feat(tank-presets): hide individual built-in tank presets from the pickers

lib/core/database/database.dart

@@ -2178,6 +2178,10 @@ class DiverSettings extends Table {
   // manual region override (ISO country code).
   TextColumn get hiddenChamberIds => text().nullable()();
   TextColumn get emergencyRegion => text().nullable()();
+
+  /// v227: built-in tank presets the diver hid from the pickers (issue
+  /// #2305), JSON list of preset slugs. Null or absent = none hidden.
+  TextColumn get hiddenTankPresetIds => text().nullable()();
   // Appearance settings
   BoolColumn get showDepthColoredDiveCards =>
       boolean().withDefault(const Constant(false))();
@@ -4295,7 +4299,7 @@ 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 = 226;
+  static const int currentSchemaVersion = 227;
 
   /// The oldest schema whose reader can apply this build's sync payloads
   /// without loss or misinterpretation (the compatibility floor).
@@ -4951,6 +4955,11 @@ class AppDatabase extends _$AppDatabase {
     // sync, not here. Additive and nullable, so the floor stays at 224.
     // 225 is held by PR #1978 (tissue loading import).
     226,
+    // v227: diver_settings.hidden_tank_preset_ids (issue #2305). Additive
+    // nullable column, no backfill. The floor stays: an older reader simply
+    // shows every built-in preset. Renumbered from 225, which is held by PR
+    // #1978, after v226 landed while this was in review.
+    227,
   ];
 
   /// Idempotent DDL for the v106 connector-suggestion columns (Lightroom
@@ -6442,6 +6451,23 @@ class AppDatabase extends _$AppDatabase {
     }
   }
 
+  /// v227: diver_settings.hidden_tank_preset_ids (issue #2305). Additive
+  /// column, default null, so every built-in preset stays visible until the
+  /// diver hides one. Idempotent, so it is safe to call from both onUpgrade
+  /// and the beforeOpen backstop.
+  Future<void> _assertHiddenTankPresetIdsColumn() 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('hidden_tank_preset_ids')) {
+      await customStatement(
+        'ALTER TABLE diver_settings ADD COLUMN hidden_tank_preset_ids TEXT',
+      );
+    }
+  }
+
   /// v223: buddies.linked_diver_id and dives.outing_id (issue #2002).
   /// Idempotent, so it is safe from both onUpgrade and the beforeOpen
   /// backstop, and a no-op for either table when it does not exist yet.
@@ -12547,8 +12573,17 @@ class AppDatabase extends _$AppDatabase {
           await _assertMediaCloudAssetIdColumn();
         }
         if (from < 226) await reportProgress();
+        // v227: diver_settings.hidden_tank_preset_ids (issue #2305).
+        // Column-only rung, no backfill: null reads back as "none hidden".
+        if (from < 227) {
+          await _assertHiddenTankPresetIdsColumn();
+        }
+        if (from < 227) await reportProgress();
       },
       beforeOpen: (details) async {
+        // v227 backstop: the hidden built-in tank presets.
+        await _assertHiddenTankPresetIdsColumn();
+
         // v222 backstop: the per-site vertical exaggeration overrides.
         await _assertSeascapeVerticalExaggerationOverridesColumn();
 

lib/features/dive_log/presentation/widgets/tank_editor.dart

@@ -14,6 +14,7 @@ import 'package:submersion/core/utils/number_input.dart';
 import 'package:submersion/core/utils/unit_formatter.dart';
 import 'package:submersion/features/settings/presentation/providers/settings_providers.dart';
 import 'package:submersion/features/tank_presets/domain/entities/tank_preset_entity.dart';
+import 'package:submersion/features/tank_presets/domain/services/tank_preset_visibility.dart';
 import 'package:submersion/features/tank_presets/presentation/providers/tank_preset_providers.dart';
 import 'package:submersion/features/dive_log/domain/entities/dive.dart';
 import 'package:submersion/features/dive_log/presentation/widgets/tank_enum_display.dart';
@@ -472,17 +473,23 @@ class _TankEditorState extends ConsumerState<TankEditor> {
         // Tank preset dropdown
         Expanded(
           child: presetsAsync.when(
+            // A reload (a synced settings change, a preset edit) keeps the
+            // dropdown in place instead of swapping it for a progress bar.
+            skipLoadingOnReload: true,
             loading: () => const LinearProgressIndicator(),
             error: (e, st) => Text('Error: $e'),
-            data: (presets) {
+            data: (visiblePresets) {
+              final presetName =
+                  _selectedPreset?.name ?? widget.tank.presetName;
+              // A tank logged with a preset the diver has since hidden keeps
+              // showing it (issue #2305).
+              final presets = withKeptTankPresets(visiblePresets, [presetName]);
               final customPresets = presets.where((p) => !p.isBuiltIn).toList();
               final builtInPresets = presets.where((p) => p.isBuiltIn).toList();
 
               // Find the matching preset from the loaded list to ensure object equality
               // This is necessary because DropdownButtonFormField requires the value
               // to be the exact same instance as one of the items
-              final presetName =
-                  _selectedPreset?.name ?? widget.tank.presetName;
               final matchingPreset = presetName != null
                   ? presets.where((p) => p.name == presetName).firstOrNull
                   : null;

lib/features/settings/data/repositories/diver_settings_repository.dart

@@ -139,6 +139,9 @@ class DiverSettingsRepository {
               ),
               hiddenChamberIds: Value(_encodeDisabledRules(s.hiddenChamberIds)),
               emergencyRegion: Value(s.emergencyRegion),
+              hiddenTankPresetIds: Value(
+                _encodeDisabledRules(s.hiddenTankPresetIds),
+              ),
               showAscentRateColors: Value(s.showAscentRateColors),
               showNdlOnProfile: Value(s.showNdlOnProfile),
               lastStopDepth: Value(s.lastStopDepth),
@@ -329,6 +332,9 @@ class DiverSettingsRepository {
             _encodeDisabledRules(settings.hiddenChamberIds),
           ),
           emergencyRegion: Value(settings.emergencyRegion),
+          hiddenTankPresetIds: Value(
+            _encodeDisabledRules(settings.hiddenTankPresetIds),
+          ),
           showAscentRateColors: Value(settings.showAscentRateColors),
           showNdlOnProfile: Value(settings.showNdlOnProfile),
           lastStopDepth: Value(settings.lastStopDepth),
@@ -561,6 +567,7 @@ class DiverSettingsRepository {
       conditionDisabledRules: _decodeDisabledRules(row.conditionDisabledRules),
       hiddenChamberIds: _decodeDisabledRules(row.hiddenChamberIds),
       emergencyRegion: row.emergencyRegion,
+      hiddenTankPresetIds: _decodeDisabledRules(row.hiddenTankPresetIds),
       showAscentRateColors: row.showAscentRateColors,
       showNdlOnProfile: row.showNdlOnProfile,
       lastStopDepth: row.lastStopDepth,

lib/features/settings/presentation/providers/settings_providers.dart

@@ -205,6 +205,10 @@ class AppSettings {
   final String? defaultTankPreset;
   final bool applyDefaultTankToImports;
 
+  /// Built-in tank preset slugs hidden from the pickers (issue #2305). The
+  /// Tank Presets page still lists them, import matching still uses them.
+  final Set<String> hiddenTankPresetIds;
+
   // Decompression & Safety settings
   /// Gradient Factor Low (0-100, typically 30)
   final int gfLow;
@@ -573,6 +577,7 @@ class AppSettings {
     this.defaultStartPressure = 200,
     this.defaultTankPreset = 'al80',
     this.applyDefaultTankToImports = false,
+    this.hiddenTankPresetIds = const {},
     // Decompression defaults
     this.gfLow = 50,
     this.gfHigh = 85,
@@ -752,6 +757,7 @@ class AppSettings {
     String? defaultTankPreset,
     bool clearDefaultTankPreset = false,
     bool? applyDefaultTankToImports,
+    Set<String>? hiddenTankPresetIds,
     int? gfLow,
     int? gfHigh,
     double? ppO2MaxWorking,
@@ -903,6 +909,7 @@ class AppSettings {
           : (defaultTankPreset ?? this.defaultTankPreset),
       applyDefaultTankToImports:
           applyDefaultTankToImports ?? this.applyDefaultTankToImports,
+      hiddenTankPresetIds: hiddenTankPresetIds ?? this.hiddenTankPresetIds,
       gfLow: gfLow ?? this.gfLow,
       gfHigh: gfHigh ?? this.gfHigh,
       ppO2MaxWorking: ppO2MaxWorking ?? this.ppO2MaxWorking,
@@ -1531,14 +1538,43 @@ class SettingsNotifier extends StateNotifier<AppSettings> {
     await _saveSettings();
   }
 
+  /// Also shows [presetName] again if it was hidden: the default preset is
+  /// always offered in the pickers (issue #2305). The outgoing default is
+  /// dropped from the hidden set too, since a stale entry for it (a synced
+  /// row can carry one) would otherwise hide it the moment it stops being
+  /// the default, without the diver ever having switched it off.
   Future<void> setDefaultTankPreset(String? presetName) async {
+    final hidden = state.hiddenTankPresetIds;
+    final previous = state.defaultTankPreset;
+    final touchesHidden =
+        hidden.contains(presetName) || hidden.contains(previous);
     state = state.copyWith(
       defaultTankPreset: presetName,
       clearDefaultTankPreset: presetName == null,
+      hiddenTankPresetIds: touchesHidden
+          ? {
+              for (final name in hidden)
+                if (name != presetName && name != previous) name,
+            }
+          : null,
     );
     await _saveSettings();
   }
 
+  /// Hides or shows a built-in tank preset in the pickers (issue #2305).
+  /// The current default preset cannot be hidden, so hiding it is a no-op.
+  Future<void> setTankPresetHidden(String presetName, bool hidden) async {
+    if (hidden && presetName == state.defaultTankPreset) return;
+    final ids = {...state.hiddenTankPresetIds};
+    if (hidden) {
+      ids.add(presetName);
+    } else {
+      ids.remove(presetName);
+    }
+    state = state.copyWith(hiddenTankPresetIds: ids);
+    await _saveSettings();
+  }
+
   Future<void> setApplyDefaultTankToImports(bool value) async {
     state = state.copyWith(applyDefaultTankToImports: value);
     await _saveSettings();

lib/features/tank_presets/domain/services/tank_preset_visibility.dart

@@ -0,0 +1,65 @@
+import 'package:submersion/core/constants/tank_presets.dart';
+import 'package:submersion/features/tank_presets/domain/entities/tank_preset_entity.dart';
+
+// Which tank presets the diver's pickers offer (issue #2305).
+//
+// A diver can hide built-in presets they never use. Hiding only narrows the
+// pickers: import matching and default resolution keep reading the full
+// catalog, and the Tank Presets settings page keeps listing everything so a
+// hidden preset can be shown again.
+
+/// [all] without the built-in presets named in [hidden].
+///
+/// Custom presets are never hidden, even when one shares a built-in slug.
+/// The [defaultPresetName] always stays, so a default that ended up in the
+/// hidden set (the settings page never allows that, but a synced row could
+/// carry it) is still offered where it is applied.
+List<TankPresetEntity> visibleTankPresets(
+  List<TankPresetEntity> all,
+  Set<String> hidden, {
+  String? defaultPresetName,
+}) {
+  if (hidden.isEmpty) return all;
+  return [
+    for (final preset in all)
+      if (!preset.isBuiltIn ||
+          preset.name == defaultPresetName ||
+          !hidden.contains(preset.name))
+        preset,
+  ];
+}
+
+/// [visible] plus any hidden built-in preset named in [keep], so a picker
+/// whose current value is a hidden preset still shows that value.
+///
+/// Restored presets go back to their catalog position among the built-in
+/// ones, custom presets stay first, and every preset already in [visible]
+/// keeps its instance. Returns [visible] itself when nothing is missing.
+List<TankPresetEntity> withKeptTankPresets(
+  List<TankPresetEntity> visible,
+  Iterable<String?> keep,
+) {
+  final present = {for (final preset in visible) preset.name};
+  final missing = {
+    for (final name in keep)
+      if (name != null &&
+          !present.contains(name) &&
+          TankPresets.byName(name) != null)
+        name,
+  };
+  if (missing.isEmpty) return visible;
+
+  final builtInByName = {
+    for (final preset in visible)
+      if (preset.isBuiltIn) preset.name: preset,
+  };
+  return [
+    for (final preset in visible)
+      if (!preset.isBuiltIn) preset,
+    for (final builtIn in TankPresets.all)
+      if (builtInByName[builtIn.name] case final existing?)
+        existing
+      else if (missing.contains(builtIn.name))
+        TankPresetEntity.fromBuiltIn(builtIn),
+  ];
+}

lib/features/tank_presets/presentation/pages/tank_presets_page.dart

@@ -98,6 +98,15 @@ class TankPresetsPage extends ConsumerWidget {
                 context,
                 context.l10n.tankPresets_builtInPresets,
               ),
+              Padding(
+                padding: const EdgeInsets.fromLTRB(16, 0, 16, 8),
+                child: Text(
+                  context.l10n.tankPresets_builtInPresets_description,
+                  style: Theme.of(context).textTheme.bodyMedium?.copyWith(
+                    color: Theme.of(context).colorScheme.onSurfaceVariant,
+                  ),
+                ),
+              ),
               ...builtInPresets.map(
                 (preset) => _buildPresetTile(
                   context,
@@ -106,6 +115,9 @@ class TankPresetsPage extends ConsumerWidget {
                   units,
                   canEdit: false,
                   isDefault: settings.defaultTankPreset == preset.name,
+                  isHidden:
+                      settings.defaultTankPreset != preset.name &&
+                      settings.hiddenTankPresetIds.contains(preset.name),
                 ),
               ),
             ],
@@ -134,6 +146,7 @@ class TankPresetsPage extends ConsumerWidget {
     UnitFormatter units, {
     required bool canEdit,
     required bool isDefault,
+    bool isHidden = false,
   }) {
     final volumeStr = units.formatTankVolume(
       preset.volumeLiters,
@@ -146,9 +159,15 @@ class TankPresetsPage extends ConsumerWidget {
     );
 
     return ListTile(
+      // A hidden built-in preset stays listed so it can be shown again, and
+      // only its text and icon are dimmed: the tile is not disabled, since
+      // its star and switch stay usable.
+      textColor: isHidden ? Theme.of(context).disabledColor : null,
       leading: Icon(
         MdiIcons.divingScubaTank,
-        color: canEdit
+        color: isHidden
+            ? Theme.of(context).disabledColor
+            : canEdit
             ? Theme.of(context).colorScheme.secondary
             : Theme.of(context).colorScheme.primary,
       ),
@@ -182,6 +201,26 @@ class TankPresetsPage extends ConsumerWidget {
                 ? context.l10n.tankPresets_currentDefault
                 : context.l10n.tankPresets_setAsDefault,
           ),
+          // Built-in presets can be hidden from the pickers (issue #2305),
+          // except the default one. Its switch keeps its space so the stars
+          // stay aligned down the list.
+          if (!canEdit)
+            Visibility(
+              visible: !isDefault,
+              maintainSize: true,
+              maintainAnimation: true,
+              maintainState: true,
+              child: Tooltip(
+                message: context.l10n.tankPresets_showInPickers,
+                child: Switch(
+                  key: ValueKey('tank-preset-visible-${preset.name}'),
+                  value: !isHidden,
+                  onChanged: (visible) => ref
+                      .read(settingsProvider.notifier)
+                      .setTankPresetHidden(preset.name, !visible),
+                ),
+              ),
+            ),
           if (canEdit) ...[
             IconButton(
               icon: const Icon(Icons.edit_outlined),