Resolve #251 - Fix rental issues

backend/src/main/java/edu/zut/bookrider/model/enums/RentalStatus.java

@@ -3,6 +3,5 @@
 public enum RentalStatus {
     RENTED,
     RETURNED,
-    RETURN_IN_PROGRESS,
     PARTIALLY_RETURNED
 }

backend/src/main/java/edu/zut/bookrider/repository/RentalReturnItemRepository.java

@@ -1,9 +1,25 @@
 package edu.zut.bookrider.repository;
 
-import edu.zut.bookrider.model.Rental;
 import edu.zut.bookrider.model.RentalReturnItem;
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
+
+import java.util.List;
 
 public interface RentalReturnItemRepository extends JpaRepository<RentalReturnItem, Integer> {
-    boolean existsByRental(Rental rental);
+    @Query("""
+        SELECT COALESCE(SUM(rri.returnedQuantity), 0)
+        FROM RentalReturnItem rri
+        WHERE rri.rental.id = :rentalId
+    """)
+    int sumReturnedQuantityByRentalId(@Param("rentalId") Integer rentalId);
+
+    @Query("""
+        SELECT rri.rental.id, SUM(rri.returnedQuantity)
+        FROM RentalReturnItem rri
+        WHERE rri.rental.id IN :rentalIds
+        GROUP BY rri.rental.id
+    """)
+    List<Object[]> sumReturnedQuantitiesByRentalIds(@Param("rentalIds") List<Integer> rentalIds);
 }

backend/src/main/java/edu/zut/bookrider/service/RentalReturnItemService.java

@@ -1,14 +1,17 @@
 package edu.zut.bookrider.service;
 
 import edu.zut.bookrider.dto.RentalWithQuantityDTO;
+import edu.zut.bookrider.exception.RentalAlreadyReturnedException;
 import edu.zut.bookrider.model.Rental;
 import edu.zut.bookrider.model.RentalReturn;
 import edu.zut.bookrider.model.RentalReturnItem;
 import edu.zut.bookrider.repository.RentalReturnItemRepository;
 import lombok.RequiredArgsConstructor;
 import org.springframework.stereotype.Service;
 
+import java.util.ArrayList;
 import java.util.List;
+import java.util.Map;
 import java.util.stream.Collectors;
 
 @RequiredArgsConstructor
@@ -18,20 +21,45 @@ public class RentalReturnItemService {
     private final RentalReturnItemRepository rentalReturnItemRepository;
 
     public List<RentalReturnItem> createRentalReturnItems(RentalReturn rentalReturn, List<RentalWithQuantityDTO> rentals) {
-        List<RentalReturnItem> returnItems = rentals.stream().map(rentalDto -> {
+        List<Integer> rentalIds = rentals.stream()
+                .map(r -> r.getRental().getId())
+                .toList();
+
+        List<Object[]> results = rentalReturnItemRepository.sumReturnedQuantitiesByRentalIds(rentalIds);
+
+        Map<Integer, Integer> returnedQuantities = results.stream()
+                .collect(Collectors.toMap(
+                        row -> (Integer) row[0],
+                        row -> ((Number) row[1]).intValue()
+                ));
+
+        List<RentalReturnItem> returnItems = new ArrayList<>();
+
+        for (RentalWithQuantityDTO dto : rentals) {
+            Rental rental = dto.getRental();
+            int alreadyReturned = returnedQuantities.getOrDefault(rental.getId(), 0);
+            int remaining = rental.getQuantity() - alreadyReturned;
+            int toReturn = dto.getQuantityToReturn();
+
+            if (toReturn < 1 || toReturn > remaining) {
+                throw new RentalAlreadyReturnedException("Invalid return quantity for rental ID " + rental.getId() +
+                        ". Requested: " + toReturn + ", Available to return: " + remaining);
+            }
+
             RentalReturnItem returnItem = new RentalReturnItem();
             returnItem.setRentalReturn(rentalReturn);
-            returnItem.setRental(rentalDto.getRental());
-            returnItem.setBook(rentalDto.getRental().getBook());
-            returnItem.setReturnedQuantity(rentalDto.getQuantityToReturn());
-            return returnItem;
-        }).collect(Collectors.toList());
+            returnItem.setRental(rental);
+            returnItem.setBook(rental.getBook());
+            returnItem.setReturnedQuantity(toReturn);
+
+            returnItems.add(returnItem);
+        }
 
         rentalReturnItemRepository.saveAll(returnItems);
         return returnItems;
     }
 
-    public boolean isAlreadyReturned(Rental rental) {
-        return rentalReturnItemRepository.existsByRental(rental);
+    int sumReturnedQuantityByRentalId(Integer rentalId) {
+        return rentalReturnItemRepository.sumReturnedQuantityByRentalId(rentalId);
     }
 }

backend/src/main/java/edu/zut/bookrider/service/RentalReturnService.java

@@ -210,12 +210,9 @@ public void checkRentals(List<RentalReturnWithQuantityRequestDTO> rentalReturnRe
             Integer rentalId = requestDTO.getRentalId();
             Rental rental = rentalService.getRentalById(rentalId);
 
-            boolean isAlreadyReturned = rentalReturnItemService.isAlreadyReturned(rental);
-            if (isAlreadyReturned) {
+            if (rental.getStatus() == RentalStatus.RETURNED) {
                 throw new RentalAlreadyReturnedException("Rental " + rental.getId() + " has already been returned.");
             }
-
-            rentalService.updateRentalStatus(rentalId, RentalStatus.RETURN_IN_PROGRESS);
         }
     }
 
@@ -229,7 +226,7 @@ public RentalReturn createRentalReturnForOrder(Order returnOrder, List<RentalWit
         RentalReturn savedRentalReturn = rentalReturnRepository.save(rentalReturn);
 
         List<RentalReturnItem> rentalReturnItems = rentalReturnItemService.createRentalReturnItems(savedRentalReturn, rentals);
-        savedRentalReturn.setRentalReturnItems(rentalReturnItems);
+        savedRentalReturn.getRentalReturnItems().addAll(rentalReturnItems);
 
         return rentalReturnRepository.save(rentalReturn);
     }
@@ -262,7 +259,7 @@ public List<RentalReturnDTO> createInPersonRentalReturn(InPersonRentalReturnRequ
             RentalReturn savedRentalReturn = rentalReturnRepository.save(rentalReturn);
 
             List<RentalReturnItem> rentalReturnItems = rentalReturnItemService.createRentalReturnItems(savedRentalReturn, rentalsForLibrary);
-            savedRentalReturn.setRentalReturnItems(rentalReturnItems);
+            savedRentalReturn.getRentalReturnItems().addAll(rentalReturnItems);
 
             BigDecimal totalLateFees = BigDecimal.ZERO;
             for (RentalWithQuantityDTO rentalWithQuantityDTO : rentalsForLibrary) {

backend/src/main/java/edu/zut/bookrider/service/RentalService.java

@@ -32,6 +32,7 @@ public class RentalService {
 
     private final RentalRepository rentalRepository;
     private final RentalMapper rentalMapper;
+    private final RentalReturnItemService rentalReturnItemService;
 
     @Transactional
     public void createRental(OrderItem orderItem) {
@@ -100,9 +101,16 @@ public PageResponseDTO<RentalDTO> getUserRentals(Pageable pageable) {
         User user = userService.getUser();
         Page<Rental> rentals = rentalRepository.findAllByUser(user, pageable);
 
-        List<RentalDTO> rentalDTOs = rentals.getContent()
-                .stream()
-                .map(rentalMapper::map)
+        List<RentalDTO> rentalDTOs = rentals.getContent().stream()
+                .map(rental -> {
+                    int remainingQuantity = rental.getQuantity();
+                    if (rental.getStatus() == RentalStatus.PARTIALLY_RETURNED) {
+                        int returned = rentalReturnItemService.sumReturnedQuantityByRentalId(rental.getId());
+                        remainingQuantity -= returned;
+                    }
+                    rental.setQuantity(remainingQuantity);
+                    return rentalMapper.map(rental);
+                })
                 .toList();
 
         return new PageResponseDTO<>(
@@ -113,11 +121,4 @@ public PageResponseDTO<RentalDTO> getUserRentals(Pageable pageable) {
                 rentals.getTotalPages()
         );
     }
-
-    public Rental updateRentalStatus(Integer rentalId, RentalStatus status) {
-        Rental rental =  getRentalById(rentalId);
-        rental.setStatus(status);
-
-        return rentalRepository.save(rental);
-    }
 }

backend/src/test/java/edu/zut/bookrider/integration/controller/RentalControllerIT.java

@@ -3,6 +3,7 @@
 import edu.zut.bookrider.model.*;
 import edu.zut.bookrider.model.enums.OrderStatus;
 import edu.zut.bookrider.model.enums.PaymentStatus;
+import edu.zut.bookrider.model.enums.RentalReturnStatus;
 import edu.zut.bookrider.model.enums.RentalStatus;
 import edu.zut.bookrider.repository.*;
 import edu.zut.bookrider.service.UserIdGeneratorService;
@@ -57,6 +58,8 @@ public class RentalControllerIT {
     private RoleRepository roleRepository;
     @Autowired
     private OrderRepository orderRepository;
+    @Autowired
+    private RentalReturnRepository rentalReturnRepository;
 
     private User user;
     private User driver;
@@ -203,4 +206,45 @@ void whenUserRequestsRentalsWithDifferentStatuses_thenReturnRentalsPage() throws
                 .andExpect(status().isOk())
                 .andExpect(jsonPath("$.totalElements").value(2));
     }
+
+    @Test
+    @WithMockUser(username = "testuser@rcit.com", roles = {"user"})
+    void whenUserRequestsRentalsWithPartialReturns_thenReturnRentalsPageWithCorrectQuantities() throws Exception {
+
+        Author author = createAuthor("Author");
+        Language language = createLanguage("language");
+
+        Book book1 = createBook("Book1", "113109022025", language, author);
+        Book book2 = createBook("Book2", "113209022025", language, author);
+
+        Order order1 = createOrder(user, driver, library1, address, book1, 2, OrderStatus.PENDING, false);
+        Order order2 = createOrder(user, driver, library1, address, book2, 1, OrderStatus.PENDING, false);
+
+        createRental(order1, 2, RentalStatus.RENTED);
+        Rental rental1 = createRental(order2, 3, RentalStatus.PARTIALLY_RETURNED);
+
+        Order returnOrder = createOrder(user, driver, library1, address, book2, 2, OrderStatus.AWAITING_LIBRARY_CONFIRMATION, true);
+
+        RentalReturn rentalReturn = new RentalReturn();
+        rentalReturn.setReturnOrder(returnOrder);
+        rentalReturn.setStatus(RentalReturnStatus.IN_PROGRESS);
+
+        RentalReturnItem rentalReturnItem = new RentalReturnItem();
+        rentalReturnItem.setRentalReturn(rentalReturn);
+        rentalReturnItem.setRental(rental1);
+        rentalReturnItem.setBook(rental1.getBook());
+        rentalReturnItem.setReturnedQuantity(2);
+
+        List<RentalReturnItem> rentalReturnItems = new ArrayList<>();
+        rentalReturnItems.add(rentalReturnItem);
+        rentalReturn.setRentalReturnItems(rentalReturnItems);
+
+        rentalReturn = rentalReturnRepository.save(rentalReturn);
+
+        mockMvc.perform(MockMvcRequestBuilders.get("/api/rentals")
+                        .contentType(MediaType.APPLICATION_JSON))
+                .andExpect(status().isOk())
+                .andExpect(jsonPath("$.totalElements").value(2))
+                .andExpect(jsonPath("$.content[1].quantity").value(1));
+    }
 }

backend/src/test/java/edu/zut/bookrider/integration/controller/RentalReturnControllerIT.java

@@ -167,6 +167,23 @@ private Rental createRental(Order order, int quantity, boolean addDays) {
         return rentalRepository.save(rental);
     }
 
+    private GeneralRentalReturnRequestDTO createSingleRentalReturnRequest(Address address, Rental rental, int quantityToReturn) {
+        RentalReturnWithQuantityRequestDTO rentalReturnRequestDTO = new RentalReturnWithQuantityRequestDTO();
+        rentalReturnRequestDTO.setRentalId(rental.getId());
+        rentalReturnRequestDTO.setQuantityToReturn(quantityToReturn);
+
+        CreateAddressDTO createAddressDTO = new CreateAddressDTO();
+        createAddressDTO.setStreet(address.getStreet());
+        createAddressDTO.setCity(address.getCity());
+        createAddressDTO.setPostalCode(address.getPostalCode());
+
+        GeneralRentalReturnRequestDTO request = new GeneralRentalReturnRequestDTO();
+        request.setCreateAddressDTO(createAddressDTO);
+        request.setRentalReturnRequests(List.of(rentalReturnRequestDTO));
+
+        return request;
+    }
+
     @BeforeEach
     void setUp() {
         user = createUser("testuser@rrcit.com", "user", 9999);
@@ -998,6 +1015,53 @@ void whenUserRequestsReturnOrderForAlreadyReturnedReturn_thenReturnConflict() th
                 .andExpect(status().isConflict());
     }
 
+    @Test
+    @WithMockUser(username = "testuser@rrcit.com:user", roles = {"user"})
+    void whenUserRequestsReturnOrderPartiallyReturnedReturn_thenReturnOk() throws Exception {
+
+        Author author = createAuthor("Author");
+        Language language = createLanguage("language");
+
+        Book book = createBook("Book1", "113109022025", language, author);
+
+        Order deliveryOrder = createOrder(user, driver, library1, address, book, 3, OrderStatus.DELIVERED, false);
+
+        Rental rental = new Rental();
+        rental.setUser(user);
+        rental.setBook(deliveryOrder.getOrderItems().get(0).getBook());
+        rental.setLibrary(deliveryOrder.getLibrary());
+        rental.setOrder(deliveryOrder);
+        rental.setQuantity(3);
+        rental.setReturnDeadline(LocalDateTime.now().plusDays(30));
+        rental.setStatus(RentalStatus.RENTED);
+        rental = rentalRepository.save(rental);
+
+        Order returnOrder = createOrder(user, driver, library1, address, book, 1, OrderStatus.DRIVER_ACCEPTED, true);
+
+        RentalReturn rentalReturn = new RentalReturn();
+        rentalReturn.setReturnOrder(returnOrder);
+        rentalReturn.setStatus(RentalReturnStatus.IN_PROGRESS);
+
+        RentalReturnItem rentalReturnItem = new RentalReturnItem();
+        rentalReturnItem.setRentalReturn(rentalReturn);
+        rentalReturnItem.setRental(rental);
+        rentalReturnItem.setBook(rental.getBook());
+        rentalReturnItem.setReturnedQuantity(1);
+
+        List<RentalReturnItem> rentalReturnItems = new ArrayList<>();
+        rentalReturnItems.add(rentalReturnItem);
+        rentalReturn.setRentalReturnItems(rentalReturnItems);
+
+        rentalReturnRepository.save(rentalReturn);
+
+        GeneralRentalReturnRequestDTO requestDTO = createSingleRentalReturnRequest(address, rental, 2);
+
+        mockMvc.perform(MockMvcRequestBuilders.post("/api/rental-returns")
+                        .content(new ObjectMapper().writeValueAsString(requestDTO))
+                        .contentType(MediaType.APPLICATION_JSON))
+                .andExpect(status().isOk());
+    }
+
     @Test
     @WithMockUser(username = "librarianRrcit:1", roles = {"librarian"})
     void whenLibrarianRequestsDeliveryReturnCompletionFromWrongLibrary_thenReturnConflict() throws Exception {