add traction import export

lib/components/pages/traction/traction.dart

@@ -1,13 +1,17 @@
 import 'dart:async';
 import 'dart:convert';
+import 'dart:typed_data';
 
+import 'package:file_selector/file_selector.dart';
 import 'package:flutter/material.dart';
 import 'package:go_router/go_router.dart';
 import 'package:mileograph_flutter/components/traction/traction_card.dart';
 import 'package:mileograph_flutter/objects/objects.dart';
+import 'package:mileograph_flutter/services/api_service.dart';
 import 'package:mileograph_flutter/services/data_service.dart';
 import 'package:mileograph_flutter/services/distance_unit_service.dart';
 import 'package:mileograph_flutter/services/authservice.dart';
+import 'package:mileograph_flutter/utils/download_helper.dart';
 import 'package:provider/provider.dart';
 import 'package:shared_preferences/shared_preferences.dart';
 

lib/components/pages/traction/traction_page.dart

@@ -5,6 +5,7 @@ enum _TractionMoreAction {
   classLeaderboard,
   adminPending,
   adminPendingChanges,
+  adminImport,
 }
 
 class TractionPage extends StatefulWidget {
@@ -74,6 +75,7 @@ class _TractionPageState extends State<TractionPage> {
   String? _lastQuerySignature;
   String? _transferFromLabel;
   bool _isSearching = false;
+  bool _classExporting = false;
 
   @override
   void initState() {
@@ -649,8 +651,11 @@ class _TractionPageState extends State<TractionPage> {
     return content;
   }
 
+  String get _currentClassLabel =>
+      (_selectedClass ?? _classController.text).trim();
+
   bool get _hasClassQuery {
-    return (_selectedClass ?? _classController.text).trim().isNotEmpty;
+    return _currentClassLabel.isNotEmpty;
   }
 
   Widget _buildHeaderActions(BuildContext context, bool isMobile) {
@@ -668,6 +673,23 @@ class _TractionPageState extends State<TractionPage> {
     );
 
     final hasClassActions = _hasClassQuery;
+    final classLabel = _currentClassLabel;
+
+    final exportClassButton = !hasClassActions
+        ? null
+        : FilledButton.tonalIcon(
+            onPressed: _classExporting ? null : _exportSelectedClass,
+            icon: _classExporting
+                ? const SizedBox(
+                    height: 16,
+                    width: 16,
+                    child: CircularProgressIndicator(strokeWidth: 2),
+                  )
+                : const Icon(Icons.download),
+            label: Text(
+              _classExporting ? 'Exporting...' : 'Export $classLabel',
+            ),
+          );
 
     final newTractionButton = FilledButton.icon(
       onPressed: () async {
@@ -730,6 +752,9 @@ class _TractionPageState extends State<TractionPage> {
                     );
                   }
                   break;
+                case _TractionMoreAction.adminImport:
+                  await _showTractionImportSheet();
+                  break;
               }
             },
             itemBuilder: (context) {
@@ -793,6 +818,12 @@ class _TractionPageState extends State<TractionPage> {
                     child: Text('Pending changes'),
                   ),
                 );
+                items.add(
+                  const PopupMenuItem(
+                    value: _TractionMoreAction.adminImport,
+                    child: Text('Import traction'),
+                  ),
+                );
               }
               return items;
             },
@@ -816,12 +847,14 @@ class _TractionPageState extends State<TractionPage> {
 
     final desktopActions = [
       refreshButton,
+      if (exportClassButton != null) exportClassButton,
       newTractionButton,
       if (moreButton != null) moreButton,
     ];
 
     final mobileActions = [
       if (moreButton != null) moreButton,
+      if (exportClassButton != null) exportClassButton,
       newTractionButton,
       refreshButton,
     ];
@@ -849,6 +882,331 @@ class _TractionPageState extends State<TractionPage> {
     );
   }
 
+  Future<void> _exportSelectedClass() async {
+    if (_classExporting) return;
+    final classLabel = _currentClassLabel;
+    if (classLabel.isEmpty) return;
+    setState(() => _classExporting = true);
+    final messenger = ScaffoldMessenger.of(context);
+    try {
+      final data = context.read<DataService>();
+      final encodedClass = Uri.encodeComponent(classLabel);
+      final response = await data.api.getBytes(
+        '/loco/class/export/$encodedClass',
+        headers: const {'accept': '*/*'},
+      );
+      final safeClassName =
+          classLabel.replaceAll(RegExp(r'[^a-zA-Z0-9-_]+'), '_');
+      final fallbackName = 'traction-${safeClassName.isEmpty ? 'class' : safeClassName}.xlsx';
+      final filename = response.filename ?? fallbackName;
+      final saveResult = await saveBytes(
+        Uint8List.fromList(response.bytes),
+        filename,
+        mimeType: response.contentType,
+      );
+      if (!mounted) return;
+      if (saveResult.canceled) {
+        messenger.showSnackBar(
+          const SnackBar(content: Text('Export canceled.')),
+        );
+      } else {
+        final path = saveResult.path;
+        messenger.showSnackBar(
+          SnackBar(
+            content: Text(
+              path == null || path.isEmpty
+                  ? 'Export started.'
+                  : 'Export saved to $path',
+            ),
+          ),
+        );
+      }
+    } on ApiException catch (e) {
+      if (!mounted) return;
+      messenger.showSnackBar(
+        SnackBar(content: Text('Export failed: ${e.message}')),
+      );
+    } catch (e) {
+      if (!mounted) return;
+      messenger.showSnackBar(
+        SnackBar(content: Text('Export failed: $e')),
+      );
+    } finally {
+      if (mounted) setState(() => _classExporting = false);
+    }
+  }
+
+  Future<void> _showTractionImportSheet() async {
+    final isElevated = context.read<AuthService>().isElevated;
+    if (!isElevated) {
+      ScaffoldMessenger.of(context).showSnackBar(
+        const SnackBar(content: Text('Import is available to admins only.')),
+      );
+      return;
+    }
+
+    XFile? selectedFile;
+    bool uploading = false;
+    Map<String, dynamic>? importResult;
+    String? statusMessage;
+    String? errorMessage;
+
+    await showModalBottomSheet<void>(
+      context: context,
+      isScrollControlled: true,
+      builder: (sheetContext) {
+        final theme = Theme.of(sheetContext);
+        return StatefulBuilder(
+          builder: (context, setModalState) {
+            Future<void> pickFile() async {
+              final file = await openFile(
+                acceptedTypeGroups: const [
+                  XTypeGroup(
+                    label: 'Spreadsheets',
+                    extensions: ['xlsx', 'xls', 'ods', 'odf'],
+                  ),
+                ],
+              );
+              if (file == null) return;
+              setModalState(() {
+                selectedFile = file;
+                importResult = null;
+                statusMessage = null;
+                errorMessage = null;
+              });
+            }
+
+            Future<void> uploadFile() async {
+              final file = selectedFile;
+              if (file == null || uploading) return;
+              setModalState(() {
+                uploading = true;
+                importResult = null;
+                statusMessage = null;
+                errorMessage = null;
+              });
+              try {
+                final data = context.read<DataService>();
+                final bytes = await file.readAsBytes();
+                final response = await data.api.postMultipartFile(
+                  '/loco/class/import',
+                  bytes: bytes,
+                  filename: file.name,
+                  headers: const {'accept': 'application/json'},
+                );
+                if (!mounted) return;
+                final parsed = response is Map
+                    ? Map<String, dynamic>.from(response)
+                    : null;
+                if (parsed != null) {
+                  final imported = _importCount(parsed['imported']);
+                  final updated = _importCount(parsed['updated']);
+                  final errors = _importErrors(parsed);
+                  final errorNote =
+                      errors.isNotEmpty ? ' (${errors.length} error(s))' : '';
+                  statusMessage =
+                      'Import complete. Imported $imported, updated $updated$errorNote.';
+                  importResult = parsed;
+                } else {
+                  statusMessage = 'Import complete.';
+                }
+                await data.fetchClassList();
+                await _refreshTraction(preservePosition: true);
+              } on ApiException catch (e) {
+                if (!mounted) return;
+                errorMessage = e.message;
+              } catch (e) {
+                if (!mounted) return;
+                errorMessage = e.toString();
+              } finally {
+                if (!mounted) return;
+                setModalState(() => uploading = false);
+              }
+            }
+
+            return SafeArea(
+              child: Padding(
+                padding: EdgeInsets.fromLTRB(
+                  16,
+                  16,
+                  16,
+                  16 + MediaQuery.of(context).viewInsets.bottom,
+                ),
+                child: SingleChildScrollView(
+                  child: Column(
+                    crossAxisAlignment: CrossAxisAlignment.start,
+                    mainAxisSize: MainAxisSize.min,
+                    children: [
+                      Text(
+                        'Import traction data',
+                        style: theme.textTheme.titleLarge,
+                      ),
+                      const SizedBox(height: 8),
+                      Text(
+                        'Upload a spreadsheet to import traction records.',
+                        style: theme.textTheme.bodyMedium,
+                      ),
+                      const SizedBox(height: 12),
+                      Row(
+                        children: [
+                          Expanded(
+                            child: Text(
+                              selectedFile?.name ?? 'No file selected',
+                              overflow: TextOverflow.ellipsis,
+                            ),
+                          ),
+                          const SizedBox(width: 8),
+                          OutlinedButton.icon(
+                            onPressed: uploading ? null : pickFile,
+                            icon: const Icon(Icons.upload_file),
+                            label: const Text('Choose file'),
+                          ),
+                        ],
+                      ),
+                      const SizedBox(height: 12),
+                      FilledButton.icon(
+                        onPressed:
+                            selectedFile == null || uploading ? null : uploadFile,
+                        icon: uploading
+                            ? const SizedBox(
+                                width: 16,
+                                height: 16,
+                                child: CircularProgressIndicator(strokeWidth: 2),
+                              )
+                            : const Icon(Icons.file_upload),
+                        label: Text(
+                          uploading ? 'Importing...' : 'Upload and import',
+                        ),
+                      ),
+                      if (statusMessage != null) ...[
+                        const SizedBox(height: 12),
+                        Text(
+                          statusMessage!,
+                          style: theme.textTheme.bodyMedium,
+                        ),
+                      ],
+                      if (errorMessage != null) ...[
+                        const SizedBox(height: 12),
+                        Text(
+                          errorMessage!,
+                          style: theme.textTheme.bodyMedium?.copyWith(
+                            color: theme.colorScheme.error,
+                          ),
+                        ),
+                      ],
+                      if (importResult != null)
+                        _buildImportSummary(context, importResult!),
+                    ],
+                  ),
+                ),
+              ),
+            );
+          },
+        );
+      },
+    );
+  }
+
+  int _importCount(dynamic value) {
+    if (value is num) return value.toInt();
+    return int.tryParse(value?.toString() ?? '') ?? 0;
+  }
+
+  List<dynamic> _importErrors(Map<String, dynamic> result) {
+    final errors = result['errors'];
+    if (errors == null) return const [];
+    if (errors is List) return errors;
+    return [errors];
+  }
+
+  String _stringifyImportError(dynamic err) {
+    if (err == null) return '';
+    if (err is String) return err;
+    try {
+      return jsonEncode(err);
+    } catch (_) {
+      return err.toString();
+    }
+  }
+
+  Widget _buildImportSummary(
+    BuildContext context,
+    Map<String, dynamic> result,
+  ) {
+    final imported = _importCount(result['imported']);
+    final updated = _importCount(result['updated']);
+    final errors = _importErrors(result);
+    return Column(
+      crossAxisAlignment: CrossAxisAlignment.start,
+      children: [
+        const SizedBox(height: 12),
+        Text(
+          'Import summary',
+          style: Theme.of(context).textTheme.titleMedium,
+        ),
+        const SizedBox(height: 8),
+        Wrap(
+          spacing: 12,
+          runSpacing: 8,
+          children: [
+            _buildImportChip(context, 'Imported', imported.toString()),
+            _buildImportChip(context, 'Updated', updated.toString()),
+            _buildImportChip(context, 'Errors', errors.length.toString()),
+          ],
+        ),
+        if (errors.isNotEmpty) ...[
+          const SizedBox(height: 8),
+          Text(
+            'Errors',
+            style: Theme.of(context).textTheme.labelLarge,
+          ),
+          const SizedBox(height: 6),
+          Column(
+            crossAxisAlignment: CrossAxisAlignment.start,
+            children: errors
+                .map(
+                  (err) => Padding(
+                    padding: const EdgeInsets.only(bottom: 4),
+                    child: Text(_stringifyImportError(err)),
+                  ),
+                )
+                .toList(),
+          ),
+        ],
+      ],
+    );
+  }
+
+  Widget _buildImportChip(
+    BuildContext context,
+    String label,
+    String value,
+  ) {
+    final scheme = Theme.of(context).colorScheme;
+    return Container(
+      padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
+      decoration: BoxDecoration(
+        color: scheme.surfaceContainerHighest,
+        borderRadius: BorderRadius.circular(8),
+        border: Border.all(color: scheme.outlineVariant),
+      ),
+      child: Column(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          Text(
+            label,
+            style: Theme.of(context).textTheme.labelSmall,
+          ),
+          const SizedBox(height: 4),
+          Text(
+            value,
+            style: const TextStyle(fontWeight: FontWeight.w700),
+          ),
+        ],
+      ),
+    );
+  }
+
   Future<void> _toggleClassStatsPanel() async {
     if (!_hasClassQuery) return;
     final targetState = !_showClassStatsPanel;