feat: budget screen improvements, UPI deep-link fixes & categories listener ordering

lib/core/utils/hive_bootstrap.dart

@@ -3,6 +3,7 @@ import 'package:hive_flutter/hive_flutter.dart';
 import '../../features/expense/data/datasource/account_local_datasource.dart';
 import '../../features/expense/data/datasource/budget_local_datasource.dart';
 import '../../features/expense/data/datasource/expense_local_datasource.dart';
+import '../../features/expense/data/datasource/month_budget_local_datasource.dart';
 import '../../features/expense/data/datasource/preferences_local_datasource.dart';
 import '../../features/expense/data/datasource/recurring_subscription_local_datasource.dart';
 import '../../features/expense/data/models/account_model.dart';
@@ -52,5 +53,8 @@ abstract final class HiveBootstrap {
         RecurringSubscriptionLocalDatasource.boxName,
       );
     }
+    if (!Hive.isBoxOpen(MonthBudgetLocalDatasource.boxName)) {
+      await Hive.openBox<double>(MonthBudgetLocalDatasource.boxName);
+    }
   }
 }

lib/features/expense/data/datasource/month_budget_local_datasource.dart

@@ -0,0 +1,79 @@
+import 'package:hive/hive.dart';
+
+/// Hive-backed store for **per-month** budget data using a plain [Box<double>].
+///
+/// Key conventions:
+///   * Total monthly budget → `"__total__::YYYY-MM"`
+///   * Category override    → `"YYYY-MM::CategoryName"`
+class MonthBudgetLocalDatasource {
+  static const String boxName = 'month_budgets';
+  static const String _kTotalPrefix = '__total__::';
+
+  Box<double> get _box => Hive.box<double>(boxName);
+
+  // ── total budget ──────────────────────────────────────────────────────────
+
+  double? getMonthTotalBudget(String monthKey) =>
+      _box.get('$_kTotalPrefix$monthKey');
+
+  Future<void> saveMonthTotalBudget(String monthKey, double amount) =>
+      _box.put('$_kTotalPrefix$monthKey', amount);
+
+  // ── per-category overrides ─────────────────────────────────────────────────
+
+  /// Returns category budget overrides stored for [monthKey].
+  ///
+  /// This scans all box keys, so prefer calling [loadAll] once at startup to
+  /// build a complete in-memory snapshot rather than calling this repeatedly.
+  Map<String, double> getCategoryBudgetsForMonth(String monthKey) {
+    final prefix = '$monthKey::';
+    final result = <String, double>{};
+    for (final rawKey in _box.keys) {
+      final key = rawKey as String;
+      if (key.startsWith(prefix)) {
+        final value = _box.get(key);
+        if (value != null) {
+          result[key.substring(prefix.length)] = value;
+        }
+      }
+    }
+    return result;
+  }
+
+  Future<void> saveCategoryBudgetForMonth(
+    String monthKey,
+    String category,
+    double amount,
+  ) =>
+      _box.put('$monthKey::$category', amount);
+
+  // ── bulk load ──────────────────────────────────────────────────────────────
+
+  /// Returns every stored entry as two maps so the provider layer can build
+  /// its in-memory state without scanning the box again later.
+  ({
+    Map<String, double> totalBudgets,
+    Map<String, Map<String, double>> categoryBudgets,
+  }) loadAll() {
+    final totalBudgets = <String, double>{};
+    final categoryBudgets = <String, Map<String, double>>{};
+
+    for (final rawKey in _box.keys) {
+      final key = rawKey as String;
+      final value = _box.get(key);
+      if (value == null) continue;
+
+      if (key.startsWith(_kTotalPrefix)) {
+        totalBudgets[key.substring(_kTotalPrefix.length)] = value;
+      } else {
+        final sep = key.indexOf('::');
+        if (sep == -1) continue;
+        final monthKey = key.substring(0, sep);
+        final category = key.substring(sep + 2);
+        (categoryBudgets[monthKey] ??= {})[category] = value;
+      }
+    }
+
+    return (totalBudgets: totalBudgets, categoryBudgets: categoryBudgets);
+  }
+}

lib/features/expense/presentation/provider/budget_state.dart

@@ -0,0 +1,226 @@
+import 'dart:developer' as dev;
+
+import 'package:flutter/foundation.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+
+import '../../data/datasource/month_budget_local_datasource.dart';
+import '../../data/models/expense_model.dart';
+import 'budget_providers.dart';
+import 'expense_providers.dart';
+
+// ── helpers ───────────────────────────────────────────────────────────────────
+
+/// Normalised "YYYY-MM" string for a given month.
+String monthKeyOf(DateTime dt) =>
+    '${dt.year}-${dt.month.toString().padLeft(2, '0')}';
+
+// ── selected month ────────────────────────────────────────────────────────────
+
+/// The currently-viewed month (always normalised to the 1st of that month).
+final selectedMonthProvider =
+    NotifierProvider<SelectedMonthNotifier, DateTime>(
+  SelectedMonthNotifier.new,
+);
+
+class SelectedMonthNotifier extends Notifier<DateTime> {
+  @override
+  DateTime build() {
+    final now = DateTime.now();
+    return DateTime(now.year, now.month);
+  }
+}
+
+// ── datasource provider ───────────────────────────────────────────────────────
+
+final monthBudgetDatasourceProvider =
+    Provider<MonthBudgetLocalDatasource>((ref) {
+  return MonthBudgetLocalDatasource();
+});
+
+// ── state model ───────────────────────────────────────────────────────────────
+
+class MonthBudgetState {
+  const MonthBudgetState({
+    this.totalBudgets = const {},
+    this.categoryBudgets = const {},
+  });
+
+  /// monthKey → total spending budget for that month.
+  final Map<String, double> totalBudgets;
+
+  /// monthKey → { categoryName → monthly limit }.
+  final Map<String, Map<String, double>> categoryBudgets;
+
+  double? totalForMonth(String monthKey) => totalBudgets[monthKey];
+
+  Map<String, double> categoriesForMonth(String monthKey) =>
+      categoryBudgets[monthKey] ?? const {};
+
+  MonthBudgetState copyWith({
+    Map<String, double>? totalBudgets,
+    Map<String, Map<String, double>>? categoryBudgets,
+  }) =>
+      MonthBudgetState(
+        totalBudgets: totalBudgets ?? this.totalBudgets,
+        categoryBudgets: categoryBudgets ?? this.categoryBudgets,
+      );
+}
+
+// ── notifier ──────────────────────────────────────────────────────────────────
+
+class MonthBudgetNotifier extends AsyncNotifier<MonthBudgetState> {
+  MonthBudgetLocalDatasource get _ds =>
+      ref.read(monthBudgetDatasourceProvider);
+
+  @override
+  Future<MonthBudgetState> build() async {
+    try {
+      final raw = _ds.loadAll();
+      return MonthBudgetState(
+        totalBudgets: Map<String, double>.from(raw.totalBudgets),
+        categoryBudgets: {
+          for (final entry in raw.categoryBudgets.entries)
+            entry.key: Map<String, double>.from(entry.value),
+        },
+      );
+    } catch (e, st) {
+      if (kDebugMode) {
+        dev.log('MonthBudgetNotifier.build failed',
+            error: e, stackTrace: st, name: 'MonthBudgetNotifier');
+      }
+      return const MonthBudgetState();
+    }
+  }
+
+  Future<void> saveMonthTotal(DateTime month, double amount) async {
+    try {
+      final key = monthKeyOf(month);
+      await _ds.saveMonthTotalBudget(key, amount);
+      final current = state.value ?? const MonthBudgetState();
+      final updatedTotals = Map<String, double>.from(current.totalBudgets)
+        ..[key] = amount;
+      state = AsyncData(current.copyWith(totalBudgets: updatedTotals));
+    } catch (e, st) {
+      if (kDebugMode) {
+        dev.log('saveMonthTotal failed',
+            error: e, stackTrace: st, name: 'MonthBudgetNotifier');
+      }
+    }
+  }
+
+  Future<void> copyFromPreviousMonth(DateTime targetMonth) async {
+    try {
+      final prevMonth =
+          DateTime(targetMonth.year, targetMonth.month - 1);
+      final prevKey = monthKeyOf(prevMonth);
+      final targetKey = monthKeyOf(targetMonth);
+
+      final current = state.value ?? const MonthBudgetState();
+
+      // Copy total budget
+      final prevTotal = current.totalForMonth(prevKey);
+
+      // Copy category budgets: month-specific overrides take precedence over
+      // global defaults; if no previous month-specific budgets exist, fall
+      // back to the global budgets.
+      final globalBudgets =
+          ref.read(budgetTargetsProvider).value ?? defaultBudgetTargets;
+      final prevCategoryOverrides = current.categoriesForMonth(prevKey);
+      final sourceBudgets = <String, double>{
+        ...globalBudgets,
+        ...prevCategoryOverrides,
+      };
+
+      // Persist to Hive
+      if (prevTotal != null) {
+        await _ds.saveMonthTotalBudget(targetKey, prevTotal);
+      }
+      for (final entry in sourceBudgets.entries) {
+        await _ds.saveCategoryBudgetForMonth(
+            targetKey, entry.key, entry.value);
+      }
+
+      // Update in-memory state
+      final updatedTotals = Map<String, double>.from(current.totalBudgets);
+      if (prevTotal != null) updatedTotals[targetKey] = prevTotal;
+
+      final updatedCategories = {
+        for (final e in current.categoryBudgets.entries)
+          e.key: Map<String, double>.from(e.value),
+      };
+      updatedCategories[targetKey] = Map<String, double>.from(sourceBudgets);
+
+      state = AsyncData(current.copyWith(
+        totalBudgets: updatedTotals,
+        categoryBudgets: updatedCategories,
+      ));
+    } catch (e, st) {
+      if (kDebugMode) {
+        dev.log('copyFromPreviousMonth failed',
+            error: e, stackTrace: st, name: 'MonthBudgetNotifier');
+      }
+    }
+  }
+}
+
+final monthBudgetProvider =
+    AsyncNotifierProvider<MonthBudgetNotifier, MonthBudgetState>(
+  MonthBudgetNotifier.new,
+);
+
+// ── derived providers ─────────────────────────────────────────────────────────
+
+/// Expense + income stats scoped to the selected month.
+final monthlyStatsForMonthProvider = Provider<ExpenseStats>((ref) {
+  final expenses =
+      ref.watch(expenseListProvider).value ?? const <ExpenseModel>[];
+  final month = ref.watch(selectedMonthProvider);
+  return ExpenseStats.fromExpenses(expenses, forMonth: month);
+});
+
+/// Total spending budget set for the selected month (may be null if not set).
+final monthTotalBudgetProvider = Provider<double?>((ref) {
+  final month = ref.watch(selectedMonthProvider);
+  final budgetState = ref.watch(monthBudgetProvider).value;
+  return budgetState?.totalForMonth(monthKeyOf(month));
+});
+
+/// How much remains in the selected month's total budget.
+/// Returns null when no total budget has been set.
+final monthRemainingBudgetProvider = Provider<double?>((ref) {
+  final total = ref.watch(monthTotalBudgetProvider);
+  if (total == null) return null;
+  final stats = ref.watch(monthlyStatsForMonthProvider);
+  return total - stats.monthTotal;
+});
+
+/// Effective category budgets for the selected month.
+/// Month-specific overrides shadow the global per-category limits.
+final effectiveMonthBudgetsProvider = Provider<Map<String, double>>((ref) {
+  final globalBudgets =
+      ref.watch(budgetTargetsProvider).value ?? defaultBudgetTargets;
+  final month = ref.watch(selectedMonthProvider);
+  final budgetState = ref.watch(monthBudgetProvider).value;
+  final monthOverrides =
+      budgetState?.categoriesForMonth(monthKeyOf(month)) ?? const {};
+  return <String, double>{...globalBudgets, ...monthOverrides};
+});
+
+// ── controller ────────────────────────────────────────────────────────────────
+
+class MonthBudgetController {
+  MonthBudgetController(this._ref);
+
+  final Ref _ref;
+
+  Future<void> saveMonthTotal(DateTime month, double amount) =>
+      _ref.read(monthBudgetProvider.notifier).saveMonthTotal(month, amount);
+
+  Future<void> copyFromPreviousMonth(DateTime targetMonth) => _ref
+      .read(monthBudgetProvider.notifier)
+      .copyFromPreviousMonth(targetMonth);
+}
+
+final monthBudgetControllerProvider = Provider<MonthBudgetController>((ref) {
+  return MonthBudgetController(ref);
+});

lib/features/expense/presentation/provider/expense_providers.dart

@@ -297,10 +297,16 @@ class ExpenseStats {
     required this.incomeCategoryTotals,
   });
 
-  factory ExpenseStats.fromExpenses(List<ExpenseModel> expenses) {
+  factory ExpenseStats.fromExpenses(
+    List<ExpenseModel> expenses, {
+    DateTime? forMonth,
+  }) {
     final now = DateTime.now();
-    final int currentYear = now.year;
-    final int currentMonth = now.month;
+    final reference = forMonth ?? now;
+    final int currentYear = reference.year;
+    final int currentMonth = reference.month;
+    final bool isCurrentMonth =
+        reference.year == now.year && reference.month == now.month;
     final int currentDay = now.day;
 
     int transactionCount = 0;
@@ -333,7 +339,8 @@ class ExpenseStats {
           ifAbsent: () => amount,
         );
 
-        final bool isToday = localDate.day == currentDay;
+        final bool isToday =
+            isCurrentMonth && localDate.day == currentDay;
 
         if (isIncome) {
           monthIncomeTotal += amount;