feat: add folder filter to admin panel

src/app/admin/page.tsx

@@ -21,6 +21,7 @@ export default function AdminDashboard() {
   const [votingOpen, setVotingOpen] = useState(false);
   const [directoryOrder, setDirectoryOrder] = useState<string[]>([]);
   const [loading, setLoading] = useState(true);
+  const [selectedFolder, setSelectedFolder] = useState<string>('');
   const router = useRouter();
 
   useEffect(() => {
@@ -121,21 +122,23 @@ export default function AdminDashboard() {
   };
 
   const handleBulkAction = async (action: 'publish' | 'unpublish') => {
-    if (!confirm(`Möchtest du wirklich alle ${action === 'publish' ? 'freigeben' : 'aufheben'}?`)) return;
+    if (!confirm(`Möchtest du wirklich alle ${selectedFolder ? 'in diesem Ordner ' : ''}${action === 'publish' ? 'freigeben' : 'aufheben'}?`)) return;
     
     const isPublished = action === 'publish';
-    const idsToUpdate = items.filter(i => i.published !== isPublished).map(i => i.id);
+    const itemsToProcess = selectedFolder ? items.filter(i => i.directory === selectedFolder) : items;
+    const idsToUpdate = itemsToProcess.filter(i => i.published !== isPublished).map(i => i.id);
     
     if (idsToUpdate.length === 0) return;
     
     // Optimistic UI
-    setItems((prev) =>
-      prev.map((i) => ({ ...i, published: isPublished }))
-    );
-    setStats({
-      total: items.length,
-      published: isPublished ? items.length : 0,
-      unpublished: isPublished ? 0 : items.length,
+    setItems((prev) => {
+      const next = prev.map((i) => idsToUpdate.includes(i.id) ? { ...i, published: isPublished } : i);
+      setStats({
+        total: next.length,
+        published: next.filter((i) => i.published).length,
+        unpublished: next.filter((i) => !i.published).length,
+      });
+      return next;
     });
 
     try {
@@ -183,6 +186,8 @@ export default function AdminDashboard() {
 
   if (!authChecked) return <div style={{ padding: '20px' }}>Prüfe Berechtigung...</div>;
 
+  const displayedItems = selectedFolder ? items.filter(i => i.directory === selectedFolder) : items;
+
   return (
     <div className="admin-content" style={{ padding: '20px', maxWidth: '1200px', margin: '0 auto' }}>
       <div style={{ display: 'flex', justifyContent: 'space-between', alignItems: 'center', marginBottom: '20px', flexWrap: 'wrap', gap: '10px' }}>
@@ -247,14 +252,51 @@ export default function AdminDashboard() {
         </div>
       </div>
 
-      <div style={{ display: 'flex', justifyContent: 'space-between', alignItems: 'center', marginBottom: '15px', flexWrap: 'wrap', gap: '10px' }}>
-        <h3 style={{ fontSize: '1.2rem' }}>Alle Medien</h3>
-        <div style={{ display: 'flex', gap: '10px' }}>
-          <button className="btn-secondary" onClick={() => handleBulkAction('publish')} disabled={loading || items.length === 0}>
-            Alle freigeben
+      <div style={{ marginBottom: '20px' }}>
+        <h3 style={{ fontSize: '1.2rem', marginBottom: '10px' }}>Filter</h3>
+        <div style={{ display: 'flex', gap: '10px', flexWrap: 'wrap' }}>
+          <button
+            onClick={() => setSelectedFolder('')}
+            style={{
+              padding: '8px 16px',
+              borderRadius: '20px',
+              border: `1px solid ${selectedFolder === '' ? 'var(--color-primary)' : 'var(--color-border)'}`,
+              background: selectedFolder === '' ? 'var(--color-primary)' : 'var(--color-surface)',
+              color: selectedFolder === '' ? 'white' : 'var(--color-text)',
+              cursor: 'pointer',
+              transition: 'all 0.2s'
+            }}
+          >
+            Alle Ordner
           </button>
-          <button className="btn-secondary" onClick={() => handleBulkAction('unpublish')} disabled={loading || items.length === 0}>
-            Alle aufheben
+          {orderedFolders.map(folder => (
+            <button
+              key={folder}
+              onClick={() => setSelectedFolder(folder)}
+              style={{
+                padding: '8px 16px',
+                borderRadius: '20px',
+                border: `1px solid ${selectedFolder === folder ? 'var(--color-primary)' : 'var(--color-border)'}`,
+                background: selectedFolder === folder ? 'var(--color-primary)' : 'var(--color-surface)',
+                color: selectedFolder === folder ? 'white' : 'var(--color-text)',
+                cursor: 'pointer',
+                transition: 'all 0.2s'
+              }}
+            >
+              {folder}
+            </button>
+          ))}
+        </div>
+      </div>
+
+      <div style={{ display: 'flex', justifyContent: 'space-between', alignItems: 'center', marginBottom: '15px', flexWrap: 'wrap', gap: '10px' }}>
+        <h3 style={{ fontSize: '1.2rem' }}>Medien {selectedFolder ? `(${selectedFolder})` : ''}</h3>
+        <div style={{ display: 'flex', gap: '10px' }}>
+          <button className="btn-secondary" onClick={() => handleBulkAction('publish')} disabled={loading || displayedItems.length === 0}>
+            {selectedFolder ? 'Sichtbare freigeben' : 'Alle freigeben'}
+          </button>
+          <button className="btn-secondary" onClick={() => handleBulkAction('unpublish')} disabled={loading || displayedItems.length === 0}>
+            {selectedFolder ? 'Sichtbare aufheben' : 'Alle aufheben'}
           </button>
           <button className="btn-secondary" onClick={fetchData} disabled={loading}>
             {loading ? 'Lädt...' : 'Aktualisieren'}
@@ -263,7 +305,7 @@ export default function AdminDashboard() {
       </div>
 
       <div style={{ display: 'grid', gridTemplateColumns: 'repeat(auto-fill, minmax(150px, 1fr))', gap: '15px' }}>
-        {items.map(item => (
+        {displayedItems.map(item => (
           <div 
             key={item.id} 
             style={{ 
@@ -305,9 +347,9 @@ export default function AdminDashboard() {
             </div>
           </div>
         ))}
-        {items.length === 0 && !loading && (
+        {displayedItems.length === 0 && !loading && (
           <div style={{ gridColumn: '1 / -1', padding: '40px', textAlign: 'center', color: 'var(--color-text-light)' }}>
-            Keine Medien gefunden. Bitte einen Scan durchführen.
+            Keine Medien gefunden. Bitte einen Scan durchführen oder anderen Filter wählen.
           </div>
         )}
       </div>