feat: implement follow and unfollow

Signed-off-by: Aman <aman2@me.iitr.ac.in>

Author: aman-singh7

lib/data/services/local/storage_service.dart

@@ -81,7 +81,7 @@ class StorageService {
   static List<User>? get recentSearches {
     try {
       return List<User>.from(json
-          .decode(_get<String>(AppStrings.recentSearchKey)!)
+          .decode(_get<String>(AppStrings.recentSearchKey) ?? '')
           .map((e) => User.fromJson(e)));
     } on Exception catch (_) {
       return null;

lib/presentation/home/bloc/home_bloc.dart

@@ -21,18 +21,18 @@ class HomeBloc extends Bloc<HomeEvent, HomeState> {
   late final List<Widget> screens;
 
   void init() async {
-    // Fetch User Details on Startup
-    try {
-      StorageService.user = await UserRepository.fetchUserDetails();
-    } on Exception catch (err) {
-      debugPrint(err.toString());
-    }
     screens = <Widget>[
       const FeedScreen(),
       const ContestsScreen(),
       const SearchScreen(),
       const ProfileScreen(),
     ];
+    // Fetch User Details on Startup
+    try {
+      StorageService.user = await UserRepository.fetchUserDetails();
+    } on Exception catch (err) {
+      debugPrint(err.toString());
+    }
   }
 
   void _changeScreen(BottomNavItemPressed event, Emitter<HomeState> emit) {

lib/presentation/profile/bloc/profile_bloc.dart

@@ -115,23 +115,42 @@ class ProfileBloc extends Bloc<ProfileEvent, ProfileState> {
     emit(state.copyWith(
       following: _followingList,
       showFollowing: event.toShow,
+      user: _user,
     ));
   }
 
-  static Future follow(String userId) async {
+  Future follow(String userId) async {
     final statuscode = await UserRepository.followUser(userId);
 
     if (statuscode != 200) {
       throw Exception(AppStrings.genericError);
     }
+
+    var _tempUser = StorageService.user;
+    _tempUser = _tempUser?.copyWith(
+      noOfFollowing: (_tempUser.noOfFollowing ?? 0) + 1,
+    );
+    StorageService.user = _tempUser;
+    if (_user?.id != _tempUser?.id) return;
+
+    _user = _tempUser;
   }
 
-  static Future unfollow(String userId) async {
+  Future unfollow(String userId) async {
     final statuscode = await UserRepository.unfollowUser(userId);
 
     if (statuscode != 200) {
       throw Exception(AppStrings.genericError);
     }
+
+    var _tempUser = StorageService.user;
+    _tempUser = _tempUser?.copyWith(
+      noOfFollowing: (_tempUser.noOfFollowing ?? 0) - 1,
+    );
+    StorageService.user = _tempUser;
+    if (_user?.id != _tempUser?.id) return;
+
+    _user = _tempUser;
   }
 
   // Index -> Index%4

lib/presentation/profile/widgets/following_view.dart

@@ -90,12 +90,12 @@ class FollowingView extends StatelessWidget {
                 /// to rebuild the whole list
                 trailing: ValueListenableBuilder<bool>(
                   valueListenable: _followNotifier,
-                  builder: (context, value, _) {
+                  builder: (_, value, child) {
                     if (value) {
                       return FollowingButton(
                         onTap: () async {
                           try {
-                            await ProfileBloc.unfollow(user.id);
+                            await context.read<ProfileBloc>().unfollow(user.id);
                             _followNotifier.value = false;
                           } on Exception catch (_) {
                             showSnackBar(message: AppStrings.genericError);
@@ -107,7 +107,7 @@ class FollowingView extends StatelessWidget {
                     return FollowButton(
                       onTap: () async {
                         try {
-                          await ProfileBloc.follow(user.id);
+                          await context.read<ProfileBloc>().follow(user.id);
                           _followNotifier.value = true;
                         } on Exception catch (_) {
                           showSnackBar(message: AppStrings.genericError);

lib/presentation/profile/widgets/profile_header.dart

@@ -22,6 +22,8 @@ class ProfileHeader extends StatelessWidget {
   Widget build(BuildContext context) {
     return BlocBuilder<ProfileBloc, ProfileState>(
       builder: (context, state) {
+        // Follow Notifier
+        final _followNotifier = ValueNotifier(state.isFollowing);
         return Container(
           color: AppColors.primary,
           child: Column(
@@ -192,18 +194,39 @@ class ProfileHeader extends StatelessWidget {
                             vertical: 8.h,
                             horizontal: 16.w,
                           ),
-                          child: Visibility(
-                            visible: state.isFollowing,
-                            replacement: FollowButton(
-                              onTap: () {
-                                // TODO(aman-singh7): Implement follow
-                              },
-                            ),
-                            child: FollowingButton(
-                              onTap: () {
-                                // TODO(aman-singh7): Implement unfollow
-                              },
-                            ),
+                          child: ValueListenableBuilder<bool>(
+                            valueListenable: _followNotifier,
+                            builder: (_, value, child) {
+                              if (value) {
+                                return FollowingButton(
+                                  onTap: () async {
+                                    try {
+                                      await context
+                                          .read<ProfileBloc>()
+                                          .unfollow(state.user!.id!);
+                                      _followNotifier.value = false;
+                                    } on Exception catch (_) {
+                                      showSnackBar(
+                                          message: AppStrings.genericError);
+                                    }
+                                  },
+                                );
+                              }
+
+                              return FollowButton(
+                                onTap: () async {
+                                  try {
+                                    await context
+                                        .read<ProfileBloc>()
+                                        .follow(state.user!.id!);
+                                    _followNotifier.value = true;
+                                  } on Exception catch (_) {
+                                    showSnackBar(
+                                        message: AppStrings.genericError);
+                                  }
+                                },
+                              );
+                            },
                           ),
                         ),
                       ],