bu commit

- 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.

.gitea/workflows/build.yml

@@ -0,0 +1,54 @@
+name: Build and Deploy Spring Boot Server
+
+on:
+  push:
+    branches:
+      - dev
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      # 1. Checkout the code
+      - name: Checkout code
+        uses: actions/checkout@v2
+
+      # 2. Set up Java and Maven
+      - name: Set up JDK (Eclipse Temurin)
+        uses: actions/setup-java@v3
+        with:
+          distribution: "temurin"
+          java-version: "17"
+          cache: maven
+
+      # 3. Verify Maven installation
+      - name: Install Maven
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y maven
+          mvn -version
+
+      # 4. Build the Spring Boot application
+      - name: Build Spring Boot Application
+        run: |
+          mvn clean package -DskipTests
+
+      # 5. Set up Docker
+      - name: Set up Docker
+        run: |
+          docker --version
+
+      # 6. Build the Docker image
+      - name: Build and Package Docker Image
+        run: |
+          docker build -t tea.zendric.de/cedric/xpensely-server:latest .
+
+      # 7. Docker login
+      - name: Login to Docker Registry
+        run: |
+          echo "${{ secrets.TEAPASSWORD }}" | docker login tea.zendric.de -u ${{ secrets.TEAUSER }} --password-stdin
+      # 8. Push Docker image
+      - name: Push the Docker Image to registry
+        run: |
+          docker push tea.zendric.de/cedric/xpensely-server:latest

.gitea/workflows/tag_release.yml

@@ -0,0 +1,84 @@
+name: Build and Deploy Versioned Spring Boot Server
+
+on:
+  push:
+    tags:
+      - "*" # Match all tags
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      # 1. Checkout the code
+      - name: Checkout code
+        uses: actions/checkout@v2
+
+      # 2. Set up Java and Maven
+      - name: Set up JDK (Eclipse Temurin)
+        uses: actions/setup-java@v3
+        with:
+          distribution: "temurin"
+          java-version: "17"
+          cache: maven
+
+      # 3. Verify Maven installation
+      - name: Install Maven
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y maven
+          mvn -version
+
+      # 4. Build the Spring Boot application
+      - name: Build Spring Boot Application
+        run: |
+          mvn clean package -DskipTests
+
+      # 5. Set up Docker
+      - name: Set up Docker
+        run: |
+          docker --version
+
+      # 6. Extract the tag name
+      - name: Extract Tag Version
+        id: extract_version
+        run: |
+          TAG_VERSION=$(echo "${GITHUB_REF}" | sed 's#refs/tags/##')
+          if [ -z "$TAG_VERSION" ]; then
+            echo "Error: TAG_VERSION is empty."
+            exit 1
+          fi
+          echo "TAG_VERSION=$TAG_VERSION" >> $GITHUB_ENV
+
+          # Extract major and minor versions
+          MAJOR_VERSION=$(echo "${TAG_VERSION}" | cut -d. -f1)
+          MINOR_VERSION=$(echo "${TAG_VERSION}" | cut -d. -f1,2)
+          echo "MAJOR_VERSION=$MAJOR_VERSION" >> $GITHUB_ENV
+          echo "MINOR_VERSION=$MINOR_VERSION" >> $GITHUB_ENV
+
+      # 7. Build the Docker image with the tag
+      - name: Build and Package Docker Image
+        run: |
+          docker build -t tea.zendric.de/cedric/xpensely-server:${{ env.TAG_VERSION }} .
+
+      # 8. Tag the image with Major Version (e.g., 0)
+      - name: Tag with Major Version
+        run: |
+          docker tag tea.zendric.de/cedric/xpensely-server:${{ env.TAG_VERSION }} tea.zendric.de/cedric/xpensely-server:${{ env.MAJOR_VERSION }}
+
+      # 9. Tag the image with Minor Version (e.g., 0.1)
+      - name: Tag with Minor Version
+        run: |
+          docker tag tea.zendric.de/cedric/xpensely-server:${{ env.TAG_VERSION }} tea.zendric.de/cedric/xpensely-server:${{ env.MINOR_VERSION }}
+
+      # 10. Docker login
+      - name: Login to Docker Registry
+        run: |
+          echo "${{ secrets.TEAPASSWORD }}" | docker login tea.zendric.de -u ${{ secrets.TEAUSER }} --password-stdin
+
+      # 11. Push the Docker images with the tags
+      - name: Push the Docker Image to registry
+        run: |
+          docker push tea.zendric.de/cedric/xpensely-server:${{ env.TAG_VERSION }}
+          docker push tea.zendric.de/cedric/xpensely-server:${{ env.MAJOR_VERSION }}
+          docker push tea.zendric.de/cedric/xpensely-server:${{ env.MINOR_VERSION }}

.gitignore

@@ -3,6 +3,7 @@ target/
 !.mvn/wrapper/maven-wrapper.jar
 !**/src/main/**/target/
 !**/src/test/**/target/
+.env
 
 ### STS ###
 .apt_generated

README.md

@@ -0,0 +1,7 @@
+Run it locally:
+
+1. build the current state:
+   mvn clean install or mvn clean install -DskipTests
+
+2. docker it up and run it
+   docker-compose -f dev-docker-compose.yml up --build

apiDesign.drawio

@@ -1,6 +1,6 @@
 <mxfile host="65bd71144e">
     <diagram id="TZX9Tq6sZIlTxQ58HocZ" name="Page-1">
-        <mxGraphModel dx="826" dy="472" grid="1" gridSize="10" guides="1" tooltips="1" connect="1" arrows="1" fold="1" page="1" pageScale="1" pageWidth="850" pageHeight="1100" math="0" shadow="0">
+        <mxGraphModel dx="989" dy="570" grid="1" gridSize="10" guides="1" tooltips="1" connect="1" arrows="1" fold="1" page="1" pageScale="1" pageWidth="850" pageHeight="1100" math="0" shadow="0">
             <root>
                 <mxCell id="0"/>
                 <mxCell id="1" parent="0"/>
@@ -193,6 +193,90 @@
                 <mxCell id="73" value="&lt;span style=&quot;font-size: 8px;&quot;&gt;24.12.24 ; Expense ; 24,12 €&lt;/span&gt;" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#76608a;fontColor=#ffffff;strokeColor=#432D57;" parent="1" vertex="1">
                     <mxGeometry x="1399" y="226" width="120" height="20" as="geometry"/>
                 </mxCell>
+                <mxCell id="86" style="edgeStyle=none;html=1;entryX=0;entryY=0.5;entryDx=0;entryDy=0;" edge="1" parent="1" source="74" target="79">
+                    <mxGeometry relative="1" as="geometry"/>
+                </mxCell>
+                <mxCell id="74" value="List" style="rounded=0;whiteSpace=wrap;html=1;fillColor=#60a917;fontColor=#ffffff;strokeColor=#2D7600;" vertex="1" parent="1">
+                    <mxGeometry x="1880" y="160" width="120" height="60" as="geometry"/>
+                </mxCell>
+                <mxCell id="75" value="DB-Structure for Categories" style="text;html=1;strokeColor=none;fillColor=none;align=center;verticalAlign=middle;whiteSpace=wrap;rounded=0;" vertex="1" parent="1">
+                    <mxGeometry x="1930" y="35" width="100" height="30" as="geometry"/>
+                </mxCell>
+                <mxCell id="78" style="edgeStyle=none;html=1;entryX=0;entryY=0.5;entryDx=0;entryDy=0;" edge="1" parent="1" source="76" target="77">
+                    <mxGeometry relative="1" as="geometry"/>
+                </mxCell>
+                <mxCell id="76" value="List Entry" style="rounded=0;whiteSpace=wrap;html=1;" vertex="1" parent="1">
+                    <mxGeometry x="1920" y="220" width="120" height="60" as="geometry"/>
+                </mxCell>
+                <mxCell id="79" value="Available Categories" style="ellipse;whiteSpace=wrap;html=1;" vertex="1" parent="1">
+                    <mxGeometry x="2160" y="150" width="120" height="80" as="geometry"/>
+                </mxCell>
+                <mxCell id="83" style="edgeStyle=none;html=1;entryX=0.5;entryY=0;entryDx=0;entryDy=0;" edge="1" parent="1" source="81" target="79">
+                    <mxGeometry relative="1" as="geometry"/>
+                </mxCell>
+                <mxCell id="81" value="Standard Categories" style="ellipse;whiteSpace=wrap;html=1;" vertex="1" parent="1">
+                    <mxGeometry x="2060" y="35" width="120" height="80" as="geometry"/>
+                </mxCell>
+                <mxCell id="84" style="edgeStyle=none;html=1;entryX=0.5;entryY=0;entryDx=0;entryDy=0;" edge="1" parent="1" source="82" target="79">
+                    <mxGeometry relative="1" as="geometry"/>
+                </mxCell>
+                <mxCell id="82" value="Custom Categories" style="ellipse;whiteSpace=wrap;html=1;" vertex="1" parent="1">
+                    <mxGeometry x="2270" y="35" width="120" height="80" as="geometry"/>
+                </mxCell>
+                <mxCell id="91" style="edgeStyle=none;html=1;entryX=0;entryY=0.5;entryDx=0;entryDy=0;" edge="1" parent="1" source="87" target="90">
+                    <mxGeometry relative="1" as="geometry"/>
+                </mxCell>
+                <mxCell id="87" value="List Entry" style="rounded=0;whiteSpace=wrap;html=1;" vertex="1" parent="1">
+                    <mxGeometry x="1920" y="280" width="120" height="60" as="geometry"/>
+                </mxCell>
+                <mxCell id="92" style="edgeStyle=none;html=1;entryX=0;entryY=0.5;entryDx=0;entryDy=0;" edge="1" parent="1" source="88" target="89">
+                    <mxGeometry relative="1" as="geometry"/>
+                </mxCell>
+                <mxCell id="88" value="List Entry" style="rounded=0;whiteSpace=wrap;html=1;" vertex="1" parent="1">
+                    <mxGeometry x="1920" y="340" width="120" height="60" as="geometry"/>
+                </mxCell>
+                <mxCell id="89" value="Category" style="ellipse;whiteSpace=wrap;html=1;" vertex="1" parent="1">
+                    <mxGeometry x="2150" y="370" width="120" height="80" as="geometry"/>
+                </mxCell>
+                <mxCell id="90" value="Category" style="ellipse;whiteSpace=wrap;html=1;" vertex="1" parent="1">
+                    <mxGeometry x="2150" y="315" width="120" height="80" as="geometry"/>
+                </mxCell>
+                <mxCell id="94" value="&lt;h1 style=&quot;font-size: 18px;&quot;&gt;- list id&lt;/h1&gt;&lt;div&gt;- List &amp;lt;String&amp;gt;&lt;/div&gt;" style="text;html=1;strokeColor=none;fillColor=none;spacing=5;spacingTop=-20;whiteSpace=wrap;overflow=hidden;rounded=0;fontSize=18;" vertex="1" parent="1">
+                    <mxGeometry x="2410" y="50" width="130" height="70" as="geometry"/>
+                </mxCell>
+                <mxCell id="77" value="Category" style="ellipse;whiteSpace=wrap;html=1;" vertex="1" parent="1">
+                    <mxGeometry x="2150" y="260" width="120" height="80" as="geometry"/>
+                </mxCell>
+                <mxCell id="97" value="" style="rounded=0;whiteSpace=wrap;html=1;" vertex="1" parent="1">
+                    <mxGeometry x="1730" y="510" width="200" height="320" as="geometry"/>
+                </mxCell>
+                <mxCell id="98" value="ExpenseList" style="rounded=1;whiteSpace=wrap;html=1;" vertex="1" parent="1">
+                    <mxGeometry x="1770" y="520" width="120" height="20" as="geometry"/>
+                </mxCell>
+                <mxCell id="100" value="+" style="rounded=1;whiteSpace=wrap;html=1;" vertex="1" parent="1">
+                    <mxGeometry x="1880" y="790" width="30" height="30" as="geometry"/>
+                </mxCell>
+                <mxCell id="101" value="Categorie" style="text;html=1;strokeColor=none;fillColor=none;align=center;verticalAlign=middle;whiteSpace=wrap;rounded=0;" vertex="1" parent="1">
+                    <mxGeometry x="1770" y="480" width="120" height="30" as="geometry"/>
+                </mxCell>
+                <mxCell id="102" value="&lt;span style=&quot;font-size: 8px;&quot;&gt;Amount : 24,12 €&lt;br&gt;Title: Expense&lt;br&gt;Date: 24.12.24&lt;br&gt;From: Jessi&lt;br&gt;Deviation: 0 €&lt;/span&gt;" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#76608a;fontColor=#ffffff;strokeColor=#432D57;align=left;spacingLeft=12;" vertex="1" parent="1">
+                    <mxGeometry x="1745" y="550" width="170" height="170" as="geometry"/>
+                </mxCell>
+                <mxCell id="105" value="&lt;span style=&quot;font-size: 8px;&quot;&gt;Essen&lt;/span&gt;" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#1ba1e2;fontColor=#ffffff;strokeColor=#006EAF;align=left;spacingLeft=12;" vertex="1" parent="1">
+                    <mxGeometry x="1760" y="680" width="40" height="10" as="geometry"/>
+                </mxCell>
+                <mxCell id="106" value="&lt;span style=&quot;font-size: 8px;&quot;&gt;Trinken&lt;/span&gt;" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#a20025;fontColor=#ffffff;strokeColor=#6F0000;align=left;spacingLeft=12;" vertex="1" parent="1">
+                    <mxGeometry x="1800" y="680" width="40" height="10" as="geometry"/>
+                </mxCell>
+                <mxCell id="107" value="&lt;span style=&quot;font-size: 8px;&quot;&gt;Auto&lt;/span&gt;" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#d80073;fontColor=#ffffff;strokeColor=#A50040;align=left;spacingLeft=12;" vertex="1" parent="1">
+                    <mxGeometry x="1840" y="680" width="40" height="10" as="geometry"/>
+                </mxCell>
+                <mxCell id="111" style="edgeStyle=none;html=1;entryX=0;entryY=0.5;entryDx=0;entryDy=0;fontSize=18;" edge="1" parent="1" source="108" target="74">
+                    <mxGeometry relative="1" as="geometry"/>
+                </mxCell>
+                <mxCell id="108" value="Actor" style="shape=umlActor;verticalLabelPosition=bottom;verticalAlign=top;html=1;outlineConnect=0;fontSize=18;" vertex="1" parent="1">
+                    <mxGeometry x="1715" y="150" width="30" height="60" as="geometry"/>
+                </mxCell>
             </root>
         </mxGraphModel>
     </diagram>

dev-docker-compose.yml

@@ -0,0 +1,52 @@
+version: "3.8"
+services:
+  xpensely-server:
+    build:
+      context: .
+      dockerfile: Dockerfile
+    image: xpensely-server:local
+    labels:
+      net.unraid.docker.icon: https://tea.zendric.de/Cedric/XpenselyServer/raw/branch/main/src/main/resources/static/xpensely_icon_white.png
+    container_name: xpensely-server
+    ports:
+      - 3636:8080
+    environment:
+      GOOGLE_CLIENT_ID: ${GOOGLE_CLIENT_ID}
+      GOOGLE_CLIENT_SECRET: ${GOOGLE_CLIENT_SECRET}
+      DB_PORT: 5432
+      DB_P_NAME: xpensely
+      DB_USERNAME: ${DB_USERNAME}
+      DB_PASSWORD: ${DB_PASSWORD}
+      SPRING_PROFILES_ACTIVE: test
+    depends_on:
+      postgresdb:
+        condition: service_healthy
+    networks:
+      - xpensely-network
+  postgresdb:
+    labels:
+      net.unraid.docker.icon: https://raw.githubusercontent.com/docker-library/docs/01c12653951b2fe592c1f93a13b4e289ada0e3a1/postgres/logo.png
+    image: postgres:14
+    container_name: postgresdb
+    ports:
+      - 5435:5432
+    environment:
+      POSTGRES_DB: xpensely
+      POSTGRES_USER: ${DB_USERNAME}
+      POSTGRES_PASSWORD: ${DB_PASSWORD}
+    networks:
+      - xpensely-network
+    volumes:
+      - db_data:/var/lib/postgresql/data
+    restart: unless-stopped
+    healthcheck:
+      test:
+        - CMD-SHELL
+        - pg_isready -U ${DB_USERNAME} -d xpensely
+      interval: 10s
+      timeout: 5s
+      retries: 5
+volumes:
+  db_data: null
+networks:
+  xpensely-network: null

docker-compose.yml

@@ -0,0 +1,49 @@
+version: "3.8"
+services:
+  xpensely-server:
+    image: tea.zendric.de/cedric/xpensely-server:0
+    labels:
+      net.unraid.docker.icon: https://tea.zendric.de/Cedric/XpenselyServer/raw/branch/main/src/main/resources/static/xpensely_icon_white.png
+    container_name: xpensely-server
+    ports:
+      - 3636:8080
+    environment:
+      GOOGLE_CLIENT_ID: ${GOOGLE_CLIENT_ID}
+      GOOGLE_CLIENT_SECRET: ${GOOGLE_CLIENT_SECRET}
+      DB_PORT: 5432
+      DB_P_NAME: xpensely
+      DB_USERNAME: ${DB_USERNAME}
+      DB_PASSWORD: ${DB_PASSWORD}
+    depends_on:
+      postgresdb:
+        condition: service_healthy
+    networks:
+      - xpensely-network
+  postgresdb:
+    labels:
+      net.unraid.docker.icon: https://raw.githubusercontent.com/docker-library/docs/01c12653951b2fe592c1f93a13b4e289ada0e3a1/postgres/logo.png
+    image: postgres:14
+    container_name: postgresdb
+    ports:
+      - 5435:5432
+    environment:
+      POSTGRES_DB: xpensely
+      POSTGRES_USER: ${DB_USERNAME}
+      POSTGRES_PASSWORD: ${DB_PASSWORD}
+    networks:
+      - xpensely-network
+    volumes:
+      - db_data:/var/lib/postgresql/data
+      - /mnt/user/appdata/xpensely_backups:/backups
+    restart: unless-stopped
+    healthcheck:
+      test:
+        - CMD-SHELL
+        - pg_isready -U ${DB_USERNAME} -d xpensely
+      interval: 10s
+      timeout: 5s
+      retries: 5
+volumes:
+  db_data: null
+networks:
+  xpensely-network: null

dockerfile

@@ -0,0 +1,7 @@
+FROM openjdk:17-jdk-slim
+
+COPY ./target/*.jar app.jar
+
+EXPOSE 8080
+
+ENTRYPOINT ["java","-jar", "app.jar"]

pom.xml

@@ -10,9 +10,9 @@
 	</parent>
 	<groupId>de.zendric.app</groupId>
 	<artifactId>XpenselyServer</artifactId>
-	<version>0.0.1-SNAPSHOT</version>
+	<version>1.0.0</version>
 	<name>XpenselyServer</name>
-	<description>Demo project for Spring Boot</description>
+	<description>XpenselyServer used to handle the Xpensely App</description>
 	<url/>
 	<licenses>
 		<license/>
@@ -37,6 +37,10 @@
 		<dependency>
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-starter-security</artifactId>
+		</dependency>
+		<dependency>
+        	<groupId>org.springframework.boot</groupId>
+        	<artifactId>spring-boot-starter-oauth2-resource-server</artifactId>
     	</dependency>
 			<dependency>
 			<groupId>org.springframework.boot</groupId>
@@ -46,7 +50,6 @@
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-starter-web</artifactId>
 		</dependency>
-
 		<dependency>
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-devtools</artifactId>

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

@@ -3,7 +3,6 @@ package de.zendric.app.xpensely_server.controller;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
-import org.springframework.security.core.Authentication;
 import org.springframework.web.bind.annotation.DeleteMapping;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PostMapping;
@@ -13,6 +12,8 @@ import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.bind.annotation.RestController;
 
 import de.zendric.app.xpensely_server.model.AppUser;
+import de.zendric.app.xpensely_server.model.AppUserCreateRequest;
+import de.zendric.app.xpensely_server.model.Exception.UsernameAlreadyExistsException;
 import de.zendric.app.xpensely_server.services.UserService;
 
 @RestController
@@ -36,18 +37,32 @@ public class AppUserController {
         return userService.getUserByName(username);
     }
 
-    @PostMapping
-    public ResponseEntity<AppUser> createUser(@RequestBody AppUser user) {
-        AppUser appUser = userService.createUser(user);
-        return ResponseEntity.status(HttpStatus.CREATED).body(appUser);
+    @GetMapping("/byGoogleId")
+    public ResponseEntity<AppUser> getUserByGoogleId(@RequestParam String id) {
+        try {
+            AppUser userByGoogleId = userService.getUserByGoogleId(id);
+            return new ResponseEntity<>(userByGoogleId, HttpStatus.OK);
+
+        } catch (IllegalArgumentException e) {
+            return new ResponseEntity<>(null, HttpStatus.BAD_REQUEST);
+        } catch (Exception e) {
+            return new ResponseEntity<>(null, HttpStatus.INTERNAL_SERVER_ERROR);
+        }
     }
 
     @PostMapping("/createUser")
-    public ResponseEntity<?> createUsername(@RequestBody AppUser user, Authentication authentication) {
-        String googleUserId = authentication.getName();
-        // Validate and store the username with googleUserId
+    public ResponseEntity<AppUser> createUser(@RequestBody AppUserCreateRequest userRequest) {
+        try {
+            AppUser convertedUser = userRequest.convertToAppUser();
+
+            AppUser nUser = userService.createUser(convertedUser);
+            return new ResponseEntity<>(nUser, HttpStatus.CREATED);
+        } catch (UsernameAlreadyExistsException e) {
+            return new ResponseEntity<>(null, HttpStatus.CONFLICT);
+        } catch (Exception e) {
+            return new ResponseEntity<>(null, HttpStatus.BAD_REQUEST);
+        }
 
-        return ResponseEntity.ok("Username created successfully");
     }
 
     @DeleteMapping

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

@@ -12,6 +12,7 @@ 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.RequestParam;
@@ -19,8 +20,12 @@ import org.springframework.web.bind.annotation.RestController;
 
 import de.zendric.app.xpensely_server.model.AppUser;
 import de.zendric.app.xpensely_server.model.Expense;
+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;
 
@@ -30,11 +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")
@@ -92,12 +100,28 @@ class ExpenseListController {
         }
     }
 
-    @PostMapping
+    @PostMapping("/create")
+    // TODO add handling of categories by using DTO
     public ResponseEntity<ExpenseList> create(@RequestBody ExpenseList expenseList) {
         try {
-            ExpenseList savedItem = (ExpenseList) expenseListService.save(expenseList);
+            if (expenseList.getOwner() != null) {
+                AppUser existingOwner = userService.getUser(expenseList.getOwner().getId());
+                if (existingOwner == null) {
+                    throw new IllegalArgumentException("Owner does not exist.");
+                }
+                expenseList.setOwner(existingOwner);
+                XpenselyStandardCategories standardCategories = categoryService.getDefaultCategories();
+                expenseList.setXpenselyStandardCategories(standardCategories);
+            } else {
+                throw new IllegalArgumentException("Owner is required.");
+            }
+
+            expenseList.setSharedWith(null);
+
+            ExpenseList savedItem = expenseListService.createList(expenseList);
             return new ResponseEntity<>(savedItem, HttpStatus.CREATED);
         } catch (Exception e) {
+            e.printStackTrace();
             return new ResponseEntity<>(null, HttpStatus.EXPECTATION_FAILED);
         }
     }
@@ -115,8 +139,11 @@ class ExpenseListController {
     @PostMapping("/{id}/add")
     public ResponseEntity<Expense> addExpenseToList(
             @PathVariable("id") Long expenseListId,
-            @RequestBody Expense expense) {
+            @RequestBody ExpenseInput expenseInput) {
         try {
+            AppUser expenseOwner = userService.getUserByName(expenseInput.getOwner());
+            Expense expense = expenseInput.convertToExpense(expenseOwner.getId());
+
             Expense addedExpense = expenseListService.addExpenseToList(expenseListId, expense);
             return new ResponseEntity<>(addedExpense, HttpStatus.CREATED);
         } catch (Exception e) {
@@ -124,6 +151,26 @@ class ExpenseListController {
         }
     }
 
+    @PutMapping("/{id}/update")
+    public ResponseEntity<Expense> updateExpenseInList(
+            @PathVariable("id") Long expenseListId,
+            @RequestBody ExpenseChangeRequest expenseChangeRequest) {
+        try {
+            AppUser expenseOwner = userService.getUserByName(expenseChangeRequest.getOwnerName());
+            Optional<ExpenseList> expenseList = expenseListService.findById(expenseListId);
+            if (expenseList.isPresent()) {
+                Expense expense = expenseChangeRequest.convertToExpense(expenseOwner.getId(), expenseList.get());
+
+                Expense addedExpense = expenseListService.updateExpense(expenseListId, expense);
+                return new ResponseEntity<>(addedExpense, HttpStatus.CREATED);
+            }
+            return new ResponseEntity<>(null, HttpStatus.BAD_REQUEST);
+
+        } catch (Exception e) {
+            return new ResponseEntity<>(null, HttpStatus.BAD_REQUEST);
+        }
+    }
+
     @DeleteMapping("/{id}/delete")
     public ResponseEntity<Expense> deleteExpenseFromList(
             @PathVariable("id") Long expenseListId,
@@ -153,6 +200,9 @@ class ExpenseListController {
         if (list.getSharedWith() != null) {
             return ResponseEntity.status(HttpStatus.IM_USED).body("List has already been shared");
         }
+        if (list.getOwner().getId() == inviteRequest.getUserId()) {
+            return ResponseEntity.status(HttpStatus.BAD_REQUEST).body("You cant join your own List");
+        }
         AppUser user = null;
         try {
             user = userService.getUser(inviteRequest.getUserId());

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

@@ -1,10 +1,17 @@
 package de.zendric.app.xpensely_server.model;
 
+import java.time.LocalDateTime;
+
+import org.hibernate.annotations.CreationTimestamp;
+
+import com.fasterxml.jackson.annotation.JsonIgnore;
+
 import jakarta.persistence.Column;
 import jakarta.persistence.Entity;
 import jakarta.persistence.GeneratedValue;
 import jakarta.persistence.GenerationType;
 import jakarta.persistence.Id;
+import lombok.EqualsAndHashCode;
 import lombok.Getter;
 import lombok.NoArgsConstructor;
 import lombok.Setter;
@@ -13,6 +20,7 @@ import lombok.Setter;
 @Setter
 @NoArgsConstructor
 @Entity
+@EqualsAndHashCode
 public class AppUser {
     @Id
     @GeneratedValue(strategy = GenerationType.IDENTITY)
@@ -21,4 +29,12 @@ public class AppUser {
     @Column(name = "username", nullable = false, unique = true)
     private String username;
 
+    @JsonIgnore
+    private String googleId;
+
+    @Column(updatable = false)
+    @CreationTimestamp
+    @JsonIgnore
+    private LocalDateTime createdAt;
+
 }

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

@@ -0,0 +1,21 @@
+package de.zendric.app.xpensely_server.model;
+
+import jakarta.persistence.Column;
+import lombok.Data;
+
+@Data
+public class AppUserCreateRequest {
+
+    @Column(name = "username", nullable = false, unique = true)
+    private String username;
+
+    private String googleId;
+
+    public AppUser convertToAppUser() {
+        AppUser appUser = new AppUser();
+        appUser.setGoogleId(googleId);
+        appUser.setUsername(username);
+
+        return appUser;
+    }
+}

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

@@ -0,0 +1,8 @@
+package de.zendric.app.xpensely_server.model.DTO;
+
+public class ExpenseListDTO {
+
+    // TODO should combine the two categories to one;
+
+    // private List<CategoryDTO> availableCategories;
+}

src/main/java/de/zendric/app/xpensely_server/model/Exception/UsernameAlreadyExistsException.java

@@ -0,0 +1,11 @@
+package de.zendric.app.xpensely_server.model.Exception;
+
+import org.springframework.http.HttpStatus;
+import org.springframework.web.bind.annotation.ResponseStatus;
+
+@ResponseStatus(HttpStatus.CONFLICT)
+public class UsernameAlreadyExistsException extends RuntimeException {
+    public UsernameAlreadyExistsException(String message) {
+        super(message);
+    }
+}

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

@@ -32,8 +32,9 @@ public class Expense {
     private AppUser owner;
 
     private Double amount;
-    private Double deviation;
-
+    private Double personalUseAmount;
+    private Double otherPersonAmount;
+    private String category;
     private LocalDate date;
 
     @ManyToOne

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

@@ -0,0 +1,41 @@
+package de.zendric.app.xpensely_server.model;
+
+import java.time.LocalDate;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+@Data
+@AllArgsConstructor
+@NoArgsConstructor
+public class ExpenseChangeRequest {
+
+    private Long id;
+    private String title;
+    private String ownerName;
+    private Double amount;
+    private Double personalUseAmount;
+    private Double otherPersonAmount;
+    private LocalDate date;
+    private String category;
+
+    public Expense convertToExpense(Long userId, ExpenseList expenseList) {
+        AppUser appUser = new AppUser();
+        appUser.setId(userId);
+        appUser.setUsername(ownerName);
+
+        Expense expense = new Expense();
+        expense.setAmount(amount);
+        expense.setDate(date);
+        expense.setPersonalUseAmount(personalUseAmount);
+        expense.setOtherPersonAmount(otherPersonAmount);
+        expense.setExpenseList(expenseList);
+        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

@@ -0,0 +1,54 @@
+package de.zendric.app.xpensely_server.model;
+
+import java.time.LocalDate;
+
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
+@Getter
+@Setter
+@AllArgsConstructor
+@NoArgsConstructor
+public class ExpenseInput {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    private String title;
+
+    private String owner;
+
+    private Double amount;
+    private Double personalUseAmount;
+    private Double otherPersonAmount;
+
+    private LocalDate date;
+    private String category;
+
+    private ExpenseList expenseList;
+
+    public Expense convertToExpense(Long userId) {
+        AppUser appUser = new AppUser();
+        appUser.setId(userId);
+        appUser.setUsername(owner);
+
+        Expense expense = new Expense();
+        expense.setAmount(amount);
+        expense.setDate(date);
+        expense.setPersonalUseAmount(personalUseAmount);
+        expense.setOtherPersonAmount(otherPersonAmount);
+        expense.setExpenseList(expenseList);
+        expense.setId(id);
+        expense.setOwner(appUser);
+        expense.setTitle(title);
+        expense.setCategory(category);
+
+        return expense;
+    }
+}

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

@@ -8,6 +8,7 @@ import com.fasterxml.jackson.annotation.JsonManagedReference;
 
 import jakarta.persistence.CascadeType;
 import jakarta.persistence.Entity;
+import jakarta.persistence.FetchType;
 import jakarta.persistence.GeneratedValue;
 import jakarta.persistence.GenerationType;
 import jakarta.persistence.Id;
@@ -40,8 +41,17 @@ public class ExpenseList {
     @ManyToOne
     private AppUser sharedWith;
 
+    @ManyToOne(fetch = FetchType.EAGER)
+    private XpenselyStandardCategories xpenselyStandardCategories;
+
     @OneToMany(mappedBy = "expenseList", cascade = CascadeType.ALL, orphanRemoval = true)
     @JsonManagedReference
+    @jakarta.persistence.OrderBy("name ASC")
+    private List<XpenselyCustomCategory> customCategories;
+
+    @OneToMany(mappedBy = "expenseList", cascade = CascadeType.ALL, orphanRemoval = true)
+    @JsonManagedReference
+    @jakarta.persistence.OrderBy("date ASC, id ASC")
     private List<Expense> expenses;
 
     public void addExpense(Expense expense) {

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

@@ -0,0 +1,37 @@
+package de.zendric.app.xpensely_server.model;
+
+import com.fasterxml.jackson.annotation.JsonBackReference;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import jakarta.persistence.JoinColumn;
+import jakarta.persistence.ManyToOne;
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
+@Entity
+@Getter
+@Setter
+@AllArgsConstructor
+@NoArgsConstructor
+public class XpenselyCustomCategory {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    private String name;
+
+    @Column(name = "color_code", length = 7, nullable = false)
+    private String colorCode;
+
+    @ManyToOne
+    @JoinColumn(name = "expense_list_id", nullable = false)
+    @JsonBackReference
+    private ExpenseList expenseList;
+}

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

@@ -0,0 +1,29 @@
+package de.zendric.app.xpensely_server.model;
+
+import java.util.List;
+
+import jakarta.persistence.CascadeType;
+import jakarta.persistence.Entity;
+import jakarta.persistence.FetchType;
+import jakarta.persistence.Id;
+import jakarta.persistence.JoinColumn;
+import jakarta.persistence.OneToMany;
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
+@Entity
+@Getter
+@Setter
+@AllArgsConstructor
+@NoArgsConstructor
+public class XpenselyStandardCategories {
+
+    @Id
+    private Long id;
+
+    @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/model/XpenselyStandardCategory.java

@@ -0,0 +1,27 @@
+package de.zendric.app.xpensely_server.model;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
+@Entity
+@Getter
+@Setter
+@AllArgsConstructor
+@NoArgsConstructor
+public class XpenselyStandardCategory {
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    private String name;
+
+    @Column(name = "color_code", length = 7, nullable = false)
+    private String colorCode;
+}

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

@@ -0,0 +1,40 @@
+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;
+import org.springframework.stereotype.Component;
+
+import de.zendric.app.xpensely_server.model.XpenselyStandardCategories;
+import de.zendric.app.xpensely_server.model.XpenselyStandardCategory;
+import de.zendric.app.xpensely_server.repo.XpenselyStandardCategoriesRepository;
+
+@Component
+public class DataInitializer implements CommandLineRunner {
+
+    @Autowired
+    private XpenselyStandardCategoriesRepository globalRepo;
+
+    @Override
+    public void run(String... args) throws Exception {
+        Optional<XpenselyStandardCategories> optional = globalRepo.findById(1L);
+
+        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/repo/ExpenseRepository.java

@@ -1,5 +1,7 @@
 package de.zendric.app.xpensely_server.repo;
 
+import java.util.List;
+
 import org.springframework.data.jpa.repository.JpaRepository;
 import org.springframework.stereotype.Repository;
 
@@ -7,4 +9,5 @@ import de.zendric.app.xpensely_server.model.Expense;
 
 @Repository
 public interface ExpenseRepository extends JpaRepository<Expense, Long> {
+    List<Expense> findAllByOrderByDateAsc();
 }

src/main/java/de/zendric/app/xpensely_server/repo/UserRepository.java

@@ -10,4 +10,8 @@ import de.zendric.app.xpensely_server.model.AppUser;
 @Repository
 public interface UserRepository extends JpaRepository<AppUser, Long> {
     Optional<AppUser> findByUsername(String username);
+
+    Optional<AppUser> findByGoogleId(String id);
+
+    Boolean existsByUsername(String username);
 }

src/main/java/de/zendric/app/xpensely_server/repo/XpenselyCustomCategoryRepository.java

@@ -0,0 +1,10 @@
+package de.zendric.app.xpensely_server.repo;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.stereotype.Repository;
+
+import de.zendric.app.xpensely_server.model.XpenselyCustomCategory;
+
+@Repository
+public interface XpenselyCustomCategoryRepository extends JpaRepository<XpenselyCustomCategory, Long> {
+}

src/main/java/de/zendric/app/xpensely_server/repo/XpenselyStandardCategoriesRepository.java

@@ -0,0 +1,11 @@
+package de.zendric.app.xpensely_server.repo;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.stereotype.Repository;
+
+import de.zendric.app.xpensely_server.model.XpenselyStandardCategories;
+
+@Repository
+public interface XpenselyStandardCategoriesRepository extends JpaRepository<XpenselyStandardCategories, Long> {
+
+}

src/main/java/de/zendric/app/xpensely_server/security/SecurityConfig.java

@@ -2,6 +2,7 @@ package de.zendric.app.xpensely_server.security;
 
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Profile;
 import org.springframework.security.config.Customizer;
 import org.springframework.security.config.annotation.web.builders.HttpSecurity;
 import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
@@ -11,9 +12,26 @@ import org.springframework.security.web.SecurityFilterChain;
 @EnableWebSecurity
 public class SecurityConfig {
         @Bean
+        @Profile("test") // Only enable this for testing
+        public SecurityFilterChain testSecurityFilterChain(HttpSecurity http) throws Exception {
+                http
+                                .authorizeHttpRequests(auth -> auth
+                                                .anyRequest().permitAll())
+                                .csrf().disable();
+
+                return http.build();
+        }
+
+        @Bean
+        @Profile("!test")
         public SecurityFilterChain securityFilterChain(HttpSecurity http) throws Exception {
-        http.authorizeHttpRequests(auth -> auth
-                .anyRequest().authenticated()).oauth2Login(Customizer.withDefaults());
+                http
+                                .authorizeHttpRequests(auth -> auth
+                                                .anyRequest().authenticated())
+                                .oauth2ResourceServer(oauth2 -> oauth2
+                                                .jwt(Customizer.withDefaults()))
+                                .oauth2Login(Customizer.withDefaults())
+                                .csrf().disable();
 
                 return http.build();
         }

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

@@ -14,8 +14,10 @@ import org.springframework.transaction.annotation.Transactional;
 import de.zendric.app.xpensely_server.model.AppUser;
 import de.zendric.app.xpensely_server.model.Expense;
 import de.zendric.app.xpensely_server.model.ExpenseList;
+import de.zendric.app.xpensely_server.model.XpenselyCustomCategory;
 import de.zendric.app.xpensely_server.repo.ExpenseListRepository;
 import de.zendric.app.xpensely_server.repo.ExpenseRepository;
+import de.zendric.app.xpensely_server.repo.XpenselyCustomCategoryRepository;
 import jakarta.persistence.EntityManager;
 
 @Service
@@ -24,14 +26,17 @@ public class ExpenseListService {
 
     private ExpenseListRepository repository;
     private final ExpenseRepository expenseRepository;
+    private XpenselyCustomCategoryRepository customCategoryRepository;
 
     @Autowired
     private EntityManager entityManager;
 
     @Autowired
-    public ExpenseListService(ExpenseListRepository repository, ExpenseRepository expenseRepository) {
+    public ExpenseListService(ExpenseListRepository repository, ExpenseRepository expenseRepository,
+            XpenselyCustomCategoryRepository customCategoryRepository) {
         this.repository = repository;
         this.expenseRepository = expenseRepository;
+        this.customCategoryRepository = customCategoryRepository;
     }
 
     public List<ExpenseList> getAllLists() {
@@ -98,15 +103,20 @@ public class ExpenseListService {
     }
 
     public Expense addExpenseToList(Long expenseListId, Expense expense) {
+        // find expenseList
         ExpenseList expenseList = repository.findById(expenseListId)
                 .orElseThrow(() -> new RuntimeException("ExpenseList not found with id: " + expenseListId));
+        // get all added expenses
         HashSet<Long> existingId = new HashSet<>();
         for (Expense e : expenseList.getExpenses()) {
             existingId.add(e.getId());
         }
+        // add the new expense
         expenseList.addExpense(expense);
+        // save
         repository.save(expenseList);
-        Expense newExpense = expense;
+
+        Expense newExpense = new Expense();
         for (Expense e : expenseList.getExpenses()) {
             if (!existingId.contains(e.getId())) {
                 newExpense = e;
@@ -137,18 +147,64 @@ public class ExpenseListService {
     public String generateInviteCode(Long listId) {
         ExpenseList list = repository.findById(listId)
                 .orElseThrow(() -> new RuntimeException("List not found"));
+        String inviteCode;
+        if (list.getInviteCode() == null || list.getInviteCodeExpiration().isBefore(LocalDateTime.now())) {
 
-        String inviteCode = UUID.randomUUID().toString().substring(0, 6).toUpperCase();
+            inviteCode = UUID.randomUUID().toString().substring(0, 6).toUpperCase();
             LocalDateTime expirationTime = LocalDateTime.now().plusWeeks(1);
 
             list.setInviteCode(inviteCode);
             list.setInviteCodeExpiration(expirationTime);
             repository.save(list);
-
+        } else {
+            inviteCode = list.getInviteCode();
+        }
         return inviteCode;
     }
 
     public ExpenseList findByInviteCode(String inviteCode) {
         return repository.findByInviteCode(inviteCode);
     }
+
+    public Expense updateExpense(Long expenseListId, Expense updatedExpense) {
+        ExpenseList expenseList = repository.findById(expenseListId)
+                .orElseThrow(() -> new IllegalArgumentException("ExpenseList not found"));
+
+        if (!expenseList.getExpenses().stream()
+                .anyMatch(expense -> expense.getId().equals(updatedExpense.getId()))) {
+            throw new IllegalArgumentException("Expense does not belong to the specified ExpenseList");
+        }
+
+        Expense existingExpense = expenseRepository.findById(updatedExpense.getId())
+                .orElseThrow(() -> new IllegalArgumentException("Expense not found"));
+        existingExpense.setTitle(updatedExpense.getTitle());
+        existingExpense.setAmount(updatedExpense.getAmount());
+        existingExpense.setPersonalUseAmount(updatedExpense.getPersonalUseAmount());
+        existingExpense.setOtherPersonAmount(updatedExpense.getOtherPersonAmount());
+        existingExpense.setDate(updatedExpense.getDate());
+        existingExpense.setOwner(updatedExpense.getOwner());
+        existingExpense.setCategory(updatedExpense.getCategory());
+
+        return expenseRepository.save(existingExpense);
+    }
+
+    // TODO implement API for this
+    public XpenselyCustomCategory addCustomCategory(Long expenseListId, XpenselyCustomCategory customCategory) {
+        ExpenseList expenseList = repository.findById(expenseListId)
+                .orElseThrow(() -> new RuntimeException("Expense List not found"));
+        customCategory.setExpenseList(expenseList);
+
+        return customCategoryRepository.save(customCategory);
+    }
+
+    // TODO implement API for this
+    public void deleteCustomCategory(Long expenseListId, Long categoryId) {
+        XpenselyCustomCategory category = customCategoryRepository.findById(categoryId)
+                .orElseThrow(() -> new RuntimeException("Custom Category not found"));
+        if (!category.getExpenseList().getId().equals(expenseListId)) {
+            throw new RuntimeException("Category does not belong to the specified Expense List");
+        }
+        customCategoryRepository.delete(category);
+    }
+
 }

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

@@ -6,6 +6,7 @@ import java.util.Optional;
 import org.springframework.stereotype.Service;
 
 import de.zendric.app.xpensely_server.model.AppUser;
+import de.zendric.app.xpensely_server.model.Exception.UsernameAlreadyExistsException;
 import de.zendric.app.xpensely_server.repo.UserRepository;
 
 @Service
@@ -21,6 +22,9 @@ public class UserService {
     }
 
     public AppUser createUser(AppUser user) {
+        if (Boolean.TRUE.equals(userRepository.existsByUsername(user.getUsername()))) {
+            throw new UsernameAlreadyExistsException("Username already exists");
+        }
         return userRepository.save(user);
     }
 
@@ -49,4 +53,12 @@ public class UserService {
             return null;
     }
 
+    public AppUser getUserByGoogleId(String id) {
+        Optional<AppUser> optUser = userRepository.findByGoogleId(id);
+        if (optUser.isPresent()) {
+            return optUser.get();
+        } else
+            return null;
+    }
+
 }

src/main/resources/application.properties

@@ -3,12 +3,14 @@ spring.application.name=XpenselyServer
 
 #Security
 spring.security.enabled=false
-#logging.level.org.springframework.security=TRACE
+spring.security.oauth2.client.registration.google.client-id=${GOOGLE_CLIENT_ID}
+spring.security.oauth2.client.registration.google.client-secret=${GOOGLE_CLIENT_SECRET}
+spring.security.oauth2.resourceserver.jwt.issuer-uri=https://accounts.google.com
 
 # PostgreSQL Configuration
-spring.datasource.url=jdbc:postgresql://localhost:5432/Xpensely
-spring.datasource.username=${XpenselyDBUser}
-spring.datasource.password=${XpenselyDBPW}
+spring.datasource.url=jdbc:postgresql://postgresdb:${DB_PORT}/${DB_P_NAME}
+spring.datasource.username=${DB_USERNAME}
+spring.datasource.password=${DB_PASSWORD}
 spring.datasource.driver-class-name=org.postgresql.Driver
 
 # Hibernate configuration

src/test/java/de/zendric/app/xpensely_Server/ExpenseListRepositoryTest.java

@@ -0,0 +1,26 @@
+package de.zendric.app.xpensely_Server;
+
+import java.util.Optional;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest;
+
+import de.zendric.app.xpensely_server.model.ExpenseList;
+import de.zendric.app.xpensely_server.repo.ExpenseListRepository;
+
+@DataJpaTest
+class ExpenseListRepositoryTest {
+
+        @Autowired
+        private ExpenseListRepository expenseListRepository;
+
+        @Test
+        void testFindExpenseListById() {
+                // Assuming an ExpenseList with id = 1 exists in your test DB.
+                Optional<ExpenseList> optionalExpenseList = expenseListRepository.findById(1L);
+
+                ExpenseList expenseList = optionalExpenseList.get();
+                System.out.println("ExpenseList name: " + expenseList.getName());
+        }
+}

src/test/java/de/zendric/app/xpensely_Server/XpenselyServerApplicationTests.java

@@ -1,13 +0,0 @@
-package de.zendric.app.xpensely_Server;
-
-import org.junit.jupiter.api.Test;
-import org.springframework.boot.test.context.SpringBootTest;
-
-@SpringBootTest
-class XpenselyServerApplicationTests {
-
-	@Test
-	void contextLoads() {
-	}
-
-}