Fix of the edeting funktion in the Library Module

Fix of a library funktion
Finisched the removal of the Author
2026-06-10 11:24:33 +02:00 · 2026-06-10 11:08:43 +02:00 · 2026-06-07 23:16:05 +02:00 · 2026-06-07 22:57:32 +02:00 · 2026-06-07 22:28:04 +02:00 · 2026-06-07 22:21:01 +02:00
9 changed files with 971 additions and 1649 deletions
@@ -3484,66 +3484,6 @@ def api_library_scan_action():
            client.close()


-@app.route('/api/scan_upload', methods=['POST'])
-def api_scan_upload():
-    """
-    Server-side barcode/QR decoding endpoint.
-    Accepts image upload and returns detected barcodes (fallback for client-side scanner).
-    """
-    if 'username' not in session:
-        return jsonify({'ok': False, 'message': 'Nicht angemeldet.'}), 401
-
-    try:
-        from pyzbar.pyzbar import decode
-        from PIL import Image
-        import io
-    except ImportError:
-        return jsonify({'ok': False, 'message': 'pyzbar library not installed on server.'}), 500
-
-    if 'image' not in request.files:
-        return jsonify({'ok': False, 'message': 'Keine Bilddatei bereitgestellt.'}), 400
-
-    file = request.files['image']
-    if file.filename == '':
-        return jsonify({'ok': False, 'message': 'Datei ist leer.'}), 400
-
-    try:
-        # Decode image
-        image = Image.open(io.BytesIO(file.read()))
-        image = image.convert('RGB')
-
-        # Detect barcodes using pyzbar
-        results = decode(image)
-
-        if not results:
-            return jsonify({'ok': False, 'message': 'Kein Barcode im Bild erkannt.'}), 400
-
-        # Return all detected barcodes, sorted by confidence (quality)
-        barcodes = [
-            {
-                'type': result.type,
-                'value': result.data.decode('utf-8'),
-                'rect': {
-                    'x': result.rect.left,
-                    'y': result.rect.top,
-                    'width': result.rect.width,
-                    'height': result.rect.height,
-                }
-            }
-            for result in results
-        ]
-
-        return jsonify({
-            'ok': True,
-            'barcodes': barcodes,
-            'message': f'{len(barcodes)} Barcode(s) erkannt.'
-        }), 200
-
-    except Exception as e:
-        app.logger.error(f"Error decoding barcode image: {e}")
-        return jsonify({'ok': False, 'message': f'Fehler beim Dekodieren: {str(e)}'}), 500
-
-
@app.route('/api/item_detail/<item_id>')
 def api_item_detail(item_id):
    """
@@ -9436,17 +9376,137 @@ def search_word(word):
    except Exception as e:
        return jsonify({"success": False, "response": str(e)})

+def _fetch_from_google_books(clean_isbn):
+    """Source 1: Google Books API (Free, No Key required for basic use)"""
+    try:
+        url = f"https://www.googleapis.com/books/v1/volumes?q=isbn:{clean_isbn}"
+        response = requests.get(url, timeout=5)
+        if response.status_code != 200:
+            return None
+        
+        data = response.json()
+        if data.get('totalItems', 0) > 0 and data.get('items'):
+            book_info = data['items'][0].get('volumeInfo', {})
+            sale_info = data['items'][0].get('saleInfo', {})
+
+            price = None
+            retail_price = sale_info.get('retailPrice', {})
+            list_price = sale_info.get('listPrice', {})
+            if retail_price and 'amount' in retail_price:
+                price = f"{retail_price['amount']} {retail_price.get('currencyCode', '€')}"
+            elif list_price and 'amount' in list_price:
+                price = f"{list_price['amount']} {list_price.get('currencyCode', '€')}"
+
+            thumbnail = book_info.get('imageLinks', {}).get('thumbnail', '')
+            if thumbnail:
+                thumbnail = thumbnail.replace('http:', 'https:')
+
+            return {
+                "title": book_info.get('title', 'Unknown Title'),
+                "authors": ', '.join(book_info.get('authors', ['Unknown Author'])),
+                "publisher": book_info.get('publisher', 'Unknown Publisher'),
+                "publishedDate": book_info.get('publishedDate', 'Unknown Date'),
+                "description": book_info.get('description', 'Keine Beschreibung verfügbar'),
+                "pageCount": book_info.get('pageCount', 'Unknown'),
+                "price": price,
+                "thumbnail": thumbnail,
+                "source": "google-books"
+            }
+    except Exception as e:
+        print(f"Google Books error: {e}")
+    return None
+
+
+def _fetch_from_lobid_germany(clean_isbn):
+    """
+    Source 2: Lobid.org (hbz Network)
+    The ultimate free, keyless fallback for German Schoolbooks and DACH literature.
+    """
+    try:
+        url = f"https://lobid.org/resources?q=isbn:{clean_isbn}&format=json"
+        response = requests.get(url, timeout=5)
+        if response.status_code != 200:
+            return None
+            
+        data = response.json()
+        if 'member' in data and len(data['member']) > 0:
+            book = data['member'][0]
+            
+            # Extract Authors (Lobid uses a nested contribution array)
+            authors = []
+            for contrib in book.get('contribution', []):
+                if 'agent' in contrib and 'label' in contrib['agent']:
+                    authors.append(contrib['agent']['label'])
+            
+            # Extract Publishers
+            publishers = []
+            for pub in book.get('publication', []):
+                if 'publishedBy' in pub:
+                    # sometimes publishedBy is a list, sometimes a string
+                    pub_data = pub['publishedBy']
+                    if isinstance(pub_data, list):
+                        publishers.extend(pub_data)
+                    else:
+                        publishers.append(pub_data)
+            
+            # Extract Date
+            pub_date = 'Unknown Date'
+            if book.get('publication'):
+                pub_date = book['publication'][0].get('startDate', 'Unknown Date')
+                
+            # Extract Pages
+            pages = book.get('extent', ['Unknown'])[0] if 'extent' in book else 'Unknown'
+            
+            return {
+                "title": book.get('title', 'Unknown Title'),
+                "authors": ', '.join(authors) if authors else 'Unknown Author',
+                "publisher": ', '.join(publishers) if publishers else 'Unknown Publisher',
+                "publishedDate": str(pub_date),
+                "description": 'Keine Beschreibung verfügbar (Schulbuch / Fachliteratur)',
+                "pageCount": pages,
+                "price": None,
+                "thumbnail": "", # Lobid rarely has covers, we will fallback to OpenLibrary cover below
+                "source": "lobid-germany"
+            }
+    except Exception as e:
+        print(f"Lobid error: {e}")
+    return None
+
+
+def _fetch_from_open_library(clean_isbn):
+    """Source 3: Open Library Search API (Free, No Key required)"""
+    try:
+        url = f"https://openlibrary.org/search.json?isbn={clean_isbn}"
+        response = requests.get(url, timeout=5)
+        if response.status_code != 200:
+            return None
+            
+        data = response.json()
+        if data.get('numFound', 0) > 0 and data.get('docs'):
+            book_info = data['docs'][0]
+            
+            return {
+                "title": book_info.get('title', 'Unknown Title'),
+                "authors": ', '.join(book_info.get('author_name', ['Unknown Author'])),
+                "publisher": ', '.join(book_info.get('publisher', ['Unknown Publisher'])),
+                "publishedDate": str(book_info.get('publish_date', ['Unknown Date'])[0]),
+                "description": 'Keine Beschreibung verfügbar',
+                "pageCount": book_info.get('number_of_pages_median', 'Unknown'),
+                "price": None,
+                "thumbnail": f"https://covers.openlibrary.org/b/isbn/{clean_isbn}-L.jpg",
+                "source": "openlibrary"
+            }
+    except Exception as e:
+        print(f"OpenLibrary Search error: {e}")
+    return None
+
@app.route('/fetch_book_info/<isbn>')
 def fetch_book_info(isbn):
    """
-    API endpoint to fetch book information by ISBN using Google Books API
-    
-    Args:
-        isbn (str): ISBN to look up
-        
-    Returns:
-        dict: Book information or error message
+    API endpoint to fetch book information by ISBN using multiple open sources.
+    Optimized for global literature AND German educational books.
    """
+    # Authorization Checks
    if 'username' not in session or not us.check_admin(session['username']):
        return jsonify({"error": "Not authorized"}), 403

@@ -9454,79 +9514,33 @@ def fetch_book_info(isbn):
        return jsonify({"error": "Bibliotheks-Modul ist deaktiviert."}), 403

    try:
+        # Validation
        clean_isbn = normalize_and_validate_isbn(isbn)
        if not clean_isbn:
            return jsonify({"error": "Ungültige ISBN. Bitte ISBN-10 oder ISBN-13 verwenden."}), 400

-        # First source: Google Books
-        response = requests.get(
-            f"https://www.googleapis.com/books/v1/volumes?q=isbn:{clean_isbn}",
-            timeout=10
-        )
+        # Define the Provider Chain (Order matters: General -> German/School -> Global Fallback)
+        providers = [
+            _fetch_from_google_books,
+            _fetch_from_lobid_germany,
+            _fetch_from_open_library
+        ]

-        if response.status_code == 200:
-            data = response.json()
-            if data.get('totalItems', 0) > 0 and data.get('items'):
-                book_info = data['items'][0].get('volumeInfo', {})
-                sale_info = data['items'][0].get('saleInfo', {})
-
-                price = None
-                retail_price = sale_info.get('retailPrice', {})
-                list_price = sale_info.get('listPrice', {})
-                if retail_price and 'amount' in retail_price:
-                    price = f"{retail_price['amount']} {retail_price.get('currencyCode', '€')}"
-                elif list_price and 'amount' in list_price:
-                    price = f"{list_price['amount']} {list_price.get('currencyCode', '€')}"
-
-                thumbnail = book_info.get('imageLinks', {}).get('thumbnail', '')
-                if thumbnail:
-                    thumbnail = thumbnail.replace('http:', 'https:')
-
-                return jsonify({
-                    "title": book_info.get('title', 'Unknown Title'),
-                    "authors": ', '.join(book_info.get('authors', ['Unknown Author'])),
-                    "publisher": book_info.get('publisher', 'Unknown Publisher'),
-                    "publishedDate": book_info.get('publishedDate', 'Unknown Date'),
-                    "description": book_info.get('description', 'No description available'),
-                    "pageCount": book_info.get('pageCount', 'Unknown'),
-                    "price": price,
-                    "thumbnail": thumbnail,
-                    "isbn": clean_isbn,
-                    "source": "google-books"
-                })
-
-        # Fallback: OpenLibrary
-        ol_response = requests.get(
-            f"https://openlibrary.org/isbn/{clean_isbn}.json",
-            timeout=10
-        )
-        if ol_response.status_code == 200:
-            ol_data = ol_response.json()
-            author_names = []
-            for author_ref in ol_data.get('authors', []):
-                key = author_ref.get('key')
-                if not key:
-                    continue
-                try:
-                    author_resp = requests.get(f"https://openlibrary.org{key}.json", timeout=8)
-                    if author_resp.status_code == 200:
-                        author_names.append(author_resp.json().get('name'))
-                except Exception:
-                    continue
-
-            return jsonify({
-                "title": ol_data.get('title', 'Unknown Title'),
-                "authors": ', '.join([a for a in author_names if a]) if author_names else 'Unknown Author',
-                "publisher": ', '.join(ol_data.get('publishers', [])) if ol_data.get('publishers') else 'Unknown Publisher',
-                "publishedDate": ol_data.get('publish_date', 'Unknown Date'),
-                "description": (ol_data.get('description', {}).get('value') if isinstance(ol_data.get('description'), dict) else ol_data.get('description')) or 'No description available',
-                "pageCount": ol_data.get('number_of_pages', 'Unknown'),
-                "price": None,
-                "thumbnail": f"https://covers.openlibrary.org/b/isbn/{clean_isbn}-L.jpg",
-                "isbn": clean_isbn,
-                "source": "openlibrary"
-            })
+        # Iterate through providers until a book is found
+        for provider in providers:
+            book_data = provider(clean_isbn)
+            
+            if book_data:
+                # Add the ISBN back into the response payload
+                book_data["isbn"] = clean_isbn
+                
+                # If a provider found the book but had no cover, assign a default OpenLibrary cover fallback
+                if not book_data.get("thumbnail"):
+                    book_data["thumbnail"] = f"https://covers.openlibrary.org/b/isbn/{clean_isbn}-L.jpg"
+                    
+                return jsonify(book_data)

+        # If all providers fail
        return jsonify({"error": f"Kein Buch zu dieser ISBN gefunden: {clean_isbn}"}), 404
        
    except Exception as e:
@@ -15,4 +15,3 @@ openpyxl
 cryptography>=42.0.0
 pywebpush
 py-vapid>=1.9.0
-pyzbar
@@ -1,353 +0,0 @@
-/**
- * Hybrid Barcode Scanner
- * Supports: Real-time camera scanning (ZXing.js), image upload fallback (server-side pyzbar),
- *           and USB/keyboard scanner emulation.
- */
-
-class HybridScanner {
-  constructor(options = {}) {
-    this.options = {
-      videoId: options.videoId || 'scanner-video',
-      canvasId: options.canvasId || 'scanner-canvas',
-      formats: options.formats || ['QR_CODE', 'CODE_128', 'EAN_13', 'ISBN', 'CODE_39', 'UPC_A'],
-      fps: options.fps || 10,
-      onSuccess: options.onSuccess || (() => {}),
-      onError: options.onError || (() => {}),
-      facingMode: options.facingMode || 'environment', // 'environment' for rear, 'user' for front
-    };
-
-    this.state = {
-      isRunning: false,
-      stream: null,
-      reader: null,
-      canvas: null,
-      videoElement: null,
-      zxingReady: false,
-      lastScanTime: 0,
-      scanDebounceMs: 300, // Prevent rapid duplicate scans
-    };
-
-    this.keyboardInputBuffer = '';
-    this.keyboardInputTimeout = null;
-  }
-
-  /**
-   * Initialize ZXing library from CDN
-   */
-  async initZXing() {
-    if (this.state.zxingReady) {
-      return true;
-    }
-
-    return new Promise((resolve) => {
-      // Load ZXing library from CDN
-      if (typeof ZXing !== 'undefined') {
-        this.state.zxingReady = true;
-        resolve(true);
-        return;
-      }
-
-      // Use fallback URL for better mobile compatibility
-      let scriptUrl = 'https://unpkg.com/@zxing/library@latest/umd/index.min.js';
-      
-      // Check if already loading
-      const existingScript = document.querySelector(`script[src="${scriptUrl}"]`);
-      if (existingScript) {
-        existingScript.addEventListener('load', () => {
-          this.state.zxingReady = typeof ZXing !== 'undefined';
-          resolve(this.state.zxingReady);
-        }, { once: true });
-        existingScript.addEventListener('error', () => {
-          console.error('Failed to load ZXing library');
-          resolve(false);
-        }, { once: true });
-        return;
-      }
-
-      const script = document.createElement('script');
-      script.src = scriptUrl;
-      script.async = true;
-      script.onload = () => {
-        this.state.zxingReady = typeof ZXing !== 'undefined';
-        resolve(this.state.zxingReady);
-      };
-      script.onerror = () => {
-        console.error('Failed to load ZXing library');
-        resolve(false);
-      };
-      document.head.appendChild(script);
-    });
-  }
-
-  /**
-   * Start real-time barcode scanning via camera
-   */
-  async start() {
-    if (this.state.isRunning) {
-      return;
-    }
-
-    try {
-      // Ensure ZXing is loaded
-      const zxingReady = await this.initZXing();
-      if (!zxingReady) {
-        this.options.onError('ZXing library failed to load. Please use image upload fallback.');
-        return;
-      }
-
-      // Get DOM elements
-      this.state.videoElement = document.getElementById(this.options.videoId);
-      this.state.canvas = document.getElementById(this.options.canvasId);
-
-      if (!this.state.videoElement || !this.state.canvas) {
-        this.options.onError('Scanner video or canvas element not found.');
-        return;
-      }
-
-      // Request camera access
-      const stream = await navigator.mediaDevices.getUserMedia({
-        video: {
-          facingMode: this.options.facingMode,
-          width: { ideal: 1280 },
-          height: { ideal: 720 },
-        },
-        audio: false,
-      });
-
-      this.state.stream = stream;
-      this.state.videoElement.srcObject = stream;
-      
-      // Make video element visible (ensure it's not hidden by display: none)
-      this.state.videoElement.style.display = 'block';
-      // Ensure autoplay works on mobile by muting and setting playsInline
-      try {
-        this.state.videoElement.muted = true;
-        this.state.videoElement.autoplay = true;
-        this.state.videoElement.playsInline = true;
-        // Some browsers require explicit play() after setting srcObject
-        const p = this.state.videoElement.play();
-        if (p && p.then) {
-          p.catch(() => {
-            // ignore play promise rejection (user gesture required on some browsers)
-          });
-        }
-      } catch (e) {
-        // ignore
-      }
-
-      // Initialize ZXing reader
-      const hints = new Map();
-      hints.set(ZXing.DecodeHintType.POSSIBLE_FORMATS, this.options.formats);
-      hints.set(ZXing.DecodeHintType.TRY_HARDER, true);
-      this.state.reader = new ZXing.BrowserMultiFormatReader(hints);
-
-      this.state.isRunning = true;
-
-      // Start scanning loop
-      this.scanLoop();
-
-      // Setup keyboard input fallback for USB scanners
-      this.setupKeyboardInput();
-    } catch (err) {
-      this.options.onError(`Camera error: ${err.message || err}`);
-    }
-  }
-
-  /**
-   * Stop barcode scanning
-   */
-  stop() {
-    if (!this.state.isRunning) {
-      return;
-    }
-
-    this.state.isRunning = false;
-
-    if (this.state.stream) {
-      this.state.stream.getTracks().forEach((track) => track.stop());
-      this.state.stream = null;
-    }
-
-    if (this.state.videoElement) {
-      this.state.videoElement.srcObject = null;
-      this.state.videoElement.style.display = 'none';
-    }
-
-    // Reset ZXing reader to stop any internal loops
-    try {
-      if (this.state.reader && typeof this.state.reader.reset === 'function') {
-        this.state.reader.reset();
-      }
-    } catch (e) {
-      // ignore
-    }
-    this.state.reader = null;
-
-    this.removeKeyboardInput();
-  }
-
-  /**
-   * Main scanning loop for real-time frame processing
-   */
-  scanLoop() {
-    if (!this.state.isRunning) {
-      return;
-    }
-
-    const canvas = this.state.canvas;
-    const video = this.state.videoElement;
-
-    if (!video || !canvas) {
-      setTimeout(() => this.scanLoop(), 100);
-      return;
-    }
-
-    if (video.readyState === video.HAVE_ENOUGH_DATA) {
-      try {
-        canvas.width = video.videoWidth;
-        canvas.height = video.videoHeight;
-        
-        if (canvas.width === 0 || canvas.height === 0) {
-          setTimeout(() => this.scanLoop(), 100);
-          return;
-        }
-
-        const context = canvas.getContext('2d');
-
-        if (context) {
-          context.drawImage(video, 0, 0);
-
-          try {
-            const luminanceSource = new ZXing.HTMLCanvasElementLuminanceSource(canvas);
-            const binaryBitmap = new ZXing.BinaryBitmap(new ZXing.HybridBinarizer(luminanceSource));
-
-            try {
-              const result = this.state.reader.decodeFromBitmap(binaryBitmap);
-              this.handleScanResult(result.text);
-            } catch (e) {
-              // No barcode found in frame; continue scanning
-            }
-          } catch (err) {
-            // Silently ignore canvas errors
-          }
-        }
-      } catch (err) {
-        console.warn('Scan loop error:', err);
-      }
-    }
-
-    // Throttle scan loop based on FPS setting
-    setTimeout(() => this.scanLoop(), 1000 / this.options.fps);
-  }
-
-  /**
-   * Handle successful barcode scan with debouncing
-   */
-  handleScanResult(scannedText) {
-    const now = Date.now();
-    if (now - this.state.lastScanTime < this.state.scanDebounceMs) {
-      return; // Ignore rapid duplicates
-    }
-
-    this.state.lastScanTime = now;
-    this.options.onSuccess(scannedText.trim());
-  }
-
-  /**
-   * Setup keyboard input listener for USB scanner emulation
-   * Most USB scanners emulate keyboard input (barcode followed by Enter)
-   */
-  setupKeyboardInput() {
-    this.keyboardListener = (event) => {
-      // Allow only alphanumeric, dash, colon (common in barcodes)
-      if (/^[a-zA-Z0-9:_\-]$/.test(event.key)) {
-        event.preventDefault();
-        this.keyboardInputBuffer += event.key;
-
-        // Reset timeout for multi-part barcodes
-        if (this.keyboardInputTimeout) {
-          clearTimeout(this.keyboardInputTimeout);
-        }
-      } else if (event.key === 'Enter') {
-        event.preventDefault();
-        if (this.keyboardInputBuffer.length > 0) {
-          this.handleScanResult(this.keyboardInputBuffer);
-          this.keyboardInputBuffer = '';
-        }
-      } else if (event.key === 'Escape') {
-        this.keyboardInputBuffer = '';
-        this.stop();
-      }
-
-      // Auto-trigger if buffer looks complete (common barcode lengths)
-      if ([8, 12, 13, 17].includes(this.keyboardInputBuffer.length)) {
-        this.keyboardInputTimeout = setTimeout(() => {
-          if (this.keyboardInputBuffer.length > 0) {
-            this.handleScanResult(this.keyboardInputBuffer);
-            this.keyboardInputBuffer = '';
-          }
-        }, 200);
-      }
-    };
-
-    document.addEventListener('keydown', this.keyboardListener);
-  }
-
-  /**
-   * Remove keyboard input listener
-   */
-  removeKeyboardInput() {
-    if (this.keyboardListener) {
-      document.removeEventListener('keydown', this.keyboardListener);
-      this.keyboardListener = null;
-    }
-    this.keyboardInputBuffer = '';
-  }
-
-  /**
-   * Upload image for server-side decoding (fallback)
-   * Requires /api/scan_upload endpoint
-   */
-  static async uploadImageForDecoding(file, onSuccess, onError) {
-    try {
-      const formData = new FormData();
-      formData.append('image', file);
-
-      const response = await fetch('/api/scan_upload', {
-        method: 'POST',
-        body: formData,
-      });
-
-      const data = await response.json();
-
-      if (data.ok && data.barcodes && data.barcodes.length > 0) {
-        // Return first detected barcode (highest confidence)
-        onSuccess(data.barcodes[0].value);
-      } else {
-        onError(data.message || 'No barcode detected in image.');
-      }
-    } catch (err) {
-      onError(`Upload error: ${err.message}`);
-    }
-  }
-
-  /**
-   * Toggle camera (front/rear on mobile)
-   */
-  toggleCamera() {
-    if (this.options.facingMode === 'environment') {
-      this.options.facingMode = 'user';
-    } else {
-      this.options.facingMode = 'environment';
-    }
-
-    // Restart scanning with new camera
-    this.stop();
-    this.start();
-  }
-}
-
-// Export for use in templates
-if (typeof window !== 'undefined') {
-  window.HybridScanner = HybridScanner;
-}
@@ -1295,11 +1295,6 @@
                        </li>
                        {% endif %}
                        {% if 'username' in session %}
-                        {% if current_permissions.pages.get('my_borrowed_items', True) %}
-                        <li class="nav-item">
-                            <a class="nav-link quick-link-pill {% if current_path == url_for('my_borrowed_items') %}nav-active{% endif %}" href="{{ url_for('my_borrowed_items') }}" data-tutorial-tip="Hier sehen Sie Ihre bibliotheksbezogenen Ausleihen.">Meine Medien</a>
-                        </li>
-                        {% endif %}
                        {% if current_permissions.pages.get('tutorial_page', True) %}
                        <li class="nav-item">
                            <a class="nav-link quick-link-pill {% if current_path == url_for('tutorial_page') %}nav-active{% endif %}" href="{{ url_for('tutorial_page') }}" data-tutorial-tip="Nutzen Sie das Tutorial, um die Bibliotheksfunktionen kennenzulernen.">Tutorial</a>
@@ -10,24 +10,6 @@
            <h1>📚 Bibliothek</h1>
            <p class="subtitle">Bücher, CDs und weitere Medien</p>
        </div>
-        
-        <div class="header-controls">
-            <!-- Favorites Toggle -->
-            <div class="view-switch">
-                <button id="favoriteToggle" class="toggle-btn" aria-label="Favoriten anzeigen/verbergen">
-                    <span class="toggle-icon">⭐</span>
-                    <span class="toggle-label">Favoriten</span>
-                </button>
-            </div>
-
-            <!-- View Mode Toggle -->
-            <div class="view-switch">
-                <button id="viewModeToggle" class="toggle-btn" aria-label="Ansichtsmodus wechseln">
-                    <span class="toggle-icon">ㄷ</span>
-                    <span class="toggle-label">Tabelle</span>
-                </button>
-            </div>
-        </div>
    </div>

    <!-- Search & Filter Section -->
@@ -67,22 +49,8 @@

    <!-- Scanner Panel -->
    <div id="qrContainer" class="qr-container" style="display: none;">
-        <div class="scanner-header">
-            <h3>Barcode/QR-Code Scanner</h3>
-            <div class="scanner-controls">
-                <button type="button" id="cameraToggle" class="scanner-button" title="Kamera wechseln">📷 Kamera</button>
-                <label for="uploadScanImage" class="scanner-button" title="Bild hochladen zum Dekodieren">📤 Upload</label>
-                <input type="file" id="uploadScanImage" accept="image/*" style="display: none;">
-            </div>
-        </div>
-        <div class="scanner-video-wrapper">
-            <video id="qr-reader" playsinline style="width: 100%; max-width: 100%; height: auto; aspect-ratio: 4/3; object-fit: cover; border-radius: 8px;"></video>
-            <canvas id="scanner-canvas" style="display: none;"></canvas>
-        </div>
-        <div id="scanMessage" class="scanner-message" style="margin-top: 10px; text-align: center; font-weight: bold; color: #666;"></div>
-        <p style="font-size: 0.85em; color: #999; margin-top: 10px; margin-bottom: 0; text-align: center;">
-            💡 Hinweis: Scan-Ergebnis wird automatisch in das Feld oben übernommen. USB-Scanner werden als Tastatureingabe erkannt.
-        </p>
+        <div id="qr-reader" style="width: auto; height: 300px;"></div>
+        <span id="qr-result" style="display: none;"></span>
    </div>

    <!-- Table Header (only in table mode) -->
@@ -219,9 +187,7 @@
        </form>
    </div>
 </div>
-
-<script src="https://unpkg.com/@zxing/library@latest/umd/index.min.js"></script>
-<script src="/static/js/scanner.js"></script>
+<script src="https://cdn.jsdelivr.net/npm/@ericblade/quagga2/dist/quagga.js"></script>
 <script>
 // View mode persistence
 const LIBRARY_VIEW_MODE_KEY = 'inventarLibraryViewMode';
@@ -564,29 +530,6 @@ document.addEventListener('DOMContentLoaded', function() {
    });

    initMobileWindowedLibraryLoading();
-    // On mobile, make tapping an item open details for easier access (tap target larger)
-    function enableMobileTapToDetails() {
-        if (!isMobileViewport()) return;
-        document.querySelectorAll('.library-item').forEach(item => {
-            item.addEventListener('click', function(e) {
-                // Ignore clicks on buttons/links inside the card
-                const tag = e.target.tagName.toLowerCase();
-                if (tag === 'button' || tag === 'a' || e.target.closest('.action-button')) return;
-                const itemId = this.dataset.itemId;
-                if (!itemId) return;
-                fetch(`/get_item_details/${itemId}`)
-                    .then(r => r.json())
-                    .then(data => {
-                        if (data.success) {
-                            displayLibraryItemDetail(data.item);
-                            document.getElementById('detailModal').style.display = 'flex';
-                        }
-                    });
-            }, { passive: true });
-        });
-    }
-
-    enableMobileTapToDetails();
 });

 function displayLibraryItemDetail(item) {
@@ -597,7 +540,7 @@ function displayLibraryItemDetail(item) {
    modalBody.innerHTML = `
        <h2>${item.Name}</h2>
        <div class="detail-content">
-            ${item.Image ? `<img src="/uploads/${item.Image}" alt="${item.Name}" class="detail-image">` : ''}
+            ${item.Image ? `<img src="/uploads/${item.Image}" alt="${item.Name}" style="max-width: 200px; margin-bottom: 20px;">` : ''}
            <p><strong>Autor:</strong> ${item.Author || '—'}</p>
            <p><strong>ISBN:</strong> ${item.ISBN || '—'}</p>
            <p><strong>Typ:</strong> ${item.ItemType || 'Medium'}</p>
@@ -663,103 +606,80 @@ document.getElementById('clearFiltersBtn').addEventListener('click', function()
    closeAllFilters();
 });

-// Favorites toggle
-document.getElementById('favoriteToggle').addEventListener('click', function() {
-    this.classList.toggle('open');
-    // TODO: Implement favorites filtering
-});
-
-// Scanner instance (hybrid: real-time + upload + keyboard)
-let scanner = null;
+// Scanner toggle
+// Scanner state tracking
+let isScanning = false; 

 document.getElementById('scannerBtn').addEventListener('click', function(e) {
    e.stopPropagation();
    const container = document.getElementById('qrContainer');
    const isOpen = container.style.display !== 'none';
+    const btn = this;
    
    if (isOpen) {
+        // Close the scanner
        container.style.display = 'none';
-        if (scanner) {
-            scanner.stop();
-            scanner = null;
-        }
-        this.classList.remove('open');
-        this.setAttribute('aria-expanded', 'false');
+        Quagga.stop();
+        isScanning = false;
+        
+        btn.classList.remove('open');
+        btn.setAttribute('aria-expanded', 'false');
    } else {
+        // Open the scanner
        container.style.display = 'block';
-        this.classList.add('open');
-        this.setAttribute('aria-expanded', 'true');
+        btn.classList.add('open');
+        btn.setAttribute('aria-expanded', 'true');
        
-        if (!scanner) {
-            initScanner();
-        }
-    }
-});
-
-function initScanner() {
-    scanner = new HybridScanner({
-        videoId: 'qr-reader',
-        canvasId: 'scanner-canvas',
-        formats: ['QR_CODE', 'CODE_128', 'EAN_13', 'ISBN', 'CODE_39', 'UPC_A', 'EAN_8'],
-        fps: 10,
-        facingMode: 'environment',
-        onSuccess: function(decodedText) {
-            const studentId = decodedText.trim();
-            document.getElementById('studentIdInput').value = studentId;
-            document.getElementById('scanMessage').textContent = '✓ Erkannt: ' + studentId;
-            document.getElementById('scanMessage').style.color = '#4CAF50';
-        },
-        onError: function(error) {
-            document.getElementById('scanMessage').textContent = '✗ ' + error;
-            document.getElementById('scanMessage').style.color = '#f44336';
-        }
-    });
-
-    scanner.start();
-}
-
-// Camera toggle
-document.getElementById('cameraToggle')?.addEventListener('click', function() {
-    if (scanner) {
-        scanner.toggleCamera();
-        this.textContent = scanner.options.facingMode === 'user' ? '📷 Rückkamera' : '🤳 Frontkamera';
-    }
-});
-
-// Image upload fallback
-document.getElementById('uploadScanImage')?.addEventListener('change', function(e) {
-    const file = e.target.files[0];
-    if (file) {
-        const messageEl = document.getElementById('scanMessage');
-        messageEl.textContent = 'Wird dekodiert...';
-        messageEl.style.color = '#2196F3';
-        
-        HybridScanner.uploadImageForDecoding(
-            file,
-            (decodedText) => {
-                document.getElementById('studentIdInput').value = decodedText;
-                messageEl.textContent = '✓ Erkannt (Upload): ' + decodedText;
-                messageEl.style.color = '#4CAF50';
-                e.target.value = ''; // Reset file input
+        Quagga.init({
+            inputStream: {
+                name: "Live",
+                type: "LiveStream",
+                // Targets the element where the video stream will inject
+                target: document.querySelector('#qr-reader'), 
+                constraints: {
+                    width: 640,
+                    height: 480,
+                    facingMode: "environment" // Forces back camera
+                },
            },
-            (error) => {
-                messageEl.textContent = '✗ ' + error;
-                messageEl.style.color = '#f44336';
-                e.target.value = '';
+            decoder: {
+                // Optimized for 1D barcodes (e.g., student IDs, member cards)
+                readers: ["code_128_reader", "ean_reader", "code_39_reader", "upc_reader"]
+            } 
+        }, function(err) {
+            if (err) {
+                console.error("Initialization error:", err);
+                alert("Kamera konnte nicht gestartet werden.");
+                return;
            }
-        );
+            Quagga.start();
+            isScanning = true;
+        });
    }
 });

-function onScanSuccess(decodedText, decodedResult) {
-    const studentId = decodedText.trim();
+// Single Quagga event listener for successful scans
+Quagga.onDetected(function(data) {
+    const decodedText = data.codeResult.code;
+    const studentId = String(decodedText || '').trim();
+    
+    // Stop scanning immediately to prevent multiple triggers
+    Quagga.stop();
+    isScanning = false;
+    
+    // Reset UI states to closed
+    const container = document.getElementById('qrContainer');
+    const btn = document.getElementById('scannerBtn');
+    if (container) container.style.display = 'none';
+    if (btn) {
+        btn.classList.remove('open');
+        btn.setAttribute('aria-expanded', 'false');
+    }
+    
+    // Route the scanned data to your input
    document.getElementById('studentIdInput').value = studentId;
    alert('Ausweis gescannt: ' + studentId);
-}
-
-function onScanError(error) {
-    // Silently ignore scan errors
-}
+});
 </script>

 <style>
@@ -814,46 +734,12 @@ function onScanError(error) {
    color: #b3261e;
 }

-/* Mobile: simplify list entries - show only title */
-@media (max-width: 900px) {
-    .library-item .item-author,
-    .library-item .item-isbn,
-    .table-cell.author-cell,
-    .table-cell.isbn-cell {
-        display: none !important;
-    }
-
-    /* Make title more prominent and full-width */
-    .library-item .item-details {
-        display: block;
-        width: calc(100% - 140px);
-        box-sizing: border-box;
-    }
-
-    .library-item .item-name {
-        font-size: 1.05rem;
-        margin: 0 0 6px 0;
-        line-height: 1.2;
-        overflow: hidden;
-        text-overflow: ellipsis;
-        white-space: nowrap;
-    }
-
-    .library-item .item-image-wrapper {
-        width: 100px;
-        height: 130px;
-    }
-}
-
 /* Mobile: allow horizontal scrolling for table-mode views */
@media (max-width: 900px) {
    .library-table-wrapper {
        overflow-x: auto;
        -webkit-overflow-scrolling: touch;
        width: 100%;
-        box-sizing: border-box;
-        margin: 0 -12px;
-        padding: 0 12px;
    }
    .library-table-wrapper .table-row {
        min-width: 720px; /* allow table to have intrinsic width and be scrolled */
@@ -862,180 +748,5 @@ function onScanError(error) {
        display: block; /* keep rows stacked but allow horizontal scroll */
    }
 }
-
-/* Hybrid Scanner Styles */
-.qr-container {
-    background: #f5f5f5;
-    border: 1px solid #ddd;
-    border-radius: 8px;
-    padding: 12px;
-    margin: 12px 0;
-    overflow-x: hidden;
-    width: 100%;
-    box-sizing: border-box;
-}
-
-.scanner-header {
-    display: flex;
-    justify-content: flex-start;
-    align-items: center;
-    margin-bottom: 12px;
-    flex-wrap: wrap;
-    gap: 8px;
-    width: 100%;
-    box-sizing: border-box;
-}
-
-.scanner-header h3 {
-    margin: 0;
-    color: #333;
-    font-size: 1em;
-    flex: 0 0 auto;
-    white-space: nowrap;
-}
-
-.scanner-controls {
-    display: flex;
-    gap: 6px;
-    flex-wrap: wrap;
-    flex: 1 1 auto;
-    min-width: 0;
-}
-
-.scanner-button {
-    background: #2196F3;
-    color: white;
-    border: none;
-    padding: 6px 10px;
-    border-radius: 4px;
-    cursor: pointer;
-    font-size: 0.85em;
-    white-space: nowrap;
-    flex: 0 1 auto;
-    transition: background-color 0.2s;
-}
-
-.scanner-button:hover {
-    background: #1976D2;
-}
-
-.scanner-button:active {
-    background: #1565C0;
-}
-
-.scanner-video-wrapper {
-    display: flex;
-    justify-content: center;
-    align-items: center;
-    margin: 12px 0;
-    width: 100%;
-    box-sizing: border-box;
-    overflow: hidden;
-}
-
-#qr-reader {
-    width: 100%;
-    max-width: 100%;
-    height: auto;
-    border: 2px solid #2196F3;
-    border-radius: 8px;
-    display: block;
-}
-
-.scanner-message {
-    min-height: 20px;
-    font-size: 0.9em;
-    text-align: center;
-    word-wrap: break-word;
-}
-
-@media (max-width: 600px) {
-    .qr-container {
-        padding: 10px;
-        margin: 10px 0;
-    }
-
-    .scanner-header {
-        flex-direction: column;
-        align-items: stretch;
-        gap: 8px;
-    }
-
-    .scanner-header h3 {
-        width: 100%;
-        font-size: 0.95em;
-    }
-
-    .scanner-controls {
-        width: 100%;
-        justify-content: space-between;
-    }
-
-    .scanner-button {
-        flex: 1 1 auto;
-        padding: 8px 6px;
-        font-size: 0.8em;
-    }
-
-    #qr-reader {
-        max-width: 100%;
-        border-radius: 6px;
-    }
-
-    .scanner-message {
-        font-size: 0.85em;
-    }
-}
-
-/* Modal styles - responsive for mobile */
-.modal {
-    position: fixed;
-    top: 0;
-    left: 0;
-    right: 0;
-    bottom: 0;
-    display: flex;
-    align-items: center;
-    justify-content: center;
-    background: rgba(0,0,0,0.5);
-    z-index: 2000;
-    padding: 16px;
-    box-sizing: border-box;
-}
-
-.modal-content {
-    background: #fff;
-    border-radius: 10px;
-    width: 100%;
-    max-width: 640px;
-    max-height: 90vh;
-    overflow-y: auto;
-    box-sizing: border-box;
-    padding: 16px;
-    position: relative;
-}
-
-.modal-close {
-    background: transparent;
-    border: none;
-    font-size: 1.1rem;
-    position: absolute;
-    right: 20px;
-    top: 18px;
-    cursor: pointer;
-}
-
-.modal-body img {
-    max-width: 100%;
-    height: auto;
-    display: block;
-    margin-bottom: 12px;
-}
-
-.modal-body p { margin: 6px 0; }
-
-@media (max-width: 420px) {
-    .modal-content { padding: 12px; }
-}
 </style>
 {% endblock %}
@@ -431,7 +431,7 @@
            type="text" 
            id="librarySearch" 
            class="library-search-input" 
-            placeholder="Nach Titel, Autor, ISBN suchen..."
+            placeholder="Nach Titel, ISBN suchen..."
        >
        <button 
            id="filterToggleBtn" 
@@ -445,7 +445,7 @@
    <!-- Customizable Filter Panel -->

    <!-- Student card / quick scan workflow -->
-    <div class="library-scan-panel">
+   <div class="library-scan-panel">
        <div class="library-scan-controls">
            <select id="scanModeSelect" aria-label="Scan-Modus">
                <option value="card_only">Nur Ausweis erfassen</option>
@@ -458,19 +458,14 @@
        <div id="scanStatus" class="library-scan-status">
            Hinweis: Im Schnellmodus zuerst den Schülerausweis scannen, danach den Buch-/Mediencode.
        </div>
-        <div id="scanReaderWrap" class="library-scan-reader-wrap">
+        <div id="scanReaderWrap" class="library-scan-reader-wrap" style="display: none;">
            <div id="libraryQrReader" class="library-scan-reader">
-                <video id="libraryQrReaderVideo" playsinline style="width: 100%; border-radius: 8px;"></video>
-                <canvas id="libraryQrReaderCanvas" style="display: none;"></canvas>
+                <div id="library-scanner-container"></div>
            </div>
        </div>
    </div>
    <div id="filterPanel" class="library-filter-panel">
        <div class="filter-row">
-            <div class="filter-item">
-                <label for="filterAuthor">Autor/Künstler:</label>
-                <input type="text" id="filterAuthor" placeholder="z.B. Goethe">
-            </div>
            <div class="filter-item">
                <label for="filterISBN">ISBN:</label>
                <input type="text" id="filterISBN" placeholder="z.B. 978-3...">
@@ -517,7 +512,6 @@
            <thead>
                <tr>
                    <th style="width: 24%;">Titel</th>
-                    <th style="width: 14%;">Autor/Künstler</th>
                    <th style="width: 12%;">ISBN/Code</th>
                    <th style="width: 8%;">Typ</th>
                    <th style="width: 8%;">Anzahl</th>
@@ -550,16 +544,17 @@
    </div>
 </div>

-<script src="https://unpkg.com/@zxing/library@latest/umd/index.min.js"></script>
-<script src="/static/js/scanner.js"></script>
+<script src="https://cdn.jsdelivr.net/npm/@ericblade/quagga2/dist/quagga.js"></script>
+<script src="https://cdn.jsdelivr.net/npm/@ericblade/quagga2/dist/quagga.js"></script>
 <script>
-    // State
+    // =========================================================================
+    // 1. GLOBAL STATE DEFINITIONS
+    // =========================================================================
    let libraryItems = [];
    let filteredItems = [];
    let visibleItems = [];
    let currentSearchTerm = '';
    let activeFilters = {
-        author: '',
        isbn: '',
        type: '',
        status: ''
@@ -575,13 +570,20 @@
    const RENDER_BATCH_COUNT = 120;
    let renderedCount = INITIAL_RENDER_COUNT;
    let filterPanelOpen = false;
+    
+    // Scanner Related State Variables
    let scannerInstance = null;
-    let scannerRunning = false;
+    let scannerRunning = false; 
+    let activeScannerCallback = null; 
    let activeStudentCardId = '';
    let lastScanValue = '';
    let lastScanAt = 0;
+    
    const canEditLibraryItems = (document.getElementById('libraryTableContainer')?.dataset.canEdit === '1');

+    // =========================================================================
+    // 2. DATA LOADING & FILTERING ENGINE
+    // =========================================================================
    async function fetchLibraryPage(offset, limit) {
        const response = await fetch(`/api/library_items?offset=${offset}&limit=${limit}`);
        if (!response.ok) {
@@ -590,7 +592,6 @@
        return response.json();
    }

-    // Load items progressively: first page immediately, rest in background
    async function loadLibraryItems() {
        if (pagingState.loading) return;
        pagingState.loading = true;
@@ -629,7 +630,6 @@
                pagingState.total = page.total || pagingState.total;
                pagingState.hasMore = Boolean(page.has_more);

-                // Keep the current view reactive while avoiding a full rerender burst.
                applyFiltersAndSearch(false);

                if ('requestIdleCallback' in window) {
@@ -645,18 +645,16 @@
    }

    function filterItems(items) {
-        const author = activeFilters.author;
        const isbn = activeFilters.isbn;
        const type = activeFilters.type;
        const status = activeFilters.status;

        return items.filter(item => {
-            const authorMatch = !author || (item.Autor || item.Author || '').toLowerCase().includes(author);
            const isbnMatch = !isbn || (item.ISBN || item.Code_4 || item.Code4 || '').toLowerCase().includes(isbn);
            const typeMatch = !type || (item.ItemType || 'book') === type;
            const statusKey = item.LibraryDisplayStatus || (item.Verfuegbar === false ? 'borrowed' : 'available');
            const statusMatch = !status || statusKey === status;
-            return authorMatch && isbnMatch && typeMatch && statusMatch;
+            return isbnMatch && typeMatch && statusMatch;
        });
    }

@@ -664,7 +662,6 @@
        if (!currentSearchTerm) return items;
        return items.filter(item =>
            (item.Name || '').toLowerCase().includes(currentSearchTerm) ||
-            (item.Autor || item.Author || '').toLowerCase().includes(currentSearchTerm) ||
            (item.ISBN || item.Code_4 || item.Code4 || '').toLowerCase().includes(currentSearchTerm)
        );
    }
@@ -681,7 +678,6 @@
        renderItems();
    }

-    // Display current view with incremental rendering
    function renderItems() {
        const tbody = document.getElementById('itemsTableBody');
        const emptyState = document.getElementById('emptyState');
@@ -699,37 +695,33 @@
        emptyState.style.display = 'none';
        const rowsToRender = visibleItems.slice(0, renderedCount);

-        tbody.innerHTML = rowsToRender.map(item => `
-            ${(() => {
-                const statusKey = item.LibraryDisplayStatus || (item.Verfuegbar === false ? 'borrowed' : 'available');
-                const statusClass = statusKey === 'damaged' ? 'status-damaged' : (statusKey === 'borrowed' ? 'status-borrowed' : 'status-available');
-                const statusText = statusKey === 'damaged' ? 'Defekt/Zerstört' : (statusKey === 'borrowed' ? 'Ausgeliehen' : 'Verfügbar');
-                const actionLabel = statusKey === 'available' ? 'Ausleihen' : (statusKey === 'borrowed' ? 'Reservieren' : 'Nicht ausleihbar');
-                const actionDisabled = statusKey === 'damaged' ? 'disabled' : '';
-                return `
-            <tr>
-                <td class="table-title">${escapeHtml(item.Name || 'Untitled')}</td>
-                <td>${escapeHtml(item.Autor || item.Author || '-')}</td>
-                <td>${escapeHtml(item.ISBN || item.Code_4 || item.Code4 || '-')}</td>
-                <td>${getItemTypeLabel(item.ItemType || 'book')}</td>
-                <td style="font-weight:600; text-align:center;">${item.Quantity || item.GroupedDisplayCount || 1}</td>
-                <td>
-                    <span class="table-status ${statusClass}">
-                        ${statusText}
-                    </span>
-                </td>
-                <td class="table-actions">
-                    <button class="button" onclick="showItemDetail('${item._id}')">Details</button>
-                    <button class="button" style="background: #28a745; color: white;" onclick="borrowItem('${item._id}')" ${actionDisabled}>
-                        ${actionLabel}
-                    </button>
-                    ${canEditLibraryItems ? `<button class="button" style="background:#0ea5e9;color:#fff;" onclick="openEditLibraryItem('${item._id}')">Bearbeiten</button>` : ''}
-                    ${canEditLibraryItems ? `<button class="button" style="background:#dc2626;color:#fff; margin-left:6px;" onclick="confirmDeleteLibraryItem('${item._id}')">Löschen</button>` : ''}
-                </td>
-            </tr>
-                `;
-            })()}
-        `).join('');
+        tbody.innerHTML = rowsToRender.map(item => {
+            const statusKey = item.LibraryDisplayStatus || (item.Verfuegbar === false ? 'borrowed' : 'available');
+            const statusClass = statusKey === 'damaged' ? 'status-damaged' : (statusKey === 'borrowed' ? 'status-borrowed' : 'status-available');
+            const statusText = statusKey === 'damaged' ? 'Defekt/Zerstört' : (statusKey === 'borrowed' ? 'Ausgeliehen' : 'Verfügbar');
+            const actionLabel = statusKey === 'available' ? 'Ausleihen' : (statusKey === 'borrowed' ? 'Reservieren' : 'Nicht ausleihbar');
+            const actionDisabled = statusKey === 'damaged' ? 'disabled' : '';
+            return `
+        <tr>
+            <td class="table-title">${escapeHtml(item.Name || 'Untitled')}</td>
+            <td>${escapeHtml(item.ISBN || item.Code_4 || item.Code4 || '-')}</td>
+            <td>${getItemTypeLabel(item.ItemType || 'book')}</td>
+            <td style="font-weight:600; text-align:center;">${item.Quantity || item.GroupedDisplayCount || 1}</td>
+            <td>
+                <span class="table-status ${statusClass}">
+                    ${statusText}
+                </span>
+            </td>
+            <td class="table-actions">
+                <button class="button" onclick="showItemDetail('${item._id}')">Details</button>
+                <button class="button" style="background: #28a745; color: white;" onclick="borrowItem('${item._id}')" ${actionDisabled}>
+                    ${actionLabel}
+                </button>
+                ${canEditLibraryItems ? `<button class="button" style="background:#0ea5e9;color:#fff;" onclick="openEditLibraryItem('${item._id}')">Bearbeiten</button>` : ''}
+                ${canEditLibraryItems ? `<button class="button" style="background:#dc2626;color:#fff; margin-left:6px;" onclick="confirmDeleteLibraryItem('${item._id}')">Löschen</button>` : ''}
+            </td>
+        </tr>`;
+        }).join('');

        const canLoadMoreRows = renderedCount < visibleItems.length;
        if (canLoadMoreRows) {
@@ -744,13 +736,6 @@
        }
    }

-    // Confirm and call library item delete endpoint
-    function confirmDeleteLibraryItem(itemId) {
-        if (!itemId) return;
-        if (!confirm('Dieses Bibliotheksmedium revisionssicher löschen? Diese Aktion deaktiviert alle zugehörigen Exemplare und archiviert Medien.')) return;
-        deleteLibraryItem(itemId);
-    }
-
    async function deleteLibraryItem(itemId) {
        if (!itemId) return;
        document.body.style.cursor = 'wait';
@@ -774,7 +759,6 @@
                }
                loadLibraryItems();
            } else {
-                // Server redirected to HTML (flash messages). Reload to show state.
                location.reload();
            }
        } catch (e) {
@@ -785,46 +769,269 @@
        }
    }

-    // Filter toggle
-    document.getElementById('filterToggleBtn').addEventListener('click', () => {
-        filterPanelOpen = !filterPanelOpen;
-        const panel = document.getElementById('filterPanel');
-        const btn = document.getElementById('filterToggleBtn');
-        panel.classList.toggle('open');
-        btn.classList.toggle('active');
+    function confirmDeleteLibraryItem(itemId) {
+        if (!itemId) return;
+        if (!confirm('Dieses Bibliotheksmedium revisionssicher löschen? Diese Aktion deaktiviert alle zugehörigen Exemplare und archiviert Medien.')) return;
+        deleteLibraryItem(itemId);
+    }
+
+    // =========================================================================
+    // 3. CORE SCANNER ROUTING ENGINE (QUAGGA2)
+    // =========================================================================
+    function startScanner(targetCallback) {
+        const readerWrap = document.getElementById('scanReaderWrap');
+        const toggleBtn = document.getElementById('toggleScannerBtn');
+        
+        activeScannerCallback = targetCallback;
+
+        if (readerWrap) readerWrap.style.display = 'block';
+        setScanStatus('Initializing camera...', 'warn');
+    
+        Quagga.init({
+            inputStream: {
+                name: "Live",
+                type: "LiveStream",
+                target: document.querySelector('#library-scanner-container'), 
+                constraints: {
+                    width: 640,
+                    height: 480,
+                    facingMode: "environment" 
+                },
+            },
+            decoder: {
+                readers: [
+                    "code_128_reader", 
+                    "ean_reader", 
+                    "code_39_reader", 
+                    "upc_reader", 
+                    "codabar_reader", 
+                    "i2of5_reader"
+                ]
+            } 
+        }, function(err) {
+            if (err) {
+                console.error('Scanner start failed:', err);
+                if (readerWrap) readerWrap.style.display = 'none';
+                const detail = (err && (err.message || err.name)) ? ` (${err.message || err.name})` : '';
+                setScanStatus(`Scanner konnte nicht gestartet werden${detail}`, 'error');
+                return;
+            }
+        
+            Quagga.start();
+            scannerRunning = true;
+            
+            if (!targetCallback && toggleBtn) {
+                toggleBtn.textContent = 'Scanner stoppen';
+            }
+            setScanStatus('Scanner aktiv. Jetzt Code scannen.', 'warn');
+        });
+    }
+    
+    function stopScanner() {
+        if (!scannerRunning) return;
+        
+        const readerWrap = document.getElementById('scanReaderWrap');
+        const toggleBtn = document.getElementById('toggleScannerBtn');
+    
+        Quagga.stop();
+        scannerRunning = false;
+        activeScannerCallback = null; 
+    
+        if (readerWrap) readerWrap.style.display = 'none';
+        if (toggleBtn) toggleBtn.textContent = 'Scanner starten';
+        setScanStatus('Scanner gestoppt.', 'warn');
+    }
+    
+    Quagga.onDetected(function(data) {
+        if (!data || !data.codeResult || !data.codeResult.code) return;
+        
+        const barcode = String(data.codeResult.code || '').trim();
+        console.log("Barcode detected:", barcode);
+    
+        const currentCallback = activeScannerCallback;
+        stopScanner();
+    
+        if (typeof currentCallback === "function") {
+            currentCallback(barcode);
+        } else {
+            handleScanSuccess(barcode);
+        }
    });

-    // Apply filters
-    document.getElementById('applyFilterBtn').addEventListener('click', () => {
-        activeFilters.author = document.getElementById('filterAuthor').value.toLowerCase();
-        activeFilters.isbn = document.getElementById('filterISBN').value.toLowerCase();
-        activeFilters.type = document.getElementById('filterType').value;
-        activeFilters.status = document.getElementById('filterStatus').value;
-        applyFiltersAndSearch(true);
-    });
+    function handleScanSuccess(decodedText) {
+        const scannedCode = normalizeScannedCode(decodedText);
+        if (!scannedCode) return;
+    
+        const now = Date.now();
+        if (scannedCode === lastScanValue && (now - lastScanAt) < 1500) {
+            return;
+        }
+        lastScanValue = scannedCode;
+        lastScanAt = now;
+    
+        const mode = (document.getElementById('scanModeSelect') || {}).value || 'card_only';
+        if (mode === 'card_only') {
+            setActiveStudentCard(scannedCode);
+            setScanStatus(`Ausweis gesetzt: ${activeStudentCardId}`, 'ok');
+            return;
+        }
+    
+        processQuickToggleScan(scannedCode);
+    }

-    // Clear filters
-    document.getElementById('clearFilterBtn').addEventListener('click', () => {
-        document.getElementById('filterAuthor').value = '';
-        document.getElementById('filterISBN').value = '';
-        document.getElementById('filterType').value = '';
-        document.getElementById('filterStatus').value = '';
-        activeFilters = { author: '', isbn: '', type: '', status: '' };
-        applyFiltersAndSearch(true);
-    });
+    async function processQuickToggleScan(scannedCode) {
+        if (!activeStudentCardId) {
+            setActiveStudentCard(scannedCode);
+            setScanStatus(`Ausweis gesetzt: ${activeStudentCardId}`, 'ok');
+            return;
+        }
+    
+        try {
+            setScanStatus('Verarbeite Mediencode...', 'warn');
+            const response = await fetch('/api/library_scan_action', {
+                method: 'POST',
+                headers: {'Content-Type': 'application/json'},
+                body: JSON.stringify({
+                    student_card_id: activeStudentCardId,
+                    item_code: scannedCode
+                })
+            });
+        
+            const result = await response.json();
+            if (!response.ok || !result.ok) {
+                setScanStatus(result.message || 'Scan-Aktion fehlgeschlagen.', 'error');
+                return;
+            }
+        
+            if (result.action === 'borrowed') {
+                setScanStatus(`Ausgeliehen: ${result.item_name}`, 'ok');
+            } else if (result.action === 'returned') {
+                setScanStatus(`Zurückgegeben: ${result.item_name}`, 'ok');
+            } else {
+                setScanStatus(result.message || 'Aktion durchgeführt.', 'ok');
+            }
+        
+            await loadLibraryItems();
+        } catch (err) {
+            console.error('Quick scan action failed:', err);
+            setScanStatus('Fehler beim Verarbeiten des Scans.', 'error');
+        }
+    }

-    // Search input
-    document.getElementById('librarySearch').addEventListener('input', (e) => {
-        currentSearchTerm = (e.target.value || '').toLowerCase();
-        applyFiltersAndSearch(true);
-    });
+    function scanIntoEditCode() {
+        const scanReaderWrap = document.getElementById('scanReaderWrap');
+        const editCodeInput = document.getElementById('edit-code4');
+        const scanEditBtn = document.getElementById('scan-edit-code-btn');
+        if (!scanReaderWrap || !editCodeInput || !scanEditBtn) {
+            return;
+        }
+    
+        if (scannerRunning && scanReaderWrap.style.display !== 'none') {
+            stopScanner();
+            scanEditBtn.textContent = 'Barcode scannen';
+            return;
+        }
+    
+        scanEditBtn.textContent = 'Scanner schließen';
+    
+        startScanner(function(decodedText) {
+            editCodeInput.value = decodedText;
+            if(typeof validateCodeField === "function") {
+                validateCodeField(editCodeInput, document.getElementById('edit-item-id')?.value || null);
+            }
+            scanEditBtn.textContent = 'Barcode scannen';
+        });
+    }

-    document.getElementById('loadMoreBtn').addEventListener('click', () => {
-        renderedCount = Math.min(renderedCount + RENDER_BATCH_COUNT, visibleItems.length);
-        renderItems();
-    });
+    // =========================================================================
+    // 4. UI INTERACTIONS & UTILITIES
+    // =========================================================================
+    function borrowItem(itemId) {
+        const selectedItem = (libraryItems || []).find(item => item._id === itemId);
+        if (selectedItem && selectedItem.LibraryDisplayStatus === 'damaged') {
+            alert('Dieses Medium ist als defekt/zerstört markiert und kann nicht ausgeliehen werden.');
+            return;
+        }
+    
+        const defaultCardId = activeStudentCardId || '';
+        const cardId = (window.prompt('Bitte Schülerausweis-ID eingeben:', defaultCardId) || '').trim().toUpperCase();
+        if (!cardId) {
+            alert('Ausleihe abgebrochen: Für Bibliotheksmedien ist eine gültige Schülerausweis-ID erforderlich.');
+            return;
+        }
+    
+        setActiveStudentCard(cardId);
+    
+        const durationInput = (window.prompt('Ausleihdauer in Tagen (optional):') || '').trim();
+        const maxAvailable = Math.max(1, parseInt(selectedItem?.AvailableGroupedCount || selectedItem?.Quantity || 1, 10) || 1);
+        const countPrompt = (window.prompt(`Anzahl ausleihen? (Standard: 1, verfügbar: ${maxAvailable})`, '1') || '').trim();
+        let borrowCount = parseInt(countPrompt || '1', 10);
+        if (!Number.isFinite(borrowCount) || borrowCount < 1) {
+            borrowCount = 1;
+        }
+        if (borrowCount > maxAvailable) {
+            alert(`Es sind nur ${maxAvailable} Exemplar(e) verfügbar.`);
+            return;
+        }
+    
+        const form = document.createElement('form');
+        form.method = 'POST';
+        form.action = `/ausleihen/${itemId}`;
+    
+        const csrfField = document.createElement('input');
+        csrfField.type = 'hidden';
+        csrfField.name = 'csrf_token';
+        csrfField.value = '{{ csrf_token }}';
+        form.appendChild(csrfField);
+    
+        const cardField = document.createElement('input');
+        cardField.type = 'hidden';
+        cardField.name = 'borrower_card_id';
+        cardField.value = cardId;
+        form.appendChild(cardField);
+    
+        const returnTargetField = document.createElement('input');
+        returnTargetField.type = 'hidden';
+        returnTargetField.name = 'return_to';
+        returnTargetField.value = 'library';
+        form.appendChild(returnTargetField);
+    
+        if (durationInput) {
+            const durationField = document.createElement('input');
+            durationField.type = 'hidden';
+            durationField.name = 'borrow_duration_days';
+            durationField.value = durationInput;
+            form.appendChild(durationField);
+        }
+    
+        const countField = document.createElement('input');
+        countField.type = 'hidden';
+        countField.name = 'exemplare_count';
+        countField.value = String(borrowCount || 1);
+        form.appendChild(countField);
+    
+        document.body.appendChild(form);
+        form.submit();
+    }
+
+    function setScanStatus(message, kind = '') {
+        const el = document.getElementById('scanStatus');
+        if (!el) return;
+        el.textContent = message;
+        el.classList.remove('ok', 'warn', 'error');
+        if (kind) el.classList.add(kind);
+    }
+    
+    function setActiveStudentCard(cardId) {
+        activeStudentCardId = (cardId || '').trim().toUpperCase();
+        const input = document.getElementById('activeStudentCard');
+        if (input) input.value = activeStudentCardId;
+    }
+    
+    function normalizeScannedCode(code) {
+        return (code || '').trim();
+    }

-    // Helper functions
    function getItemTypeLabel(type) {
        const labels = { 'book': 'Buch', 'cd': 'CD', 'dvd': 'DVD', 'other': 'Sonstige' };
        return labels[type] || type;
@@ -837,7 +1044,6 @@
    }

    function showItemDetail(itemId) {
-        // Load and show detail modal
        fetch(`/api/item_detail/${itemId}`)
            .then(r => r.text())
            .then(html => {
@@ -851,322 +1057,165 @@
        document.getElementById('detailModal').style.display = 'none';
    }

-    function borrowItem(itemId) {
-        const selectedItem = (libraryItems || []).find(item => item._id === itemId);
-        if (selectedItem && selectedItem.LibraryDisplayStatus === 'damaged') {
-            alert('Dieses Medium ist als defekt/zerstört markiert und kann nicht ausgeliehen werden.');
-            return;
-        }
-
-        const defaultCardId = activeStudentCardId || '';
-        const cardId = (window.prompt('Bitte Schülerausweis-ID eingeben:', defaultCardId) || '').trim().toUpperCase();
-        if (!cardId) {
-            alert('Ausleihe abgebrochen: Für Bibliotheksmedien ist eine gültige Schülerausweis-ID erforderlich.');
-            return;
-        }
-
-        setActiveStudentCard(cardId);
-
-        const durationInput = (window.prompt('Ausleihdauer in Tagen (optional):') || '').trim();
-        const maxAvailable = Math.max(1, parseInt(selectedItem?.AvailableGroupedCount || selectedItem?.Quantity || 1, 10) || 1);
-        const countPrompt = (window.prompt(`Anzahl ausleihen? (Standard: 1, verfügbar: ${maxAvailable})`, '1') || '').trim();
-        let borrowCount = parseInt(countPrompt || '1', 10);
-        if (!Number.isFinite(borrowCount) || borrowCount < 1) {
-            borrowCount = 1;
-        }
-        if (borrowCount > maxAvailable) {
-            alert(`Es sind nur ${maxAvailable} Exemplar(e) verfügbar.`);
-            return;
-        }
-
-        const form = document.createElement('form');
-        form.method = 'POST';
-        form.action = `/ausleihen/${itemId}`;
-
-        const csrfField = document.createElement('input');
-        csrfField.type = 'hidden';
-        csrfField.name = 'csrf_token';
-        csrfField.value = '{{ csrf_token }}';
-        form.appendChild(csrfField);
-
-        const cardField = document.createElement('input');
-        cardField.type = 'hidden';
-        cardField.name = 'borrower_card_id';
-        cardField.value = cardId;
-        form.appendChild(cardField);
-
-        const returnTargetField = document.createElement('input');
-        returnTargetField.type = 'hidden';
-        returnTargetField.name = 'return_to';
-        returnTargetField.value = 'library';
-        form.appendChild(returnTargetField);
-
-        if (durationInput) {
-            const durationField = document.createElement('input');
-            durationField.type = 'hidden';
-            durationField.name = 'borrow_duration_days';
-            durationField.value = durationInput;
-            form.appendChild(durationField);
-        }
-
-        const countField = document.createElement('input');
-        countField.type = 'hidden';
-        countField.name = 'exemplare_count';
-        countField.value = String(borrowCount || 1);
-        form.appendChild(countField);
-
-        document.body.appendChild(form);
-        form.submit();
-    }
-
-    function setScanStatus(message, kind = '') {
-        const el = document.getElementById('scanStatus');
-        if (!el) return;
-        el.textContent = message;
-        el.classList.remove('ok', 'warn', 'error');
-        if (kind) {
-            el.classList.add(kind);
-        }
-    }
-
-    function setActiveStudentCard(cardId) {
-        activeStudentCardId = (cardId || '').trim().toUpperCase();
-        const input = document.getElementById('activeStudentCard');
-        if (input) {
-            input.value = activeStudentCardId;
-        }
-    }
-
-    function normalizeScannedCode(code) {
-        return (code || '').trim();
-    }
-
-    async function processQuickToggleScan(scannedCode) {
-        if (!activeStudentCardId) {
-            setActiveStudentCard(scannedCode);
-            setScanStatus(`Ausweis gesetzt: ${activeStudentCardId}`, 'ok');
-            return;
-        }
-
-        try {
-            setScanStatus('Verarbeite Mediencode...', 'warn');
-            const response = await fetch('/api/library_scan_action', {
-                method: 'POST',
-                headers: {'Content-Type': 'application/json'},
-                body: JSON.stringify({
-                    student_card_id: activeStudentCardId,
-                    item_code: scannedCode
-                })
-            });
-
-            const result = await response.json();
-            if (!response.ok || !result.ok) {
-                setScanStatus(result.message || 'Scan-Aktion fehlgeschlagen.', 'error');
-                return;
-            }
-
-            if (result.action === 'borrowed') {
-                setScanStatus(`Ausgeliehen: ${result.item_name}`, 'ok');
-            } else if (result.action === 'returned') {
-                setScanStatus(`Zurückgegeben: ${result.item_name}`, 'ok');
-            } else {
-                setScanStatus(result.message || 'Aktion durchgeführt.', 'ok');
-            }
-
-            await loadLibraryItems();
-        } catch (err) {
-            console.error('Quick scan action failed:', err);
-            setScanStatus('Fehler beim Verarbeiten des Scans.', 'error');
-        }
-    }
-
-    function handleScanSuccess(decodedText) {
-        const scannedCode = normalizeScannedCode(decodedText);
-        if (!scannedCode) return;
-
-        const now = Date.now();
-        if (scannedCode === lastScanValue && (now - lastScanAt) < 1500) {
-            return;
-        }
-        lastScanValue = scannedCode;
-        lastScanAt = now;
-
-        const mode = (document.getElementById('scanModeSelect') || {}).value || 'card_only';
-        if (mode === 'card_only') {
-            setActiveStudentCard(scannedCode);
-            setScanStatus(`Ausweis gesetzt: ${activeStudentCardId}`, 'ok');
-            return;
-        }
-
-        processQuickToggleScan(scannedCode);
-    }
-
-    function handleScanError() {
-        // Intentionally silent to avoid UI spam while camera searches codes.
-    }
-
-    async function ensureScannerLibraryLoaded() {
-        // HybridScanner is loaded globally via script tag
-        return typeof HybridScanner !== 'undefined';
-    }
-
-    async function startScanner() {
-        if (scannerRunning) return;
-
-        const scannerLoaded = await ensureScannerLibraryLoaded();
-        if (!scannerLoaded) {
-            setScanStatus('Scanner-Bibliothek konnte nicht geladen werden.', 'error');
-            return;
-        }
-
-        const readerWrap = document.getElementById('scanReaderWrap');
-        const toggleBtn = document.getElementById('toggleScannerBtn');
-        readerWrap.style.display = 'block';
-
-        try {
-            scannerInstance = scannerInstance || new HybridScanner({
-                videoId: 'libraryQrReaderVideo',
-                canvasId: 'libraryQrReaderCanvas',
-                formats: ['QR_CODE', 'EAN_13', 'EAN_8', 'CODE_128', 'CODE_39', 'UPC_A', 'UPC_E', 'ITF', 'CODABAR'],
-                fps: 10,
-                facingMode: 'environment',
-                onSuccess: handleScanSuccess,
-                onError: handleScanError
-            });
-
-            scannerInstance.start();
-            scannerRunning = true;
-            toggleBtn.textContent = 'Scanner stoppen';
-            setScanStatus('Scanner aktiv. Jetzt Code scannen.', 'warn');
-        } catch (err) {
-            console.error('Scanner start failed:', err);
-            readerWrap.style.display = 'none';
-            const detail = (err && (err.message || err.name)) ? ` (${err.message || err.name})` : '';
-            setScanStatus(`Scanner konnte nicht gestartet werden${detail}`, 'error');
-        }
-    }
-
-    async function stopScanner() {
-        if (!scannerRunning || !scannerInstance) return;
-        const readerWrap = document.getElementById('scanReaderWrap');
-        const toggleBtn = document.getElementById('toggleScannerBtn');
-        try {
-            scannerInstance.stop();
-        } catch (err) {
-            console.error('Scanner stop failed:', err);
-        }
-        scannerRunning = false;
-        scannerInstance = null;
-        readerWrap.style.display = 'none';
-        toggleBtn.textContent = 'Scanner starten';
-        setScanStatus('Scanner gestoppt.', 'warn');
-    }
-
+// =========================================================================
+    // 5. EVENT LISTENERS INITIALIZATION & ON-LOAD INITIALIZER
+    // =========================================================================
    function wireScannerUi() {
        const toggleBtn = document.getElementById('toggleScannerBtn');
        const resetBtn = document.getElementById('resetCardBtn');
        const modeSelect = document.getElementById('scanModeSelect');
-
+    
        if (toggleBtn) {
            toggleBtn.addEventListener('click', async () => {
                if (scannerRunning) {
                    await stopScanner();
                } else {
-                    await startScanner();
+                    await startScanner(null);
                }
            });
        }
-
+    
        if (resetBtn) {
            resetBtn.addEventListener('click', () => {
                setActiveStudentCard('');
                setScanStatus('Ausweis zurückgesetzt. Bitte neu scannen.', 'warn');
            });
        }
-
+    
        if (modeSelect) {
            modeSelect.addEventListener('change', () => {
                if (modeSelect.value === 'quick_toggle' && !activeStudentCardId) {
                    setScanStatus('Schnellmodus: zuerst Schülerausweis scannen.', 'warn');
                } else if (modeSelect.value === 'card_only') {
-                    setScanStatus('Modus aktiv: Nur Ausweis erfassen.', 'warn');
-                } else {
-                    setScanStatus('Schnellmodus aktiv: jetzt Mediencode scannen.', 'warn');
+                    setScanStatus('Nur Ausweis-Modus aktiv.', 'warn');
                }
            });
        }
    }

-    function getLibraryItemById(itemId) {
-        return libraryItems.find(i => String(i._id) === String(itemId));
-    }
+    // Run when DOM structure is entirely ready
+    document.addEventListener('DOMContentLoaded', () => {
+        wireScannerUi();       // Setup scanner control buttons 
+        loadLibraryItems();   // Fetch your database items right away!

+        // Safely connect standard Filters and Search inputs inside DOMContentLoaded
+        const filterToggleBtn = document.getElementById('filterToggleBtn');
+        if (filterToggleBtn) {
+            filterToggleBtn.addEventListener('click', () => {
+                filterPanelOpen = !filterPanelOpen;
+                document.getElementById('filterPanel').classList.toggle('open');
+                filterToggleBtn.classList.toggle('active');
+            });
+        }
+
+        const applyFilterBtn = document.getElementById('applyFilterBtn');
+        if (applyFilterBtn) {
+            applyFilterBtn.addEventListener('click', () => {
+                activeFilters.isbn = document.getElementById('filterISBN').value.toLowerCase();
+                activeFilters.type = document.getElementById('filterType').value;
+                activeFilters.status = document.getElementById('filterStatus').value;
+                applyFiltersAndSearch(true);
+            });
+        }
+
+        const clearFilterBtn = document.getElementById('clearFilterBtn');
+        if (clearFilterBtn) {
+            clearFilterBtn.addEventListener('click', () => {
+                document.getElementById('filterISBN').value = '';
+                document.getElementById('filterType').value = '';
+                document.getElementById('filterStatus').value = '';
+                activeFilters = { isbn: '', type: '', status: '' };
+                applyFiltersAndSearch(true);
+            });
+        }
+
+        const librarySearch = document.getElementById('librarySearch');
+        if (librarySearch) {
+            librarySearch.addEventListener('input', (e) => {
+                currentSearchTerm = (e.target.value || '').toLowerCase();
+                applyFiltersAndSearch(true);
+            });
+        }
+
+        const loadMoreBtn = document.getElementById('loadMoreBtn');
+        if (loadMoreBtn) {
+            loadMoreBtn.addEventListener('click', () => {
+                renderedCount = Math.min(renderedCount + RENDER_BATCH_COUNT, visibleItems.length);
+                renderItems();
+            });
+        }
+
+        // Edit Modal Form processing
+        const editForm = document.getElementById('editLibraryForm');
+        if (editForm) {
+            editForm.addEventListener('submit', async function(e) {
+                e.preventDefault(); 
+
+                const itemId = document.getElementById('editLibraryItemId').value;
+
+                const updatedData = {
+                    name: document.getElementById('editLibraryName').value,
+                    item_type: document.getElementById('editLibraryType').value,
+                    isbn: document.getElementById('editLibraryIsbn').value,
+                    code_4: document.getElementById('editLibraryCode4').value, 
+                    ort: document.getElementById('editLibraryLocation').value,
+                    beschreibung: document.getElementById('editLibraryDescription').value
+                };
+
+                try {
+                    const response = await fetch(`/api/library_item/${itemId}/update`, {
+                        method: 'POST',
+                        headers: {
+                            'Content-Type': 'application/json',
+                            'X-CSRFToken': '{{ csrf_token }}', 
+                            'X-CSRF-Token': '{{ csrf_token }}'
+                        },
+                        body: JSON.stringify(updatedData)
+                    });
+
+                    const result = await response.json();
+
+                    if (response.ok && result.ok) {
+                        alert(result.message || 'Medium erfolgreich aktualisiert!');
+                        closeEditLibraryModal();
+
+                        pagingState.loading = false; 
+                        loadLibraryItems(); 
+                    } else {
+                        alert(result.message || 'Fehler beim Speichern der Änderungen.');
+                    }
+                } catch (error) {
+                    console.error('Update failed:', error);
+                    alert('Netzwerkfehler beim Aktualisieren des Mediums.');
+                }
+            });
+        }
+    });
+
+    // Modal Control Functions (accessible globally from table buttons)
    function openEditLibraryItem(itemId) {
-        const item = getLibraryItemById(itemId);
+        const item = libraryItems.find(i => i._id === itemId);
+        
        if (!item) {
-            alert('Element nicht gefunden.');
+            alert('Fehler: Das Medium konnte nicht gefunden werden.');
            return;
        }

-        const modal = document.getElementById('editLibraryModal');
+        // Populate the form fields - Using correct German properties from MongoDB fields
        document.getElementById('editLibraryItemId').value = item._id || '';
        document.getElementById('editLibraryName').value = item.Name || '';
-        document.getElementById('editLibraryAuthor').value = item.Autor || item.Author || '';
-        document.getElementById('editLibraryDescription').value = item.Beschreibung || '';
-        document.getElementById('editLibraryLocation').value = item.Ort || '';
+        document.getElementById('editLibraryType').value = item.ItemType || 'book';
        document.getElementById('editLibraryIsbn').value = item.ISBN || '';
-        document.getElementById('editLibraryCode4').value = item.Code_4 || '';
-        document.getElementById('editLibraryType').value = (item.ItemType || 'book');
-        modal.style.display = 'flex';
+        document.getElementById('editLibraryCode4').value = item.Code_4 || item.Code4 || '';
+        document.getElementById('editLibraryLocation').value = item.Ort || ''; 
+        document.getElementById('editLibraryDescription').value = item.Beschreibung || '';
+
+        document.getElementById('editLibraryModal').style.display = 'block'; 
    }

    function closeEditLibraryModal() {
-        const modal = document.getElementById('editLibraryModal');
-        modal.style.display = 'none';
+        document.getElementById('editLibraryModal').style.display = 'none';
    }
-
-    async function submitEditLibraryItem(event) {
-        event.preventDefault();
-        const itemId = document.getElementById('editLibraryItemId').value;
-        const payload = {
-            name: document.getElementById('editLibraryName').value,
-            autor: document.getElementById('editLibraryAuthor').value,
-            beschreibung: document.getElementById('editLibraryDescription').value,
-            ort: document.getElementById('editLibraryLocation').value,
-            isbn: document.getElementById('editLibraryIsbn').value,
-            code_4: document.getElementById('editLibraryCode4').value,
-            item_type: document.getElementById('editLibraryType').value
-        };
-
-        try {
-            const response = await fetch(`/api/library_item/${itemId}/update`, {
-                method: 'POST',
-                headers: {'Content-Type': 'application/json'},
-                body: JSON.stringify(payload)
-            });
-            const result = await response.json();
-            if (!response.ok || !result.ok) {
-                alert(result.message || 'Bearbeiten fehlgeschlagen.');
-                return;
-            }
-            closeEditLibraryModal();
-            await loadLibraryItems();
-            setScanStatus('Bibliotheksmedium aktualisiert.', 'ok');
-        } catch (err) {
-            console.error('Library edit failed:', err);
-            alert('Fehler beim Bearbeiten des Bibliotheksmediums.');
-        }
-    }
-
-    // Load on page init
-    document.addEventListener('DOMContentLoaded', () => {
-        loadLibraryItems();
-        wireScannerUi();
-        const editForm = document.getElementById('editLibraryForm');
-        if (editForm) {
-            editForm.addEventListener('submit', submitEditLibraryItem);
-        }
-    });
 </script>

 <div id="editLibraryModal" class="modal" style="display:none;">
@@ -1180,10 +1229,6 @@
                    <label for="editLibraryName">Titel</label>
                    <input id="editLibraryName" required>
                </div>
-                <div>
-                    <label for="editLibraryAuthor">Autor/Künstler</label>
-                    <input id="editLibraryAuthor">
-                </div>
                <div>
                    <label for="editLibraryType">Medientyp</label>
                    <select id="editLibraryType">
@@ -1218,4 +1263,4 @@
        </form>
    </div>
 </div>
-{% endblock %}
+{% endblock %}
@@ -413,10 +413,7 @@
        </div>
        <div class="qr-container">
            <button id="scanButton" class="scan-button" aria-controls="qr-reader" aria-expanded="false">Barcode scannen</button>
-            <div id="qr-reader" style="display: none;">
-                <video id="qr-reader-video" playsinline style="width: 100%; max-width: 500px; border-radius: 8px;"></video>
-                <canvas id="qr-reader-canvas" style="display: none;"></canvas>
-            </div>
+            <div id="qr-reader"></div>
        </div>
        <div id="table-view-header" class="table-view-header" aria-hidden="true">
            <span>Name</span>
@@ -528,9 +525,7 @@
    
    window.isDebug = false; // Set to true only for development environment
 </script>
-
-<script src="https://unpkg.com/@zxing/library@latest/umd/index.min.js"></script>
-<script src="/static/js/scanner.js"></script>
+<script src="https://cdn.jsdelivr.net/npm/@ericblade/quagga2/dist/quagga.js"></script>
 <script>
    // Global state
    const highlightItemId = (window.serverVars && window.serverVars.highlightItemId && window.serverVars.highlightItemId !== 'null')
@@ -539,59 +534,114 @@
    let codeSearchTerm = '';
    let descSearchIds = null; // Set of matching IDs or null when disabled

-    // QR scanner toggle setup
-    document.addEventListener('DOMContentLoaded', function() {
-        const scanButton = document.getElementById('scanButton');
+    // Keep track of the scanner state globally/outer scope
+    let isScanning = false; 
+    let activeScannerCallback = null; // Tracks which function currently owns the scanner output
+
+    function startScanner(targetCallback) {
        const qrReader = document.getElementById('qr-reader');
-        let hybridScanner = null;
+        const statusText = document.getElementById('status');

-        if (!scanButton || !qrReader) return;
+        // Store the custom action that should happen when a barcode is found
+        activeScannerCallback = targetCallback;

-        const setScannerUi = (isOpen) => {
-            scanButton.classList.toggle('is-active', isOpen);
-            scanButton.setAttribute('aria-expanded', isOpen ? 'true' : 'false');
-            scanButton.textContent = isOpen ? 'Scanner schliessen' : 'Barcode scannen';
-        };
+        // Show the container
+        if (qrReader) qrReader.style.display = 'block';
+        if (statusText) statusText.innerText = "Initializing camera...";

-        scanButton.addEventListener('click', function() {
-            if (qrReader.style.display !== 'block') {
-                qrReader.style.display = 'block';
-                
-                hybridScanner = new HybridScanner({
-                    videoId: 'qr-reader-video',
-                    canvasId: 'qr-reader-canvas',
-                    formats: ['QR_CODE', 'CODE_128', 'EAN_13', 'EAN_8', 'CODE_39'],
-                    fps: 10,
-                    facingMode: 'environment',
-                    onSuccess: function(decodedText) {
-                        hybridScanner.stop();
-                        qrReader.style.display = 'none';
-                        
-                        // Put scanned code into the search box and trigger search
-                        const searchInput = document.getElementById('code-search');
-                        if (searchInput) {
-                            searchInput.value = decodedText;
-                            searchByCode();
-                        }
-
-                        setScannerUi(false);
-                    },
-                    onError: function(error) {
-                        console.error('Scanner error:', error);
-                    }
-                });
-
-                hybridScanner.start();
-                setScannerUi(true);
-            } else {
-                if (hybridScanner) {
-                    hybridScanner.stop();
-                    hybridScanner = null;
-                }
-                qrReader.style.display = 'none';
-                setScannerUi(false);
+        Quagga.init({
+            inputStream: {
+                name: "Live",
+                type: "LiveStream",
+                // Make sure this targets your correct HTML container element 
+                target: document.querySelector('#scanner-container'), 
+                constraints: {
+                    width: 640,
+                    height: 480,
+                    facingMode: "environment" // Force rear camera
+                },
+            },
+            decoder: {
+                // Your required formats mapped to Quagga2 reader strings
+                readers: ["code_128_reader", "ean_reader", "code_39_reader", "upc_reader"]
+            } 
+        }, function(err) {
+            if (err) {
+                console.error("Initialization error:", err);
+                if (statusText) statusText.innerText = "Camera Error";
+                return;
            }
+
+            Quagga.start();
+            isScanning = true;
+
+            // If we are using the main search button, manage its UI state
+            if (!targetCallback) {
+                setScannerUi(true);
+            }
+
+            if (statusText) statusText.innerText = "Scanning...";
        });
+    }
+
+    function stopScanner() {
+        Quagga.stop();
+        isScanning = false;
+        activeScannerCallback = null; // Reset the callback routing
+
+        const qrReader = document.getElementById('qr-reader');
+        if (qrReader) qrReader.style.display = 'none';
+
+        setScannerUi(false);
+    }
+
+    function setScannerUi(isOpen) {
+        const scanBtn = document.getElementById('scanButton');
+        if (!scanBtn) return;
+
+        scanBtn.classList.toggle('is-active', isOpen);
+        scanBtn.setAttribute('aria-expanded', isOpen ? 'true' : 'false');
+        scanBtn.textContent = isOpen ? 'Scanner schliessen' : 'Barcode scannen';
+    }
+
+    // Unified global reader callback
+    Quagga.onDetected(function(data) {
+        const barcode = String(data.codeResult.code || '').trim();
+        console.log("Barcode detected:", barcode);
+
+        // Keep a local reference to the active callback before shutting down the engine
+        const currentCallback = activeScannerCallback;
+
+        // Critical: Stop scanning immediately to prevent multiple triggers
+        stopScanner();
+
+        // Route data based on who opened the scanner
+        if (typeof currentCallback === "function") {
+            // Send data directly to the specific edit field's logic
+            currentCallback(barcode);
+        } else {
+            // Fallback Default: Main search box logic
+            const resultText = document.getElementById('barcode-result');
+            if (resultText) resultText.innerText = barcode;
+
+            const searchInput = document.getElementById('code-search');
+            if (searchInput) {
+                searchInput.value = barcode;
+                if (typeof searchByCode === "function") {
+                    searchByCode();
+                }
+            }
+        }
+    });
+
+    // Event Listener for the main standalone search button
+    document.getElementById('scanButton')?.addEventListener('click', function() {
+        if (!isScanning) {
+            // Pass null so it defaults to filling the standard search box
+            startScanner(null); 
+        } else {
+            stopScanner();
+        }
    });

    // Return preferred primary and fallback image URLs based on extension
@@ -2436,8 +2436,8 @@ document.addEventListener('DOMContentLoaded', ()=>{
        <div class="qr-container">
            <button id="scanButton" class="scan-button" aria-controls="qr-reader" aria-expanded="false">Barcode scannen</button>
            <div id="qr-reader" style="display: none;">
-                <video id="qr-reader-video" playsinline style="width: 100%; max-width: 100%; height: auto; aspect-ratio: 4/3; object-fit: cover; border-radius: 8px;"></video>
-                <canvas id="qr-reader-canvas" style="display: none;"></canvas>
+                <h3>Status: <span id="status">Bereit</span></h3>
+                <div id="scanner-container"></div>
            </div>
        </div>

@@ -2732,8 +2732,7 @@ document.addEventListener('DOMContentLoaded', ()=>{
    
    window.isDebug = false; // Set to true only for development environment
 </script>
-<script src="https://unpkg.com/@zxing/library@latest/umd/index.min.js"></script>
-<script src="/static/js/scanner.js"></script>
+<script src="https://cdn.jsdelivr.net/npm/@ericblade/quagga2/dist/quagga.js"></script>
 <script>
    // Function to check if a file is a video
    function isVideoFile(filename) {
@@ -2743,7 +2742,6 @@ document.addEventListener('DOMContentLoaded', ()=>{
    }

    // Initialize QR Code scanner and global variables
-    let hybridScanner = null;
    let codeSearchTerm = '';
    let descSearchIds = null; // Set of matching IDs or null when disabled
    let currentUsername = '';
@@ -2772,55 +2770,114 @@ document.addEventListener('DOMContentLoaded', ()=>{
        // No-op in production
        return;
    }
-    
-    document.getElementById('scanButton').addEventListener('click', function() {
+
+    // Keep track of the scanner state globally/outer scope
+    let isScanning = false; 
+    let activeScannerCallback = null; // Tracks which function currently owns the scanner output
+
+    function startScanner(targetCallback) {
        const qrReader = document.getElementById('qr-reader');
-        const scanBtn = document.getElementById('scanButton');
+        const statusText = document.getElementById('status');

-        const setScannerUi = (isOpen) => {
-            if (!scanBtn) return;
-            scanBtn.classList.toggle('is-active', isOpen);
-            scanBtn.setAttribute('aria-expanded', isOpen ? 'true' : 'false');
-            scanBtn.textContent = isOpen ? 'Scanner schliessen' : 'Barcode scannen';
-        };
-        
-        if (qrReader.style.display === 'none') {
-            qrReader.style.display = 'block';
-            
-            hybridScanner = new HybridScanner({
-                videoId: 'qr-reader-video',
-                canvasId: 'qr-reader-canvas',
-                formats: ['QR_CODE', 'CODE_128', 'EAN_13', 'EAN_8', 'CODE_39', 'UPC_A'],
-                fps: 10,
-                facingMode: 'environment',
-                onSuccess: function(decodedText) {
-                    hybridScanner.stop();
-                    qrReader.style.display = 'none';
-                    
-                    // Put the scanned code in the search box
-                    const searchInput = document.getElementById('code-search');
-                    if (searchInput) {
-                        searchInput.value = decodedText;
-                        // Trigger search automatically
-                        searchByCode();
-                    }
+        // Store the custom action that should happen when a barcode is found
+        activeScannerCallback = targetCallback;

-                    setScannerUi(false);
+        // Show the container
+        if (qrReader) qrReader.style.display = 'block';
+        if (statusText) statusText.innerText = "Initializing camera...";
+
+        Quagga.init({
+            inputStream: {
+                name: "Live",
+                type: "LiveStream",
+                // Make sure this targets your correct HTML container element 
+                target: document.querySelector('#scanner-container'), 
+                constraints: {
+                    width: 640,
+                    height: 480,
+                    facingMode: "environment" // Force rear camera
                },
-                onError: function(error) {
-                    console.error('Scanner error:', error);
-                }
-            });
-
-            hybridScanner.start();
-            setScannerUi(true);
-        } else {
-            if (hybridScanner) {
-                hybridScanner.stop();
-                hybridScanner = null;
+            },
+            decoder: {
+                // Your required formats mapped to Quagga2 reader strings
+                readers: ["code_128_reader", "ean_reader", "code_39_reader", "upc_reader"]
+            } 
+        }, function(err) {
+            if (err) {
+                console.error("Initialization error:", err);
+                if (statusText) statusText.innerText = "Camera Error";
+                return;
            }
-            qrReader.style.display = 'none';
-            setScannerUi(false);
+
+            Quagga.start();
+            isScanning = true;
+
+            // If we are using the main search button, manage its UI state
+            if (!targetCallback) {
+                setScannerUi(true);
+            }
+
+            if (statusText) statusText.innerText = "Scanning...";
+        });
+    }
+
+    function stopScanner() {
+        Quagga.stop();
+        isScanning = false;
+        activeScannerCallback = null; // Reset the callback routing
+
+        const qrReader = document.getElementById('qr-reader');
+        if (qrReader) qrReader.style.display = 'none';
+
+        setScannerUi(false);
+    }
+
+    function setScannerUi(isOpen) {
+        const scanBtn = document.getElementById('scanButton');
+        if (!scanBtn) return;
+
+        scanBtn.classList.toggle('is-active', isOpen);
+        scanBtn.setAttribute('aria-expanded', isOpen ? 'true' : 'false');
+        scanBtn.textContent = isOpen ? 'Scanner schliessen' : 'Barcode scannen';
+    }
+
+    // Unified global reader callback
+    Quagga.onDetected(function(data) {
+        const barcode = String(data.codeResult.code || '').trim();
+        console.log("Barcode detected:", barcode);
+
+        // Keep a local reference to the active callback before shutting down the engine
+        const currentCallback = activeScannerCallback;
+
+        // Critical: Stop scanning immediately to prevent multiple triggers
+        stopScanner();
+
+        // Route data based on who opened the scanner
+        if (typeof currentCallback === "function") {
+            // Send data directly to the specific edit field's logic
+            currentCallback(barcode);
+        } else {
+            // Fallback Default: Main search box logic
+            const resultText = document.getElementById('barcode-result');
+            if (resultText) resultText.innerText = barcode;
+
+            const searchInput = document.getElementById('code-search');
+            if (searchInput) {
+                searchInput.value = barcode;
+                if (typeof searchByCode === "function") {
+                    searchByCode();
+                }
+            }
+        }
+    });
+
+    // Event Listener for the main standalone search button
+    document.getElementById('scanButton')?.addEventListener('click', function() {
+        if (!isScanning) {
+            // Pass null so it defaults to filling the standard search box
+            startScanner(null); 
+        } else {
+            stopScanner();
        }
    });

@@ -2832,37 +2889,21 @@ document.addEventListener('DOMContentLoaded', ()=>{
            return;
        }

-        if (qrReader.style.display !== 'none') {
-            if (hybridScanner) {
-                hybridScanner.stop();
-                hybridScanner = null;
-            }
-            qrReader.style.display = 'none';
+        // Toggle close if it's already running
+        if (isScanning && qrReader.style.display !== 'none') {
+            stopScanner();
            scanEditBtn.textContent = 'Barcode scannen';
            return;
        }

-        qrReader.style.display = 'block';
        scanEditBtn.textContent = 'Scanner schließen';
-        hybridScanner = new HybridScanner({
-            videoId: 'qr-reader-video',
-            canvasId: 'qr-reader-canvas',
-            formats: ['CODE_128', 'CODE_39', 'QR_CODE'],
-            fps: 10,
-            facingMode: 'environment',
-            onSuccess: function(decodedText) {
-                hybridScanner.stop();
-                qrReader.style.display = 'none';
-                editCodeInput.value = String(decodedText || '').trim();
-                validateCodeField(editCodeInput, document.getElementById('edit-item-id')?.value || null);
-                scanEditBtn.textContent = 'Barcode scannen';
-            },
-            onError: function(error) {
-                console.error('Scanner error:', error);
-            }
+
+        // Start scanner with custom logic mapping to the Code input field
+        startScanner(function(decodedText) {
+            editCodeInput.value = decodedText;
+            validateCodeField(editCodeInput, document.getElementById('edit-item-id')?.value || null);
+            scanEditBtn.textContent = 'Barcode scannen';
        });
-        
-        hybridScanner.start();
    }

    function scanIntoEditIsbn() {
@@ -2873,39 +2914,23 @@ document.addEventListener('DOMContentLoaded', ()=>{
            return;
        }

-        if (qrReader.style.display !== 'none') {
-            if (hybridScanner) {
-                hybridScanner.stop();
-                hybridScanner = null;
-            }
-            qrReader.style.display = 'none';
+        // Toggle close if it's already running
+        if (isScanning && qrReader.style.display !== 'none') {
+            stopScanner();
            scanIsbnBtn.textContent = 'ISBN scannen';
            return;
        }

-        qrReader.style.display = 'block';
        scanIsbnBtn.textContent = 'Scanner schließen';
-        hybridScanner = new HybridScanner({
-            videoId: 'qr-reader-video',
-            canvasId: 'qr-reader-canvas',
-            formats: ['ISBN', 'EAN_13', 'EAN_8', 'QR_CODE'],
-            fps: 10,
-            facingMode: 'environment',
-            onSuccess: function(decodedText) {
-                hybridScanner.stop();
-                qrReader.style.display = 'none';
-                editIsbnInput.value = String(decodedText || '').trim();
-                scanIsbnBtn.textContent = 'ISBN scannen';
-                if (typeof fetchBookInfo === 'function') {
-                    fetchBookInfo('edit');
-                }
-            },
-            onError: function(error) {
-                console.error('Scanner error:', error);
+
+        // Start scanner with custom logic mapping to the ISBN input field
+        startScanner(function(decodedText) {
+            editIsbnInput.value = decodedText;
+            scanIsbnBtn.textContent = 'ISBN scannen';
+            if (typeof fetchBookInfo === 'function') {
+                fetchBookInfo('edit');
            }
        });
-        
-        hybridScanner.start();
    }

    function rebuildFilter3Options() {
@@ -876,10 +876,7 @@
                    <button type="button" id="scan-code4-btn" class="fetch-isbn-button">Barcode scannen</button>
                </div>
                <small style="display:block; color:#666;">Einzelcode manuell setzen oder per Scanner erfassen.</small>
-                <div id="code4-scanner" style="width:100%; max-width:520px; display:none; margin-top:10px;">
-                    <video id="code4-scanner-video" playsinline style="width: 100%; border-radius: 8px;"></video>
-                    <canvas id="code4-scanner-canvas" style="display: none;"></canvas>
-                </div>
+                <div id="code4-scanner" style="width:100%; max-width:520px; display:none; margin-top:10px;"></div>
                <small id="code4-scan-status" style="display:block; color:#666; margin-top:6px;"></small>
            </div>
            <div class="form-group">
@@ -910,10 +907,7 @@
                    <button type="button" id="scan-isbn-btn" class="fetch-isbn-button">Barcode scannen</button>
                    <button type="button" class="fetch-isbn-button" onclick="fetchBookInfo('upload')">Bild abrufen</button>
                </div>
-                <div id="isbn-scanner" style="width:100%; max-width:520px; display:none; margin-top:10px;">
-                    <video id="isbn-scanner-video" playsinline style="width: 100%; border-radius: 8px;"></video>
-                    <canvas id="isbn-scanner-canvas" style="display: none;"></canvas>
-                </div>
+                <div id="isbn-scanner" style="width:100%; max-width:520px; display:none; margin-top:10px;"></div>
                <small id="isbn-scan-status" style="display:block; color:#666; margin-top:6px;">Scannen oder manuell eingeben. Gültige ISBNs helfen beim Abruf von Buchdaten, andere Codes werden trotzdem akzeptiert.</small>
                <div id="book-info-container" class="book-info-container"></div>
            </div>
@@ -976,9 +970,7 @@
        document.getElementById('csv-help-modal').style.display = 'none';
    }
 </script>
-
-<script src="https://unpkg.com/@zxing/library@latest/umd/index.min.js"></script>
-<script src="/static/js/scanner.js"></script>
+<script src="https://cdn.jsdelivr.net/npm/@ericblade/quagga2/dist/quagga.js"></script>
 <script>
    const libraryModuleEnabled = {{ 'true' if library_module_enabled else 'false' }};

@@ -991,12 +983,12 @@

    // Global variable to store fetched book data
    let currentBookData = null;
-    let code4ScannerInstance = null;
-    let code4ScannerRunning = false;
+    
+    // Quagga2 engine state management properties
+    let scannerRunning = false;
+    let activeScannerCallback = null; // Dynamically handles routing data to the active caller field
    let code4LastScanned = '';
    let code4LastScannedAt = 0;
-    let isbnScannerInstance = null;
-    let isbnScannerRunning = false;

    function setCode4ScanStatus(message, isError = false) {
        const statusEl = document.getElementById('code4-scan-status');
@@ -1049,66 +1041,109 @@
        statusEl.style.color = '#b00020';
    }

+    // Centered Quagga2 Engine Initialization Pattern
+    function runEngineInitialization(targetSelector, activeCallback, completionMsg, errorStatusSetter) {
+        if (scannerRunning) {
+            Quagga.stop();
+            scannerRunning = false;
+        }
+
+        activeScannerCallback = activeCallback;
+
+        Quagga.init({
+            inputStream: {
+                name: "Live",
+                type: "LiveStream",
+                target: document.querySelector(targetSelector), 
+                constraints: {
+                    width: 640,
+                    height: 480,
+                    facingMode: "environment" // Force rear camera lenses
+                },
+            },
+            decoder: {
+                readers: ["code_128_reader", "ean_reader", "code_39_reader", "upc_reader"]
+            } 
+        }, function(err) {
+            if (err) {
+                console.error("Initialization error:", err);
+                errorStatusSetter("Kamera konnte nicht gestartet werden.", true);
+                return;
+            }
+
+            Quagga.start();
+            scannerRunning = true;
+            errorStatusSetter(completionMsg, false);
+        });
+    }
+
+    function killScannerHardware() {
+        if (!scannerRunning) return;
+        Quagga.stop();
+        scannerRunning = false;
+        activeScannerCallback = null;
+    }
+
+    // Unified tracking capture listener
+    Quagga.onDetected(function(data) {
+        if (!data || !data.codeResult || !data.codeResult.code) return;
+        
+        const rawBarcode = String(data.codeResult.code || '').trim();
+        const currentTargetCallback = activeScannerCallback;
+
+        if (typeof currentTargetCallback === "function") {
+            currentTargetCallback(rawBarcode);
+        }
+    });
+
    function startCode4Scanner() {
        const scannerBox = document.getElementById('code4-scanner');
        const scanButton = document.getElementById('scan-code4-btn');
        const codeField = document.getElementById('code_4');
        if (!scannerBox || !scanButton || !codeField) return;

-        // Stop ISBN scanner if currently running to avoid camera conflicts.
-        if (isbnScannerRunning && isbnScannerInstance) {
-            isbnScannerInstance.stop();
-            isbnScannerInstance = null;
-            const isbnScannerBox = document.getElementById('isbn-scanner');
-            const isbnScanButton = document.getElementById('scan-isbn-btn');
+        // Automatically clean up running ISBN scanner to prevent track multi-binding
+        const isbnScannerBox = document.getElementById('isbn-scanner');
+        const isbnScanButton = document.getElementById('scan-isbn-btn');
+        if (isbnScannerBox && isbnScannerBox.style.display !== 'none') {
+            killScannerHardware();
            if (isbnScannerBox) isbnScannerBox.style.display = 'none';
            if (isbnScanButton) isbnScanButton.textContent = 'ISBN scannen';
-            isbnScannerRunning = false;
            setIsbnScanStatus('Scanner gestoppt.');
        }

-        if (code4ScannerRunning && code4ScannerInstance) {
-            code4ScannerInstance.stop();
-            code4ScannerInstance = null;
+        if (scannerBox.style.display !== 'none') {
+            killScannerHardware();
            scannerBox.style.display = 'none';
            scanButton.textContent = 'Barcode scannen';
-            code4ScannerRunning = false;
            setCode4ScanStatus('Scanner gestoppt.');
            return;
        }

        scannerBox.style.display = 'block';
        scanButton.textContent = 'Scanner stoppen';
-        code4ScannerRunning = true;
-        setCode4ScanStatus('Scanner läuft. Der Scan wird im Basis-Codefeld übernommen.');
-
-        code4ScannerInstance = new HybridScanner({
-            videoId: 'code4-scanner-video',
-            canvasId: 'code4-scanner-canvas',
-            formats: ['CODE_128', 'CODE_39', 'QR_CODE'],
-            fps: 10,
-            facingMode: 'environment',
-            onSuccess: function(decodedText) {
-                const scannedCode = String(decodedText || '').trim();
-                if (!scannedCode) return;

+        runEngineInitialization(
+            '#code4-scanner', 
+            function(decodedText) {
                const now = Date.now();
-                if (scannedCode === code4LastScanned && (now - code4LastScannedAt) < 1500) {
+                if (decodedText === code4LastScanned && (now - code4LastScannedAt) < 1500) {
                    return;
                }
-                code4LastScanned = scannedCode;
+                code4LastScanned = decodedText;
                code4LastScannedAt = now;

-                codeField.value = scannedCode;
-                validateCodeField(codeField);
-                setCode4ScanStatus(`Code_4 gesetzt: ${scannedCode}`);
-            },
-            onError: function(error) {
-                setCode4ScanStatus(`Fehler: ${error}`, true);
-            }
-        });
+                killScannerHardware();
+                scannerBox.style.display = 'none';
+                scanButton.textContent = 'Barcode scannen';

-        code4ScannerInstance.start();
+                codeField.value = decodedText;
+                validateCodeField(codeField);
+                setCode4ScanStatus(`Code_4 gesetzt: ${decodedText}`);
+            },
+            'Scanner läuft. Der Scan wird im Basis-Codefeld übernommen.',
+            setCode4ScanStatus
+        );
    }

    function startIsbnScanner() {
@@ -1121,72 +1156,49 @@
        const isbnField = document.getElementById('isbn');
        if (!scannerBox || !scanButton || !isbnField) return;

-        // Stop Code_4 scanner if currently running to avoid camera conflicts.
-        if (code4ScannerRunning && code4ScannerInstance) {
-            code4ScannerInstance.stop();
-            code4ScannerInstance = null;
-            const codeScannerBox = document.getElementById('code4-scanner');
-            const codeScanButton = document.getElementById('scan-code4-btn');
+        // Automatically clean up running Base Code_4 scanner to prevent track multi-binding
+        const codeScannerBox = document.getElementById('code4-scanner');
+        const codeScanButton = document.getElementById('scan-code4-btn');
+        if (codeScannerBox && codeScannerBox.style.display !== 'none') {
+            killScannerHardware();
            if (codeScannerBox) codeScannerBox.style.display = 'none';
            if (codeScanButton) codeScanButton.textContent = 'Barcode scannen';
-            code4ScannerRunning = false;
            setCode4ScanStatus('Scanner gestoppt.');
        }

-        if (isbnScannerRunning && isbnScannerInstance) {
-            isbnScannerInstance.stop();
-            isbnScannerInstance = null;
+        if (scannerBox.style.display !== 'none') {
+            killScannerHardware();
            scannerBox.style.display = 'none';
            scanButton.textContent = 'ISBN scannen';
-            isbnScannerRunning = false;
            setIsbnScanStatus('Scanner gestoppt.');
            return;
        }

        scannerBox.style.display = 'block';
        scanButton.textContent = 'Scanner stoppen';
-        isbnScannerRunning = true;
-        setIsbnScanStatus('Scanner läuft. Bitte ISBN-Code erfassen.');

-        isbnScannerInstance = new HybridScanner({
-            videoId: 'isbn-scanner-video',
-            canvasId: 'isbn-scanner-canvas',
-            formats: ['ISBN', 'EAN_13', 'EAN_8', 'QR_CODE'],
-            fps: 10,
-            facingMode: 'environment',
-            onSuccess: function(decodedText) {
-            const scannedCode = String(decodedText || '').trim();
-            if (!scannedCode) return;
+        runEngineInitialization(
+            '#isbn-scanner',
+            function(decodedText) {
+                killScannerHardware();
+                scannerBox.style.display = 'none';
+                scanButton.textContent = 'ISBN scannen';

-            const normalizedIsbn = normalizeIsbnClient(scannedCode);
-            isbnField.value = normalizedIsbn || scannedCode;
-            updateIsbnLiveValidation();
-            if (normalizedIsbn) {
-                setIsbnScanStatus(`ISBN gesetzt: ${normalizedIsbn}`);
-            } else {
-                setIsbnScanStatus('Kein gültiges ISBN-Format erkannt, der gescannte Wert bleibt aber im Feld.', true);
-            }
+                const normalizedIsbn = normalizeIsbnClient(decodedText);
+                isbnField.value = normalizedIsbn || decodedText;
+                updateIsbnLiveValidation();

-            // Stop scanner after successful scan
-            if (isbnScannerInstance) {
-                isbnScannerInstance.stop();
-                isbnScannerInstance = null;
-            }
-            scannerBox.style.display = 'none';
-            scanButton.textContent = 'ISBN scannen';
-            isbnScannerRunning = false;
-
-            if (normalizedIsbn) {
-                // Automatically load book metadata after a valid ISBN scan.
-                fetchBookInfo('upload');
-            }
+                if (normalizedIsbn) {
+                    setIsbnScanStatus(`ISBN gesetzt: ${normalizedIsbn}`);
+                    // Automatically load book metadata after a valid ISBN scan.
+                    fetchBookInfo('upload');
+                } else {
+                    setIsbnScanStatus('Kein gültiges ISBN-Format erkannt, der gescannte Wert bleibt aber im Feld.', true);
+                }
            },
-            onError: function(error) {
-                setIsbnScanStatus(`Fehler: ${error}`, true);
-            }
-        });
-
-        isbnScannerInstance.start();
+            'Scanner läuft. Bitte ISBN-Code erfassen.',
+            setIsbnScanStatus
+        );
    }

    // Load predefined filter values for dropdowns
@@ -1588,6 +1600,7 @@
        }, 10000);
    }

+    // Exported function for use within parent layout fields
    function validateCodeField(input, excludeId = null) {
        const code = input.value.trim();
        
@@ -1762,188 +1775,11 @@
            if (typeof duplicateData.images === 'string') {
                try {
                    duplicateData.images = JSON.parse(duplicateData.images);
-                    console.log("Parsed images from string:", duplicateData.images);
                } catch (e) {
-                    console.warn("Failed to parse images string, using as single item:", duplicateData.images);
-                    duplicateData.images = [duplicateData.images];
+                    console.error("Error parsing duplicate images array:", e);
                }
            }
-            console.log(`Final duplicateData.images (${Array.isArray(duplicateData.images) ? 'array' : typeof duplicateData.images}):`, duplicateData.images);
-        }
-    }
-    
-    // Then check for sessionStorage data (takes priority)
-    const sessionData = sessionStorage.getItem('duplicateItemData');
-    if (sessionData) {
-        try {
-            duplicateData = JSON.parse(sessionData);
-            sessionStorage.removeItem('duplicateItemData'); // Clean up
-            console.log("Session storage duplicate data:", duplicateData);
-        } catch (e) {
-            console.error('Error parsing session duplicate data:', e);
-        }
-    }
-    
-    // Function to prefill form with duplicate data
-    function prefillFormWithDuplicateData() {
-        if (!duplicateData) return;
-        
-        // Fill basic fields
-        const nameField = document.getElementById('name');
-        if (nameField && duplicateData.name) nameField.value = duplicateData.name;
-        
-        const descField = document.getElementById('beschreibung');
-        if (descField && duplicateData.description) descField.value = duplicateData.description;
-        
-        const yearField = document.getElementById('anschaffungsjahr');
-        if (yearField && duplicateData.year) yearField.value = duplicateData.year;
-        
-        const costField = document.getElementById('anschaffungskosten');
-        if (costField && duplicateData.cost) costField.value = duplicateData.cost;
-        
-        // Fill location dropdown
-        const locationField = document.getElementById('ort');
-        if (locationField && duplicateData.location) {
-            // Wait for locations to load, then set value
-            setTimeout(() => {
-                locationField.value = duplicateData.location;
-            }, 100);
-        }
-        
-        // Fill filter arrays - handle up to 4 values per filter type
-        setTimeout(() => {
-            // Filter 1 (Unterrichtsfach)
-            if (duplicateData.filter1 && Array.isArray(duplicateData.filter1)) {
-                for (let j = 1; j <= Math.min(4, duplicateData.filter1.length); j++) {
-                    const filterField = document.getElementById(`filter1-${j}`);
-                    if (filterField && duplicateData.filter1[j-1]) {
-                        filterField.value = duplicateData.filter1[j-1];
-                    }
-                }
-            }
-            
-            // Filter 2 (Jahrgangsstufe)
-            if (duplicateData.filter2 && Array.isArray(duplicateData.filter2)) {
-                for (let j = 1; j <= Math.min(4, duplicateData.filter2.length); j++) {
-                    const filterField = document.getElementById(`filter2-${j}`);
-                    if (filterField && duplicateData.filter2[j-1]) {
-                        filterField.value = duplicateData.filter2[j-1];
-                    }
-                }
-            }
-            
-            // Filter 3 (Thema) - text inputs
-            if (duplicateData.filter3 && Array.isArray(duplicateData.filter3)) {
-                for (let j = 1; j <= Math.min(4, duplicateData.filter3.length); j++) {
-                    const filterField = document.getElementById(`filter3-${j}`);
-                    if (filterField && duplicateData.filter3[j-1]) {
-                        filterField.value = duplicateData.filter3[j-1];
-                    }
-                }
-            }
-        }, 200); // Wait for filter options to load
-        
-        // Handle images - add hidden inputs for duplicate images
-        if (duplicateData.images && duplicateData.images.length > 0) {
-            console.log("Duplicate images data:", duplicateData.images);
-            const form = document.querySelector('form[action*="upload_item"]');
-            if (form) {
-                // Add hidden field to indicate duplication
-                const isDuplicatingField = document.createElement('input');
-                isDuplicatingField.type = 'hidden';
-                isDuplicatingField.name = 'is_duplicating';
-                isDuplicatingField.value = 'true';
-                form.appendChild(isDuplicatingField);
-                
-                // Add each image as a duplicate image
-                const images = duplicateData.images || [];
-                console.log(`Adding ${images.length} images as hidden fields`);
-                
-                if (Array.isArray(images)) {
-                    images.forEach((imageName, index) => {
-                        if (imageName) {
-                            console.log(`Adding duplicate image ${index}: ${imageName}`);
-                            const imageField = document.createElement('input');
-                            imageField.type = 'hidden';
-                            imageField.name = 'duplicate_images';
-                            imageField.value = imageName;
-                            form.appendChild(imageField);
-                        }
-                    });
-                } else {
-                    console.warn("Images is not an array:", images);
-                    // Try to handle as single item if it's a string
-                    if (typeof images === 'string' && images) {
-                        console.log("Adding single image:", images);
-                        const imageField = document.createElement('input');
-                        imageField.type = 'hidden';
-                        imageField.name = 'duplicate_images';
-                        imageField.value = images;
-                        form.appendChild(imageField);
-                    }
-                }
-                
-                // Show image preview
-                showDuplicateImagePreview(duplicateData.images);
-            }
-        }
-    }
-    
-    // Function to show preview of duplicate images
-    function showDuplicateImagePreview(images) {
-        const previewContainer = document.getElementById('image-preview-container');
-        if (!previewContainer) return;
-        
-        console.log("showDuplicateImagePreview called with:", images);
-        
-        // Make sure images is treated as an array
-        if (!Array.isArray(images)) {
-            if (typeof images === 'string') {
-                // Try to parse if it's a JSON string
-                try {
-                    images = JSON.parse(images);
-                } catch (e) {
-                    // If parsing fails, wrap the single string in an array
-                    images = [images];
-                }
-            } else {
-                console.error("Invalid images data:", images);
-                return;
-            }
-        }
-        
-        previewContainer.innerHTML = '';
-        console.log(`Processing ${images.length} images for preview`);
-        
-        images.forEach((imageName, index) => {
-            console.log(`Processing image ${index}:`, imageName);
-            const preview = document.createElement('div');
-            preview.className = 'image-preview-item';
-            preview.innerHTML = `
-                <img src="/uploads/${imageName}" alt="Duplicate Image ${index + 1}" class="duplicate-image-preview">
-                <div class="image-controls">
-                    <span>Von Original übernommen</span>
-                    <button type="button" onclick="removeDuplicateImage('${imageName}', this)" class="remove-duplicate-image-button">Entfernen</button>
-                </div>
-            `;
-            previewContainer.appendChild(preview);
-        });
-    }
-    
-    // Function to remove a duplicate image
-    function removeDuplicateImage(imageName, button) {
-        // Remove the hidden input
-        const hiddenInputs = document.querySelectorAll('input[name="duplicate_images"]');
-        hiddenInputs.forEach(input => {
-            if (input.value === imageName) {
-                input.remove();
-            }
-        });
-        
-        // Remove the preview
-        const previewItem = button.closest('.image-preview-item');
-        if (previewItem) {
-            previewItem.remove();
+            console.log("Parsed duplicate images successfully.");
        }
    }
 </script>
Author	SHA1	Message	Date
Aiirondev_dev	1b9bfe1b14	Fix of the edeting funktion in the Library Module	2026-06-10 11:24:33 +02:00
Aiirondev_dev	3cdd1552d9	Fix of a library funktion	2026-06-10 11:08:43 +02:00
Aiirondev_dev	80a206f524	Finisched the removal of the Author	2026-06-07 23:16:05 +02:00
Aiirondev_dev	3217da8b15	Improved ISBN Funktionality	2026-06-07 22:57:32 +02:00
Aiirondev_dev	22bc7c9c3c	upload barcode implementation	2026-06-07 22:28:04 +02:00
Aiirondev_dev	f156cc178a	library author removing	2026-06-07 22:21:01 +02:00
Aiirondev_dev	116261d334	Slight fixes of thew Code scanning and Items processing	2026-06-07 12:42:27 +02:00
Aiirondev_dev	042afc19e2	slight changes to the Bar code scanner	2026-06-07 12:33:13 +02:00
Aiirondev_dev	28d049b52a	smal changes fixes for the library Code Scanner	2026-06-07 00:14:57 +02:00
Aiirondev_dev	8e478aeba4	slight fixes	2026-06-07 00:03:21 +02:00
Aiirondev_dev	1b38d1f0c8	changed the wrapper of the new code scanning library	2026-06-06 23:52:19 +02:00
Aiirondev_dev	e7e24b3fae	further changes to the new Barcode system	2026-06-06 23:41:37 +02:00
Aiirondev_dev	fc80857fbe	minor changes to the Inpout scanning	2026-06-06 23:31:50 +02:00
Aiirondev_dev	f763ad064d	Changes from the deprecated qrcode scanning tool, to a more modern option in the library	2026-06-06 22:46:50 +02:00
Aiirondev_dev	bc94ffdc18	further fixes	2026-06-06 17:17:15 +02:00
Aiirondev_dev	76e9670cee	implementation of a new Framework for the Barcode scanning via Quagga2 -> only test implementation	2026-06-06 16:53:11 +02:00
Aiirondev_dev	577c6c4bed	Removing more of the broken funktionaliti	2026-06-06 15:39:51 +02:00
Aiirondev_dev	3aa19b10d1	Reverted Faulti changes that have proven not worth implementing	2026-06-06 15:03:43 +02:00