feat: show when order book filters are active

lib/features/home/providers/home_order_providers.dart

@@ -7,12 +7,64 @@ import 'package:mostro_mobile/shared/providers/order_repository_provider.dart';
 
 final homeOrderTypeProvider = StateProvider((ref) => OrderType.sell);
 
+// Default values for the order book filters. A filter is considered active
+// only when its state differs from these defaults.
+const double kDefaultRatingMin = 0.0;
+const double kDefaultRatingMax = 5.0;
+const double kDefaultPremiumMin = -10.0;
+const double kDefaultPremiumMax = 10.0;
+const int kDefaultMinDays = 0;
+
 // Filter state providers
 final currencyFilterProvider = StateProvider<List<String>>((ref) => []);
 final paymentMethodFilterProvider = StateProvider<List<String>>((ref) => []);
-final ratingFilterProvider = StateProvider<({double min, double max})>((ref) => (min: 0.0, max: 5.0));
-final premiumRangeFilterProvider = StateProvider<({double min, double max})>((ref) => (min: -10.0, max: 10.0));
-final minDaysFilterProvider = StateProvider<int>((ref) => 0);
+final ratingFilterProvider = StateProvider<({double min, double max})>(
+    (ref) => (min: kDefaultRatingMin, max: kDefaultRatingMax));
+final premiumRangeFilterProvider = StateProvider<({double min, double max})>(
+    (ref) => (min: kDefaultPremiumMin, max: kDefaultPremiumMax));
+final minDaysFilterProvider = StateProvider<int>((ref) => kDefaultMinDays);
+
+/// Single definition of "this filter is active", so the count shown in the UI
+/// can never disagree with the filtering actually applied.
+bool _isMinDaysActive(int minDays) => minDays > kDefaultMinDays;
+
+bool _isRatingActive(({double min, double max}) range) =>
+    range.min > kDefaultRatingMin || range.max < kDefaultRatingMax;
+
+bool _isPremiumActive(({double min, double max}) range) =>
+    range.min > kDefaultPremiumMin || range.max < kDefaultPremiumMax;
+
+/// Number of filters that currently differ from their default value.
+final activeFilterCountProvider = Provider<int>((ref) {
+  final selectedCurrencies = ref.watch(currencyFilterProvider);
+  final selectedPaymentMethods = ref.watch(paymentMethodFilterProvider);
+  final ratingRange = ref.watch(ratingFilterProvider);
+  final premiumRange = ref.watch(premiumRangeFilterProvider);
+  final minDays = ref.watch(minDaysFilterProvider);
+
+  var count = 0;
+  if (selectedCurrencies.isNotEmpty) count++;
+  if (selectedPaymentMethods.isNotEmpty) count++;
+  if (_isMinDaysActive(minDays)) count++;
+  if (_isRatingActive(ratingRange)) count++;
+  if (_isPremiumActive(premiumRange)) count++;
+  return count;
+});
+
+/// Signature shared by `WidgetRef.read` and `ProviderContainer.read`, so
+/// [clearAllOrderFilters] can be called from widgets and from tests alike.
+typedef ProviderReader = T Function<T>(ProviderListenable<T> provider);
+
+/// Resets every order book filter to its default value.
+void clearAllOrderFilters(ProviderReader read) {
+  read(currencyFilterProvider.notifier).state = [];
+  read(paymentMethodFilterProvider.notifier).state = [];
+  read(ratingFilterProvider.notifier).state =
+      (min: kDefaultRatingMin, max: kDefaultRatingMax);
+  read(premiumRangeFilterProvider.notifier).state =
+      (min: kDefaultPremiumMin, max: kDefaultPremiumMax);
+  read(minDaysFilterProvider.notifier).state = kDefaultMinDays;
+}
 
 final filteredOrdersProvider = Provider<List<NostrEvent>>((ref) {
   final allOrdersAsync = ref.watch(orderEventsProvider);
@@ -56,12 +108,12 @@ final filteredOrdersProvider = Provider<List<NostrEvent>>((ref) {
       }
 
       // Apply minimum days filter (maker's account age as reported in rating.days)
-      if (minDays > 0) {
+      if (_isMinDaysActive(minDays)) {
         filtered = filtered.where((o) => (o.rating?.days ?? 0) >= minDays);
       }
 
       // Apply rating filter
-      if (ratingRange.min > 0.0 || ratingRange.max < 5.0) {
+      if (_isRatingActive(ratingRange)) {
         filtered = filtered.where((o) => 
           o.rating != null && 
           o.rating!.totalRating >= ratingRange.min &&
@@ -70,7 +122,7 @@ final filteredOrdersProvider = Provider<List<NostrEvent>>((ref) {
       }
 
       // Apply premium/discount filter
-      if (premiumRange.min > -10.0 || premiumRange.max < 10.0) {
+      if (_isPremiumActive(premiumRange)) {
         filtered = filtered.where((o) {
           if (o.premium == null || o.premium!.isEmpty) return false;
           final premiumValue = double.tryParse(o.premium!) ?? 0.0;

lib/features/home/screens/home_screen.dart

@@ -197,6 +197,16 @@ class HomeScreen extends ConsumerWidget {
 
   Widget _buildFilterButton(BuildContext context, WidgetRef ref) {
     final filteredOrders = ref.watch(filteredOrdersProvider);
+    final activeFilterCount = ref.watch(activeFilterCountProvider);
+    final hasFilters = activeFilterCount > 0;
+
+    // When filters are active the pill is highlighted so the user can tell at a
+    // glance that the offers list is being narrowed down.
+    final foregroundColor =
+        hasFilters ? AppTheme.mostroGreen : Colors.white70;
+    final dividerColor = hasFilters
+        ? AppTheme.mostroGreen.withValues(alpha: 0.4)
+        : Colors.white.withValues(alpha: 0.2);
 
     return Container(
       padding: const EdgeInsets.symmetric(vertical: 16, horizontal: 16),
@@ -205,9 +215,15 @@ class HomeScreen extends ConsumerWidget {
         alignment: Alignment.centerLeft,
         child: Container(
           decoration: BoxDecoration(
-            color: AppTheme.backgroundInput,
+            color: hasFilters
+                ? AppTheme.mostroGreen.withValues(alpha: 0.12)
+                : AppTheme.backgroundInput,
             borderRadius: BorderRadius.circular(30),
-            border: Border.all(color: Colors.white.withValues(alpha: 0.05)),
+            border: Border.all(
+              color: hasFilters
+                  ? AppTheme.mostroGreen.withValues(alpha: 0.6)
+                  : Colors.white.withValues(alpha: 0.05),
+            ),
             boxShadow: [
               BoxShadow(
                 color: Colors.black.withValues(alpha: 0.2),
@@ -219,65 +235,131 @@ class HomeScreen extends ConsumerWidget {
           child: Material(
             color: Colors.transparent,
             borderRadius: BorderRadius.circular(30),
-            child: InkWell(
-              onTap: () {
-                showDialog<void>(
-                  context: context,
-                  builder: (BuildContext context) {
-                    return const Dialog(
-                      child: OrderFilter(),
+            child: Row(
+              mainAxisSize: MainAxisSize.min,
+              children: [
+                InkWell(
+                  onTap: () {
+                    showDialog<void>(
+                      context: context,
+                      builder: (BuildContext context) {
+                        return const Dialog(
+                          child: OrderFilter(),
+                        );
+                      },
                     );
                   },
-                );
-              },
-              borderRadius: BorderRadius.circular(30),
-              splashColor: AppTheme.activeColor.withValues(alpha: 0.3),
-              highlightColor: AppTheme.activeColor.withValues(alpha: 0.15),
-              child: Padding(
-                padding:
-                    const EdgeInsets.symmetric(horizontal: 16, vertical: 12),
-                child: Row(
-                  mainAxisSize: MainAxisSize.min,
-                  children: [
-                    const HeroIcon(
-                      HeroIcons.funnel,
-                      style: HeroIconStyle.outline,
-                      color: Colors.white70,
-                      size: 18,
-                    ),
-                    const SizedBox(width: 8),
-                    Text(
-                      S.of(context)!.filter,
-                      style: const TextStyle(
-                        color: Colors.white70,
-                        fontSize: 13,
-                        fontWeight: FontWeight.w500,
-                        letterSpacing: 0.5,
-                      ),
+                  borderRadius: BorderRadius.circular(30),
+                  splashColor: AppTheme.activeColor.withValues(alpha: 0.3),
+                  highlightColor: AppTheme.activeColor.withValues(alpha: 0.15),
+                  child: Padding(
+                    padding: EdgeInsets.only(
+                      left: 16,
+                      right: hasFilters ? 8 : 16,
+                      top: 12,
+                      bottom: 12,
                     ),
-                    Container(
-                      margin: const EdgeInsets.symmetric(horizontal: 8),
-                      height: 16,
-                      width: 1,
-                      color: Colors.white.withValues(alpha: 0.2),
-                    ),
-                    Text(
-                      S
-                          .of(context)!
-                          .offersCount(filteredOrders.length.toString()),
-                      style: const TextStyle(
-                        color: Colors.grey,
-                        fontSize: 12,
-                        fontWeight: FontWeight.normal,
-                      ),
+                    child: Row(
+                      mainAxisSize: MainAxisSize.min,
+                      children: [
+                        HeroIcon(
+                          HeroIcons.funnel,
+                          style: hasFilters
+                              ? HeroIconStyle.solid
+                              : HeroIconStyle.outline,
+                          color: foregroundColor,
+                          size: 18,
+                        ),
+                        const SizedBox(width: 8),
+                        Text(
+                          hasFilters
+                              ? S
+                                  .of(context)!
+                                  .filterWithCount(activeFilterCount.toString())
+                              : S.of(context)!.filter,
+                          style: TextStyle(
+                            color: foregroundColor,
+                            fontSize: 13,
+                            fontWeight:
+                                hasFilters ? FontWeight.w600 : FontWeight.w500,
+                            letterSpacing: 0.5,
+                          ),
+                        ),
+                        Container(
+                          margin: const EdgeInsets.symmetric(horizontal: 8),
+                          height: 16,
+                          width: 1,
+                          color: dividerColor,
+                        ),
+                        Text(
+                          S
+                              .of(context)!
+                              .offersCount(filteredOrders.length.toString()),
+                          style: const TextStyle(
+                            color: Colors.grey,
+                            fontSize: 12,
+                            fontWeight: FontWeight.normal,
+                          ),
+                        ),
+                      ],
                     ),
-                  ],
+                  ),
                 ),
-              ),
+                if (hasFilters)
+                  _buildClearFiltersButton(context, ref, dividerColor),
+              ],
             ),
           ),
         ),
       ),
     );
   }
+
+  /// Quick "clear all filters" action shown inside the filter pill.
+  ///
+  /// It sits outside the pill's main [InkWell] so tapping it resets the filters
+  /// without also opening the filter dialog.
+  Widget _buildClearFiltersButton(
+    BuildContext context,
+    WidgetRef ref,
+    Color dividerColor,
+  ) {
+    final label = S.of(context)!.clearFilters;
+
+    return Row(
+      mainAxisSize: MainAxisSize.min,
+      children: [
+        Container(
+          height: 16,
+          width: 1,
+          color: dividerColor,
+        ),
+        Semantics(
+          button: true,
+          label: label,
+          child: Tooltip(
+            message: label,
+            child: InkWell(
+              onTap: () => clearAllOrderFilters(ref.read),
+              borderRadius: BorderRadius.circular(30),
+              splashColor: AppTheme.mostroGreen.withValues(alpha: 0.3),
+              highlightColor: AppTheme.mostroGreen.withValues(alpha: 0.15),
+              child: const SizedBox(
+                width: 40,
+                height: 40,
+                child: Center(
+                  child: HeroIcon(
+                    HeroIcons.xMark,
+                    style: HeroIconStyle.outline,
+                    color: AppTheme.mostroGreen,
+                    size: 16,
+                  ),
+                ),
+              ),
+            ),
+          ),
+        ),
+      ],
+    );
+  }
 }

lib/l10n/intl_de.arb

@@ -217,6 +217,15 @@
             }
         }
     },
+    "filterWithCount": "FILTER ({count})",
+    "@filterWithCount": {
+        "placeholders": {
+            "count": {
+                "type": "String"
+            }
+        }
+    },
+    "clearFilters": "Filter zurücksetzen",
     "creatingNewOrder": "NEUE ORDER ERSTELLEN",
     "enterSatsAmountBuy": "Gib den Sats-Betrag ein, den du kaufen möchtest",
     "enterSatsAmountSell": "Gib den Sats-Betrag ein, den du verkaufen möchtest",

lib/l10n/intl_en.arb

@@ -217,6 +217,15 @@
             }
         }
     },
+    "filterWithCount": "FILTER ({count})",
+    "@filterWithCount": {
+        "placeholders": {
+            "count": {
+                "type": "String"
+            }
+        }
+    },
+    "clearFilters": "Clear filters",
     "creatingNewOrder": "CREATING NEW ORDER",
     "enterSatsAmountBuy": "Enter the Sats amount you want to Buy",
     "enterSatsAmountSell": "Enter the Sats amount you want to Sell",

lib/l10n/intl_es.arb

@@ -181,6 +181,15 @@
             }
         }
     },
+    "filterWithCount": "FILTRO ({count})",
+    "@filterWithCount": {
+        "placeholders": {
+            "count": {
+                "type": "String"
+            }
+        }
+    },
+    "clearFilters": "Limpiar filtros",
     "creatingNewOrder": "CREANDO NUEVA ORDEN",
     "enterSatsAmountBuy": "Ingresa la cantidad de Sats que quieres Comprar",
     "enterSatsAmountSell": "Ingresa la cantidad de Sats que quieres Vender",

lib/l10n/intl_fr.arb

@@ -217,6 +217,15 @@
             }
         }
     },
+    "filterWithCount": "FILTRE ({count})",
+    "@filterWithCount": {
+        "placeholders": {
+            "count": {
+                "type": "String"
+            }
+        }
+    },
+    "clearFilters": "Effacer les filtres",
     "creatingNewOrder": "CRÉATION D'UNE NOUVELLE COMMANDE",
     "enterSatsAmountBuy": "Entrez le montant de Sats que vous voulez acheter",
     "enterSatsAmountSell": "Entrez le montant de Sats que vous voulez vendre",

lib/l10n/intl_it.arb

@@ -216,6 +216,15 @@
             }
         }
     },
+    "filterWithCount": "FILTRO ({count})",
+    "@filterWithCount": {
+        "placeholders": {
+            "count": {
+                "type": "String"
+            }
+        }
+    },
+    "clearFilters": "Rimuovi filtri",
     "creatingNewOrder": "CREAZIONE NUOVO ORDINE",
     "enterSatsAmountBuy": "Inserisci la quantità di Sats che vuoi Comprare",
     "enterSatsAmountSell": "Inserisci la quantità di Sats che vuoi Vendere",