feat: 5197 - first product price page (#5271)

* feat: 5197 - first product price page

New files:
* `emoji_helper.dart`: Generic helper about emoji display.
* `product_price_item.dart`: Single product price widget.
* `product_prices_list.dart`: List of the latest prices for a given product.
* `product_prices_page.dart`: Page that displays the latest prices for a given product.

Impacted files:
* `new_product_page.dart`: now linking to the new `ProductPricesPage` page
* `product_query_page_helper.dart`: added a `bool compact` parameter to the `getDurationString`* methods
* `pubspec.yaml`: upgraded `openfoodfacts` to `3.9.0`
* `pubspec.lock`: wtf

* feat: 5197 - new link to "add a price for that product" in web app

New file:
* `prices_card.dart`: Card that displays buttons related to prices.

Impacted files:
* `app_en.arb`: added 3 "prices" labels
* `app_fr.arb`: added 3 "prices" labels
* `new_product_page.dart`: now using the new "PricesCard" widget
* `product_prices_list.dart`: minor refactoring
* `product_prices_page.dart`: minor refactoring

* feat: 5197 - minor fix

packages/smooth_app/lib/l10n/app_en.arb

@@ -1645,6 +1645,9 @@
     },
     "prices_app_dev_mode_flag": "Shortcut to Prices app on product page",
     "prices_app_button": "Go to Prices app",
+    "prices_generic_title": "Prices",
+    "prices_add_a_price": "Add a price",
+    "prices_view_prices": "View the prices",
     "dev_preferences_import_history_result_success": "Done",
     "@dev_preferences_import_history_result_success": {
         "description": "User dev preferences - Import history - Result successful"

packages/smooth_app/lib/l10n/app_fr.arb

@@ -1623,6 +1623,9 @@
     },
     "prices_app_dev_mode_flag": "Raccourci vers l'application Prix sur la page produit",
     "prices_app_button": "Accéder à l'application Prix",
+    "prices_generic_title": "Prix",
+    "prices_add_a_price": "Ajouter un prix",
+    "prices_view_prices": "Voir les prix",
     "dev_preferences_import_history_result_success": "Fait",
     "@dev_preferences_import_history_result_success": {
         "description": "User dev preferences - Import history - Result successful"

packages/smooth_app/lib/pages/prices/emoji_helper.dart

@@ -0,0 +1,44 @@
+import 'package:openfoodfacts/openfoodfacts.dart';
+
+/// Generic helper about emoji display.
+class EmojiHelper {
+  /// Returns the country flag emoji.
+  ///
+  /// cf. https://emojipedia.org/flag-italy
+  String? getCountryEmoji(final OpenFoodFactsCountry? country) {
+    if (country == null) {
+      return null;
+    }
+    return _getCountryEmojiFromUnicode(country.offTag);
+  }
+
+  static const int _emojiCountryLetterA = 0x1F1E6;
+  static const int _asciiCapitalA = 65;
+  static const int _asciiCapitalZ = 90;
+
+  static String? _getCountryEmojiFromUnicode(final String unicode) {
+    final String? countryLetterEmoji1 = _getCountryLetterEmoji(
+      unicode.substring(0, 1),
+    );
+    if (countryLetterEmoji1 == null) {
+      return null;
+    }
+    //OpenFoodFactsCountry
+    final String? countryLetterEmoji2 = _getCountryLetterEmoji(
+      unicode.substring(1, 2),
+    );
+    if (countryLetterEmoji2 == null) {
+      return null;
+    }
+    return '$countryLetterEmoji1$countryLetterEmoji2';
+  }
+
+  static String? _getCountryLetterEmoji(final String letter) {
+    final int ascii = letter.toUpperCase().codeUnitAt(0);
+    if (ascii < _asciiCapitalA || ascii > _asciiCapitalZ) {
+      return null;
+    }
+    final int code = _emojiCountryLetterA + ascii - _asciiCapitalA;
+    return String.fromCharCode(code);
+  }
+}

packages/smooth_app/lib/pages/prices/prices_card.dart

@@ -0,0 +1,64 @@
+import 'package:flutter/cupertino.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_gen/gen_l10n/app_localizations.dart';
+import 'package:openfoodfacts/openfoodfacts.dart';
+import 'package:smooth_app/generic_lib/buttons/smooth_large_button_with_icon.dart';
+import 'package:smooth_app/generic_lib/design_constants.dart';
+import 'package:smooth_app/helpers/launch_url_helper.dart';
+import 'package:smooth_app/helpers/product_cards_helper.dart';
+import 'package:smooth_app/pages/prices/product_prices_page.dart';
+
+/// Card that displays buttons related to prices.
+class PricesCard extends StatelessWidget {
+  const PricesCard(this.product);
+
+  final Product product;
+
+  @override
+  Widget build(BuildContext context) {
+    final AppLocalizations appLocalizations = AppLocalizations.of(context);
+    return buildProductSmoothCard(
+      body: Container(
+        width: double.infinity,
+        padding: const EdgeInsetsDirectional.all(LARGE_SPACE),
+        child: Column(
+          crossAxisAlignment: CrossAxisAlignment.start,
+          mainAxisAlignment: MainAxisAlignment.start,
+          children: <Widget>[
+            Text(
+              AppLocalizations.of(context).prices_generic_title,
+              style: Theme.of(context).textTheme.displaySmall,
+            ),
+            const SizedBox(height: SMALL_SPACE),
+            Padding(
+              padding: const EdgeInsets.all(SMALL_SPACE),
+              child: SmoothLargeButtonWithIcon(
+                text: appLocalizations.prices_view_prices,
+                icon: CupertinoIcons.tag_fill,
+                onPressed: () async => Navigator.of(context).push(
+                  MaterialPageRoute<void>(
+                    builder: (BuildContext context) =>
+                        ProductPricesPage(product),
+                  ),
+                ),
+              ),
+            ),
+            Padding(
+              padding: const EdgeInsets.all(SMALL_SPACE),
+              child: SmoothLargeButtonWithIcon(
+                text: appLocalizations.prices_add_a_price,
+                icon: Icons.add,
+                onPressed: () async =>
+                    // TODO(monsieurtanuki): link to the local to-be-developed ProductPriceAddPage page
+                    // TODO(monsieurtanuki): make it work for TEST too
+                    LaunchUrlHelper.launchURL(
+                  'https://prices.openfoodfacts.org/app/add/single?code=${product.barcode}',
+                ),
+              ),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+}

packages/smooth_app/lib/pages/prices/product_price_item.dart

@@ -0,0 +1,130 @@
+import 'package:flutter/material.dart';
+import 'package:intl/intl.dart';
+import 'package:openfoodfacts/openfoodfacts.dart';
+import 'package:smooth_app/generic_lib/design_constants.dart';
+import 'package:smooth_app/generic_lib/widgets/smooth_card.dart';
+import 'package:smooth_app/helpers/launch_url_helper.dart';
+import 'package:smooth_app/pages/prices/emoji_helper.dart';
+import 'package:smooth_app/pages/product/common/product_query_page_helper.dart';
+import 'package:smooth_app/query/product_query.dart';
+
+/// Single product price widget.
+class ProductPriceItem extends StatelessWidget {
+  const ProductPriceItem(this.price);
+
+  final Price price;
+
+  @override
+  Widget build(BuildContext context) {
+    final String locale = ProductQuery.getLocaleString();
+    final DateFormat dateFormat = DateFormat.yMd(locale);
+    final DateFormat timeFormat = DateFormat.Hms(locale);
+    final NumberFormat currencyFormat = NumberFormat.simpleCurrency(
+      locale: locale,
+      name: price.currency.name,
+    );
+    final String? locationTitle = _getLocationTitle(price.location);
+    final double? pricePerKg = _getPricePerKg(price);
+    return SmoothCard(
+      child: ListTile(
+        title: Text(
+          '${currencyFormat.format(price.price)}'
+          '${pricePerKg == null ? '' : ' (${currencyFormat.format(pricePerKg)} / kg)'}'
+          '   '
+          '${dateFormat.format(price.date)}',
+        ),
+        subtitle: Wrap(
+          spacing: MEDIUM_SPACE,
+          children: <Widget>[
+            if (locationTitle != null)
+              ElevatedButton.icon(
+                // TODO(monsieurtanuki): open a still-to-be-done "price x location" page
+                onPressed: () {},
+                icon: const Icon(Icons.location_on_outlined),
+                label: Text(locationTitle),
+              ),
+            ElevatedButton.icon(
+              // TODO(monsieurtanuki): open a still-to-be-done "price x user" page
+              onPressed: () {},
+              icon: const Icon(Icons.account_box),
+              label: Text(price.owner),
+            ),
+            Tooltip(
+              message: '${dateFormat.format(price.created)}'
+                  ' '
+                  '${timeFormat.format(price.created)}',
+              child: ElevatedButton.icon(
+                // TODO(monsieurtanuki): misleading "active" button
+                onPressed: () {},
+                icon: const Icon(Icons.history),
+                label: Text(
+                  ProductQueryPageHelper.getDurationStringFromTimestamp(
+                    price.created.millisecondsSinceEpoch,
+                    context,
+                    compact: true,
+                  ),
+                ),
+              ),
+            ),
+            if (price.proof?.filePath != null)
+              ElevatedButton(
+                onPressed: () async => LaunchUrlHelper.launchURL(
+                  // TODO(monsieurtanuki): probably won't work in TEST env
+                  'https://prices.openfoodfacts.org/img/${price.proof?.filePath}',
+                ),
+                child: const Icon(Icons.image),
+              ),
+          ],
+        ),
+      ),
+    );
+  }
+
+  static double? _getPricePerKg(final Price price) {
+    if (price.product == null) {
+      return null;
+    }
+    if (price.product!.quantityUnit != 'g') {
+      return null;
+    }
+    return price.price / (price.product!.quantity! / 1000);
+  }
+
+  static String? _getLocationTitle(final Location? location) {
+    if (location == null) {
+      return null;
+    }
+    final StringBuffer result = StringBuffer();
+    final String? countryEmoji = EmojiHelper().getCountryEmoji(
+      _getCountry(location),
+    );
+    if (location.name != null) {
+      result.write(location.name);
+    }
+    if (location.city != null) {
+      if (result.isNotEmpty) {
+        result.write(', ');
+      }
+      result.write(location.city);
+    }
+    if (countryEmoji != null) {
+      if (result.isNotEmpty) {
+        result.write('  ');
+      }
+      result.write(countryEmoji);
+    }
+    if (result.isEmpty) {
+      return null;
+    }
+    return result.toString();
+  }
+
+  // TODO(monsieurtanuki): enrich the data or find something more elegant
+  static OpenFoodFactsCountry? _getCountry(final Location location) =>
+      switch (location.country) {
+        'France' => OpenFoodFactsCountry.FRANCE,
+        'Italia' => OpenFoodFactsCountry.ITALY,
+        'Monaco' => OpenFoodFactsCountry.MONACO,
+        _ => null,
+      };
+}

packages/smooth_app/lib/pages/prices/product_prices_list.dart

@@ -0,0 +1,95 @@
+import 'package:flutter/material.dart';
+import 'package:openfoodfacts/openfoodfacts.dart';
+import 'package:smooth_app/generic_lib/widgets/smooth_card.dart';
+import 'package:smooth_app/pages/prices/product_price_item.dart';
+import 'package:smooth_app/query/product_query.dart';
+
+/// List of the latest prices for a given product.
+class ProductPricesList extends StatefulWidget {
+  const ProductPricesList(this.barcode);
+
+  final String barcode;
+
+  @override
+  State<ProductPricesList> createState() => _ProductPricesListState();
+}
+
+class _ProductPricesListState extends State<ProductPricesList> {
+  late final Future<MaybeError<GetPricesResult>> _prices =
+      _showProductPrices(widget.barcode);
+
+  static const int _pageSize = 10;
+
+  // TODO(monsieurtanuki): add a refresh gesture
+  // TODO(monsieurtanuki): add a "download the next 10" items
+  // TODO(monsieurtanuki): localize
+  @override
+  Widget build(BuildContext context) =>
+      FutureBuilder<MaybeError<GetPricesResult>>(
+        future: _prices,
+        builder: (
+          final BuildContext context,
+          final AsyncSnapshot<MaybeError<GetPricesResult>> snapshot,
+        ) {
+          if (snapshot.connectionState != ConnectionState.done) {
+            return const CircularProgressIndicator();
+          }
+          if (snapshot.hasError) {
+            return Text(snapshot.error!.toString());
+          }
+          // highly improbable
+          if (!snapshot.hasData) {
+            return const Text('no data');
+          }
+          if (snapshot.data!.isError) {
+            return Text(snapshot.data!.error!);
+          }
+          final GetPricesResult result = snapshot.data!.value;
+          // highly improbable
+          if (result.items == null) {
+            return const Text('empty list');
+          }
+          final List<Widget> children = <Widget>[];
+          for (final Price price in result.items!) {
+            children.add(ProductPriceItem(price));
+          }
+          final String title;
+          if (children.isEmpty) {
+            title = 'No price for that product yet!';
+          } else if (result.total == 1) {
+            title = 'Only one price found for that product.';
+          } else if (result.numberOfPages == 1) {
+            title = 'All ${result.total} prices for that product';
+          } else {
+            title =
+                'Latest $_pageSize prices for that product (total: ${result.total})';
+          }
+          children.insert(
+            0,
+            SmoothCard(child: ListTile(title: Text(title))),
+          );
+          return ListView(
+            children: children,
+          );
+        },
+      );
+
+  static Future<MaybeError<GetPricesResult>> _showProductPrices(
+    final String barcode, {
+    final int pageSize = _pageSize,
+    final int pageNumber = 1,
+  }) async =>
+      OpenPricesAPIClient.getPrices(
+        GetPricesParameters()
+          ..productCode = barcode
+          ..orderBy = <OrderBy<GetPricesOrderField>>[
+            const OrderBy<GetPricesOrderField>(
+              field: GetPricesOrderField.created,
+              ascending: false,
+            ),
+          ]
+          ..pageSize = pageSize
+          ..pageNumber = pageNumber,
+        uriHelper: ProductQuery.uriProductHelper,
+      );
+}