feat(equipment): currency presets, a default currency, and correct symbols

lib/core/database/database.dart

@@ -1465,6 +1465,7 @@ class DiverSettings extends Table {
   TextColumn get altitudeUnit => text().withDefault(const Constant('meters'))();
   TextColumn get sacUnit =>
       text().withDefault(const Constant('litersPerMin'))();
+  TextColumn get defaultCurrency => text().withDefault(const Constant('USD'))();
   // Time/Date format settings
   TextColumn get timeFormat =>
       text().withDefault(const Constant('twelveHour'))();
@@ -2927,7 +2928,7 @@ class AppDatabase extends _$AppDatabase {
 
   /// The current schema version as a static constant so that pre-open checks
   /// (e.g. version-mismatch guard) can reference it without an instance.
-  static const int currentSchemaVersion = 139;
+  static const int currentSchemaVersion = 141;
 
   /// Every schema version that has a migration block in onUpgrade.
   /// Used to calculate progress step counts. When adding a new migration,
@@ -3100,6 +3101,11 @@ class AppDatabase extends _$AppDatabase {
     // v139: cylinder_configs + cylinder_config_items (reusable diluent and
     // bailout setups).
     139,
+    // v140 is reserved by the media-section branch (media.retain_in_library).
+    // v141: diver_settings.default_currency (default currency for priced
+    // items). Renumbered from v138 and then v139 as those went to the
+    // divelogs.de branch and the cylinder configs respectively.
+    141,
   ];
 
   /// Idempotent DDL for the v106 connector-suggestion columns (Lightroom
@@ -4075,6 +4081,22 @@ class AppDatabase extends _$AppDatabase {
     }
   }
 
+  /// Idempotent DDL for the v141 diver_settings.default_currency column.
+  /// Called from the v141 onUpgrade step and the beforeOpen backstop, and
+  /// self-guarding when the table is absent (minimal migration-test fixtures).
+  Future<void> _assertDefaultCurrencyColumn() async {
+    final cols = await customSelect(
+      "PRAGMA table_info('diver_settings')",
+    ).get();
+    if (cols.isEmpty) return;
+    final names = cols.map((c) => c.read<String>('name')).toSet();
+    if (!names.contains('default_currency')) {
+      await customStatement(
+        "ALTER TABLE diver_settings ADD COLUMN default_currency TEXT NOT NULL DEFAULT 'USD'",
+      );
+    }
+  }
+
   /// One-time clear of weather descriptions this app generated itself.
   ///
   /// Only rows whose weather_source is 'openMeteo' are touched -- those are
@@ -7299,6 +7321,13 @@ class AppDatabase extends _$AppDatabase {
           await _assertCylinderConfigSchema();
           await reportProgress();
         }
+        // v141: default currency for priced items (e.g. equipment). A DB
+        // that upgraded past 141 on a parallel branch never enters this block;
+        // the beforeOpen backstop below is its only path to the column.
+        if (from < 141) {
+          await _assertDefaultCurrencyColumn();
+        }
+        if (from < 141) await reportProgress();
       },
       beforeOpen: (details) async {
         // Enable foreign keys
@@ -7320,6 +7349,9 @@ class AppDatabase extends _$AppDatabase {
         // v137 backstop: re-assert dives.weather_code.
         await _assertWeatherCodeColumn();
 
+        // v141 backstop: re-assert diver_settings.default_currency.
+        await _assertDefaultCurrencyColumn();
+
         // v106 backstop: re-assert connector-suggestion columns (the helper
         // is self-guarding when the suggestions table is absent).
         await _assertConnectorSuggestionColumns();

lib/core/utils/currency.dart

@@ -0,0 +1,91 @@
+import 'package:intl/intl.dart';
+
+/// Common currency codes offered as presets in pickers. Free-text entry still
+/// allows any other ISO 4217 code.
+const List<String> kCommonCurrencyCodes = [
+  'USD',
+  'EUR',
+  'GBP',
+  'CHF',
+  'AUD',
+  'CAD',
+  'NZD',
+  'JPY',
+  'SEK',
+  'NOK',
+  'DKK',
+  'THB',
+  'EGP',
+  'MXN',
+  'IDR',
+  'PHP',
+  'ZAR',
+];
+
+/// The preset codes, with [currentCode] prepended when it is a real code
+/// outside the presets. Free-text entry means a stored currency can be
+/// anything; without this it would vanish from every picker that offers only
+/// the presets, leaving the current value unselectable.
+List<String> currencyCodesWith(String? currentCode) {
+  final current = (currentCode ?? '').trim().toUpperCase();
+  if (current.isEmpty || kCommonCurrencyCodes.contains(current)) {
+    return kCommonCurrencyCodes;
+  }
+  return [current, ...kCommonCurrencyCodes];
+}
+
+/// The symbol for [currencyCode] (e.g. 'EUR' -> '€'), falling back to the
+/// upper-cased code itself for anything intl doesn't recognise (or an empty
+/// string for a blank code).
+String currencySymbol(String currencyCode) {
+  final code = currencyCode.trim().toUpperCase();
+  if (code.isEmpty) return '';
+  try {
+    return NumberFormat.simpleCurrency(name: code).currencySymbol;
+  } catch (_) {
+    return code;
+  }
+}
+
+/// Formats [amount] in [currencyCode] using the currency's symbol, falling back
+/// to "CODE 12.34" for unrecognised codes.
+String formatMoney(double amount, String currencyCode) {
+  final code = currencyCode.trim().toUpperCase();
+  try {
+    return NumberFormat.simpleCurrency(name: code).format(amount);
+  } catch (_) {
+    final prefix = code.isEmpty ? '' : '$code ';
+    return '$prefix${amount.toStringAsFixed(2)}';
+  }
+}
+
+/// Sums the amounts in [items] grouped by their currency, so a collection
+/// priced in more than one currency is never added into a single misleading
+/// figure.
+///
+/// [amountOf] returns null for items with no price (those are skipped), and a
+/// blank [currencyOf] falls back to [fallbackCode] - legacy rows can carry an
+/// empty code. Entries come back ordered by descending total, then by code, so
+/// the display order is stable across rebuilds.
+List<MapEntry<String, double>> sumByCurrency<T>(
+  Iterable<T> items, {
+  required double? Function(T item) amountOf,
+  required String Function(T item) currencyOf,
+  required String fallbackCode,
+}) {
+  final fallback = fallbackCode.trim().toUpperCase();
+  final totals = <String, double>{};
+  for (final item in items) {
+    final amount = amountOf(item);
+    if (amount == null) continue;
+    final raw = currencyOf(item).trim().toUpperCase();
+    final code = raw.isEmpty ? fallback : raw;
+    totals[code] = (totals[code] ?? 0) + amount;
+  }
+  final entries = totals.entries.toList()
+    ..sort((a, b) {
+      final byTotal = b.value.compareTo(a.value);
+      return byTotal != 0 ? byTotal : a.key.compareTo(b.key);
+    });
+  return entries;
+}

lib/features/equipment/data/repositories/service_record_repository.dart

@@ -195,20 +195,32 @@ class ServiceRecordRepository {
     return results.map(_mapCustomRowToServiceRecord).toList();
   }
 
-  /// Get total cost of services for an equipment item
-  Future<double> getTotalServiceCost(String equipmentId) async {
-    final result = await _db
+  /// Total service cost for an equipment item, keyed by the currency each
+  /// record was priced in.
+  ///
+  /// Grouped rather than summed into one figure: records can carry different
+  /// currencies, and adding them together would produce a number that is not
+  /// a real amount in any of them.
+  Future<Map<String, double>> getTotalServiceCostByCurrency(
+    String equipmentId,
+  ) async {
+    final results = await _db
         .customSelect(
           '''
-      SELECT COALESCE(SUM(cost), 0) as total
+      SELECT currency, COALESCE(SUM(cost), 0) as total
       FROM service_records
-      WHERE equipment_id = ?
+      WHERE equipment_id = ? AND cost IS NOT NULL
+      GROUP BY currency
     ''',
           variables: [Variable.withString(equipmentId)],
         )
-        .getSingle();
+        .get();
 
-    return (result.data['total'] as num?)?.toDouble() ?? 0.0;
+    return {
+      for (final row in results)
+        (row.data['currency'] as String?) ?? '':
+            (row.data['total'] as num?)?.toDouble() ?? 0.0,
+    };
   }
 
   /// Get service record count for an equipment item

lib/features/equipment/domain/constants/equipment_field.dart

@@ -1,7 +1,7 @@
 import 'package:flutter/material.dart';
-import 'package:intl/intl.dart';
 
 import 'package:submersion/core/constants/enums.dart';
+import 'package:submersion/core/utils/currency.dart';
 import 'package:submersion/core/utils/unit_formatter.dart';
 import 'package:submersion/features/equipment/domain/entities/equipment_item.dart';
 import 'package:submersion/features/equipment/domain/entities/service_clock_status.dart';
@@ -257,7 +257,7 @@ class EquipmentFieldAdapter
       EquipmentField.status => (value as EquipmentStatus).displayName,
       EquipmentField.isActive => (value as bool) ? 'Yes' : 'No',
       EquipmentField.purchaseDate => units.formatDate(value as DateTime),
-      EquipmentField.purchasePrice => _formatPrice(value as double),
+      EquipmentField.purchasePrice => _formatPrice(value as double, units),
       EquipmentField.lastServiceDate => units.formatDate(value as DateTime),
       EquipmentField.nextServiceDue => units.formatDate(value as DateTime),
       EquipmentField.daysUntilService => _formatDaysUntilService(value as int),
@@ -266,8 +266,10 @@ class EquipmentFieldAdapter
     };
   }
 
-  String _formatPrice(double price) {
-    return NumberFormat.currency(symbol: r'$', decimalDigits: 2).format(price);
+  String _formatPrice(double price, UnitFormatter units) {
+    // No per-item currency in this configurable-column context; use the
+    // diver's default currency instead of a hardcoded '$'.
+    return formatMoney(price, units.settings.defaultCurrency);
   }
 
   String _formatDaysUntilService(int days) {