Botao de remover materiais

lib/features/materials/presentation/pages/teacher_materials_page.dart

@@ -176,10 +176,15 @@ class _TeacherMaterialsPageState extends State<TeacherMaterialsPage> {
                   final fileType = extension == '.pdf' ? 'pdf' :
                                    (extension == '.jpg' || extension == '.jpeg' || extension == '.png') ? 'image' : 'other';
 
+                  final docId = materials[index].id;
+                  final url = material['url'] as String?;
+
                   return _buildMaterialCard(
+                    docId: docId,
                     fileName: fileName,
                     fileType: fileType,
                     createdAt: createdAt,
+                    url: url,
                   );
                 },
               );
@@ -459,6 +464,75 @@ class _TeacherMaterialsPageState extends State<TeacherMaterialsPage> {
     }
   }
 
+  Future<void> _deleteMaterial({
+    required String docId,
+    required String fileName,
+    String? url,
+  }) async {
+    try {
+      // Apagar ficheiro do Firebase Storage
+      if (url != null && url.isNotEmpty) {
+        try {
+          final ref = _storage.refFromURL(url);
+          await ref.delete();
+        } catch (_) {
+          // Se o ficheiro já não existir no Storage, continuar na mesma
+        }
+      }
+
+      // Apagar documento no Firestore
+      await _firestore.collection('materials').doc(docId).delete();
+
+      if (mounted) {
+        _showSuccessSnackBar('Material eliminado com sucesso!');
+      }
+    } catch (e) {
+      if (mounted) {
+        _showErrorSnackBar('Erro ao eliminar material: $e');
+      }
+    }
+  }
+
+  void _showDeleteConfirmation({
+    required String docId,
+    required String fileName,
+    String? url,
+  }) {
+    showDialog(
+      context: context,
+      builder: (dialogContext) => AlertDialog(
+        shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(16)),
+        title: const Text(
+          'Eliminar Material',
+          style: TextStyle(fontWeight: FontWeight.bold),
+        ),
+        content: Text(
+          'Tens a certeza que queres eliminar "$fileName"?\nEsta ação não pode ser desfeita.',
+        ),
+        actions: [
+          TextButton(
+            onPressed: () => Navigator.of(dialogContext).pop(),
+            child: const Text('Cancelar'),
+          ),
+          ElevatedButton(
+            onPressed: () {
+              Navigator.of(dialogContext).pop();
+              _deleteMaterial(docId: docId, fileName: fileName, url: url);
+            },
+            style: ElevatedButton.styleFrom(
+              backgroundColor: Colors.red,
+              foregroundColor: Colors.white,
+              shape: RoundedRectangleBorder(
+                borderRadius: BorderRadius.circular(10),
+              ),
+            ),
+            child: const Text('Eliminar'),
+          ),
+        ],
+      ),
+    );
+  }
+
   void _showSuccessSnackBar(String message) {
     ScaffoldMessenger.of(context).showSnackBar(
       SnackBar(
@@ -496,9 +570,11 @@ class _TeacherMaterialsPageState extends State<TeacherMaterialsPage> {
   }
 
   Widget _buildMaterialCard({
+    required String docId,
     required String fileName,
     required String fileType,
     required Timestamp? createdAt,
+    String? url,
   }) {
     IconData iconData;
     Color iconColor;
@@ -566,6 +642,15 @@ class _TeacherMaterialsPageState extends State<TeacherMaterialsPage> {
             fontSize: 13,
           ),
         ),
+        trailing: IconButton(
+          icon: const Icon(Icons.delete_outline, color: Colors.red),
+          tooltip: 'Eliminar',
+          onPressed: () => _showDeleteConfirmation(
+            docId: docId,
+            fileName: fileName,
+            url: url,
+          ),
+        ),
       ),
     );
   }