docs: add comments to functions in the services

frontend/src/app/services/api.service.ts

@@ -9,8 +9,64 @@ import { catchError } from 'rxjs/operators';
   providedIn: 'root',
 })
 export class ApiService {
+  /**
+   * Initializes the ApiService with HttpClient and TokenService.
+   */
   constructor(private http: HttpClient, private tokenService: TokenService) {}
 
+  /**
+   * Sends a GET request to the specified endpoint.
+   *
+   * @template T The expected type of the response.
+   * @param endpoint The API endpoint to send the request to.
+   * @param auth Whether to include authentication headers. Defaults to false.
+   * @returns An Observable of type T.
+   */
+  get<T>(endpoint: string, auth: boolean = false): Observable<T> {
+    const headers = auth ? { headers: this.getAuthHeaders() } : {};
+    return this.http
+      .get<T>(`${environment.baseUrl}${endpoint}`, headers)
+      .pipe(catchError(this.handleError));
+  }
+
+  /**
+   * Sends a POST request to the specified endpoint with a request body.
+   *
+   * @template T The expected type of the response.
+   * @param endpoint The API endpoint to send the request to.
+   * @param body The request payload to send.
+   * @param auth Whether to include authentication headers. Defaults to false.
+   * @returns An Observable of type T.
+   */
+  post<T>(endpoint: string, body: any, auth: boolean = false): Observable<T> {
+    const headers = auth ? { headers: this.getAuthHeaders() } : {};
+    return this.http
+      .post<T>(`${environment.baseUrl}${endpoint}`, body, headers)
+      .pipe(catchError(this.handleError));
+  }
+
+  /**
+   * Sends a PUT request to the specified endpoint with a request body.
+   *
+   * @template T The expected type of the response.
+   * @param endpoint The API endpoint to send the request to.
+   * @param body The request payload to update.
+   * @param auth Whether to include authentication headers. Defaults to false.
+   * @returns An Observable of type T.
+   */
+  put<T>(endpoint: string, body: any, auth: boolean = false): Observable<T> {
+    const headers = auth ? { headers: this.getAuthHeaders() } : {};
+    return this.http
+      .put<T>(`${environment.baseUrl}${endpoint}`, body, headers)
+      .pipe(catchError(this.handleError));
+  }
+
+  /**
+   * Generates HTTP headers containing the Authorization token.
+   * If no token is found, the session is cleared.
+   *
+   * @returns A set of HTTP headers including the Authorization token.
+   */
   private getAuthHeaders(): HttpHeaders {
     const token = this.tokenService.getToken();
     if (!token) {
@@ -19,27 +75,12 @@ export class ApiService {
     return new HttpHeaders({ Authorization: `Token ${token}` });
   }
 
-  get<T>(endpoint: string, auth: boolean = false): Observable<T> {
-    const headers = auth ? { headers: this.getAuthHeaders() } : {};
-    return this.http
-      .get<T>(`${environment.baseUrl}${endpoint}`, headers)
-      .pipe(catchError(this.handleError));
-  }
-
-  post<T>(endpoint: string, body: any, auth: boolean = false): Observable<T> {
-    const headers = auth ? { headers: this.getAuthHeaders() } : {};
-    return this.http
-      .post<T>(`${environment.baseUrl}${endpoint}`, body, headers)
-      .pipe(catchError(this.handleError));
-  }
-
-  put<T>(endpoint: string, body: any, auth: boolean = false): Observable<T> {
-    const headers = auth ? { headers: this.getAuthHeaders() } : {};
-    return this.http
-      .put<T>(`${environment.baseUrl}${endpoint}`, body, headers)
-      .pipe(catchError(this.handleError));
-  }
-
+  /**
+   * Handles HTTP request errors by logging them and returning a throwError observable.
+   *
+   * @param error The error object received from the HTTP request.
+   * @returns An observable that emits the error.
+   */
   private handleError(error: any) {
     console.error('API error:', error);
     return throwError(() => error);

frontend/src/app/services/auth.service.ts

@@ -13,13 +13,22 @@ export class AuthService {
   passwordFieldType = 'password';
   passwordIcon = './assets/img/close-eye.svg';
 
+  /**
+   * Initializes the AuthService with ApiService, UserService, and TokenService.
+   */
   constructor(
-    private router: Router,
     private apiService: ApiService,
     private userService: UserService,
     private tokenService: TokenService
   ) {}
 
+  /**
+   * Attempts to log in the user with the provided credentials.
+   *
+   * @param body The login credentials.
+   * @param storage Whether to persist the token in local storage.
+   * @throws Error if no token is received upon successful login.
+   */
   async login(body: any, storage: boolean) {
     const data = await firstValueFrom(
       this.apiService.post<{ token: string }>('/auth/login/', body)
@@ -31,30 +40,63 @@ export class AuthService {
     }
   }
 
+  /**
+   * Logs out the user by calling the API endpoint.
+   */
   async logout() {
     await firstValueFrom(this.apiService.post('/auth/logout/', null, true));
   }
 
+  /**
+   * Registers a new user.
+   *
+   * @param body The registration details.
+   */
   async register(body: any) {
     await firstValueFrom(this.apiService.post('/auth/register/', body));
   }
 
+  /**
+   * Verifies a user's email address.
+   *
+   * @param body The verification data.
+   */
   async verifyEmail(body: any) {
     await firstValueFrom(this.apiService.post('/auth/verify-email/', body));
   }
 
+  /**
+   * Initiates a forgot password request.
+   *
+   * @param body The email address or related information.
+   */
   async forgotPassword(body: any) {
     await firstValueFrom(this.apiService.post('/auth/forgot-password/', body));
   }
 
+  /**
+   * Changes the user's password.
+   *
+   * @param body The password change details.
+   */
   async changePassword(body: any) {
     await firstValueFrom(this.apiService.post('/auth/change-password/', body));
   }
 
+  /**
+   * Checks if a user's email is associated with an authenticated account.
+   *
+   * @param body The email to verify.
+   */
   async checkAuthUserMail(body: any) {
     await firstValueFrom(this.apiService.post('/auth/', body));
   }
 
+  /**
+   * Verifies if the current user is authenticated.
+   *
+   * @returns An Observable emitting true if authenticated, false otherwise.
+   */
   checkAuthUser(): Observable<boolean> {
     return this.apiService.get<any>('/auth/', true).pipe(
       map((response) => {
@@ -65,12 +107,18 @@ export class AuthService {
     );
   }
 
+  /**
+   * Toggles the visibility of the password input field.
+   */
   togglePasswordVisibility() {
     this.passwordFieldType =
       this.passwordFieldType === 'password' ? 'text' : 'password';
     this.toggleIcon();
   }
 
+  /**
+   * Toggles the password visibility icon based on the current state.
+   */
   toggleIcon() {
     this.passwordIcon =
       this.passwordIcon === './assets/img/close-eye.svg'

frontend/src/app/services/error.service.ts

@@ -8,18 +8,32 @@ import { HttpErrorResponse } from '@angular/common/http';
 export class ErrorService {
   private errorSubject = new BehaviorSubject<string>('');
   errorText$ = this.errorSubject.asObservable();
+
   displayError = false;
 
+  /**
+   * Sets a new error message and enables error display.
+   *
+   * @param message The error message to display.
+   */
   errorMsg(message: string) {
     this.errorSubject.next(message);
     this.displayError = true;
   }
 
+  /**
+   * Clears the current error message and hides the error display.
+   */
   clearError() {
     this.errorSubject.next('');
     this.displayError = false;
   }
 
+  /**
+   * Handles an unknown or HTTP error, setting an appropriate error message.
+   *
+   * @param error The error object to process.
+   */
   handleError(error: unknown) {
     if (error instanceof HttpErrorResponse) {
       const errorMessage = error.error.error || 'An unknown error occurred';

frontend/src/app/services/movie.service.ts

@@ -13,6 +13,12 @@ export class MovieService {
   } = {};
   private availableResolutions: string[];
 
+  /**
+   * Initializes the MovieService with ApiService, AuthService, and ResolutionService
+   *
+   * It fetches the available resolutions from the ResolutionService and stores
+   * them in the availableResolutions field.
+   */
   constructor(
     private apiService: ApiService,
     private authService: AuthService,

frontend/src/app/services/resolution.service.ts

@@ -7,14 +7,14 @@ export class ResolutionService {
   private readonly AVAILABLE_RESOLUTIONS = ['360p', '720p', '1080p'];
 
   /**
-   * Gibt die zentral definierten verfügbaren Auflösungen zurück
+   * Returns the centrally defined available resolutions
    */
   getAvailableResolutions(): string[] {
     return this.AVAILABLE_RESOLUTIONS;
   }
 
   /**
-   * Initialisiert ein Objekt, das alle Auflösungen auf `false` setzt
+   * Initializes an object that sets all resolutions to `false`
    */
   initMovieIsUploaded(): { [resolution: string]: boolean } {
     return Object.fromEntries(
@@ -23,7 +23,7 @@ export class ResolutionService {
   }
 
   /**
-   * Gibt eine Standardauflösung zurück (z.B. '720p'), oder die erste verfügbare
+   * Returns a default resolution (e.g. '720p'), or the first available resolution.
    */
   getDefaultResolution(): string {
     return this.AVAILABLE_RESOLUTIONS.includes('720p')

frontend/src/app/services/token.service.ts

@@ -7,6 +7,9 @@ import { Router } from '@angular/router';
 export class TokenService {
   private readonly TOKEN_KEY = 'authToken';
 
+  /**
+   * Initializes the TokenService with the Router.
+   */
   constructor(private router: Router) {}
 
   /**

frontend/src/app/services/user.service.ts

@@ -8,6 +8,9 @@ import { firstValueFrom } from 'rxjs';
 export class UserService {
   currentUserId: string | null = null;
 
+  /**
+   * Initializes the UserService with ApiService.
+   */
   constructor(private apiService: ApiService) {}
 
   /**
@@ -39,6 +42,12 @@ export class UserService {
     );
   }
 
+  /**
+   * Update the list of watched movies for the current user
+   *
+   * @param watchedMovies a list of movie IDs watched by the current user
+   * @returns a promise resolved when the update is successful
+   */
   updateWatchedMovies(watchedMovies: any): Promise<any> {
     return firstValueFrom(
       this.apiService.put(