feat: Refactor inventory screen to improve type safety and enhance UI structure with dedicated widget methods

flutter/lib/features/inventory/presentation/inventory_screen.dart

@@ -6,6 +6,7 @@ import '../../../core/api/api_error_mapper.dart';
 import '../../../core/l10n/l10n.dart';
 import '../../../core/ui/async_state_views.dart';
 import '../../auth/data/auth_providers.dart';
+import '../domain/inventory_item.dart';
 import '../data/inventory_providers.dart';
 import 'swipeable_inventory_tile.dart';
 
@@ -56,11 +57,11 @@ class _InventoryScreenState extends ConsumerState<InventoryScreen> {
     });
   }
 
-  void _selectAllVisible(List<dynamic> visibleItems) {
+  void _selectAllVisible(List<InventoryItem> visibleItems) {
     setState(() {
       _selectedIds
         ..clear()
-        ..addAll(visibleItems.map<int>((item) => item.id as int));
+        ..addAll(visibleItems.map<int>((item) => item.id));
     });
   }
 
@@ -130,7 +131,7 @@ class _InventoryScreenState extends ConsumerState<InventoryScreen> {
     );
   }
 
-  Future<void> _mergeSelected(BuildContext context, List<dynamic> allItems) async {
+  Future<void> _mergeSelected(BuildContext context, List<InventoryItem> allItems) async {
     final selectedItems = allItems
         .where((item) => _selectedIds.contains(item.id))
         .toList();
@@ -165,7 +166,7 @@ class _InventoryScreenState extends ConsumerState<InventoryScreen> {
 
     try {
       final token = await ref.read(authStateProvider.future);
-      final ids = selectedItems.map<int>((item) => item.id as int).toList();
+      final ids = selectedItems.map<int>((item) => item.id).toList();
       await ref.read(inventoryRepositoryProvider).mergeInventoryItems(
             ids,
             targetUnit: units.length > 1 ? targetUnit : null,
@@ -185,10 +186,10 @@ class _InventoryScreenState extends ConsumerState<InventoryScreen> {
     }
   }
 
-  Future<void> _deleteSelected(BuildContext context, List<dynamic> allItems) async {
+  Future<void> _deleteSelected(BuildContext context, List<InventoryItem> allItems) async {
     final ids = allItems
         .where((item) => _selectedIds.contains(item.id))
-        .map<int>((item) => item.id as int)
+        .map<int>((item) => item.id)
         .toList();
     if (ids.isEmpty) return;
 
@@ -229,7 +230,7 @@ class _InventoryScreenState extends ConsumerState<InventoryScreen> {
     }
   }
 
-  Future<void> _openBulkActions(BuildContext context, List<dynamic> allItems) async {
+  Future<void> _openBulkActions(BuildContext context, List<InventoryItem> allItems) async {
     if (_selectedIds.isEmpty) return;
     final action = await showDialog<String>(
       context: context,
@@ -260,30 +261,7 @@ class _InventoryScreenState extends ConsumerState<InventoryScreen> {
     }
   }
 
-  @override
-  Widget build(BuildContext context, WidgetRef ref) {
-    final location = ref.watch(inventoryLocationFilterProvider);
-    final sort = ref.watch(inventorySortFilterProvider);
-    final inventoryAsync = ref.watch(inventoryProvider);
-
-    return inventoryAsync.when(
-      loading: () => LoadingStateView(label: context.l10n.inventoryLoading),
-      error: (e, _) => ErrorStateView(
-        message: mapErrorToUserMessage(e, context),
-        onRetry: () => ref.invalidate(inventoryProvider),
-      ),
-      data: (items) {
-        final itemIds = items.map((item) => item.id).toSet();
-        final staleIds = _selectedIds.where((id) => !itemIds.contains(id)).toList();
-        if (staleIds.isNotEmpty) {
-          WidgetsBinding.instance.addPostFrameCallback((_) {
-            if (!mounted) return;
-            setState(() {
-              _selectedIds.removeWhere((id) => !itemIds.contains(id));
-            });
-          });
-        }
-
+  List<InventoryItem> _sortedVisibleItems(List<InventoryItem> items, String sort) {
     final visibleItems = [...items];
     if (sort == 'l1CategoryAsc') {
       visibleItems.sort((a, b) {
@@ -294,8 +272,11 @@ class _InventoryScreenState extends ConsumerState<InventoryScreen> {
         return a.displayName.toLowerCase().compareTo(b.displayName.toLowerCase());
       });
     }
+    return visibleItems;
+  }
 
-        final filterSection = Padding(
+  Widget _buildFilterSection(BuildContext context, String location, String sort) {
+    return Padding(
       padding: const EdgeInsets.fromLTRB(12, 12, 12, 4),
       child: Column(
         crossAxisAlignment: CrossAxisAlignment.start,
@@ -337,16 +318,16 @@ class _InventoryScreenState extends ConsumerState<InventoryScreen> {
                 )
                 .toList(),
             onChanged: (value) {
-                  ref
-                      .read(inventorySortFilterProvider.notifier)
-                      .setValue(value ?? '');
+              ref.read(inventorySortFilterProvider.notifier).setValue(value ?? '');
             },
           ),
         ],
       ),
     );
+  }
 
-        final headerSection = Padding(
+  Widget _buildHeaderSection(BuildContext context) {
+    return Padding(
       padding: const EdgeInsets.fromLTRB(12, 12, 12, 4),
       child: Card(
         child: Padding(
@@ -375,10 +356,14 @@ class _InventoryScreenState extends ConsumerState<InventoryScreen> {
         ),
       ),
     );
+  }
 
-        final selectedSection = _selectedIds.isEmpty
-            ? const SizedBox.shrink()
-            : Padding(
+  Widget _buildSelectedSection(
+    BuildContext context,
+    List<InventoryItem> visibleItems,
+    List<InventoryItem> allItems,
+  ) {
+    return Padding(
       padding: const EdgeInsets.fromLTRB(12, 4, 12, 4),
       child: Card(
         child: Padding(
@@ -396,7 +381,7 @@ class _InventoryScreenState extends ConsumerState<InventoryScreen> {
                 runSpacing: 8,
                 children: [
                   FilledButton.icon(
-                              onPressed: () => _openBulkActions(context, items),
+                    onPressed: () => _openBulkActions(context, allItems),
                     icon: const Icon(Icons.playlist_add_check),
                     label: const Text('Hantera markerade'),
                   ),
@@ -417,6 +402,37 @@ class _InventoryScreenState extends ConsumerState<InventoryScreen> {
         ),
       ),
     );
+  }
+
+  Widget _buildEmptyState(BuildContext context) {
+    return EmptyStateView(title: context.l10n.inventoryEmpty);
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final location = ref.watch(inventoryLocationFilterProvider);
+    final sort = ref.watch(inventorySortFilterProvider);
+    final inventoryAsync = ref.watch(inventoryProvider);
+
+    return inventoryAsync.when(
+      loading: () => LoadingStateView(label: context.l10n.inventoryLoading),
+      error: (e, _) => ErrorStateView(
+        message: mapErrorToUserMessage(e, context),
+        onRetry: () => ref.invalidate(inventoryProvider),
+      ),
+      data: (items) {
+        final itemIds = items.map((item) => item.id).toSet();
+        final staleIds = _selectedIds.where((id) => !itemIds.contains(id)).toList();
+        if (staleIds.isNotEmpty) {
+          WidgetsBinding.instance.addPostFrameCallback((_) {
+            if (!mounted) return;
+            setState(() {
+              _selectedIds.removeWhere((id) => !itemIds.contains(id));
+            });
+          });
+        }
+
+        final visibleItems = _sortedVisibleItems(items, sort);
 
         if (visibleItems.isEmpty) {
           return Stack(
@@ -425,10 +441,10 @@ class _InventoryScreenState extends ConsumerState<InventoryScreen> {
                 key: const PageStorageKey<String>('inventory-empty-list'),
                 padding: const EdgeInsets.only(bottom: 88),
                 children: [
-                  headerSection,
-                  selectedSection,
-                  filterSection,
-                  EmptyStateView(title: context.l10n.inventoryEmpty),
+                  _buildHeaderSection(context),
+                  if (_selectedIds.isNotEmpty) _buildSelectedSection(context, visibleItems, items),
+                  _buildFilterSection(context, location, sort),
+                  _buildEmptyState(context),
                 ],
               ),
               Positioned(
@@ -452,9 +468,11 @@ class _InventoryScreenState extends ConsumerState<InventoryScreen> {
               itemCount: visibleItems.length + (_selectedIds.isEmpty ? 2 : 3),
               separatorBuilder: (_, __) => const Divider(height: 1),
               itemBuilder: (context, index) {
-                if (index == 0) return filterSection;
-                if (index == 1) return headerSection;
-                if (_selectedIds.isNotEmpty && index == 2) return selectedSection;
+                if (index == 0) return _buildFilterSection(context, location, sort);
+                if (index == 1) return _buildHeaderSection(context);
+                if (_selectedIds.isNotEmpty && index == 2) {
+                  return _buildSelectedSection(context, visibleItems, items);
+                }
                 final item = visibleItems[index - (_selectedIds.isEmpty ? 2 : 3)];
                 return SwipeableInventoryTile(
                   item: item,