Add CategoryService and integrate category handling in ExpenseListController

- Introduced CategoryService to manage standard categories.
- Updated ExpenseListController to set default categories when creating an expense list.
- Modified ExpenseChangeRequest and ExpenseInput to include category field.
- Enhanced DataInitializer to ensure standard categories are initialized.

src/main/java/de/zendric/app/xpensely_server/controller/ExpenseListController.java

@@ -24,6 +24,8 @@ import de.zendric.app.xpensely_server.model.ExpenseChangeRequest;
 import de.zendric.app.xpensely_server.model.ExpenseInput;
 import de.zendric.app.xpensely_server.model.ExpenseList;
 import de.zendric.app.xpensely_server.model.InviteRequest;
+import de.zendric.app.xpensely_server.model.XpenselyStandardCategories;
+import de.zendric.app.xpensely_server.services.CategoryService;
 import de.zendric.app.xpensely_server.services.ExpenseListService;
 import de.zendric.app.xpensely_server.services.UserService;
 
@@ -33,11 +35,14 @@ class ExpenseListController {
 
     private ExpenseListService expenseListService;
     private UserService userService;
+    private CategoryService categoryService;
 
     @Autowired
-    public ExpenseListController(ExpenseListService expenseListService, UserService userService) {
+    public ExpenseListController(ExpenseListService expenseListService, UserService userService,
+            CategoryService categoryService) {
         this.expenseListService = expenseListService;
         this.userService = userService;
+        this.categoryService = categoryService;
     }
 
     @GetMapping("/all")
@@ -105,6 +110,8 @@ class ExpenseListController {
                     throw new IllegalArgumentException("Owner does not exist.");
                 }
                 expenseList.setOwner(existingOwner);
+                XpenselyStandardCategories standardCategories = categoryService.getDefaultCategories();
+                expenseList.setXpenselyStandardCategories(standardCategories);
             } else {
                 throw new IllegalArgumentException("Owner is required.");
             }

src/main/java/de/zendric/app/xpensely_server/model/DTO/ExpenseListDTO.java

@@ -2,7 +2,7 @@ package de.zendric.app.xpensely_server.model.DTO;
 
 public class ExpenseListDTO {
 
-    // TODO should combine the two categories two one;
+    // TODO should combine the two categories to one;
 
     // private List<CategoryDTO> availableCategories;
 }

src/main/java/de/zendric/app/xpensely_server/model/ExpenseChangeRequest.java

@@ -18,6 +18,7 @@ public class ExpenseChangeRequest {
     private Double personalUseAmount;
     private Double otherPersonAmount;
     private LocalDate date;
+    private String category;
 
     public Expense convertToExpense(Long userId, ExpenseList expenseList) {
         AppUser appUser = new AppUser();
@@ -33,6 +34,7 @@ public class ExpenseChangeRequest {
         expense.setId(id);
         expense.setOwner(appUser);
         expense.setTitle(title);
+        expense.setCategory(category);
 
         return expense;
     }

src/main/java/de/zendric/app/xpensely_server/model/ExpenseInput.java

@@ -29,6 +29,7 @@ public class ExpenseInput {
     private Double otherPersonAmount;
 
     private LocalDate date;
+    private String category;
 
     private ExpenseList expenseList;
 
@@ -46,6 +47,7 @@ public class ExpenseInput {
         expense.setId(id);
         expense.setOwner(appUser);
         expense.setTitle(title);
+        expense.setCategory(category);
 
         return expense;
     }

src/main/java/de/zendric/app/xpensely_server/model/XpenselyStandardCategories.java

@@ -23,7 +23,7 @@ public class XpenselyStandardCategories {
     @Id
     private Long id;
 
-    @OneToMany(cascade = CascadeType.ALL, fetch = FetchType.EAGER)
+    @OneToMany(cascade = CascadeType.ALL, fetch = FetchType.EAGER, orphanRemoval = true)
     @JoinColumn(name = "global_categories_id")
     private List<XpenselyStandardCategory> categories;
 }

src/main/java/de/zendric/app/xpensely_server/preparation/DataInitializer.java

@@ -1,6 +1,7 @@
 package de.zendric.app.xpensely_server.preparation;
 
 import java.util.List;
+import java.util.Optional;
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.CommandLineRunner;
@@ -18,18 +19,22 @@ public class DataInitializer implements CommandLineRunner {
 
     @Override
     public void run(String... args) throws Exception {
-        if (!globalRepo.findById(1L).isPresent()) {
-            XpenselyStandardCategories global = new XpenselyStandardCategories();
-            global.setId(1L);
+        Optional<XpenselyStandardCategories> optional = globalRepo.findById(1L);
 
-            List<XpenselyStandardCategory> categories = List.of(
-                    new XpenselyStandardCategory(null, "Food", "#FF5733"),
-                    new XpenselyStandardCategory(null, "Transportation", "#33C3FF"),
-                    new XpenselyStandardCategory(null, "Entertainment", "#33FF57"),
-                    new XpenselyStandardCategory(null, "Shopping", "#FF33A8"),
-                    new XpenselyStandardCategory(null, "Bills", "#33FFEA"));
-            global.setCategories(categories);
-            globalRepo.save(global);
-        }
+        XpenselyStandardCategories global = optional.orElseGet(() -> {
+            XpenselyStandardCategories g = new XpenselyStandardCategories();
+            g.setId(1L);
+            return g;
+        });
+
+        List<XpenselyStandardCategory> categories = List.of(
+                new XpenselyStandardCategory(null, "Food", "#FF5733"),
+                new XpenselyStandardCategory(null, "Transportation", "#33C3FF"),
+                new XpenselyStandardCategory(null, "Entertainment", "#33FF57"),
+                new XpenselyStandardCategory(null, "Shopping", "#FF33A8"),
+                new XpenselyStandardCategory(null, "Household", "#FFC733"),
+                new XpenselyStandardCategory(null, "Other", "#9D33FF"));
+        global.setCategories(categories);
+        globalRepo.save(global);
     }
 }

src/main/java/de/zendric/app/xpensely_server/services/CategoryService.java

@@ -0,0 +1,24 @@
+package de.zendric.app.xpensely_server.services;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Service;
+
+import de.zendric.app.xpensely_server.model.XpenselyStandardCategories;
+import de.zendric.app.xpensely_server.repo.XpenselyStandardCategoriesRepository;
+
+@Service
+public class CategoryService {
+
+    private final XpenselyStandardCategoriesRepository standardCategoriesRepo;
+
+    @Autowired
+    public CategoryService(XpenselyStandardCategoriesRepository standardCategoriesRepo) {
+        this.standardCategoriesRepo = standardCategoriesRepo;
+    }
+
+    public XpenselyStandardCategories getDefaultCategories() {
+        return standardCategoriesRepo.findById(1L)
+                .orElseThrow(() -> new IllegalStateException("Standard categories not found"));
+    }
+
+}

src/main/java/de/zendric/app/xpensely_server/services/ExpenseListService.java

@@ -183,6 +183,7 @@ public class ExpenseListService {
         existingExpense.setOtherPersonAmount(updatedExpense.getOtherPersonAmount());
         existingExpense.setDate(updatedExpense.getDate());
         existingExpense.setOwner(updatedExpense.getOwner());
+        existingExpense.setCategory(updatedExpense.getCategory());
 
         return expenseRepository.save(existingExpense);
     }