A whole bunch of changes

lib/services/app_state.dart

@@ -3,6 +3,7 @@ import 'dart:io';
 
 import 'package:connectivity_plus/connectivity_plus.dart';
 import 'package:flutter/foundation.dart';
+import 'package:flutter/material.dart' show ThemeMode;
 import 'package:shared_preferences/shared_preferences.dart';
 import 'package:uuid/uuid.dart';
 
@@ -22,6 +23,7 @@ const _prefsKeyCloudFolderPath = 'cloud_folder_path';
 const _prefsKeyKeepReceiptPhotosLocally = 'keep_receipt_photos_locally';
 const _prefsKeyStaleLockMinutes = 'stale_lock_minutes';
 const _prefsKeyKeepMaxQualityReceiptPhotos = 'keep_max_quality_receipt_photos';
+const _prefsKeyThemeMode = 'theme_mode';
 
 const defaultStaleLockMinutes = 10;
 const minStaleLockMinutes = 1;
@@ -85,6 +87,8 @@ class AppState extends ChangeNotifier {
   /// the original camera/gallery image is kept as-is.
   bool keepMaxQualityReceiptPhotos = false;
 
+  ThemeMode themeMode = ThemeMode.system;
+
   /// Set if [init] fails. The UI shows this (with a retry option) instead
   /// of spinning forever — an unhandled exception here previously left
   /// `isLoading` stuck at true with no feedback at all.
@@ -109,6 +113,10 @@ class AppState extends ChangeNotifier {
       staleLockMinutes = prefs.getInt(_prefsKeyStaleLockMinutes) ?? defaultStaleLockMinutes;
       keepMaxQualityReceiptPhotos =
           prefs.getBool(_prefsKeyKeepMaxQualityReceiptPhotos) ?? false;
+      themeMode = ThemeMode.values.firstWhere(
+        (mode) => mode.name == prefs.getString(_prefsKeyThemeMode),
+        orElse: () => ThemeMode.system,
+      );
     } catch (e) {
       initError = e;
       isLoading = false;
@@ -289,6 +297,13 @@ class AppState extends ChangeNotifier {
     notifyListeners();
   }
 
+  Future<void> setThemeMode(ThemeMode mode) async {
+    themeMode = mode;
+    final prefs = await SharedPreferences.getInstance();
+    await prefs.setString(_prefsKeyThemeMode, mode.name);
+    notifyListeners();
+  }
+
   /// Clamped to [minStaleLockMinutes, maxStaleLockMinutes] — see the
   /// Settings "Advanced" section, which restricts the picker to that range
   /// anyway; this is a defensive backstop for any other caller.
@@ -373,6 +388,34 @@ class AppState extends ChangeNotifier {
     return entry;
   }
 
+  /// Corrects the logged values (date, gallons, price/gal, total cost) for
+  /// an existing fuel entry — the receipt photo itself isn't editable here,
+  /// only the data recorded about it (e.g. fixing a misread OCR value).
+  /// [entryId]'s receipt photo reference (local path and/or cloud file id)
+  /// carries over untouched.
+  Future<void> updateFuelEntry({
+    required String entryId,
+    required DateTime date,
+    required double gallons,
+    required double pricePerGallon,
+    required double totalCost,
+  }) async {
+    final existing = fuelEntries.firstWhere((e) => e.id == entryId);
+    final updated = FuelEntry(
+      id: existing.id,
+      vehicleId: existing.vehicleId,
+      date: date,
+      gallons: gallons,
+      pricePerGallon: pricePerGallon,
+      totalCost: totalCost,
+      receiptImagePath: existing.receiptImagePath,
+      receiptDriveFileId: existing.receiptDriveFileId,
+      updatedAt: DateTime.now().toUtc(),
+    );
+    await database.saveFuelEntry(updated);
+    await _persist();
+  }
+
   Future<void> deleteFuelEntry(String entryId) async {
     final entry = fuelEntries.firstWhere((e) => e.id == entryId);
     await database.deleteReceiptImageFile(entry.receiptImagePath);
@@ -380,6 +423,30 @@ class AppState extends ChangeNotifier {
     await _persist();
   }
 
+  /// Wipes every vehicle, fuel entry, and local receipt photo — "starting
+  /// completely fresh". Uses the same soft-delete tombstones as any other
+  /// delete rather than a hard SQL `DELETE`, so if a cloud sync is
+  /// connected, the deletion pushes on next sync instead of the old data
+  /// just getting silently re-imported from the remote copy. This is purely
+  /// local + whatever propagates through sync — it never reaches into the
+  /// cloud folder directly to delete anything sitting there.
+  Future<void> purgeAllData() async {
+    await database.purgeAllData(DateTime.now().toUtc());
+    await _persist();
+  }
+
+  /// Wipes every fuel entry (and its local receipt photo) dated within
+  /// [start]–[end] inclusive, across all vehicles. Vehicles themselves are
+  /// left alone. Same soft-delete/sync-propagation reasoning as
+  /// [purgeAllData].
+  Future<void> purgeFuelEntriesInRange(DateTime start, DateTime end) async {
+    final localPaths = await database.purgeFuelEntriesInRange(start, end, DateTime.now().toUtc());
+    for (final path in localPaths) {
+      await database.deleteReceiptImageFile(path);
+    }
+    await _persist();
+  }
+
   List<FuelEntry> entriesForVehicle(String vehicleId) {
     final list = fuelEntries.where((e) => e.vehicleId == vehicleId).toList();
     list.sort((a, b) => b.date.compareTo(a.date));
@@ -401,6 +468,14 @@ class AppState extends ChangeNotifier {
     }
   }
 
+  FuelEntry? fuelEntryById(String id) {
+    try {
+      return fuelEntries.firstWhere((e) => e.id == id);
+    } catch (_) {
+      return null;
+    }
+  }
+
   /// Exact match against an active vehicle's VIN — same comparison
   /// [DatabaseService.vinExists] does, not case-insensitive, since VIN
   /// isn't normalized to any particular case on manual entry (only OCR