[nmoosapet]Implememted the Cart functionality and pushing the changes to Branch

ecom-service/src/main/java/com/nisum/ecomservice/controller/CartController.java

+package com.nisum.ecomservice.controller;
+
+import com.nisum.ecomservice.dto.CartDTO;
+import com.nisum.ecomservice.model.CartItemEntity;
+import com.nisum.ecomservice.repository.CartRepository;
+import com.nisum.ecomservice.service.CartService;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.*;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+
+
+@RestController
+@CrossOrigin(origins = "*")
+public class CartController {
+    @Autowired
+    private CartService cartService;
+
+    @Autowired
+    private CartRepository cartRepository;
+
+    @GetMapping("/api/carts")
+    public ResponseEntity<Flux<CartDTO>>getAllUserCarts(){
+        return ResponseEntity.ok(cartService.getAllUsersCartItems());
+    }
+
+    @GetMapping("/api/carts/{userId}")
+    public ResponseEntity<Mono<CartDTO>>getCartByUserId(@PathVariable String userId) {
+        Mono<CartDTO> cartDto= cartService.getUserIdCartItems(userId);
+        HttpStatus status = cartDto != null ? HttpStatus.OK : HttpStatus.NOT_FOUND;
+        return new ResponseEntity<>(cartDto, status);
+    }
+
+    @PostMapping("/api/carts")
+    @ResponseStatus(HttpStatus.CREATED)
+    public Mono<CartDTO>addToCartByUserId(@RequestBody CartDTO cartDTO) {
+        return cartService.addUserIdItemsToCart(cartDTO);
+    }
+
+    @PutMapping("/api/carts/{userId}")
+    public Mono<ResponseEntity<CartDTO>>updateCartByUserId(@PathVariable String userId, @RequestBody CartDTO cartDTO){
+        return cartService.updateUserIdCartItems(userId, cartDTO)
+                .map(updatedItem->ResponseEntity.ok(updatedItem))
+                .defaultIfEmpty(ResponseEntity.badRequest().build());
+    }
+
+    @DeleteMapping("/api/carts/{userId}")
+    public Mono<ResponseEntity<Void>>deleteCartByUserId(@PathVariable String userId){
+        return cartService.deleteUserIdCartItems(userId)
+                .map(res-> ResponseEntity.ok().<Void>build())
+                .defaultIfEmpty(ResponseEntity.notFound().build());
+    }
+}
\ No newline at end of file

ecom-service/src/main/java/com/nisum/ecomservice/controller/UsersController.java

 package com.nisum.ecomservice.controller;
 
-import com.nisum.ecomservice.model.CartItem;
-import com.nisum.ecomservice.model.Product;
 import com.nisum.ecomservice.model.User;
 import com.nisum.ecomservice.repository.UserRepository;
 import com.nisum.ecomservice.service.UserService;
 import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
-import org.springframework.http.HttpStatus;
-import org.springframework.stereotype.Component;
 import org.springframework.web.bind.annotation.*;
 import reactor.core.publisher.Flux;
-import reactor.core.publisher.Mono;
 
 @RestController
 @RequestMapping("/api/users")

ecom-service/src/main/java/com/nisum/ecomservice/dto/CartDTO.java

+package com.nisum.ecomservice.dto;
+
+import lombok.*;
+
+import java.util.List;
+
+
+@Getter
+@Setter
+@AllArgsConstructor
+@NoArgsConstructor
+@Data
+public class CartDTO {
+    private String userId;
+    private List<CartItemDTO> cartItems;
+
+}

ecom-service/src/main/java/com/nisum/ecomservice/dto/CartItemDTO.java

+package com.nisum.ecomservice.dto;
+
+
+import com.nisum.ecomservice.model.ProductRef;
+import lombok.*;
+
+@Getter
+@Setter
+@AllArgsConstructor
+@Data
+@NoArgsConstructor
+public class CartItemDTO {
+    private ProductRef productRef;
+    private Integer quantity;
+}
+

ecom-service/src/main/java/com/nisum/ecomservice/dto/OrderRequest.java

 package com.nisum.ecomservice.dto;
 
 import com.nisum.ecomservice.model.Address;
-import com.nisum.ecomservice.model.Cart;
+import com.nisum.ecomservice.model.CartEntity;
 import com.nisum.ecomservice.model.User;
 import lombok.AllArgsConstructor;
 import lombok.Getter;
@@ -13,5 +13,5 @@ import lombok.Setter;
 public class OrderRequest {
     private User user;
     private Address address;
-    private Cart cart;
+    private CartEntity cartEntity;
 }

ecom-service/src/main/java/com/nisum/ecomservice/exception/ResourceAlreadyExistsException.java

+package com.nisum.ecomservice.exception;
+
+import org.springframework.http.HttpStatus;
+import org.springframework.web.bind.annotation.ResponseStatus;
+
+@ResponseStatus(value = HttpStatus.NOT_ACCEPTABLE)
+public class ResourceAlreadyExistsException extends RuntimeException {
+
+    public ResourceAlreadyExistsException() {
+        super("A User with the provided userId already exists");
+    }
+}

ecom-service/src/main/java/com/nisum/ecomservice/exception/ResourceNotFoundException.java

+package com.nisum.ecomservice.exception;
+
+import org.springframework.http.HttpStatus;
+import org.springframework.web.bind.annotation.ResponseStatus;
+
+@ResponseStatus(value = HttpStatus.NOT_FOUND)
+public class ResourceNotFoundException extends Exception{
+    HttpStatus status;
+
+    public ResourceNotFoundException(HttpStatus status, String message) {
+        super(message);
+        this.status = status;
+    }
+}

ecom-service/src/main/java/com/nisum/ecomservice/model/Cart.java → ecom-service/src/main/java/com/nisum/ecomservice/model/CartEntity.java

 package com.nisum.ecomservice.model;
 
-import lombok.AllArgsConstructor;
-import lombok.Getter;
-import lombok.Setter;
+import lombok.*;
 import org.springframework.data.annotation.Id;
 import org.springframework.data.mongodb.core.mapping.Document;
 
 import java.util.List;
 
-@Document(collection = "carts")
 @Getter
 @Setter
 @AllArgsConstructor
-public class Cart {
+@NoArgsConstructor
+@Data
+@Document(collection = "carts")
+public class CartEntity {
     @Id
-    private String id;
     private String userId;
-    private List<CartItem> cartItems;
+    private List<CartItemEntity> cartItems;
 }

ecom-service/src/main/java/com/nisum/ecomservice/model/CartItem.java

-package com.nisum.ecomservice.model;
-
-
-import lombok.AllArgsConstructor;
-import lombok.Data;
-import lombok.Getter;
-import lombok.Setter;
-import lombok.ToString;
-
-@Getter
-@Setter
-@AllArgsConstructor
-@ToString
-@Data
-public class CartItem {
-    private ProductRef productRef;
-    private Integer quantity;
-
-    @Override
-    public String toString() {
-        return "CartItem{" +
-                "productRef = " + productRef + '\'' +
-                ", quantity = " + quantity +
-                '}';
-    }
-}

ecom-service/src/main/java/com/nisum/ecomservice/model/CartItemEntity.java

+package com.nisum.ecomservice.model;
+
+
+import lombok.*;
+import org.springframework.data.mongodb.core.mapping.Document;
+
+@Getter
+@Setter
+@AllArgsConstructor
+@NoArgsConstructor
+@Data
+public class CartItemEntity {
+    private ProductRef productRef;
+    private Integer quantity;
+
+}

ecom-service/src/main/java/com/nisum/ecomservice/repository/CartRepository.java

+package com.nisum.ecomservice.repository;
+
+import com.nisum.ecomservice.model.CartEntity;
+import org.springframework.data.mongodb.repository.ReactiveMongoRepository;
+
+public interface CartRepository extends ReactiveMongoRepository<CartEntity, String> {
+}

ecom-service/src/main/java/com/nisum/ecomservice/repository/UserRepository.java

 package com.nisum.ecomservice.repository;
 
-import com.nisum.ecomservice.model.CartItem;
 import com.nisum.ecomservice.model.User;
-import org.springframework.data.mongodb.repository.Query;
 import org.springframework.data.mongodb.repository.ReactiveMongoRepository;
 import org.springframework.stereotype.Repository;
-import org.springframework.stereotype.Service;
-import reactor.core.publisher.Mono;
 
-@Repository
 public interface UserRepository extends ReactiveMongoRepository<User, String> {
 }

ecom-service/src/main/java/com/nisum/ecomservice/service/CartService.java

+package com.nisum.ecomservice.service;
+
+import com.nisum.ecomservice.dto.CartDTO;
+import com.nisum.ecomservice.dto.CartItemDTO;
+import com.nisum.ecomservice.exception.ResourceNotFoundException;
+import com.nisum.ecomservice.model.CartEntity;
+import com.nisum.ecomservice.model.CartItemEntity;
+import com.nisum.ecomservice.repository.CartRepository;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.http.HttpStatus;
+import org.springframework.stereotype.Service;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Optional;
+import java.util.stream.Collectors;
+
+@Service
+public class CartService {
+
+    @Autowired
+    private CartRepository cartRepository;
+
+
+    public Flux<CartDTO> getAllUsersCartItems() {
+        return cartRepository.findAll().map(cartItems->convertEntitytoDTO(cartItems));
+    }
+
+    public Mono<CartDTO> getUserIdCartItems(String userId){
+        return cartRepository.findById(userId)
+                .map(existingItems->convertEntitytoDTO(existingItems))
+                .switchIfEmpty(Mono.error(new ResourceNotFoundException(HttpStatus.NOT_FOUND,
+                        "CartItem for UserId" + userId + "not found")));
+    }
+
+    public Mono<CartDTO>addUserIdItemsToCart(CartDTO cartDTO) {
+        cartRepository.deleteById(cartDTO.getUserId());
+        Mono<CartEntity>  cartEntityDB=  cartRepository.save(convertDTOtoEntity(cartDTO));
+        return   cartEntityDB.map(newItem->convertEntitytoDTO(newItem));
+    }
+
+    public Mono<CartDTO>updateUserIdCartItems(String userId, CartDTO cartDTO) {
+        Mono<CartEntity>  cartEntityDB=  cartRepository.save(convertDTOtoEntity(cartDTO));
+        return   cartEntityDB.map(updatedItem->convertEntitytoDTO(updatedItem));
+    }
+
+    public Mono<CartEntity> deleteUserIdCartItems(String userId) {
+        return cartRepository.findById(userId)
+                .flatMap(existingCartItem->
+                    cartRepository.delete(existingCartItem)
+                            .then(Mono.just(existingCartItem)))
+                .switchIfEmpty(Mono.error(new ResourceNotFoundException(HttpStatus.NOT_FOUND,
+                        "CartItem for UserId" + userId + "not found")));
+    }
+
+
+    private CartDTO convertEntitytoDTO(CartEntity cartEntity){
+
+        CartDTO cartDTO=new CartDTO();
+        cartDTO.setUserId(cartEntity.getUserId());
+        List<CartItemDTO> cartItemDtos= Optional.ofNullable(cartEntity.getCartItems()).orElse(new ArrayList<>())
+                .stream().map(entity->{
+                    CartItemDTO cartItemDTO=new CartItemDTO();
+                    cartItemDTO.setProductRef(entity.getProductRef());
+                    cartItemDTO.setQuantity(entity.getQuantity());
+                    return cartItemDTO;})
+                .collect(Collectors.toList());
+        cartDTO.setCartItems(cartItemDtos);
+        return cartDTO;
+    }
+
+    private CartEntity convertDTOtoEntity(CartDTO cartDTO){
+        CartEntity cartEntity=new CartEntity();
+        cartEntity.setUserId(cartDTO.getUserId());
+        List<CartItemEntity> cartItemEntities=   Optional.ofNullable(cartDTO.getCartItems()).orElse(new ArrayList<>()).stream().map(dto->{
+            CartItemEntity cartItemEntity=new com.nisum.ecomservice.model.CartItemEntity();
+            cartItemEntity.setProductRef(dto.getProductRef());
+            cartItemEntity.setQuantity(dto.getQuantity());
+            return cartItemEntity;})
+                .collect(Collectors.toList());
+
+        cartEntity.setCartItems(cartItemEntities);
+        return cartEntity;
+    }
+}
\ No newline at end of file

ecom-service/src/main/java/com/nisum/ecomservice/service/OrderService.java

@@ -26,10 +26,10 @@ public class OrderService {
         //create user object from user object details
         User user = orderRequest.getUser();
         Address address = orderRequest.getAddress();
-        Cart cart = orderRequest.getCart();
+        CartEntity cartEntity = orderRequest.getCartEntity();
 
         //for each item grab product details from products API
-        List<Mono<Product>> productsToOrder = cart.getCartItems().stream()
+        List<Mono<Product>> productsToOrder = cartEntity.getCartItems().stream()
                 .map(cartItem -> cartItem.getProductRef().getSku())
                 .map(sku -> productService.getProductBySku(sku))
 
@@ -44,7 +44,7 @@ public class OrderService {
             orderItem.setItemSku(product.getSku());
             orderItem.setItemPrice(product.getPrice());
 
-            List<CartItem> items = cart.getCartItems().stream().filter(cartItem -> cartItem.getProductRef().getSku()
+            List<CartItemEntity> items = cartEntity.getCartItems().stream().filter(cartItem -> cartItem.getProductRef().getSku()
                     .equals(product.getSku()))
                     .collect(Collectors.toList());
 

ecom-service/src/main/java/com/nisum/ecomservice/service/UserService.java

 package com.nisum.ecomservice.service;
 
-import com.nisum.ecomservice.model.CartItem;
 import com.nisum.ecomservice.model.User;
 import com.nisum.ecomservice.repository.UserRepository;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Service;
 import reactor.core.publisher.Flux;
-import reactor.core.publisher.Mono;
 
 @Service
 public class UserService {