoCode(
+                customerId, promoCode);
+        log.debug("Promo code applied, updated cart: "
+                + "{}", updatedCart);
+        return ResponseEntity.ok(updatedCart);
+    }
+
+    @Operation(summary = "Remove the applied promo code from the cart")
+    @ApiResponses(value = {
+            @ApiResponse(responseCode = "200",
+                    description = "Promo code removed successfully"),
+            @ApiResponse(responseCode = "404",
+                    description = "Active cart not found")
+    })
+    @DeleteMapping("/{customerId}/promo")
+    public ResponseEntity<Cart> removePromoCode(
+            @PathVariable("customerId") final String customerId) {
+        log.debug("Entering removePromoCode "
+                + "endpoint with customerId: {}", customerId);
+        Cart updatedCart = cartService.removePromoCode(customerId);
+        log.debug("Promo code removed (if any),"
+                + " updated cart: {}", updatedCart);
+        return ResponseEntity.ok(updatedCart);
+    }
 }

src/main/java/cart/controller/PromoCodeController.java

@@ -0,0 +1,72 @@
+package cart.controller;
+
+import cart.model.PromoCode;
+import cart.service.PromoCodeService;
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.tags.Tag;
+import jakarta.validation.Valid;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.DeleteMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+
+
+import java.util.List;
+
+@RestController
+@RequestMapping("/api/admin/promocodes")
+@RequiredArgsConstructor
+@Tag(name = "PromoCode Admin", description = "Manage promotional codes (Requires Admin Role)")
+@Slf4j
+public class PromoCodeController {
+
+    private final PromoCodeService promoCodeService;
+
+    @Operation(summary = "Create a Promo Code")
+    @PostMapping
+    public ResponseEntity<PromoCode> createOrUpdatePromoCode(
+            @Valid @RequestBody final PromoCode promoCode) {
+        log.info("Admin request to create promo code: {}", promoCode.getCode());
+        PromoCode savedPromoCode = promoCodeService.createOrUpdatePromoCode(promoCode);
+        return ResponseEntity.ok(savedPromoCode);
+    }
+
+    @Operation(summary = "Get all Promo Codes")
+    @GetMapping
+    public ResponseEntity<List<PromoCode>> getAllPromoCodes() {
+        log.info("Admin request to get all promo codes");
+        return ResponseEntity.ok(promoCodeService.findAll());
+    }
+
+    @Operation(summary = "Get a specific Promo Code by code")
+    @GetMapping("/{code}")
+    public ResponseEntity<PromoCode> getPromoCodeByCode(
+            @PathVariable final String code) {
+        log.info("Admin request to get promo code: {}", code);
+        return promoCodeService.findByCode(code)
+                .map(ResponseEntity::ok)
+                .orElse(ResponseEntity.notFound().build());
+    }
+
+    @Operation(summary = "Delete a Promo Code by code")
+    @DeleteMapping("/{code}")
+    public ResponseEntity<Void> deletePromoCode(
+            @PathVariable final String code) {
+        log.info("Admin request to delete promo code: {}", code);
+        try {
+            promoCodeService.deletePromoCode(code);
+            return ResponseEntity.noContent().build();
+        } catch (Exception e) {
+            log.error("Error deleting promo code", code, e.getMessage());
+            return ResponseEntity.status(
+                    HttpStatus.INTERNAL_SERVER_ERROR).build();
+        }
+    }
+}

src/main/java/cart/model/Cart.java

@@ -8,6 +8,7 @@
 import org.springframework.data.mongodb.core.mapping.Document;
 import org.springframework.data.mongodb.core.mapping.Field;
 
+import java.math.BigDecimal;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -28,5 +29,12 @@ public class Cart {
 
     private boolean archived = false;
 
+    private String appliedPromoCode;
+
+    private BigDecimal subTotal = BigDecimal.ZERO;
+    private BigDecimal discountAmount = BigDecimal.ZERO;
+    private BigDecimal totalPrice = BigDecimal.ZERO;
+
+
 }
 

src/main/java/cart/model/CartItem.java

@@ -1,10 +1,14 @@
 package cart.model;
 
 import jakarta.validation.constraints.NotBlank;
+import jakarta.validation.constraints.NotNull;
+import jakarta.validation.constraints.PositiveOrZero;
 import lombok.AllArgsConstructor;
 import lombok.Data;
 import lombok.NoArgsConstructor;
 
+import java.math.BigDecimal;
+
 @Data
 @NoArgsConstructor
 @AllArgsConstructor
@@ -13,6 +17,15 @@ public class CartItem {
     @NotBlank
     private String productId;
 
+    @NotNull
+    @PositiveOrZero
     private int quantity;
 
+    @NotNull
+    @PositiveOrZero
+    private BigDecimal unitPrice;
+
+    public BigDecimal getItemTotal() {
+        return unitPrice.multiply(BigDecimal.valueOf(quantity));
+    }
 }

src/main/java/cart/model/OrderRequest.java

@@ -1,21 +1,24 @@
 package cart.model;
 
 
-import jakarta.validation.constraints.NotBlank;
 import lombok.AllArgsConstructor;
 import lombok.Data;
 import lombok.NoArgsConstructor;
 
+import java.math.BigDecimal;
 import java.util.List;
 
 @Data
 @NoArgsConstructor
 @AllArgsConstructor
 public class OrderRequest {
-
-    @NotBlank
+    private String eventId;
     private String customerId;
-
+    private String cartId;
     private List<CartItem> items;
+    private BigDecimal subTotal;
+    private BigDecimal discountAmount;
+    private BigDecimal totalPrice;
+    private String appliedPromoCode;
 
 }

src/main/java/cart/model/PromoCode.java

@@ -0,0 +1,49 @@
+package cart.model;
+
+import jakarta.validation.constraints.NotBlank;
+import jakarta.validation.constraints.NotNull;
+import jakarta.validation.constraints.Positive;
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+import org.springframework.data.annotation.Id;
+import org.springframework.data.mongodb.core.index.Indexed;
+import org.springframework.data.mongodb.core.mapping.Document;
+
+import java.math.BigDecimal;
+import java.time.Instant;
+
+@Document(collection = "promo_codes")
+@Data
+@NoArgsConstructor
+@AllArgsConstructor
+public class PromoCode {
+
+    public enum DiscountType {
+        PERCENTAGE,
+        FIXED_AMOUNT
+    }
+
+    @Id
+    private String id;
+
+    @NotBlank
+    @Indexed(unique = true)
+    private String code;
+
+    private String description;
+
+    @NotNull
+    private DiscountType discountType;
+
+    @NotNull
+    @Positive
+    private BigDecimal discountValue;
+
+    private boolean active = true;
+
+    private Instant expiryDate;
+
+    private BigDecimal minimumPurchaseAmount;
+
+}

src/main/java/cart/repository/PromoCodeRepository.java

@@ -0,0 +1,13 @@
+package cart.repository;
+
+
+import cart.model.PromoCode;
+import org.springframework.data.mongodb.repository.MongoRepository;
+import org.springframework.stereotype.Repository;
+
+import java.util.Optional;
+
+@Repository
+public interface PromoCodeRepository extends MongoRepository<PromoCode, String> {
+    Optional<PromoCode> findByCode(String code);
+}