Merge pull request #10 from viacheslav-torbin/shopping-cart

Shopping cart implemented

src/main/java/org/bookstore/controller/ShoppingCartController.java

@@ -0,0 +1,77 @@
+package org.bookstore.controller;
+
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.tags.Tag;
+import jakarta.validation.Valid;
+import jakarta.validation.constraints.Positive;
+import lombok.RequiredArgsConstructor;
+import org.bookstore.dto.shoppingcart.CartItemRequestDto;
+import org.bookstore.dto.shoppingcart.CartItemUpdateDto;
+import org.bookstore.dto.shoppingcart.ShoppingCartDto;
+import org.bookstore.model.User;
+import org.bookstore.service.ShoppingCartService;
+import org.springframework.http.HttpStatus;
+import org.springframework.security.access.prepost.PreAuthorize;
+import org.springframework.security.core.Authentication;
+import org.springframework.validation.annotation.Validated;
+import org.springframework.web.bind.annotation.DeleteMapping;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.PutMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.ResponseStatus;
+import org.springframework.web.bind.annotation.RestController;
+
+@Tag(name = "Shopping cart management",
+        description = "Endpoints for managing user`s shopping carts")
+@RestController
+@RequiredArgsConstructor
+@Validated
+@RequestMapping(value = "/cart")
+public class ShoppingCartController {
+    private final ShoppingCartService cartService;
+
+    @Operation(summary = "Get the shopping cart of a user")
+    @GetMapping
+    @PreAuthorize("hasRole('USER')")
+    public ShoppingCartDto getShoppingCart(Authentication authentication) {
+        User user = (User) authentication.getPrincipal();
+        return cartService.getCart(user.getId());
+    }
+
+    @Operation(summary = "Add a book to the shopping cart", description = """
+                    Add a new book or update the quantity of existing in the cart of user""")
+    @PostMapping
+    @PreAuthorize("hasRole('USER')")
+    public ShoppingCartDto addBook(Authentication authentication,
+                                   @RequestBody @Valid CartItemRequestDto cartItem) {
+        User user = (User) authentication.getPrincipal();
+        return cartService.addBook(user.getId(), cartItem);
+    }
+
+    @Operation(summary = "Update the number of books in the cart", description = """
+                    Update the number of existing books in the cart of a logged-in user.
+                    Parameters : cart item id and new quantity""")
+    @PutMapping("/cart-items/{cartItemId}")
+    @PreAuthorize("hasRole('USER')")
+    public ShoppingCartDto updateBookQuantity(Authentication authentication,
+                                              @PathVariable @Positive Long cartItemId,
+                                              @RequestBody @Valid CartItemUpdateDto item) {
+        User user = (User) authentication.getPrincipal();
+        return cartService.updateQuantity(user.getId(), cartItemId, item);
+    }
+
+    @Operation(summary = "Delete book from the cart of user", description = """
+                    Delete book from the cart of a user.
+                    Parameter: id of cart item""")
+    @DeleteMapping("/cart-items/{cartItemId}")
+    @PreAuthorize("hasRole('USER')")
+    @ResponseStatus(HttpStatus.NO_CONTENT)
+    public void deleteBookFromCart(Authentication authentication,
+                                   @PathVariable @Positive Long cartItemId) {
+        User user = (User) authentication.getPrincipal();
+        cartService.deleteBook(user.getId(), cartItemId);
+    }
+}

src/main/java/org/bookstore/dto/shoppingcart/CartItemDto.java

@@ -0,0 +1,7 @@
+package org.bookstore.dto.shoppingcart;
+
+public record CartItemDto(Long id,
+                          Long bookId,
+                          String bookTitle,
+                          Integer quantity) {
+}

src/main/java/org/bookstore/dto/shoppingcart/CartItemRequestDto.java

@@ -0,0 +1,8 @@
+package org.bookstore.dto.shoppingcart;
+
+import jakarta.validation.constraints.NotNull;
+import jakarta.validation.constraints.Positive;
+
+public record CartItemRequestDto(@NotNull @Positive Long bookId,
+                                 @NotNull @Positive Integer quantity) {
+}

src/main/java/org/bookstore/dto/shoppingcart/CartItemUpdateDto.java

@@ -0,0 +1,7 @@
+package org.bookstore.dto.shoppingcart;
+
+import jakarta.validation.constraints.NotNull;
+import jakarta.validation.constraints.Positive;
+
+public record CartItemUpdateDto(@NotNull @Positive Integer quantity) {
+}

src/main/java/org/bookstore/dto/shoppingcart/ShoppingCartDto.java

@@ -0,0 +1,8 @@
+package org.bookstore.dto.shoppingcart;
+
+import java.util.List;
+
+public record ShoppingCartDto(Long id,
+                              Long userId,
+                              List<CartItemDto> cartItems) {
+}

src/main/java/org/bookstore/mapper/CartItemMapper.java

@@ -0,0 +1,24 @@
+package org.bookstore.mapper;
+
+import org.bookstore.dto.shoppingcart.CartItemDto;
+import org.bookstore.dto.shoppingcart.CartItemRequestDto;
+import org.bookstore.model.CartItem;
+import org.mapstruct.InjectionStrategy;
+import org.mapstruct.Mapper;
+import org.mapstruct.Mapping;
+import org.mapstruct.NullValueCheckStrategy;
+
+@Mapper(
+        componentModel = "spring",
+        injectionStrategy = InjectionStrategy.CONSTRUCTOR,
+        nullValueCheckStrategy = NullValueCheckStrategy.ALWAYS,
+        implementationPackage = "<PACKAGE_NAME>.impl"
+)
+public interface CartItemMapper {
+    @Mapping(source = "book.id", target = "bookId")
+    @Mapping(source = "book.title", target = "bookTitle")
+    CartItemDto toDto(CartItem cartItem);
+
+    CartItem toCartItem(CartItemRequestDto itemDto);
+}
+

src/main/java/org/bookstore/mapper/ShoppingCartMapper.java

@@ -0,0 +1,25 @@
+package org.bookstore.mapper;
+
+import org.bookstore.dto.shoppingcart.CartItemDto;
+import org.bookstore.dto.shoppingcart.ShoppingCartDto;
+import org.bookstore.model.CartItem;
+import org.bookstore.model.ShoppingCart;
+import org.mapstruct.InjectionStrategy;
+import org.mapstruct.Mapper;
+import org.mapstruct.Mapping;
+import org.mapstruct.NullValueCheckStrategy;
+
+@Mapper(
+        componentModel = "spring",
+        injectionStrategy = InjectionStrategy.CONSTRUCTOR,
+        nullValueCheckStrategy = NullValueCheckStrategy.ALWAYS,
+        implementationPackage = "<PACKAGE_NAME>.impl"
+)
+public interface ShoppingCartMapper {
+    @Mapping(source = "user.id", target = "userId")
+    ShoppingCartDto toDto(ShoppingCart shoppingCart);
+
+    @Mapping(source = "book.id", target = "bookId")
+    @Mapping(source = "book.title", target = "bookTitle")
+    CartItemDto toCartItemDto(CartItem cartItem);
+}

src/main/java/org/bookstore/model/CartItem.java

@@ -0,0 +1,35 @@
+package org.bookstore.model;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.FetchType;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import jakarta.persistence.JoinColumn;
+import jakarta.persistence.ManyToOne;
+import jakarta.persistence.OneToOne;
+import jakarta.persistence.Table;
+import lombok.Getter;
+import lombok.Setter;
+
+@Entity
+@Getter
+@Setter
+@Table(name = "cart_items")
+public class CartItem {
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @JoinColumn(name = "shopping_cart_id", nullable = false)
+    @ManyToOne(fetch = FetchType.LAZY, optional = false)
+    private ShoppingCart shoppingCart;
+
+    @JoinColumn(name = "book_id", nullable = false)
+    @OneToOne(fetch = FetchType.LAZY, optional = false, orphanRemoval = true)
+    private Book book;
+
+    @Column(nullable = false)
+    private int quantity;
+}

src/main/java/org/bookstore/model/ShoppingCart.java

@@ -0,0 +1,45 @@
+package org.bookstore.model;
+
+import jakarta.persistence.CascadeType;
+import jakarta.persistence.Entity;
+import jakarta.persistence.FetchType;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import jakarta.persistence.JoinColumn;
+import jakarta.persistence.OneToMany;
+import jakarta.persistence.OneToOne;
+import jakarta.persistence.Table;
+import java.util.HashSet;
+import java.util.Set;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+import lombok.ToString;
+
+@Entity
+@Data
+@Table(name = "shopping_carts")
+public class ShoppingCart {
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @OneToOne(fetch = FetchType.LAZY, optional = false)
+    @JoinColumn(name = "user_id", nullable = false)
+    @EqualsAndHashCode.Exclude
+    @ToString.Exclude
+    private User user;
+
+    @OneToMany(mappedBy = "shoppingCart", cascade = CascadeType.ALL, orphanRemoval = true)
+    private Set<CartItem> cartItems = new HashSet<>();
+
+    public void addItemToCart(CartItem cartItem) {
+        cartItem.setShoppingCart(this);
+        cartItems.add(cartItem);
+    }
+
+    public void removeItemFromCart(CartItem cartItem) {
+        cartItems.remove(cartItem);
+        cartItem.setShoppingCart(null);
+    }
+}

src/main/java/org/bookstore/repository/CartItemRepository.java

@@ -0,0 +1,11 @@
+package org.bookstore.repository;
+
+import java.util.Optional;
+import org.bookstore.model.CartItem;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.stereotype.Repository;
+
+@Repository
+public interface CartItemRepository extends JpaRepository<CartItem, Long> {
+    Optional<CartItem> findByIdAndShoppingCartId(Long cartItemId, Long id);
+}

src/main/java/org/bookstore/repository/ShoppingCartRepository.java

@@ -0,0 +1,12 @@
+package org.bookstore.repository;
+
+import org.bookstore.model.ShoppingCart;
+import org.springframework.data.jpa.repository.EntityGraph;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.stereotype.Repository;
+
+@Repository
+public interface ShoppingCartRepository extends JpaRepository<ShoppingCart, Long> {
+    @EntityGraph(attributePaths = {"cartItems", "user", "cartItems.book"})
+    ShoppingCart findByUserId(Long id);
+}

src/main/java/org/bookstore/service/ShoppingCartService.java

@@ -0,0 +1,18 @@
+package org.bookstore.service;
+
+import org.bookstore.dto.shoppingcart.CartItemRequestDto;
+import org.bookstore.dto.shoppingcart.CartItemUpdateDto;
+import org.bookstore.dto.shoppingcart.ShoppingCartDto;
+import org.bookstore.model.User;
+
+public interface ShoppingCartService {
+    void createShoppingCart(User user);
+
+    ShoppingCartDto getCart(Long userId);
+
+    ShoppingCartDto addBook(Long userId, CartItemRequestDto item);
+
+    ShoppingCartDto updateQuantity(Long userId, Long cartItemId, CartItemUpdateDto itemDto);
+
+    void deleteBook(Long userId, Long itemId);
+}

src/main/java/org/bookstore/service/impl/ShoppingCartServiceImpl.java

@@ -0,0 +1,103 @@
+package org.bookstore.service.impl;
+
+import jakarta.transaction.Transactional;
+import java.util.Objects;
+import java.util.Set;
+import lombok.RequiredArgsConstructor;
+import org.bookstore.dto.shoppingcart.CartItemRequestDto;
+import org.bookstore.dto.shoppingcart.CartItemUpdateDto;
+import org.bookstore.dto.shoppingcart.ShoppingCartDto;
+import org.bookstore.exceptions.EntityNotFoundException;
+import org.bookstore.mapper.CartItemMapper;
+import org.bookstore.mapper.ShoppingCartMapper;
+import org.bookstore.model.Book;
+import org.bookstore.model.CartItem;
+import org.bookstore.model.ShoppingCart;
+import org.bookstore.model.User;
+import org.bookstore.repository.BookRepository;
+import org.bookstore.repository.CartItemRepository;
+import org.bookstore.repository.ShoppingCartRepository;
+import org.bookstore.service.ShoppingCartService;
+import org.springframework.stereotype.Service;
+
+@Service
+@RequiredArgsConstructor
+public class ShoppingCartServiceImpl implements ShoppingCartService {
+    private final CartItemRepository cartItemRepository;
+    private final ShoppingCartRepository shoppingCartRepository;
+    private final BookRepository bookRepository;
+    private final ShoppingCartMapper shoppingCartMapper;
+    private final CartItemMapper cartItemMapper;
+
+    @Transactional
+    @Override
+    public void createShoppingCart(User user) {
+        ShoppingCart shoppingCart = new ShoppingCart();
+        shoppingCart.setUser(user);
+        shoppingCartRepository.save(shoppingCart);
+    }
+
+    @Transactional
+    @Override
+    public ShoppingCartDto getCart(Long userId) {
+        return shoppingCartMapper.toDto(shoppingCartRepository.findByUserId(userId));
+    }
+
+    @Transactional
+    @Override
+    public ShoppingCartDto addBook(Long userId, CartItemRequestDto itemDto) {
+        Book book = bookRepository.findById(itemDto.bookId())
+                .orElseThrow(() -> new EntityNotFoundException(
+                        String.format("Book with id: %d is not found", itemDto.bookId())
+                ));
+        ShoppingCart cart = shoppingCartRepository.findByUserId(userId);
+        Set<CartItem> cartItems = cart.getCartItems();
+        for (CartItem item : cartItems) {
+            if (Objects.equals(item.getBook().getId(), itemDto.bookId())) {
+                item.setQuantity(item.getQuantity() + itemDto.quantity());
+                shoppingCartRepository.save(cart);
+                return shoppingCartMapper.toDto(cart);
+            }
+        }
+        addCartItemToShoppingCart(itemDto, book, cart);
+        shoppingCartRepository.save(cart);
+        return shoppingCartMapper.toDto(cart);
+    }
+
+    @Transactional
+    @Override
+    public ShoppingCartDto updateQuantity(Long userId,
+                                          Long cartItemId, CartItemUpdateDto itemDto) {
+        ShoppingCart cart = shoppingCartRepository.findByUserId(userId);
+        CartItem cartItem = cartItemRepository
+                .findByIdAndShoppingCartId(cartItemId, cart.getId())
+                .map(item -> {
+                    item.setQuantity(itemDto.quantity());
+                    return item;
+                }).orElseThrow(() -> new EntityNotFoundException(
+                        String.format("No cart item with id: %d for user: %d", cartItemId, userId)
+                ));
+        cartItemRepository.save(cartItem);
+        return shoppingCartMapper.toDto(cart);
+    }
+
+    @Transactional
+    @Override
+    public void deleteBook(Long userId, Long itemId) {
+        ShoppingCart shoppingCart = shoppingCartRepository.findByUserId(userId);
+        CartItem cartItem = cartItemRepository
+                .findByIdAndShoppingCartId(itemId, shoppingCart.getId())
+                .orElseThrow(() -> new EntityNotFoundException(
+                        String.format("No such cartItem with id %d in shopping cart", itemId)
+                ));
+        shoppingCart.removeItemFromCart(cartItem);
+    }
+
+    private void addCartItemToShoppingCart(CartItemRequestDto itemDto,
+                                           Book book,
+                                           ShoppingCart cart) {
+        CartItem cartItem = cartItemMapper.toCartItem(itemDto);
+        cartItem.setBook(book);
+        cart.addItemToCart(cartItem);
+    }
+}