Add new friends system, and sharing legs support

lib/components/widgets/friend_request_notification_card.dart

@@ -0,0 +1,127 @@
+import 'package:flutter/material.dart';
+import 'package:mileograph_flutter/objects/objects.dart';
+import 'package:mileograph_flutter/services/data_service.dart';
+import 'package:provider/provider.dart';
+
+class FriendRequestNotificationCard extends StatelessWidget {
+  const FriendRequestNotificationCard({super.key, required this.notification});
+
+  final UserNotification notification;
+
+  @override
+  Widget build(BuildContext context) {
+    final data = context.read<DataService>();
+    final friendshipId = notification.body.trim();
+    if (friendshipId.isEmpty) {
+      return const Text('Invalid friend request notification.');
+    }
+    final future = data.fetchFriendshipById(friendshipId);
+    return FutureBuilder<Friendship?>(
+      future: future,
+      builder: (context, snapshot) {
+        if (snapshot.connectionState == ConnectionState.waiting) {
+          return const Padding(
+            padding: EdgeInsets.symmetric(vertical: 6.0),
+            child: SizedBox(
+              height: 20,
+              width: 20,
+              child: CircularProgressIndicator(strokeWidth: 2),
+            ),
+          );
+        }
+        if (snapshot.hasError) {
+          return const Text('Failed to load request details.');
+        }
+        final friendship = snapshot.data;
+        final requester = friendship?.requester;
+        if (friendship == null || requester == null) {
+          return const Text('Friend request details unavailable.');
+        }
+        final buttonStyle = ElevatedButton.styleFrom(
+          minimumSize: const Size(0, 36),
+        );
+        return Column(
+          crossAxisAlignment: CrossAxisAlignment.start,
+          children: [
+            Row(
+              children: [
+                const Icon(Icons.person_add_alt, size: 18),
+                const SizedBox(width: 6),
+                Text(
+                  requester.displayName.isNotEmpty
+                      ? requester.displayName
+                      : '@${requester.username}',
+                  style: Theme.of(context).textTheme.titleSmall,
+                ),
+              ],
+            ),
+            const SizedBox(height: 6),
+            Wrap(
+              spacing: 8,
+              children: [
+                ElevatedButton(
+                  style: buttonStyle,
+                  onPressed: () =>
+                      _respond(context, friendship.id, accept: true),
+                  child: const Text('Accept'),
+                ),
+                ElevatedButton(
+                  style: buttonStyle,
+                  onPressed: () =>
+                      _respond(context, friendship.id, accept: false),
+                  child: const Text('Reject'),
+                ),
+              ],
+            ),
+          ],
+        );
+      },
+    );
+  }
+
+  Future<void> _respond(
+    BuildContext context,
+    String? friendshipId, {
+    required bool accept,
+  }) async {
+    if (friendshipId == null || friendshipId.isEmpty) return;
+    final data = context.read<DataService>();
+    final messenger = ScaffoldMessenger.maybeOf(context);
+    try {
+      if (accept) {
+        await data.acceptFriendship(friendshipId);
+        if (!context.mounted) return;
+        messenger?.showSnackBar(
+          const SnackBar(content: Text('Friend request accepted')),
+        );
+        await _dismissNotification(context, messenger);
+      } else {
+        await data.rejectFriendship(friendshipId);
+        if (!context.mounted) return;
+        messenger?.showSnackBar(
+          const SnackBar(content: Text('Friend request rejected')),
+        );
+        await _dismissNotification(context, messenger);
+      }
+      await data.fetchPendingFriendships();
+    } catch (e) {
+      if (!context.mounted) return;
+      messenger?.showSnackBar(
+        SnackBar(content: Text('Failed to respond: $e')),
+      );
+    }
+  }
+
+  Future<void> _dismissNotification(
+    BuildContext context,
+    ScaffoldMessengerState? messenger,
+  ) async {
+    try {
+      await context.read<DataService>().dismissNotifications([notification.id]);
+    } catch (e) {
+      messenger?.showSnackBar(
+        SnackBar(content: Text('Failed to dismiss notification: $e')),
+      );
+    }
+  }
+}