Feat: Offline-Funktionalität mit IndexedDB implementiert

static/css/styles.css

@@ -253,4 +253,82 @@ body {
 .search-options .form-check-label {
     cursor: pointer;
     user-select: none;
+}
+
+/* Offline-Indikator */
+.offline-indicator {
+    position: fixed;
+    bottom: 20px;
+    right: 20px;
+    background-color: #ff9800;
+    color: white;
+    padding: 10px 20px;
+    border-radius: 5px;
+    display: flex;
+    align-items: center;
+    gap: 10px;
+    box-shadow: 0 2px 5px rgba(0,0,0,0.2);
+    z-index: 1000;
+}
+
+.offline-icon {
+    font-size: 1.2em;
+}
+
+/* Synchronisations-Status */
+.sync-status {
+    position: fixed;
+    bottom: 20px;
+    right: 20px;
+    background-color: #4CAF50;
+    color: white;
+    padding: 10px 20px;
+    border-radius: 5px;
+    display: flex;
+    align-items: center;
+    gap: 10px;
+    box-shadow: 0 2px 5px rgba(0,0,0,0.2);
+    z-index: 1000;
+}
+
+.sync-icon {
+    font-size: 1.2em;
+    animation: spin 1s linear infinite;
+}
+
+@keyframes spin {
+    from { transform: rotate(0deg); }
+    to { transform: rotate(360deg); }
+}
+
+/* Offline-Modus Styling */
+body.offline {
+    filter: grayscale(20%);
+}
+
+body.offline .search-container {
+    opacity: 0.9;
+}
+
+body.offline .footer::after {
+    content: "Offline-Modus";
+    display: block;
+    text-align: center;
+    color: #ff9800;
+    font-size: 0.8em;
+    margin-top: 5px;
+}
+
+/* Offline-Fallback für Bilder */
+.offline img {
+    opacity: 0.8;
+}
+
+/* Verbesserte Sichtbarkeit im Offline-Modus */
+.offline .search-field input {
+    background-color: rgba(255, 255, 255, 0.9);
+}
+
+.offline .result-count {
+    color: #666;
 } 

static/js/db.js

@@ -0,0 +1,144 @@
+// IndexedDB Konfiguration
+const DB_NAME = 'mediCustomersDB';
+const DB_VERSION = 1;
+const STORE_NAME = 'customers';
+
+// Datenbank initialisieren
+const initDB = () => {
+    return new Promise((resolve, reject) => {
+        const request = indexedDB.open(DB_NAME, DB_VERSION);
+        
+        request.onerror = () => {
+            console.error('Fehler beim Öffnen der Datenbank:', request.error);
+            reject(request.error);
+        };
+        
+        request.onsuccess = () => {
+            console.log('Datenbank erfolgreich geöffnet');
+            resolve(request.result);
+        };
+        
+        request.onupgradeneeded = (event) => {
+            const db = event.target.result;
+            if (!db.objectStoreNames.contains(STORE_NAME)) {
+                const store = db.createObjectStore(STORE_NAME, { keyPath: 'nummer' });
+                // Indizes für die Suche erstellen
+                store.createIndex('name', 'name', { unique: false });
+                store.createIndex('ort', 'ort', { unique: false });
+                store.createIndex('plz', 'plz', { unique: false });
+                store.createIndex('fachrichtung', 'fachrichtung', { unique: false });
+            }
+        };
+    });
+};
+
+// Kunden in IndexedDB speichern
+const saveCustomers = async (customers) => {
+    const db = await initDB();
+    const tx = db.transaction(STORE_NAME, 'readwrite');
+    const store = tx.objectStore(STORE_NAME);
+    
+    return Promise.all(customers.map(customer => {
+        return new Promise((resolve, reject) => {
+            const request = store.put(customer);
+            request.onsuccess = () => resolve();
+            request.onerror = () => reject(request.error);
+        });
+    }));
+};
+
+// Kunden aus IndexedDB suchen
+const searchCustomersOffline = async (searchParams) => {
+    const db = await initDB();
+    const tx = db.transaction(STORE_NAME, 'readonly');
+    const store = tx.objectStore(STORE_NAME);
+    
+    return new Promise((resolve, reject) => {
+        const request = store.getAll();
+        
+        request.onsuccess = () => {
+            let results = request.result;
+            
+            // Filtern basierend auf den Suchparametern
+            if (searchParams.q) {
+                const searchTerms = searchParams.q.toLowerCase().split(' ');
+                const operator = searchParams.operator || 'or';
+                
+                results = results.filter(customer => {
+                    const searchableText = `${customer.name} ${customer.ort} ${customer.nummer} ${customer.plz} ${customer.fachrichtung}`.toLowerCase();
+                    
+                    if (operator === 'and') {
+                        return searchTerms.every(term => searchableText.includes(term));
+                    } else {
+                        return searchTerms.some(term => searchableText.includes(term));
+                    }
+                });
+            }
+            
+            // Spezifische Feldsuche
+            if (searchParams.name) {
+                results = results.filter(c => c.name.toLowerCase().includes(searchParams.name.toLowerCase()));
+            }
+            if (searchParams.ort) {
+                results = results.filter(c => c.ort.toLowerCase().includes(searchParams.ort.toLowerCase()));
+            }
+            if (searchParams.nummer) {
+                results = results.filter(c => c.nummer.toString().includes(searchParams.nummer));
+            }
+            if (searchParams.plz) {
+                results = results.filter(c => c.plz.includes(searchParams.plz));
+            }
+            if (searchParams.fachrichtung) {
+                results = results.filter(c => c.fachrichtung.toLowerCase().includes(searchParams.fachrichtung.toLowerCase()));
+            }
+            
+            resolve(results);
+        };
+        
+        request.onerror = () => {
+            reject(request.error);
+        };
+    });
+};
+
+// Synchronisationsstatus speichern
+const syncStatus = {
+    lastSync: null,
+    isOnline: navigator.onLine
+};
+
+// Event Listener für Online/Offline Status
+window.addEventListener('online', () => {
+    syncStatus.isOnline = true;
+    document.body.classList.remove('offline');
+    synchronizeData();
+});
+
+window.addEventListener('offline', () => {
+    syncStatus.isOnline = false;
+    document.body.classList.add('offline');
+});
+
+// Daten mit dem Server synchronisieren
+const synchronizeData = async () => {
+    if (!syncStatus.isOnline) return;
+    
+    try {
+        const response = await fetch('/api/customers');
+        const customers = await response.json();
+        await saveCustomers(customers);
+        syncStatus.lastSync = new Date();
+        console.log('Daten erfolgreich synchronisiert');
+    } catch (error) {
+        console.error('Fehler bei der Synchronisation:', error);
+    }
+};
+
+// Export der Funktionen
+window.dbHelper = {
+    initDB,
+    saveCustomers,
+    searchCustomersOffline,
+    synchronizeData,
+    syncStatus
+};