mark as read gesture

lib/api/api.dart

@@ -48,7 +48,8 @@ class FeverAPI {
   /// Checks whether the given API URL is a valid Fever API endpoint and the given API key is authorized to access it
   static Future<bool> isAuthenticated(String url, String key) async {
     try {
-      final response = jsonDecode((await http.post(Uri.parse(url), body: { 'api_key': key })).body);
+      final response = jsonDecode(
+          (await http.post(Uri.parse(url), body: {'api_key': key})).body);
       return response['api_version'] == 3 && response['auth'] == 1;
     } catch (e) {
       print(e);
@@ -71,6 +72,8 @@ class APIRequestBuilder {
   final http.Client _httpClient;
 
   List<String> args = [];
+  Item? _markedItem;
+  ItemMarkType? _markedItemAs;
 
   APIRequestBuilder(this.api, this._httpClient);
 
@@ -100,11 +103,23 @@ class APIRequestBuilder {
     return this;
   }
 
+  APIRequestBuilder markItem(Item item, ItemMarkType markAs) {
+    _addArg('mark=item');
+    _addArg('as=${markAs.name}');
+    _addArg('id=${item.id}');
+    _markedItem = item;
+    _markedItemAs = markAs;
+    return this;
+  }
+
   /// Executes the API request and returns the JSON data
   Future<Map<String, dynamic>> fetch() async {
-    if (api.apiKey == null || api.apiUrl == null) throw Exception('API Key or API URL not set');
+    if (api.apiKey == null || api.apiUrl == null) {
+      throw Exception('API Key or API URL not set');
+    }
 
-    final response = await _httpClient.post(generateUrl(), body: { 'api_key': api.apiKey });
+    final response =
+        await _httpClient.post(generateUrl(), body: {'api_key': api.apiKey});
     final data = jsonDecode((response).body);
     if (data['auth'] == 0) throw UnauthenticatedException(data['auth']);
     return data;
@@ -152,5 +167,30 @@ class APIRequestBuilder {
       api.cache.feedsGroups.clear();
       api.cache.feedsGroups.addAll(feedsGroups);
     }
+
+    if (_markedItem != null && _markedItemAs != null) {
+      switch (_markedItemAs!) {
+        case ItemMarkType.read:
+          _markedItem!.isRead = true;
+          break;
+        case ItemMarkType.unread:
+          _markedItem!.isRead = false;
+          break;
+        case ItemMarkType.saved:
+          _markedItem!.isSaved = true;
+          break;
+        case ItemMarkType.unsaved:
+          _markedItem!.isSaved = false;
+          break;
+      }
+      api.cache.items.set(_markedItem!.id, _markedItem!);
     }
   }
+}
+
+enum ItemMarkType {
+  read,
+  unread,
+  saved,
+  unsaved,
+}

lib/widgets/homepage_post.dart

@@ -7,12 +7,18 @@ String formatDate(DateTime date) {
   return '${date.day}.${date.month}.${date.year}, ${date.hour}:${date.minute < 10 ? '0${date.minute}' : date.minute}';
 }
 
-class HomepagePost extends StatelessWidget {
+class HomepagePost extends StatefulWidget {
   final Item post;
   const HomepagePost({super.key, required this.post});
 
+  @override
+  State<StatefulWidget> createState() => _HomepagePostState();
+}
+
+class _HomepagePostState extends State<HomepagePost> {
   @override
   Widget build(BuildContext context) {
+    var post = widget.post;
     return Container(
       margin: const EdgeInsets.symmetric(vertical: 6.0, horizontal: 8.0),
       decoration: BoxDecoration(
@@ -27,9 +33,29 @@ class HomepagePost extends StatelessWidget {
       child: InkWell(
           onTap: () {
             Navigator.of(context).push(
-              MaterialPageRoute(builder: (context) => ArticlePage(article: post)),
+              MaterialPageRoute(
+                  builder: (context) => ArticlePage(article: post)),
             );
           },
+          onLongPress: () async {
+            var theme = Theme.of(context);
+            ScaffoldMessenger.of(context).showSnackBar(
+              SnackBar(
+                content: Text(
+                  'Marking post as ${post.isRead ? 'Unread' : 'Read'}',
+                  style: TextStyle(color: theme.colorScheme.onBackground)
+                ),
+                duration: const Duration(seconds: 2),
+                backgroundColor: theme.colorScheme.secondaryContainer,
+              ),
+            );
+            await post.api
+                .request()
+                .markItem(
+                    post, post.isRead ? ItemMarkType.unread : ItemMarkType.read)
+                .execute();
+            setState(() {});
+          },
           borderRadius: const BorderRadius.all(Radius.circular(15)),
           child: Container(
             margin: const EdgeInsets.all(8.0),