Resolve "Add Fridge functionality"

Closes #26 (closed)

src/main/java/edu/ntnu/idatt2106/backend/controller/FridgeController.java

+package edu.ntnu.idatt2106.backend.controller;
+
+import edu.ntnu.idatt2106.backend.model.fridge.FridgeItem;
+import edu.ntnu.idatt2106.backend.model.user.User;
+import edu.ntnu.idatt2106.backend.service.FridgeService;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.http.ResponseEntity;
+import org.springframework.security.core.annotation.AuthenticationPrincipal;
+import org.springframework.web.bind.annotation.*;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.List;
+
+@RestController
+@CrossOrigin("*")
+public class FridgeController {
+
+    private final FridgeService fridgeService;
+
+    @Autowired
+    public FridgeController(FridgeService fridgeService) {
+        this.fridgeService = fridgeService;
+    }
+
+    @GetMapping("/user/fridge-items")
+    public ResponseEntity<List<FridgeItem>> getFridgeItemsByUserId(@AuthenticationPrincipal User user) {
+        return fridgeService.getFridgeItemsByUserId(user.getId());
+    }
+
+    @PostMapping("/fridge/add")
+    public ResponseEntity<String> addFridgeItem(@RequestBody FridgeItem fridgeItem, @AuthenticationPrincipal User user) {
+        return fridgeService.addFridgeItem(user.getId(), fridgeItem);
+    }
+
+    @DeleteMapping("/fridge-items/{fridgeItemId}")
+    public ResponseEntity<String> removeFridgeItem(@PathVariable Long fridgeItemId) {
+        return fridgeService.removeFridgeItem(fridgeItemId);
+    }
+
+    @PutMapping("/fridge-items/editQuantity/{fridgeItemId}")
+    public ResponseEntity<String> updateFridgeItemQuantity(@PathVariable Long fridgeItemId
+            , @RequestBody FridgeItem updatedFridgeItem) {
+        return fridgeService.updateFridgeItemQuantity(fridgeItemId, updatedFridgeItem);
+    }
+
+    @PutMapping("/fridge-items/editExpirationDate/{fridgeItemId}")
+    public ResponseEntity<String> updateFridgeItemExpirationDate(@PathVariable Long fridgeItemId
+            , @RequestBody FridgeItem updatedFridgeItem) {
+        return fridgeService.updateFridgeItemExpirationDate(fridgeItemId, updatedFridgeItem);
+    }
+}