Added FridgeRepository and FridgeService. Started writing FridgeController

src/main/java/ntnu/idatt2016/v233/SmartMat/controller/group/FridgeController.java

+package ntnu.idatt2016.v233.SmartMat.controller.group;
+
+import lombok.AllArgsConstructor;
+import ntnu.idatt2016.v233.SmartMat.entity.Fridge;
+import ntnu.idatt2016.v233.SmartMat.service.group.FridgeService;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.*;
+
+/**
+ * Controller for fridges API, providing endpoints for fridge management
+ *
+ * @author Anders Austlid
+ * @version 1.0
+ * @since 24.04.2023
+ */
+@AllArgsConstructor
+@RestController
+@RequestMapping("/api/fridges")
+public class FridgeController {
+
+    private final FridgeService fridgeService;
+
+    /**
+     * Gets the fridge of a group
+     * @param groupId the id of the group
+     *                group must exist
+     * @return the fridge of the group if it exists, or a 404 if it doesn't
+     */
+    @GetMapping("/group/{groupId}")
+    public ResponseEntity<Fridge> getFridgeByGroupId(@PathVariable("groupId") long groupId) {
+        return fridgeService.getFridgeByGroupId(groupId)
+                .map(ResponseEntity::ok)
+                .orElseGet(() -> ResponseEntity.notFound().build());
+    }
+
+    /**
+     * Adds a product to the fridge of a group
+     *
+     * @param groupId the id of the group
+     *                group must exist
+     * @param productId the id of the product
+     * @return success if the product was added, bad request if the product was already in the fridge, or not found if the group or product doesn't exist
+     */
+    @PostMapping("")
+
+}

src/main/java/ntnu/idatt2016/v233/SmartMat/entity/group/FridgeRepository.java

+package ntnu.idatt2016.v233.SmartMat.entity.group;
+
+import ntnu.idatt2016.v233.SmartMat.entity.Fridge;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+import java.util.Optional;
+
+public interface FridgeRepository extends JpaRepository<Fridge, Long> {
+    /**
+     * Gets the fridge of a group
+     *
+     * @param groupId the id of the group
+     * @return an Optional containing the fridge of the group if it exists
+     */
+    Optional<Fridge> findByGroupId(long groupId);
+}

src/main/java/ntnu/idatt2016/v233/SmartMat/service/group/FridgeService.java

+package ntnu.idatt2016.v233.SmartMat.service.group;
+
+import lombok.AllArgsConstructor;
+import ntnu.idatt2016.v233.SmartMat.entity.Fridge;
+import ntnu.idatt2016.v233.SmartMat.entity.group.FridgeRepository;
+import ntnu.idatt2016.v233.SmartMat.entity.product.Product;
+import ntnu.idatt2016.v233.SmartMat.service.product.ProductService;
+import org.springframework.stereotype.Service;
+
+import java.util.Optional;
+
+/**
+ * Service for management of a group fridge
+ *
+ * @author Anders Austlid
+ * @version 1.0
+ * @since 24.04.2023
+ */
+@AllArgsConstructor
+@Service
+public class FridgeService {
+
+    private final FridgeRepository fridgeRepository;
+    private final ProductService productService;
+
+    /**
+     * Gets the fridge of a group
+     *
+     * @param groupId the id of the group
+     * @return the fridge of the group
+     */
+    public Optional<Fridge> getFridgeByGroupId(long groupId) {
+        return fridgeRepository.findByGroupId(groupId);
+    }
+
+    /**
+     * Add a product to the fridge of a group
+     *
+     * @param groupId the id of the group
+     *                group must exist
+     * @param ean the ean of the product
+     * @return true if the product was added
+     */
+    public boolean addProduct(long groupId, long ean) {
+        Optional<Product> product = productService.getProductById(ean);
+        Fridge fridge = fridgeRepository.findByGroupId(groupId).orElseThrow(() -> new IllegalArgumentException("Fridge does not exist"));
+        if(product.isPresent()) {
+            fridge.getProducts().add(product.get());
+            fridgeRepository.save(fridge);
+            return true;
+        } else {
+            return false;
+        }
+    }
+
+    /**
+     * Remove a product from the fridge of a group
+     *
+     * @param groupId the id of the group
+     *                group must exist
+     * @param ean the ean of the product
+     * @return true if the product was removed
+     */
+    public boolean removeProduct(long groupId, long ean) {
+        Optional<Product> product = productService.getProductById(ean);
+        Fridge fridge = fridgeRepository.findByGroupId(groupId).orElseThrow(() -> new IllegalArgumentException("Fridge does not exist"));
+        if (product.isPresent()) {
+            fridge.getProducts().remove(product.get());
+            fridgeRepository.save(fridge);
+            return true;
+        } else {
+            return false;
+        }
+    }
+}