Update Discover tab

app/build.gradle

@@ -49,7 +49,7 @@ dependencies {
     coreLibraryDesugaring 'com.android.tools:desugar_jdk_libs:1.0.10'
 
     def appcompat_version = "1.2.0"
-    def nav_version = "2.3.0"
+    def nav_version = '2.3.1'
 
     implementation 'com.google.android.material:material:1.3.0-alpha03'
     implementation 'com.google.android.exoplayer:exoplayer:2.12.0'
@@ -61,9 +61,10 @@ dependencies {
     implementation "androidx.viewpager2:viewpager2:1.0.0"
     implementation "androidx.navigation:navigation-fragment:$nav_version"
     implementation "androidx.navigation:navigation-ui:$nav_version"
-    implementation "androidx.constraintlayout:constraintlayout:2.0.2"
+    implementation "androidx.constraintlayout:constraintlayout:2.0.4"
     implementation "androidx.preference:preference:1.1.1"
     implementation "androidx.work:work-runtime:2.4.0"
+    implementation 'androidx.palette:palette:1.0.0'
 
     implementation 'com.google.guava:guava:27.0.1-android'
 

app/src/main/java/awais/instagrabber/activities/MainActivity.java

@@ -421,7 +421,7 @@ public class MainActivity extends BaseLanguageActivity implements FragmentManage
                 R.id.main_nav_host,
                 getIntent(),
                 firstFragmentGraphIndex);
-        navControllerLiveData.observe(this, this::setupNavigation);
+        navControllerLiveData.observe(this, navController -> setupNavigation(binding.toolbar, navController));
         currentNavControllerLiveData = navControllerLiveData;
     }
 
@@ -446,8 +446,11 @@ public class MainActivity extends BaseLanguageActivity implements FragmentManage
         return mainNavList;
     }
 
-    private void setupNavigation(final NavController navController) {
-        NavigationUI.setupWithNavController(binding.toolbar, navController);
+    private void setupNavigation(final Toolbar toolbar, final NavController navController) {
+        if (navController == null) {
+            return;
+        }
+        NavigationUI.setupWithNavController(toolbar, navController);
         navController.addOnDestinationChangedListener((controller, destination, arguments) -> {
             // below is a hack to check if we are at the end of the current stack, to setup the search view
             binding.appBarLayout.setExpanded(true, true);
@@ -640,4 +643,16 @@ public class MainActivity extends BaseLanguageActivity implements FragmentManage
     public int getNavHostContainerId() {
         return binding.mainNavHost.getId();
     }
+
+    public void setToolbar(final Toolbar toolbar) {
+        binding.appBarLayout.setVisibility(View.GONE);
+        setSupportActionBar(toolbar);
+        setupNavigation(toolbar, currentNavControllerLiveData.getValue());
+    }
+
+    public void resetToolbar() {
+        binding.appBarLayout.setVisibility(View.VISIBLE);
+        setSupportActionBar(binding.toolbar);
+        setupNavigation(binding.toolbar, currentNavControllerLiveData.getValue());
+    }
 }

app/src/main/java/awais/instagrabber/adapters/DiscoverTopicsAdapter.java

@@ -0,0 +1,53 @@
+package awais.instagrabber.adapters;
+
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+
+import androidx.annotation.NonNull;
+import androidx.recyclerview.widget.DiffUtil;
+import androidx.recyclerview.widget.ListAdapter;
+
+import awais.instagrabber.adapters.viewholder.TopicClusterViewHolder;
+import awais.instagrabber.databinding.ItemDiscoverTopicBinding;
+import awais.instagrabber.models.TopicCluster;
+
+public class DiscoverTopicsAdapter extends ListAdapter<TopicCluster, TopicClusterViewHolder> {
+    private static final DiffUtil.ItemCallback<TopicCluster> DIFF_CALLBACK = new DiffUtil.ItemCallback<TopicCluster>() {
+        @Override
+        public boolean areItemsTheSame(@NonNull final TopicCluster oldItem, @NonNull final TopicCluster newItem) {
+            return oldItem.getId().equals(newItem.getId());
+        }
+
+        @Override
+        public boolean areContentsTheSame(@NonNull final TopicCluster oldItem, @NonNull final TopicCluster newItem) {
+            return oldItem.getCoverMedia().getDisplayUrl().equals(newItem.getCoverMedia().getDisplayUrl())
+                    && oldItem.getTitle().equals(newItem.getTitle());
+        }
+    };
+
+    private final OnTopicClickListener onTopicClickListener;
+
+    public DiscoverTopicsAdapter(final OnTopicClickListener onTopicClickListener) {
+        super(DIFF_CALLBACK);
+        this.onTopicClickListener = onTopicClickListener;
+    }
+
+    @NonNull
+    @Override
+    public TopicClusterViewHolder onCreateViewHolder(@NonNull final ViewGroup parent, final int viewType) {
+        final LayoutInflater layoutInflater = LayoutInflater.from(parent.getContext());
+        final ItemDiscoverTopicBinding binding = ItemDiscoverTopicBinding.inflate(layoutInflater, parent, false);
+        return new TopicClusterViewHolder(binding, onTopicClickListener);
+    }
+
+    @Override
+    public void onBindViewHolder(@NonNull final TopicClusterViewHolder holder, final int position) {
+        final TopicCluster topicCluster = getItem(position);
+        holder.bind(topicCluster);
+    }
+
+    public interface OnTopicClickListener {
+        void onTopicClick(TopicCluster topicCluster, View root, View cover, View title, int titleColor, int backgroundColor);
+    }
+}

app/src/main/java/awais/instagrabber/adapters/viewholder/TopicClusterViewHolder.java

@@ -0,0 +1,99 @@
+package awais.instagrabber.adapters.viewholder;
+
+import android.content.res.Resources;
+import android.graphics.Bitmap;
+import android.graphics.Color;
+import android.graphics.drawable.GradientDrawable;
+import android.net.Uri;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.palette.graphics.Palette;
+import androidx.recyclerview.widget.RecyclerView;
+
+import com.facebook.common.executors.CallerThreadExecutor;
+import com.facebook.common.references.CloseableReference;
+import com.facebook.datasource.DataSource;
+import com.facebook.drawee.backends.pipeline.Fresco;
+import com.facebook.imagepipeline.core.ImagePipeline;
+import com.facebook.imagepipeline.datasource.BaseBitmapDataSubscriber;
+import com.facebook.imagepipeline.image.CloseableImage;
+import com.facebook.imagepipeline.request.ImageRequest;
+import com.facebook.imagepipeline.request.ImageRequestBuilder;
+
+import java.util.concurrent.atomic.AtomicInteger;
+
+import awais.instagrabber.R;
+import awais.instagrabber.adapters.DiscoverTopicsAdapter;
+import awais.instagrabber.databinding.ItemDiscoverTopicBinding;
+import awais.instagrabber.models.TopicCluster;
+
+public class TopicClusterViewHolder extends RecyclerView.ViewHolder {
+    private final ItemDiscoverTopicBinding binding;
+    private final DiscoverTopicsAdapter.OnTopicClickListener onTopicClickListener;
+
+    public TopicClusterViewHolder(@NonNull final ItemDiscoverTopicBinding binding,
+                                  final DiscoverTopicsAdapter.OnTopicClickListener onTopicClickListener) {
+        super(binding.getRoot());
+        this.binding = binding;
+        this.onTopicClickListener = onTopicClickListener;
+    }
+
+    public void bind(final TopicCluster topicCluster) {
+        if (topicCluster == null) {
+            return;
+        }
+        final AtomicInteger titleColor = new AtomicInteger(-1);
+        final AtomicInteger backgroundColor = new AtomicInteger(-1);
+        if (onTopicClickListener != null) {
+            itemView.setOnClickListener(v -> onTopicClickListener.onTopicClick(
+                    topicCluster,
+                    binding.getRoot(),
+                    binding.cover,
+                    binding.title,
+                    titleColor.get(),
+                    backgroundColor.get()
+            ));
+        }
+        // binding.title.setTransitionName("title-" + topicCluster.getId());
+        binding.cover.setTransitionName("cover-" + topicCluster.getId());
+        final ImageRequest imageRequest = ImageRequestBuilder
+                .newBuilderWithSource(Uri.parse(topicCluster.getCoverMedia().getDisplayUrl()))
+                .build();
+        final ImagePipeline imagePipeline = Fresco.getImagePipeline();
+        final DataSource<CloseableReference<CloseableImage>> dataSource = imagePipeline
+                .fetchDecodedImage(imageRequest, CallerThreadExecutor.getInstance());
+        dataSource.subscribe(new BaseBitmapDataSubscriber() {
+            @Override
+            public void onNewResultImpl(@Nullable Bitmap bitmap) {
+                if (dataSource.isFinished()) {
+                    dataSource.close();
+                }
+                if (bitmap != null) {
+                    Palette.from(bitmap).generate(p -> {
+                        final Palette.Swatch swatch = p.getDominantSwatch();
+                        final Resources resources = itemView.getResources();
+                        int titleTextColor = resources.getColor(R.color.white);
+                        if (swatch != null) {
+                            backgroundColor.set(swatch.getRgb());
+                            GradientDrawable gd = new GradientDrawable(
+                                    GradientDrawable.Orientation.TOP_BOTTOM,
+                                    new int[]{Color.TRANSPARENT, backgroundColor.get()});
+                            titleTextColor = swatch.getTitleTextColor();
+                            binding.background.setBackground(gd);
+                        }
+                        titleColor.set(titleTextColor);
+                        binding.title.setTextColor(titleTextColor);
+                    });
+                }
+            }
+
+            @Override
+            public void onFailureImpl(@NonNull DataSource dataSource) {
+                dataSource.close();
+            }
+        }, CallerThreadExecutor.getInstance());
+        binding.cover.setImageRequest(imageRequest);
+        binding.title.setText(topicCluster.getTitle());
+    }
+}

app/src/main/java/awais/instagrabber/asyncs/DiscoverPostFetchService.java

@@ -0,0 +1,56 @@
+package awais.instagrabber.asyncs;
+
+import java.util.List;
+
+import awais.instagrabber.customviews.helpers.PostFetcher;
+import awais.instagrabber.interfaces.FetchListener;
+import awais.instagrabber.models.FeedModel;
+import awais.instagrabber.webservices.DiscoverService;
+import awais.instagrabber.webservices.ServiceCallback;
+
+public class DiscoverPostFetchService implements PostFetcher.PostFetchService {
+    private static final String TAG = "DiscoverPostFetchService";
+    private final DiscoverService discoverService;
+    private final DiscoverService.TopicalExploreRequest topicalExploreRequest;
+    private boolean moreAvailable = false;
+
+    public DiscoverPostFetchService(final DiscoverService.TopicalExploreRequest topicalExploreRequest) {
+        this.topicalExploreRequest = topicalExploreRequest;
+        discoverService = DiscoverService.getInstance();
+    }
+
+    @Override
+    public void fetch(final FetchListener<List<FeedModel>> fetchListener) {
+        discoverService.topicalExplore(topicalExploreRequest, new ServiceCallback<DiscoverService.TopicalExploreResponse>() {
+            @Override
+            public void onSuccess(final DiscoverService.TopicalExploreResponse result) {
+                if (result == null) {
+                    onFailure(new RuntimeException("result is null"));
+                    return;
+                }
+                moreAvailable = result.isMoreAvailable();
+                topicalExploreRequest.setMaxId(result.getNextMaxId());
+                if (fetchListener != null) {
+                    fetchListener.onResult(result.getItems());
+                }
+            }
+
+            @Override
+            public void onFailure(final Throwable t) {
+                if (fetchListener != null) {
+                    fetchListener.onFailure(t);
+                }
+            }
+        });
+    }
+
+    @Override
+    public void reset() {
+        topicalExploreRequest.setMaxId(-1);
+    }
+
+    @Override
+    public boolean hasNextPage() {
+        return moreAvailable;
+    }
+}

app/src/main/java/awais/instagrabber/asyncs/FeedPostFetchService.java

@@ -20,8 +20,8 @@ public class FeedPostFetchService implements PostFetcher.PostFetchService {
     }
 
     @Override
-    public void fetch(final String cursor, final FetchListener<List<FeedModel>> fetchListener) {
-        feedService.fetch(25, cursor, new ServiceCallback<PostsFetchResponse>() {
+    public void fetch(final FetchListener<List<FeedModel>> fetchListener) {
+        feedService.fetch(25, nextCursor, new ServiceCallback<PostsFetchResponse>() {
             @Override
             public void onSuccess(final PostsFetchResponse result) {
                 if (result == null) return;
@@ -43,8 +43,8 @@ public class FeedPostFetchService implements PostFetcher.PostFetchService {
     }
 
     @Override
-    public String getNextCursor() {
-        return nextCursor;
+    public void reset() {
+        nextCursor = null;
     }
 
     @Override

app/src/main/java/awais/instagrabber/asyncs/ProfilePostFetchService.java

@@ -23,8 +23,8 @@ public class ProfilePostFetchService implements PostFetcher.PostFetchService {
     }
 
     @Override
-    public void fetch(final String cursor, final FetchListener<List<FeedModel>> fetchListener) {
-        profileService.fetchPosts(profileModel, 30, cursor, new ServiceCallback<PostsFetchResponse>() {
+    public void fetch(final FetchListener<List<FeedModel>> fetchListener) {
+        profileService.fetchPosts(profileModel, 30, nextCursor, new ServiceCallback<PostsFetchResponse>() {
             @Override
             public void onSuccess(final PostsFetchResponse result) {
                 if (result == null) return;
@@ -46,8 +46,8 @@ public class ProfilePostFetchService implements PostFetcher.PostFetchService {
     }
 
     @Override
-    public String getNextCursor() {
-        return nextCursor;
+    public void reset() {
+        nextCursor = null;
     }
 
     @Override

app/src/main/java/awais/instagrabber/customviews/PostsRecyclerView.java

@@ -167,7 +167,7 @@ public class PostsRecyclerView extends RecyclerView {
         setNestedScrollingEnabled(true);
         lazyLoader = new RecyclerLazyLoaderAtBottom(layoutManager, (page) -> {
             if (postFetcher.hasMore()) {
-                postFetcher.fetchNextPage();
+                postFetcher.fetch();
                 dispatchFetchStatus();
             }
         });
@@ -204,6 +204,7 @@ public class PostsRecyclerView extends RecyclerView {
 
     public void refresh() {
         lazyLoader.resetState();
+        postFetcher.reset();
         postFetcher.fetch();
         dispatchFetchStatus();
     }

app/src/main/java/awais/instagrabber/customviews/helpers/PostFetcher.java

@@ -17,21 +17,17 @@ public class PostFetcher {
     }
 
     public void fetch() {
-        fetch(null);
-    }
-
-    public void fetchNextPage() {
-        fetch(postFetchService.getNextCursor());
-    }
-
-    public void fetch(final String cursor) {
         fetching = true;
-        postFetchService.fetch(cursor, result -> {
+        postFetchService.fetch(result -> {
             fetching = false;
             fetchListener.onResult(result);
         });
     }
 
+    public void reset() {
+        postFetchService.reset();
+    }
+
     public boolean isFetching() {
         return fetching;
     }
@@ -41,9 +37,9 @@ public class PostFetcher {
     }
 
     public interface PostFetchService {
-        void fetch(String cursor, FetchListener<List<FeedModel>> fetchListener);
+        void fetch(FetchListener<List<FeedModel>> fetchListener);
 
-        String getNextCursor();
+        void reset();
 
         boolean hasNextPage();
     }

app/src/main/java/awais/instagrabber/customviews/helpers/RecyclerLazyLoaderAtBottom.java

@@ -30,7 +30,7 @@ public final class RecyclerLazyLoaderAtBottom extends RecyclerView.OnScrollListe
         if (!recyclerView.canScrollVertically(RecyclerView.SCROLL_AXIS_HORIZONTAL) && newState == RecyclerView.SCROLL_STATE_IDLE) {
             if (!loading && lazyLoadListener != null) {
                 loading = true;
-                new Handler().postDelayed(() -> lazyLoadListener.onLoadMore(++currentPage), 1000);
+                new Handler().postDelayed(() -> lazyLoadListener.onLoadMore(++currentPage), 500);
             }
         }
     }

app/src/main/java/awais/instagrabber/fragments/HashTagFragment.java

@@ -4,7 +4,6 @@ import android.content.Context;
 import android.graphics.Typeface;
 import android.os.AsyncTask;
 import android.os.Bundle;
-import android.os.Handler;
 import android.text.SpannableStringBuilder;
 import android.text.style.RelativeSizeSpan;
 import android.text.style.StyleSpan;
@@ -209,7 +208,7 @@ public class HashTagFragment extends Fragment implements SwipeRefreshLayout.OnRe
         isLoggedIn = !TextUtils.isEmpty(cookie) && CookieUtils.getUserIdFromCookie(cookie) != null;
         final HashTagFragmentArgs fragmentArgs = HashTagFragmentArgs.fromBundle(getArguments());
         hashtag = fragmentArgs.getHashtag();
-        setTitle();
+        // setTitle();
         setupPosts();
         fetchHashtagModel();
     }
@@ -284,6 +283,7 @@ public class HashTagFragment extends Fragment implements SwipeRefreshLayout.OnRe
                 Toast.makeText(context, R.string.error_loading_profile, Toast.LENGTH_SHORT).show();
                 return;
             }
+            setTitle();
             fetchPosts();
         }).executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
     }
@@ -324,9 +324,35 @@ public class HashTagFragment extends Fragment implements SwipeRefreshLayout.OnRe
             binding.btnFollowTag.setOnClickListener(v -> {
                 final String cookie = settingsHelper.getString(Constants.COOKIE);
                 final String csrfToken = CookieUtils.getCsrfTokenFromCookie(cookie);
-                binding.btnFollowTag.setClickable(false);
-                if (!hashtagModel.getFollowing()) {
-                    tagsService.follow(hashtag.substring(1), csrfToken, new ServiceCallback<Boolean>() {
+                if (csrfToken != null) {
+                    binding.btnFollowTag.setClickable(false);
+                    if (!hashtagModel.getFollowing()) {
+                        tagsService.follow(hashtag.substring(1), csrfToken, new ServiceCallback<Boolean>() {
+                            @Override
+                            public void onSuccess(final Boolean result) {
+                                binding.btnFollowTag.setClickable(true);
+                                if (!result) {
+                                    Log.e(TAG, "onSuccess: result is false");
+                                    return;
+                                }
+                                onRefresh();
+                            }
+
+                            @Override
+                            public void onFailure(@NonNull final Throwable t) {
+                                binding.btnFollowTag.setClickable(true);
+                                Log.e(TAG, "onFailure: ", t);
+                                final String message = t.getMessage();
+                                Snackbar.make(root,
+                                              message != null ? message
+                                                              : getString(R.string.downloader_unknown_error),
+                                              BaseTransientBottomBar.LENGTH_LONG)
+                                        .show();
+                            }
+                        });
+                        return;
+                    }
+                    tagsService.unfollow(hashtag.substring(1), csrfToken, new ServiceCallback<Boolean>() {
                         @Override
                         public void onSuccess(final Boolean result) {
                             binding.btnFollowTag.setClickable(true);
@@ -349,31 +375,7 @@ public class HashTagFragment extends Fragment implements SwipeRefreshLayout.OnRe
                                     .show();
                         }
                     });
-                    return;
                 }
-                tagsService.unfollow(hashtag.substring(1), csrfToken, new ServiceCallback<Boolean>() {
-                    @Override
-                    public void onSuccess(final Boolean result) {
-                        binding.btnFollowTag.setClickable(true);
-                        if (!result) {
-                            Log.e(TAG, "onSuccess: result is false");
-                            return;
-                        }
-                        onRefresh();
-                    }
-
-                    @Override
-                    public void onFailure(@NonNull final Throwable t) {
-                        binding.btnFollowTag.setClickable(true);
-                        Log.e(TAG, "onFailure: ", t);
-                        final String message = t.getMessage();
-                        Snackbar.make(root,
-                                      message != null ? message
-                                                      : getString(R.string.downloader_unknown_error),
-                                      BaseTransientBottomBar.LENGTH_LONG)
-                                .show();
-                    }
-                });
             });
         } else {
             binding.btnFollowTag.setVisibility(View.GONE);
@@ -425,7 +427,6 @@ public class HashTagFragment extends Fragment implements SwipeRefreshLayout.OnRe
                 final NavDirections action = HashTagFragmentDirections
                         .actionHashtagFragmentToStoryViewerFragment(-1, null, true, false, hashtagModel.getName(), hashtagModel.getName());
                 NavHostFragment.findNavController(this).navigate(action);
-                return;
             }
         });
     }
@@ -445,9 +446,10 @@ public class HashTagFragment extends Fragment implements SwipeRefreshLayout.OnRe
     private void setTitle() {
         final ActionBar actionBar = fragmentActivity.getSupportActionBar();
         if (actionBar != null) {
-            Log.d(TAG, "setting title: " + hashtag);
-            final Handler handler = new Handler();
-            handler.postDelayed(() -> actionBar.setTitle(hashtag), 200);
+            // Log.d(TAG, "setting title: " + hashtag);
+            actionBar.setTitle(hashtag);
+            // final Handler handler = new Handler();
+            // handler.postDelayed(() -> , 1000);
         }
     }
 

app/src/main/java/awais/instagrabber/fragments/PostViewV2Fragment.java

@@ -920,7 +920,7 @@ public class PostViewV2Fragment extends SharedElementTransitionDialogFragment {
         binding.playerControls.getRoot().setVisibility(View.GONE);
         binding.sliderParent.setVisibility(View.VISIBLE);
         binding.mediaCounter.setVisibility(View.VISIBLE);
-        if (sharedMainPostElement != null) {
+        if (!wasPaused && sharedMainPostElement != null) {
             addSharedElement(sharedMainPostElement, binding.sliderParent);
         }
         sliderItemsAdapter = new SliderItemsAdapter(onVerticalDragListener, binding.playerControls, true, new SliderCallbackAdapter() {
@@ -1014,7 +1014,7 @@ public class PostViewV2Fragment extends SharedElementTransitionDialogFragment {
         binding.sliderParent.setVisibility(View.GONE);
         binding.mediaCounter.setVisibility(View.GONE);
         // binding.playerControls.getRoot().setVisibility(View.VISIBLE);
-        if (sharedMainPostElement != null) {
+        if (!wasPaused && sharedMainPostElement != null) {
             final GenericDraweeHierarchy hierarchy = binding.videoPost.thumbnail.getHierarchy();
             hierarchy.setActualImageScaleType(ScalingUtils.ScaleType.CENTER_CROP);
             addSharedElement(sharedMainPostElement, binding.videoPost.thumbnailParent);

app/src/main/java/awais/instagrabber/fragments/TopicPostsFragment.java

@@ -0,0 +1,363 @@
+package awais.instagrabber.fragments;
+
+import android.animation.ArgbEvaluator;
+import android.content.Context;
+import android.graphics.Color;
+import android.graphics.PorterDuff;
+import android.graphics.drawable.Animatable;
+import android.graphics.drawable.Drawable;
+import android.graphics.drawable.GradientDrawable;
+import android.os.Bundle;
+import android.os.Handler;
+import android.view.LayoutInflater;
+import android.view.Menu;
+import android.view.MenuInflater;
+import android.view.MenuItem;
+import android.view.View;
+import android.view.ViewGroup;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.core.content.PermissionChecker;
+import androidx.core.graphics.ColorUtils;
+import androidx.fragment.app.Fragment;
+import androidx.navigation.NavController;
+import androidx.navigation.NavDirections;
+import androidx.navigation.fragment.NavHostFragment;
+import androidx.swiperefreshlayout.widget.SwipeRefreshLayout;
+import androidx.transition.ChangeBounds;
+import androidx.transition.TransitionInflater;
+import androidx.transition.TransitionSet;
+
+import com.facebook.drawee.backends.pipeline.Fresco;
+import com.facebook.drawee.controller.BaseControllerListener;
+import com.facebook.drawee.interfaces.DraweeController;
+import com.facebook.imagepipeline.image.ImageInfo;
+
+import awais.instagrabber.R;
+import awais.instagrabber.activities.MainActivity;
+import awais.instagrabber.adapters.FeedAdapterV2;
+import awais.instagrabber.asyncs.DiscoverPostFetchService;
+import awais.instagrabber.customviews.helpers.NestedCoordinatorLayout;
+import awais.instagrabber.databinding.FragmentTopicPostsBinding;
+import awais.instagrabber.dialogs.PostsLayoutPreferencesDialogFragment;
+import awais.instagrabber.fragments.main.DiscoverFragmentDirections;
+import awais.instagrabber.models.FeedModel;
+import awais.instagrabber.models.PostsLayoutPreferences;
+import awais.instagrabber.models.TopicCluster;
+import awais.instagrabber.utils.Constants;
+import awais.instagrabber.utils.DownloadUtils;
+import awais.instagrabber.utils.Utils;
+import awais.instagrabber.webservices.DiscoverService;
+
+import static androidx.core.content.PermissionChecker.checkSelfPermission;
+import static awais.instagrabber.utils.DownloadUtils.WRITE_PERMISSION;
+import static awais.instagrabber.utils.Utils.settingsHelper;
+
+public class TopicPostsFragment extends Fragment implements SwipeRefreshLayout.OnRefreshListener {
+    private static final int STORAGE_PERM_REQUEST_CODE = 8020;
+    private MainActivity fragmentActivity;
+    private FragmentTopicPostsBinding binding;
+    private NestedCoordinatorLayout root;
+    private boolean shouldRefresh = true;
+    private TopicCluster topicCluster;
+
+    private final FeedAdapterV2.FeedItemCallback feedItemCallback = new FeedAdapterV2.FeedItemCallback() {
+        @Override
+        public void onPostClick(final FeedModel feedModel, final View profilePicView, final View mainPostImage) {
+            openPostDialog(feedModel, profilePicView, mainPostImage, -1);
+        }
+
+        @Override
+        public void onSliderClick(final FeedModel feedModel, final int position) {
+            openPostDialog(feedModel, null, null, position);
+        }
+
+        @Override
+        public void onCommentsClick(final FeedModel feedModel) {
+            final NavDirections commentsAction = DiscoverFragmentDirections.actionGlobalCommentsViewerFragment(
+                    feedModel.getShortCode(),
+                    feedModel.getPostId(),
+                    feedModel.getProfileModel().getId()
+            );
+            NavHostFragment.findNavController(TopicPostsFragment.this).navigate(commentsAction);
+        }
+
+        @Override
+        public void onDownloadClick(final FeedModel feedModel) {
+            final Context context = getContext();
+            if (context == null) return;
+            if (checkSelfPermission(context, WRITE_PERMISSION) == PermissionChecker.PERMISSION_GRANTED) {
+                showDownloadDialog(feedModel);
+                return;
+            }
+            requestPermissions(DownloadUtils.PERMS, STORAGE_PERM_REQUEST_CODE);
+        }
+
+        @Override
+        public void onHashtagClick(final String hashtag) {
+            final NavDirections action = DiscoverFragmentDirections.actionGlobalHashTagFragment(hashtag);
+            NavHostFragment.findNavController(TopicPostsFragment.this).navigate(action);
+        }
+
+        @Override
+        public void onLocationClick(final FeedModel feedModel) {
+            final NavDirections action = DiscoverFragmentDirections.actionGlobalLocationFragment(feedModel.getLocationId());
+            NavHostFragment.findNavController(TopicPostsFragment.this).navigate(action);
+        }
+
+        @Override
+        public void onMentionClick(final String mention) {
+            navigateToProfile(mention.trim());
+        }
+
+        @Override
+        public void onNameClick(final FeedModel feedModel, final View profilePicView) {
+            navigateToProfile("@" + feedModel.getProfileModel().getUsername());
+        }
+
+        @Override
+        public void onProfilePicClick(final FeedModel feedModel, final View profilePicView) {
+            navigateToProfile("@" + feedModel.getProfileModel().getUsername());
+        }
+
+        @Override
+        public void onURLClick(final String url) {
+            Utils.openURL(getContext(), url);
+        }
+
+        @Override
+        public void onEmailClick(final String emailId) {
+            Utils.openEmailAddress(getContext(), emailId);
+        }
+
+        private void openPostDialog(final FeedModel feedModel,
+                                    final View profilePicView,
+                                    final View mainPostImage,
+                                    final int position) {
+            final PostViewV2Fragment.Builder builder = PostViewV2Fragment
+                    .builder(feedModel);
+            if (position >= 0) {
+                builder.setPosition(position);
+            }
+            final PostViewV2Fragment fragment = builder
+                    .setSharedProfilePicElement(profilePicView)
+                    .setSharedMainPostElement(mainPostImage)
+                    .build();
+            fragment.show(getChildFragmentManager(), "post_view");
+        }
+    };
+
+    @Override
+    public void onCreate(@Nullable final Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        fragmentActivity = (MainActivity) requireActivity();
+        final TransitionSet transitionSet = new TransitionSet();
+        transitionSet.addTransition(new ChangeBounds())
+                     .addTransition(TransitionInflater.from(getContext()).inflateTransition(android.R.transition.move))
+                     .setDuration(200);
+        setSharedElementEnterTransition(transitionSet);
+        postponeEnterTransition();
+        setHasOptionsMenu(true);
+    }
+
+    @Nullable
+    @Override
+    public View onCreateView(@NonNull final LayoutInflater inflater,
+                             @Nullable final ViewGroup container,
+                             @Nullable final Bundle savedInstanceState) {
+        if (root != null) {
+            shouldRefresh = false;
+            return root;
+        }
+        binding = FragmentTopicPostsBinding.inflate(inflater, container, false);
+        root = binding.getRoot();
+        return root;
+    }
+
+    @Override
+    public void onViewCreated(@NonNull final View view, @Nullable final Bundle savedInstanceState) {
+        if (!shouldRefresh) return;
+        binding.swipeRefreshLayout.setOnRefreshListener(this);
+        init();
+        shouldRefresh = false;
+    }
+
+    @Override
+    public void onCreateOptionsMenu(@NonNull final Menu menu, @NonNull final MenuInflater inflater) {
+        inflater.inflate(R.menu.topic_posts_menu, menu);
+    }
+
+    @Override
+    public boolean onOptionsItemSelected(@NonNull final MenuItem item) {
+        if (item.getItemId() == R.id.layout) {
+            showPostsLayoutPreferences();
+            return true;
+        }
+        return super.onOptionsItemSelected(item);
+    }
+
+    @Override
+    public void onRefresh() {
+        binding.posts.refresh();
+    }
+
+    @Override
+    public void onDestroy() {
+        super.onDestroy();
+        resetToolbar();
+    }
+
+    @Override
+    public void onDestroyView() {
+        super.onDestroyView();
+        resetToolbar();
+    }
+
+    private void resetToolbar() {
+        fragmentActivity.resetToolbar();
+    }
+
+    private void init() {
+        if (getArguments() == null) return;
+        final TopicPostsFragmentArgs fragmentArgs = TopicPostsFragmentArgs.fromBundle(getArguments());
+        topicCluster = fragmentArgs.getTopicCluster();
+        setupToolbar(fragmentArgs.getTitleColor(), fragmentArgs.getBackgroundColor());
+        setupPosts();
+    }
+
+    private void setupToolbar(final int titleColor, final int backgroundColor) {
+        if (topicCluster == null) {
+            return;
+        }
+        binding.cover.setTransitionName("cover-" + topicCluster.getId());
+        fragmentActivity.setToolbar(binding.toolbar);
+        binding.collapsingToolbarLayout.setTitle(topicCluster.getTitle());
+        final int collapsedTitleTextColor = ColorUtils.setAlphaComponent(titleColor, 0xFF);
+        final int expandedTitleTextColor = ColorUtils.setAlphaComponent(titleColor, 0x99);
+        binding.collapsingToolbarLayout.setExpandedTitleColor(expandedTitleTextColor);
+        binding.collapsingToolbarLayout.setCollapsedTitleTextColor(collapsedTitleTextColor);
+        binding.collapsingToolbarLayout.setContentScrimColor(backgroundColor);
+        final Drawable navigationIcon = binding.toolbar.getNavigationIcon();
+        final Drawable overflowIcon = binding.toolbar.getOverflowIcon();
+        if (navigationIcon != null && overflowIcon != null) {
+            final Drawable navDrawable = navigationIcon.mutate();
+            final Drawable overflowDrawable = overflowIcon.mutate();
+            navDrawable.setAlpha(0xFF);
+            overflowDrawable.setAlpha(0xFF);
+            final ArgbEvaluator argbEvaluator = new ArgbEvaluator();
+            binding.appBarLayout.addOnOffsetChangedListener((appBarLayout, verticalOffset) -> {
+                final int totalScrollRange = appBarLayout.getTotalScrollRange();
+                final float current = totalScrollRange + verticalOffset;
+                final float fraction = current / totalScrollRange;
+                final int tempColor = (int) argbEvaluator.evaluate(fraction, collapsedTitleTextColor, expandedTitleTextColor);
+                navDrawable.setColorFilter(tempColor, PorterDuff.Mode.SRC_ATOP);
+                overflowDrawable.setColorFilter(tempColor, PorterDuff.Mode.SRC_ATOP);
+
+            });
+        }
+        final GradientDrawable gd = new GradientDrawable(
+                GradientDrawable.Orientation.TOP_BOTTOM,
+                new int[]{Color.TRANSPARENT, backgroundColor});
+        binding.background.setBackground(gd);
+        setupCover();
+    }
+
+    private void setupCover() {
+        final String coverUrl = topicCluster.getCoverMedia().getDisplayUrl();
+        final DraweeController controller = Fresco
+                .newDraweeControllerBuilder()
+                .setOldController(binding.cover.getController())
+                .setUri(coverUrl)
+                .setControllerListener(new BaseControllerListener<ImageInfo>() {
+
+                    @Override
+                    public void onFailure(final String id, final Throwable throwable) {
+                        super.onFailure(id, throwable);
+                        startPostponedEnterTransition();
+                    }
+
+                    @Override
+                    public void onFinalImageSet(final String id,
+                                                @Nullable final ImageInfo imageInfo,
+                                                @Nullable final Animatable animatable) {
+                        startPostponedEnterTransition();
+                    }
+                })
+                .build();
+        binding.cover.setController(controller);
+    }
+
+    private void setupPosts() {
+        final DiscoverService.TopicalExploreRequest topicalExploreRequest = new DiscoverService.TopicalExploreRequest();
+        topicalExploreRequest.setClusterId(topicCluster.getId());
+        binding.posts.setViewModelStoreOwner(this)
+                     .setLifeCycleOwner(this)
+                     .setPostFetchService(new DiscoverPostFetchService(topicalExploreRequest))
+                     .setLayoutPreferences(PostsLayoutPreferences.fromJson(settingsHelper.getString(Constants.PREF_TOPIC_POSTS_LAYOUT)))
+                     .addFetchStatusChangeListener(fetching -> updateSwipeRefreshState())
+                     .setFeedItemCallback(feedItemCallback)
+                     .init();
+        binding.swipeRefreshLayout.setRefreshing(true);
+    }
+
+    private void updateSwipeRefreshState() {
+        binding.swipeRefreshLayout.setRefreshing(binding.posts.isFetching());
+    }
+
+    private void showDownloadDialog(final FeedModel feedModel) {
+        final Context context = getContext();
+        if (context == null) return;
+        DownloadUtils.download(context, feedModel);
+        // switch (feedModel.getItemType()) {
+        //     case MEDIA_TYPE_IMAGE:
+        //     case MEDIA_TYPE_VIDEO:
+        //         break;
+        //     case MEDIA_TYPE_SLIDER:
+        //         break;
+        // }
+        // final List<ViewerPostModel> postModelsToDownload = new ArrayList<>();
+        // // if (!session) {
+        // final DialogInterface.OnClickListener clickListener = (dialog, which) -> {
+        //     if (which == DialogInterface.BUTTON_NEGATIVE) {
+        //         postModelsToDownload.addAll(postModels);
+        //     } else if (which == DialogInterface.BUTTON_POSITIVE) {
+        //         postModelsToDownload.add(postModels.get(childPosition));
+        //     } else {
+        //         session = true;
+        //         postModelsToDownload.add(postModels.get(childPosition));
+        //     }
+        //     if (postModelsToDownload.size() > 0) {
+        //         DownloadUtils.batchDownload(context,
+        //                                     username,
+        //                                     DownloadMethod.DOWNLOAD_POST_VIEWER,
+        //                                     postModelsToDownload);
+        //     }
+        // };
+        // new AlertDialog.Builder(context)
+        //         .setTitle(R.string.post_viewer_download_dialog_title)
+        //         .setMessage(R.string.post_viewer_download_message)
+        //         .setNeutralButton(R.string.post_viewer_download_session, clickListener)
+        //         .setPositiveButton(R.string.post_viewer_download_current, clickListener)
+        //         .setNegativeButton(R.string.post_viewer_download_album, clickListener).show();
+        // } else {
+        //     DownloadUtils.batchDownload(context,
+        //                                 username,
+        //                                 DownloadMethod.DOWNLOAD_POST_VIEWER,
+        //                                 Collections.singletonList(postModels.get(childPosition)));
+    }
+
+    private void navigateToProfile(final String username) {
+        final NavController navController = NavHostFragment.findNavController(this);
+        final Bundle bundle = new Bundle();
+        bundle.putString("username", username);
+        navController.navigate(R.id.action_global_profileFragment, bundle);
+    }
+
+    private void showPostsLayoutPreferences() {
+        final PostsLayoutPreferencesDialogFragment fragment = new PostsLayoutPreferencesDialogFragment(
+                Constants.PREF_TOPIC_POSTS_LAYOUT,
+                preferences -> new Handler().postDelayed(() -> binding.posts.setLayoutPreferences(preferences), 200));
+        fragment.show(getChildFragmentManager(), "posts_layout_preferences");
+    }
+}

app/src/main/java/awais/instagrabber/fragments/main/DiscoverFragment.java

@@ -1,126 +1,84 @@
 package awais.instagrabber.fragments.main;
 
-import android.content.Context;
-import android.os.AsyncTask;
 import android.os.Bundle;
+import android.util.Log;
 import android.view.ActionMode;
 import android.view.LayoutInflater;
 import android.view.MenuItem;
 import android.view.View;
 import android.view.ViewGroup;
-import android.widget.AdapterView;
-import android.widget.ArrayAdapter;
-import android.widget.Toast;
 
 import androidx.activity.OnBackPressedCallback;
-import androidx.activity.OnBackPressedDispatcher;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.coordinatorlayout.widget.CoordinatorLayout;
 import androidx.fragment.app.Fragment;
 import androidx.lifecycle.ViewModelProvider;
-import androidx.navigation.NavDirections;
+import androidx.navigation.fragment.FragmentNavigator;
 import androidx.navigation.fragment.NavHostFragment;
 import androidx.swiperefreshlayout.widget.SwipeRefreshLayout;
 
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.List;
-
 import awais.instagrabber.R;
 import awais.instagrabber.activities.MainActivity;
-import awais.instagrabber.adapters.DiscoverAdapter;
-import awais.instagrabber.asyncs.DiscoverFetcher;
-import awais.instagrabber.asyncs.i.iTopicFetcher;
+import awais.instagrabber.adapters.DiscoverTopicsAdapter;
 import awais.instagrabber.customviews.PrimaryActionModeCallback;
-import awais.instagrabber.customviews.helpers.GridAutofitLayoutManager;
 import awais.instagrabber.customviews.helpers.GridSpacingItemDecoration;
-import awais.instagrabber.customviews.helpers.RecyclerLazyLoader;
 import awais.instagrabber.databinding.FragmentDiscoverBinding;
-import awais.instagrabber.interfaces.FetchListener;
-import awais.instagrabber.models.DiscoverItemModel;
-import awais.instagrabber.models.DiscoverTopicModel;
-import awais.instagrabber.models.enums.DownloadMethod;
-import awais.instagrabber.utils.DownloadUtils;
 import awais.instagrabber.utils.Utils;
-import awais.instagrabber.viewmodels.DiscoverItemViewModel;
+import awais.instagrabber.viewmodels.TopicClusterViewModel;
+import awais.instagrabber.webservices.DiscoverService;
+import awais.instagrabber.webservices.ServiceCallback;
 
 public class DiscoverFragment extends Fragment implements SwipeRefreshLayout.OnRefreshListener {
+    private static final String TAG = "DiscoverFragment";
 
     private MainActivity fragmentActivity;
     private CoordinatorLayout root;
     private FragmentDiscoverBinding binding;
-    private DiscoverAdapter discoverAdapter;
-    private RecyclerLazyLoader lazyLoader;
-    private boolean discoverHasMore = false;
-    private String[] topicIds;
-    private String rankToken;
-    private String currentTopic;
-    private String discoverEndMaxId;
     private ActionMode actionMode;
-    private DiscoverItemViewModel discoverItemViewModel;
+    private TopicClusterViewModel topicClusterViewModel;
     private boolean shouldRefresh = true;
-    private boolean isPullToRefresh;
-
-    private final FetchListener<DiscoverTopicModel> topicFetchListener = new FetchListener<DiscoverTopicModel>() {
-        @Override
-        public void doBefore() {}
-
-        @Override
-        public void onResult(final DiscoverTopicModel result) {
-            if (result != null) {
-                topicIds = result.getIds();
-                rankToken = result.getToken();
-                final Context context = getContext();
-                if (context == null) return;
-                final ArrayAdapter<String> spinnerArrayAdapter = new ArrayAdapter<>(
-                        context,
-                        android.R.layout.simple_spinner_dropdown_item,
-                        result.getNames()
-                );
-                binding.discoverType.setAdapter(spinnerArrayAdapter);
-            }
-        }
-    };
-    private final FetchListener<DiscoverItemModel[]> postsFetchListener = new FetchListener<DiscoverItemModel[]>() {
-        @Override
-        public void doBefore() {}
+    private DiscoverService discoverService;
 
-        @Override
-        public void onResult(final DiscoverItemModel[] result) {
-            if (result == null || result.length <= 0) {
-                binding.discoverSwipeRefreshLayout.setRefreshing(false);
-                final Context context = getContext();
-                if (context == null) return;
-                Toast.makeText(context, R.string.discover_empty, Toast.LENGTH_SHORT).show();
-                return;
-            }
-            List<DiscoverItemModel> current = discoverItemViewModel.getList().getValue();
-            final List<DiscoverItemModel> resultList = Arrays.asList(result);
-            current = current == null ? new ArrayList<>() : new ArrayList<>(current); // copy to modifiable list
-            if (isPullToRefresh) {
-                current = resultList;
-                isPullToRefresh = false;
-            } else {
-                current.addAll(resultList);
-            }
-            discoverItemViewModel.getList().postValue(current);
-            binding.discoverSwipeRefreshLayout.setRefreshing(false);
-            final DiscoverItemModel discoverItemModel = result[result.length - 1];
-            if (discoverItemModel != null) {
-                discoverEndMaxId = discoverItemModel.getNextMaxId();
-                discoverHasMore = discoverItemModel.hasMore();
-                discoverItemModel.setMore(false, null);
-            }
-        }
-    };
+    // private final FetchListener<DiscoverItemModel[]> postsFetchListener = new FetchListener<DiscoverItemModel[]>() {
+    //     @Override
+    //     public void doBefore() {}
+    //
+    //     @Override
+    //     public void onResult(final DiscoverItemModel[] result) {
+    //         if (result == null || result.length <= 0) {
+    //             binding.swipeRefreshLayout.setRefreshing(false);
+    //             final Context context = getContext();
+    //             if (context == null) return;
+    //             Toast.makeText(context, R.string.discover_empty, Toast.LENGTH_SHORT).show();
+    //             return;
+    //         }
+    //         List<DiscoverItemModel> current = discoverItemViewModel.getList().getValue();
+    //         final List<DiscoverItemModel> resultList = Arrays.asList(result);
+    //         current = current == null ? new ArrayList<>() : new ArrayList<>(current); // copy to modifiable list
+    //         if (isPullToRefresh) {
+    //             current = resultList;
+    //             isPullToRefresh = false;
+    //         } else {
+    //             current.addAll(resultList);
+    //         }
+    //         discoverItemViewModel.getList().postValue(current);
+    //         binding.swipeRefreshLayout.setRefreshing(false);
+    //         final DiscoverItemModel discoverItemModel = result[result.length - 1];
+    //         if (discoverItemModel != null) {
+    //             discoverEndMaxId = discoverItemModel.getNextMaxId();
+    //             discoverHasMore = discoverItemModel.hasMore();
+    //             discoverItemModel.setMore(false, null);
+    //         }
+    //     }
+    // };
     private final OnBackPressedCallback onBackPressedCallback = new OnBackPressedCallback(false) {
         @Override
         public void handleOnBackPressed() {
             setEnabled(false);
             remove();
-            if (discoverAdapter == null) return;
-            discoverAdapter.clearSelection();
+            // if (discoverAdapter == null) return;
+            // discoverAdapter.clearSelection();
         }
     };
     private final PrimaryActionModeCallback multiSelectAction = new PrimaryActionModeCallback(
@@ -134,14 +92,14 @@ public class DiscoverFragment extends Fragment implements SwipeRefreshLayout.OnR
                 @Override
                 public boolean onActionItemClicked(final ActionMode mode, final MenuItem item) {
                     if (item.getItemId() == R.id.action_download) {
-                        if (discoverAdapter == null) return false;
-                        final Context context = getContext();
-                        if (context == null) return false;
-                        DownloadUtils.batchDownload(context,
-                                                    null,
-                                                    DownloadMethod.DOWNLOAD_DISCOVER,
-                                                    discoverAdapter.getSelectedModels());
-                        checkAndResetAction();
+                        // if (discoverAdapter == null) return false;
+                        // final Context context = getContext();
+                        // if (context == null) return false;
+                        // DownloadUtils.batchDownload(context,
+                        //                             null,
+                        //                             DownloadMethod.DOWNLOAD_DISCOVER,
+                        //                             discoverAdapter.getSelectedModels());
+                        // checkAndResetAction();
                         return true;
                     }
                     return false;
@@ -152,6 +110,7 @@ public class DiscoverFragment extends Fragment implements SwipeRefreshLayout.OnR
     public void onCreate(@Nullable final Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         fragmentActivity = (MainActivity) requireActivity();
+        discoverService = DiscoverService.getInstance();
     }
 
     @Override
@@ -170,95 +129,158 @@ public class DiscoverFragment extends Fragment implements SwipeRefreshLayout.OnR
     @Override
     public void onViewCreated(@NonNull final View view, @Nullable final Bundle savedInstanceState) {
         if (!shouldRefresh) return;
-        binding.discoverSwipeRefreshLayout.setOnRefreshListener(this);
-        setupExplore();
+        binding.swipeRefreshLayout.setOnRefreshListener(this);
+        init();
         shouldRefresh = false;
     }
 
+    private void init() {
+        // setExitSharedElementCallback(new SharedElementCallback() {
+        //     @Override
+        //     public void onSharedElementsArrived(final List<String> sharedElementNames,
+        //                                         final List<View> sharedElements,
+        //                                         final OnSharedElementsReadyListener listener) {
+        //         super.onSharedElementsArrived(sharedElementNames, sharedElements, listener);
+        //         Log.d(TAG, "onSharedElementsArrived: sharedElementNames: " + sharedElementNames);
+        //     }
+        //
+        //     @Override
+        //     public void onSharedElementEnd(final List<String> sharedElementNames,
+        //                                    final List<View> sharedElements,
+        //                                    final List<View> sharedElementSnapshots) {
+        //         super.onSharedElementEnd(sharedElementNames, sharedElements, sharedElementSnapshots);
+        //         Log.d(TAG, "onSharedElementEnd: sharedElementNames: " + sharedElementNames);
+        //     }
+        //
+        //     @Override
+        //     public void onSharedElementStart(final List<String> sharedElementNames,
+        //                                      final List<View> sharedElements,
+        //                                      final List<View> sharedElementSnapshots) {
+        //         super.onSharedElementStart(sharedElementNames, sharedElements, sharedElementSnapshots);
+        //         Log.d(TAG, "onSharedElementStart: sharedElementNames: " + sharedElementNames);
+        //     }
+        // });
+        setupTopics();
+        fetchTopics();
+    }
+
     @Override
     public void onRefresh() {
-        isPullToRefresh = true;
-        discoverEndMaxId = null;
-        lazyLoader.resetState();
-        fetchPosts();
+        fetchTopics();
+    }
+
+    public void setupTopics() {
+        topicClusterViewModel = new ViewModelProvider(fragmentActivity).get(TopicClusterViewModel.class);
+        binding.topicsRecyclerView.addItemDecoration(new GridSpacingItemDecoration(Utils.convertDpToPx(2)));
+        final DiscoverTopicsAdapter adapter = new DiscoverTopicsAdapter((topicCluster, root, cover, title, titleColor, backgroundColor) -> {
+            final FragmentNavigator.Extras.Builder builder = new FragmentNavigator.Extras.Builder()
+                    .addSharedElement(cover, "cover-" + topicCluster.getId());
+            // .addSharedElement(title, "title-" + topicCluster.getId());
+            final DiscoverFragmentDirections.ActionDiscoverFragmentToTopicPostsFragment action = DiscoverFragmentDirections
+                    .actionDiscoverFragmentToTopicPostsFragment(topicCluster, titleColor, backgroundColor);
+            NavHostFragment.findNavController(this).navigate(action, builder.build());
+        });
+        binding.topicsRecyclerView.setAdapter(adapter);
+        topicClusterViewModel.getList().observe(getViewLifecycleOwner(), adapter::submitList);
     }
 
     private void setupExplore() {
-        discoverItemViewModel = new ViewModelProvider(fragmentActivity).get(DiscoverItemViewModel.class);
-        final Context context = getContext();
-        if (context == null) return;
-        final GridAutofitLayoutManager layoutManager = new GridAutofitLayoutManager(context, Utils.convertDpToPx(110));
-        binding.discoverPosts.setLayoutManager(layoutManager);
-        binding.discoverPosts.addItemDecoration(new GridSpacingItemDecoration(Utils.convertDpToPx(4)));
-        binding.discoverType.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
+        // discoverItemViewModel = new ViewModelProvider(fragmentActivity).get(DiscoverItemViewModel.class);
+        // final Context context = getContext();
+        // if (context == null) return;
+        // final GridAutofitLayoutManager layoutManager = new GridAutofitLayoutManager(context, Utils.convertDpToPx(110));
+        // binding.postsRecyclerView.setLayoutManager(layoutManager);
+        // binding.postsRecyclerView.addItemDecoration(new GridSpacingItemDecoration(Utils.convertDpToPx(4)));
+        // binding.discoverType.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
+        //     @Override
+        //     public void onItemSelected(AdapterView<?> parent, View view, int pos, long id) {
+        //         if (topicIds == null || topicIds.length <= 0) return;
+        //         currentTopic = topicIds[pos];
+        //         onRefresh();
+        //     }
+        //
+        //     @Override
+        //     public void onNothingSelected(AdapterView<?> parent) {}
+        // });
+        // discoverAdapter = new DiscoverAdapter((model, position) -> {
+        //     if (discoverAdapter.isSelecting()) {
+        //         if (actionMode == null) return;
+        //         final String title = getString(R.string.number_selected, discoverAdapter.getSelectedModels().size());
+        //         actionMode.setTitle(title);
+        //         return;
+        //     }
+        //     if (checkAndResetAction()) return;
+        //     final List<DiscoverItemModel> discoverItemModels = discoverItemViewModel.getList().getValue();
+        //     if (discoverItemModels == null || discoverItemModels.size() == 0) return;
+        //     if (discoverItemModels.get(0) == null) return;
+        //     final String postId = discoverItemModels.get(0).getPostId();
+        //     final boolean isId = postId != null;
+        //     final String[] idsOrShortCodes = new String[discoverItemModels.size()];
+        //     for (int i = 0; i < discoverItemModels.size(); i++) {
+        //         idsOrShortCodes[i] = isId ? discoverItemModels.get(i).getPostId()
+        //                                   : discoverItemModels.get(i).getShortCode();
+        //     }
+        //     final NavDirections action = DiscoverFragmentDirections.actionGlobalPostViewFragment(
+        //             position,
+        //             idsOrShortCodes,
+        //             isId);
+        //     NavHostFragment.findNavController(this).navigate(action);
+        // }, (model, position) -> {
+        //     if (!discoverAdapter.isSelecting()) {
+        //         checkAndResetAction();
+        //         return true;
+        //     }
+        //     final OnBackPressedDispatcher onBackPressedDispatcher = fragmentActivity.getOnBackPressedDispatcher();
+        //     if (onBackPressedCallback.isEnabled()) {
+        //         return true;
+        //     }
+        //     actionMode = fragmentActivity.startActionMode(multiSelectAction);
+        //     final String title = getString(R.string.number_selected, 1);
+        //     actionMode.setTitle(title);
+        //     onBackPressedDispatcher.addCallback(getViewLifecycleOwner(), onBackPressedCallback);
+        //     return true;
+        // });
+        // binding.postsRecyclerView.setAdapter(discoverAdapter);
+        // discoverItemViewModel.getList().observe(fragmentActivity, discoverAdapter::submitList);
+        // lazyLoader = new RecyclerLazyLoader(layoutManager, (page, totalItemsCount) -> {
+        //     if (discoverHasMore) {
+        //         fetchPosts();
+        //     }
+        // }, 3);
+        // binding.postsRecyclerView.addOnScrollListener(lazyLoader);
+        // binding.postsRecyclerView.setViewModelStoreOwner(this)
+        //                          .setLifeCycleOwner(this)
+        //                          .setPostFetchService(new DiscoverPostFetchService())
+        //                          .setLayoutPreferences(PostsLayoutPreferences.fromJson(settingsHelper.getString(Constants.PREF_PROFILE_POSTS_LAYOUT)))
+        //                          .addFetchStatusChangeListener(fetching -> updateSwipeRefreshState())
+        //                          .setFeedItemCallback(feedItemCallback)
+        //                          .init();
+        // binding.swipeRefreshLayout.setRefreshing(true);
+    }
+
+    private void fetchTopics() {
+        // new iTopicFetcher(topicFetchListener).executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
+        binding.swipeRefreshLayout.setRefreshing(true);
+        discoverService.topicalExplore(new DiscoverService.TopicalExploreRequest(), new ServiceCallback<DiscoverService.TopicalExploreResponse>() {
             @Override
-            public void onItemSelected(AdapterView<?> parent, View view, int pos, long id) {
-                if (topicIds == null || topicIds.length <= 0) return;
-                currentTopic = topicIds[pos];
-                onRefresh();
+            public void onSuccess(final DiscoverService.TopicalExploreResponse result) {
+                topicClusterViewModel.getList().postValue(result.getClusters());
+                binding.swipeRefreshLayout.setRefreshing(false);
             }
 
             @Override
-            public void onNothingSelected(AdapterView<?> parent) {}
-        });
-        discoverAdapter = new DiscoverAdapter((model, position) -> {
-            if (discoverAdapter.isSelecting()) {
-                if (actionMode == null) return;
-                final String title = getString(R.string.number_selected, discoverAdapter.getSelectedModels().size());
-                actionMode.setTitle(title);
-                return;
-            }
-            if (checkAndResetAction()) return;
-            final List<DiscoverItemModel> discoverItemModels = discoverItemViewModel.getList().getValue();
-            if (discoverItemModels == null || discoverItemModels.size() == 0) return;
-            if (discoverItemModels.get(0) == null) return;
-            final String postId = discoverItemModels.get(0).getPostId();
-            final boolean isId = postId != null;
-            final String[] idsOrShortCodes = new String[discoverItemModels.size()];
-            for (int i = 0; i < discoverItemModels.size(); i++) {
-                idsOrShortCodes[i] = isId ? discoverItemModels.get(i).getPostId()
-                                          : discoverItemModels.get(i).getShortCode();
+            public void onFailure(final Throwable t) {
+                Log.e(TAG, "onFailure", t);
+                binding.swipeRefreshLayout.setRefreshing(false);
             }
-            final NavDirections action = DiscoverFragmentDirections.actionGlobalPostViewFragment(
-                    position,
-                    idsOrShortCodes,
-                    isId);
-            NavHostFragment.findNavController(this).navigate(action);
-        }, (model, position) -> {
-            if (!discoverAdapter.isSelecting()) {
-                checkAndResetAction();
-                return true;
-            }
-            final OnBackPressedDispatcher onBackPressedDispatcher = fragmentActivity.getOnBackPressedDispatcher();
-            if (onBackPressedCallback.isEnabled()) {
-                return true;
-            }
-            actionMode = fragmentActivity.startActionMode(multiSelectAction);
-            final String title = getString(R.string.number_selected, 1);
-            actionMode.setTitle(title);
-            onBackPressedDispatcher.addCallback(getViewLifecycleOwner(), onBackPressedCallback);
-            return true;
         });
-        binding.discoverPosts.setAdapter(discoverAdapter);
-        discoverItemViewModel.getList().observe(fragmentActivity, discoverAdapter::submitList);
-        lazyLoader = new RecyclerLazyLoader(layoutManager, (page, totalItemsCount) -> {
-            if (discoverHasMore) {
-                fetchPosts();
-            }
-        }, 3);
-        binding.discoverPosts.addOnScrollListener(lazyLoader);
-        fetchTopics();
     }
 
-    private void fetchTopics() {
-        new iTopicFetcher(topicFetchListener).executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
-    }
-
-    private void fetchPosts() {
-        binding.discoverSwipeRefreshLayout.setRefreshing(true);
-        new DiscoverFetcher(currentTopic, discoverEndMaxId, rankToken, postsFetchListener, false)
-                .executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
-    }
+    // private void fetchPosts() {
+    // binding.swipeRefreshLayout.setRefreshing(true);
+    // new DiscoverFetcher(currentTopic, discoverEndMaxId, rankToken, postsFetchListener, false)
+    //         .executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
+    // }
 
     private boolean checkAndResetAction() {
         if (!onBackPressedCallback.isEnabled() && actionMode == null) {

app/src/main/java/awais/instagrabber/fragments/main/FeedFragment.java

@@ -58,17 +58,10 @@ public class FeedFragment extends Fragment implements SwipeRefreshLayout.OnRefre
     private CoordinatorLayout root;
     private FragmentFeedBinding binding;
     private StoriesService storiesService;
-    // private boolean feedHasNextPage = false;
-    // private String feedEndCursor = null;
-    // private FeedViewModel feedViewModel;
-    // private VideoAwareRecyclerScroller videoAwareRecyclerScroller;
     private boolean shouldRefresh = true;
-    // private boolean isPullToRefresh;
     private FeedStoriesViewModel feedStoriesViewModel;
-    // private StaggeredGridLayoutManager gridLayoutManager;
     private boolean storiesFetching;
 
-    // private final boolean shouldAutoPlay = settingsHelper.getBoolean(Constants.AUTOPLAY_VIDEOS);
     private final FeedAdapterV2.FeedItemCallback feedItemCallback = new FeedAdapterV2.FeedItemCallback() {
         @Override
         public void onPostClick(final FeedModel feedModel, final View profilePicView, final View mainPostImage) {
@@ -226,15 +219,11 @@ public class FeedFragment extends Fragment implements SwipeRefreshLayout.OnRefre
 
     @Override
     public void onRefresh() {
-        // isPullToRefresh = true;
-        // feedEndCursor = null;
         binding.feedRecyclerView.refresh();
         fetchStories();
     }
 
     private void setupFeed() {
-        final Context context = getContext();
-        if (context == null) return;
         binding.feedRecyclerView.setViewModelStoreOwner(this)
                                 .setLifeCycleOwner(this)
                                 .setPostFetchService(new FeedPostFetchService())
@@ -331,8 +320,9 @@ public class FeedFragment extends Fragment implements SwipeRefreshLayout.OnRefre
     }
 
     private void showPostsLayoutPreferences() {
-        final PostsLayoutPreferencesDialogFragment fragment = new PostsLayoutPreferencesDialogFragment(Constants.PREF_POSTS_LAYOUT, preferences -> new Handler()
-                .postDelayed(() -> binding.feedRecyclerView.setLayoutPreferences(preferences), 200));
+        final PostsLayoutPreferencesDialogFragment fragment = new PostsLayoutPreferencesDialogFragment(
+                Constants.PREF_POSTS_LAYOUT,
+                preferences -> new Handler().postDelayed(() -> binding.feedRecyclerView.setLayoutPreferences(preferences), 200));
         fragment.show(getChildFragmentManager(), "posts_layout_preferences");
     }
 }

app/src/main/java/awais/instagrabber/models/TopicCluster.java

@@ -0,0 +1,57 @@
+package awais.instagrabber.models;
+
+import java.io.Serializable;
+
+public class TopicCluster implements Serializable {
+    private String id;
+    private String title;
+    private String type;
+    private boolean canMute;
+    private boolean isMuted;
+    private int rankedPosition;
+    private FeedModel coverMedia;
+
+    public TopicCluster(final String id,
+                        final String title,
+                        final String type,
+                        final boolean canMute,
+                        final boolean isMuted,
+                        final int rankedPosition,
+                        final FeedModel coverMedia) {
+        this.id = id;
+        this.title = title;
+        this.type = type;
+        this.canMute = canMute;
+        this.isMuted = isMuted;
+        this.rankedPosition = rankedPosition;
+        this.coverMedia = coverMedia;
+    }
+
+    public String getId() {
+        return id;
+    }
+
+    public String getTitle() {
+        return title;
+    }
+
+    public String getType() {
+        return type;
+    }
+
+    public boolean isCanMute() {
+        return canMute;
+    }
+
+    public boolean isMuted() {
+        return isMuted;
+    }
+
+    public int getRankedPosition() {
+        return rankedPosition;
+    }
+
+    public FeedModel getCoverMedia() {
+        return coverMedia;
+    }
+}

app/src/main/java/awais/instagrabber/repositories/DiscoverRepository.java

@@ -0,0 +1,12 @@
+package awais.instagrabber.repositories;
+
+import java.util.Map;
+
+import retrofit2.Call;
+import retrofit2.http.GET;
+import retrofit2.http.QueryMap;
+
+public interface DiscoverRepository {
+    @GET("/api/v1/discover/topical_explore/")
+    Call<String> topicalExplore(@QueryMap Map<String, String> queryParams);
+}

app/src/main/java/awais/instagrabber/utils/Constants.java

@@ -89,4 +89,5 @@ public final class Constants {
     public static final String SHARED_PREFERENCES_NAME = "settings";
     public static final String PREF_POSTS_LAYOUT = "posts_layout";
     public static final String PREF_PROFILE_POSTS_LAYOUT = "profile_posts_layout";
+    public static final String PREF_TOPIC_POSTS_LAYOUT = "topic_posts_layout";
 }

app/src/main/java/awais/instagrabber/utils/ResponseBodyUtils.java

@@ -99,7 +99,7 @@ public final class ResponseBodyUtils {
             if (Utils.logCollector != null)
                 Utils.logCollector.appendException(e, LogCollector.LogFile.UTILS, "getLowQualityImage",
                                                    new Pair<>("resourcesNull", resources == null));
-            if (BuildConfig.DEBUG) Log.e("AWAISKING_APP", "", e);
+            if (BuildConfig.DEBUG) Log.e(TAG, "Error in getLowQualityImage", e);
         }
         return src;
     }
@@ -152,12 +152,24 @@ public final class ResponseBodyUtils {
     }
 
     public static String getVideoUrl(@NonNull final JSONObject mediaObj) {
-        String thumbnail = null;
-        final JSONArray imageVersions = mediaObj.optJSONArray("video_versions");
-        if (imageVersions != null) {
-            thumbnail = getItemThumbnail(imageVersions).url;
+        String url = null;
+        final JSONArray videoVersions = mediaObj.optJSONArray("video_versions");
+        if (videoVersions == null) {
+            return null;
         }
-        return thumbnail;
+        int largestWidth = 0;
+        for (int i = 0; i < videoVersions.length(); i++) {
+            final JSONObject videoVersionJson = videoVersions.optJSONObject(i);
+            if (videoVersionJson == null) {
+                continue;
+            }
+            final int width = videoVersionJson.optInt("width");
+            if (largestWidth == 0 || width > largestWidth) {
+                largestWidth = width;
+                url = videoVersionJson.optString("url");
+            }
+        }
+        return url;
     }
 
     @Nullable

app/src/main/java/awais/instagrabber/utils/SettingsHelper.java

@@ -32,6 +32,7 @@ import static awais.instagrabber.utils.Constants.PREF_DARK_THEME;
 import static awais.instagrabber.utils.Constants.PREF_LIGHT_THEME;
 import static awais.instagrabber.utils.Constants.PREF_POSTS_LAYOUT;
 import static awais.instagrabber.utils.Constants.PREF_PROFILE_POSTS_LAYOUT;
+import static awais.instagrabber.utils.Constants.PREF_TOPIC_POSTS_LAYOUT;
 import static awais.instagrabber.utils.Constants.PREV_INSTALL_VERSION;
 import static awais.instagrabber.utils.Constants.SHOW_QUICK_ACCESS_DIALOG;
 import static awais.instagrabber.utils.Constants.SKIPPED_VERSION;
@@ -115,7 +116,8 @@ public final class SettingsHelper {
 
     @StringDef(
             {APP_LANGUAGE, APP_THEME, COOKIE, FOLDER_PATH, DATE_TIME_FORMAT, DATE_TIME_SELECTION, CUSTOM_DATE_TIME_FORMAT,
-                    DEVICE_UUID, SKIPPED_VERSION, DEFAULT_TAB, PREF_DARK_THEME, PREF_LIGHT_THEME, PREF_POSTS_LAYOUT, PREF_PROFILE_POSTS_LAYOUT})
+                    DEVICE_UUID, SKIPPED_VERSION, DEFAULT_TAB, PREF_DARK_THEME, PREF_LIGHT_THEME, PREF_POSTS_LAYOUT, PREF_PROFILE_POSTS_LAYOUT,
+                    PREF_TOPIC_POSTS_LAYOUT})
     public @interface StringSettings {}
 
     @StringDef({DOWNLOAD_USER_FOLDER, FOLDER_SAVE_TO, AUTOPLAY_VIDEOS, SHOW_QUICK_ACCESS_DIALOG, MUTED_VIDEOS,

app/src/main/java/awais/instagrabber/viewmodels/TopicClusterViewModel.java

@@ -0,0 +1,19 @@
+package awais.instagrabber.viewmodels;
+
+import androidx.lifecycle.MutableLiveData;
+import androidx.lifecycle.ViewModel;
+
+import java.util.List;
+
+import awais.instagrabber.models.TopicCluster;
+
+public class TopicClusterViewModel extends ViewModel {
+    private MutableLiveData<List<TopicCluster>> list;
+
+    public MutableLiveData<List<TopicCluster>> getList() {
+        if (list == null) {
+            list = new MutableLiveData<>();
+        }
+        return list;
+    }
+}

app/src/main/java/awais/instagrabber/webservices/DiscoverService.java

@@ -0,0 +1,501 @@
+package awais.instagrabber.webservices;
+
+import androidx.annotation.NonNull;
+
+import com.google.common.collect.ImmutableBiMap;
+
+import org.json.JSONArray;
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.Objects;
+
+import awais.instagrabber.models.FeedModel;
+import awais.instagrabber.models.PostChild;
+import awais.instagrabber.models.ProfileModel;
+import awais.instagrabber.models.TopicCluster;
+import awais.instagrabber.models.enums.MediaItemType;
+import awais.instagrabber.repositories.DiscoverRepository;
+import awais.instagrabber.utils.Constants;
+import awais.instagrabber.utils.ResponseBodyUtils;
+import awais.instagrabber.utils.TextUtils;
+import retrofit2.Call;
+import retrofit2.Callback;
+import retrofit2.Response;
+import retrofit2.Retrofit;
+
+public class DiscoverService extends BaseService {
+
+    private static final String TAG = "DiscoverService";
+
+    private final DiscoverRepository repository;
+
+    private static DiscoverService instance;
+
+    private DiscoverService() {
+        final Retrofit retrofit = getRetrofitBuilder()
+                .baseUrl("https://i.instagram.com")
+                .build();
+        repository = retrofit.create(DiscoverRepository.class);
+    }
+
+    public static DiscoverService getInstance() {
+        if (instance == null) {
+            instance = new DiscoverService();
+        }
+        return instance;
+    }
+
+    public void topicalExplore(@NonNull final TopicalExploreRequest request,
+                               final ServiceCallback<TopicalExploreResponse> callback) {
+        final ImmutableBiMap.Builder<String, String> builder = ImmutableBiMap.<String, String>builder()
+                .put("module", "explore_popular");
+        if (!TextUtils.isEmpty(request.getModule())) {
+            builder.put("module", request.getModule());
+        }
+        if (!TextUtils.isEmpty(request.getClusterId())) {
+            builder.put("cluster_id", request.getClusterId());
+        }
+        if (request.getMaxId() >= 0) {
+            builder.put("max_id", String.valueOf(request.getMaxId()));
+        }
+        final Call<String> req = repository.topicalExplore(builder.build());
+        req.enqueue(new Callback<String>() {
+            @Override
+            public void onResponse(@NonNull final Call<String> call, @NonNull final Response<String> response) {
+                if (callback == null) {
+                    return;
+                }
+                final String body = response.body();
+                if (TextUtils.isEmpty(body)) {
+                    callback.onSuccess(null);
+                    return;
+                }
+                try {
+                    final TopicalExploreResponse topicalExploreResponse = parseTopicalExploreResponse(body);
+                    callback.onSuccess(topicalExploreResponse);
+                } catch (JSONException e) {
+                    callback.onFailure(e);
+                    // Log.e(TAG, "Error parsing topicalExplore response", e);
+                }
+            }
+
+            @Override
+            public void onFailure(@NonNull final Call<String> call, @NonNull final Throwable t) {
+                callback.onFailure(t);
+            }
+        });
+    }
+
+    private TopicalExploreResponse parseTopicalExploreResponse(@NonNull final String body) throws JSONException {
+        final JSONObject root = new JSONObject(body);
+        final boolean moreAvailable = root.optBoolean("more_available");
+        final int nextMaxId = root.optInt("next_max_id", -1);
+        final int numResults = root.optInt("num_results");
+        final String status = root.optString("status");
+        final JSONArray clustersJson = root.optJSONArray("clusters");
+        final List<TopicCluster> clusters = parseClusters(clustersJson);
+        final JSONArray itemsJson = root.optJSONArray("items");
+        final List<FeedModel> items = parseItems(itemsJson);
+        return new TopicalExploreResponse(
+                moreAvailable,
+                nextMaxId,
+                numResults,
+                status,
+                clusters,
+                items
+        );
+    }
+
+    private List<TopicCluster> parseClusters(final JSONArray clustersJson) throws JSONException {
+        if (clustersJson == null) {
+            return Collections.emptyList();
+        }
+        final List<TopicCluster> clusters = new ArrayList<>();
+        for (int i = 0; i < clustersJson.length(); i++) {
+            final JSONObject clusterJson = clustersJson.getJSONObject(i);
+            final String id = clusterJson.optString("id");
+            final String title = clusterJson.optString("title");
+            if (id == null || title == null) {
+                continue;
+            }
+            final String type = clusterJson.optString("type");
+            final boolean canMute = clusterJson.optBoolean("can_mute");
+            final boolean isMuted = clusterJson.optBoolean("is_muted");
+            final JSONObject coverMediaJson = clusterJson.optJSONObject("cover_media");
+            final int rankedPosition = clusterJson.optInt("ranked_position");
+            final FeedModel feedModel = parseClusterCover(coverMediaJson);
+            final TopicCluster topicCluster = new TopicCluster(
+                    id,
+                    title,
+                    type,
+                    canMute,
+                    isMuted,
+                    rankedPosition,
+                    feedModel
+            );
+            clusters.add(topicCluster);
+        }
+        return clusters;
+    }
+
+    private FeedModel parseClusterCover(final JSONObject coverMediaJson) throws JSONException {
+        if (coverMediaJson == null) {
+            return null;
+        }
+        ProfileModel profileModel = null;
+        if (coverMediaJson.has("user")) {
+            final JSONObject user = coverMediaJson.getJSONObject("user");
+            profileModel = new ProfileModel(
+                    user.optBoolean("is_private"),
+                    false,
+                    user.optBoolean("is_verified"),
+                    user.getString("pk"),
+                    user.getString(Constants.EXTRAS_USERNAME),
+                    user.optString("full_name"),
+                    null,
+                    null,
+                    user.getString("profile_pic_url"),
+                    null,
+                    0,
+                    0,
+                    0,
+                    false,
+                    false,
+                    false,
+                    false);
+        }
+        final String resourceUrl = ResponseBodyUtils.getHighQualityImage(coverMediaJson);
+        final String thumbnailUrl = ResponseBodyUtils.getLowQualityImage(coverMediaJson);
+        final int width = coverMediaJson.optInt("original_width");
+        final int height = coverMediaJson.optInt("original_height");
+        return new FeedModel.Builder()
+                .setProfileModel(profileModel)
+                .setItemType(MediaItemType.MEDIA_TYPE_IMAGE)
+                .setViewCount(0)
+                .setPostId(coverMediaJson.getString(Constants.EXTRAS_ID))
+                .setDisplayUrl(resourceUrl)
+                .setThumbnailUrl(thumbnailUrl)
+                .setShortCode(coverMediaJson.getString("code"))
+                .setPostCaption(null)
+                .setCommentsCount(0)
+                .setTimestamp(coverMediaJson.optLong("taken_at", -1))
+                .setLiked(false)
+                .setBookmarked(false)
+                .setLikesCount(0)
+                .setLocationName(null)
+                .setLocationId(null)
+                .setImageHeight(height)
+                .setImageWidth(width)
+                .build();
+    }
+
+    private List<FeedModel> parseItems(final JSONArray items) throws JSONException {
+        if (items == null) {
+            return Collections.emptyList();
+        }
+        final List<FeedModel> feedModels = new ArrayList<>();
+        for (int i = 0; i < items.length(); i++) {
+            final JSONObject itemJson = items.optJSONObject(i);
+            if (itemJson == null) {
+                continue;
+            }
+            final JSONObject mediaJson = itemJson.optJSONObject("media");
+            final FeedModel feedModel = parseClusterItemMedia(mediaJson);
+            if (feedModel != null) {
+                feedModels.add(feedModel);
+            }
+        }
+        return feedModels;
+    }
+
+    private FeedModel parseClusterItemMedia(final JSONObject mediaJson) throws JSONException {
+        if (mediaJson == null) {
+            return null;
+        }
+        ProfileModel profileModel = null;
+        if (mediaJson.has("user")) {
+            final JSONObject user = mediaJson.getJSONObject("user");
+            final JSONObject friendshipStatus = user.optJSONObject("friendship_status");
+            boolean following = false;
+            boolean restricted = false;
+            boolean requested = false;
+            if (friendshipStatus != null) {
+                following = friendshipStatus.optBoolean("following");
+                requested = friendshipStatus.optBoolean("outgoing_request");
+                restricted = friendshipStatus.optBoolean("is_restricted");
+            }
+            profileModel = new ProfileModel(
+                    user.optBoolean("is_private"),
+                    false, // if you can see it then you def follow
+                    user.optBoolean("is_verified"),
+                    user.getString("pk"),
+                    user.getString(Constants.EXTRAS_USERNAME),
+                    user.optString("full_name"),
+                    null,
+                    null,
+                    user.getString("profile_pic_url"),
+                    null,
+                    0,
+                    0,
+                    0,
+                    following,
+                    restricted,
+                    false,
+                    requested);
+        }
+        final JSONObject captionJson = mediaJson.optJSONObject("caption");
+        final JSONObject locationJson = mediaJson.optJSONObject("location");
+        final MediaItemType mediaType = ResponseBodyUtils.getMediaItemType(mediaJson.optInt("media_type"));
+        final FeedModel.Builder feedModelBuilder = new FeedModel.Builder()
+                .setItemType(mediaType)
+                .setProfileModel(profileModel)
+                .setPostId(mediaJson.getString(Constants.EXTRAS_ID))
+                .setThumbnailUrl(mediaType != MediaItemType.MEDIA_TYPE_SLIDER ? ResponseBodyUtils.getLowQualityImage(mediaJson) : null)
+                .setShortCode(mediaJson.getString("code"))
+                .setPostCaption(captionJson != null ? captionJson.optString("text") : null)
+                .setCommentsCount(mediaJson.optInt("comment_count"))
+                .setTimestamp(mediaJson.optLong("taken_at", -1))
+                .setLiked(mediaJson.optBoolean("has_liked"))
+                // .setBookmarked()
+                .setLikesCount(mediaJson.optInt("like_count"))
+                .setLocationName(locationJson != null ? locationJson.optString("name") : null)
+                .setLocationId(locationJson != null ? String.valueOf(locationJson.optInt("pk")) : null)
+                .setImageHeight(mediaJson.optInt("original_height"))
+                .setImageWidth(mediaJson.optInt("original_width"));
+        switch (mediaType) {
+            case MEDIA_TYPE_VIDEO:
+                final long videoViews = mediaJson.optLong("view_count", 0);
+                feedModelBuilder.setViewCount(videoViews)
+                                .setDisplayUrl(ResponseBodyUtils.getVideoUrl(mediaJson));
+                break;
+            case MEDIA_TYPE_IMAGE:
+                feedModelBuilder.setDisplayUrl(ResponseBodyUtils.getHighQualityImage(mediaJson));
+                break;
+            case MEDIA_TYPE_SLIDER:
+                final List<PostChild> childPosts = getChildPosts(mediaJson);
+                feedModelBuilder.setSliderItems(childPosts);
+                break;
+        }
+        return feedModelBuilder.build();
+    }
+
+    private List<PostChild> getChildPosts(final JSONObject mediaJson) throws JSONException {
+        if (mediaJson == null) {
+            return Collections.emptyList();
+        }
+        final JSONArray carouselMedia = mediaJson.optJSONArray("carousel_media");
+        if (carouselMedia == null) {
+            return Collections.emptyList();
+        }
+        final List<PostChild> children = new ArrayList<>();
+        for (int i = 0; i < carouselMedia.length(); i++) {
+            final JSONObject childJson = carouselMedia.optJSONObject(i);
+            final PostChild childPost = getChildPost(childJson);
+            if (childPost != null) {
+                children.add(childPost);
+            }
+        }
+        return children;
+    }
+
+    private PostChild getChildPost(final JSONObject childJson) throws JSONException {
+        if (childJson == null) {
+            return null;
+        }
+        final MediaItemType mediaType = ResponseBodyUtils.getMediaItemType(childJson.optInt("media_type"));
+        final PostChild.Builder builder = new PostChild.Builder();
+        switch (mediaType) {
+            case MEDIA_TYPE_VIDEO:
+                builder.setDisplayUrl(ResponseBodyUtils.getVideoUrl(childJson));
+                break;
+            case MEDIA_TYPE_IMAGE:
+                builder.setDisplayUrl(ResponseBodyUtils.getHighQualityImage(childJson));
+                break;
+        }
+        return builder.setItemType(mediaType)
+                      .setPostId(childJson.getString("id"))
+                      .setThumbnailUrl(ResponseBodyUtils.getLowQualityImage(childJson))
+                      .setHeight(childJson.optInt("original_height"))
+                      .setWidth(childJson.optInt("original_width"))
+                      .build();
+    }
+
+    public static class TopicalExploreRequest {
+
+        private String module;
+        private String clusterId;
+        private int maxId = -1;
+
+        public TopicalExploreRequest() {}
+
+        public TopicalExploreRequest(final String module, final String clusterId, final int maxId) {
+            this.module = module;
+            this.clusterId = clusterId;
+            this.maxId = maxId;
+        }
+
+        public String getModule() {
+            return module;
+        }
+
+        public TopicalExploreRequest setModule(final String module) {
+            this.module = module;
+            return this;
+        }
+
+        public String getClusterId() {
+            return clusterId;
+        }
+
+        public TopicalExploreRequest setClusterId(final String clusterId) {
+            this.clusterId = clusterId;
+            return this;
+        }
+
+        public int getMaxId() {
+            return maxId;
+        }
+
+        public TopicalExploreRequest setMaxId(final int maxId) {
+            this.maxId = maxId;
+            return this;
+        }
+
+        @Override
+        public boolean equals(final Object o) {
+            if (this == o) return true;
+            if (o == null || getClass() != o.getClass()) return false;
+            final TopicalExploreRequest that = (TopicalExploreRequest) o;
+            return maxId == that.maxId &&
+                    Objects.equals(module, that.module) &&
+                    Objects.equals(clusterId, that.clusterId);
+        }
+
+        @Override
+        public int hashCode() {
+            return Objects.hash(module, clusterId, maxId);
+        }
+
+        @Override
+        public String toString() {
+            return "TopicalExploreRequest{" +
+                    "module='" + module + '\'' +
+                    ", clusterId='" + clusterId + '\'' +
+                    ", maxId=" + maxId +
+                    '}';
+        }
+    }
+
+    public static class TopicalExploreResponse {
+
+        private boolean moreAvailable;
+        private int nextMaxId;
+        private int numResults;
+        private String status;
+        private List<TopicCluster> clusters;
+        private List<FeedModel> items;
+
+        public TopicalExploreResponse() {}
+
+        public TopicalExploreResponse(final boolean moreAvailable,
+                                      final int nextMaxId,
+                                      final int numResults,
+                                      final String status,
+                                      final List<TopicCluster> clusters, final List<FeedModel> items) {
+            this.moreAvailable = moreAvailable;
+            this.nextMaxId = nextMaxId;
+            this.numResults = numResults;
+            this.status = status;
+            this.clusters = clusters;
+            this.items = items;
+        }
+
+        public boolean isMoreAvailable() {
+            return moreAvailable;
+        }
+
+        public TopicalExploreResponse setMoreAvailable(final boolean moreAvailable) {
+            this.moreAvailable = moreAvailable;
+            return this;
+        }
+
+        public int getNextMaxId() {
+            return nextMaxId;
+        }
+
+        public TopicalExploreResponse setNextMaxId(final int nextMaxId) {
+            this.nextMaxId = nextMaxId;
+            return this;
+        }
+
+        public int getNumResults() {
+            return numResults;
+        }
+
+        public TopicalExploreResponse setNumResults(final int numResults) {
+            this.numResults = numResults;
+            return this;
+        }
+
+        public String getStatus() {
+            return status;
+        }
+
+        public TopicalExploreResponse setStatus(final String status) {
+            this.status = status;
+            return this;
+        }
+
+        public List<TopicCluster> getClusters() {
+            return clusters;
+        }
+
+        public TopicalExploreResponse setClusters(final List<TopicCluster> clusters) {
+            this.clusters = clusters;
+            return this;
+        }
+
+        public List<FeedModel> getItems() {
+            return items;
+        }
+
+        public TopicalExploreResponse setItems(final List<FeedModel> items) {
+            this.items = items;
+            return this;
+        }
+
+        @Override
+        public boolean equals(final Object o) {
+            if (this == o) return true;
+            if (o == null || getClass() != o.getClass()) return false;
+            final TopicalExploreResponse that = (TopicalExploreResponse) o;
+            return moreAvailable == that.moreAvailable &&
+                    nextMaxId == that.nextMaxId &&
+                    numResults == that.numResults &&
+                    Objects.equals(status, that.status) &&
+                    Objects.equals(clusters, that.clusters) &&
+                    Objects.equals(items, that.items);
+        }
+
+        @Override
+        public int hashCode() {
+            return Objects.hash(moreAvailable, nextMaxId, numResults, status, clusters, items);
+        }
+
+        @Override
+        public String toString() {
+            return "TopicalExploreResponse{" +
+                    "moreAvailable=" + moreAvailable +
+                    ", nextMaxId=" + nextMaxId +
+                    ", numResults=" + numResults +
+                    ", status='" + status + '\'' +
+                    ", clusters=" + clusters +
+                    ", items=" + items +
+                    '}';
+        }
+    }
+}

app/src/main/res/layout/fragment_discover.xml

@@ -7,37 +7,39 @@
     android:animateLayoutChanges="true"
     android:background="?attr/colorSurface">
 
-    <com.google.android.material.appbar.AppBarLayout
-        android:layout_width="match_parent"
-        android:layout_height="wrap_content"
-        android:background="?attr/colorSurface"
-        app:elevation="0dp">
+    <!--<com.google.android.material.appbar.AppBarLayout-->
+    <!--    android:layout_width="match_parent"-->
+    <!--    android:layout_height="wrap_content"-->
+    <!--    android:background="?attr/colorSurface"-->
+    <!--    app:elevation="0dp">-->
 
-        <com.google.android.material.appbar.CollapsingToolbarLayout
-            android:layout_width="match_parent"
-            android:layout_height="wrap_content"
-            app:layout_scrollFlags="scroll|snap|enterAlways">
+    <!--    <com.google.android.material.appbar.CollapsingToolbarLayout-->
+    <!--        android:layout_width="match_parent"-->
+    <!--        android:layout_height="wrap_content"-->
+    <!--        app:layout_scrollFlags="scroll|snap|enterAlways">-->
 
-            <androidx.appcompat.widget.AppCompatSpinner
-                android:id="@+id/discoverType"
-                android:layout_width="match_parent"
-                android:layout_height="wrap_content"
-                android:entries="@array/discover_placeholder"
-                android:spinnerMode="dialog" />
-        </com.google.android.material.appbar.CollapsingToolbarLayout>
-    </com.google.android.material.appbar.AppBarLayout>
+    <!--        <androidx.appcompat.widget.AppCompatSpinner-->
+    <!--            android:id="@+id/discoverType"-->
+    <!--            android:layout_width="match_parent"-->
+    <!--            android:layout_height="wrap_content"-->
+    <!--            android:entries="@array/discover_placeholder"-->
+    <!--            android:spinnerMode="dialog" />-->
+    <!--    </com.google.android.material.appbar.CollapsingToolbarLayout>-->
+    <!--</com.google.android.material.appbar.AppBarLayout>-->
 
     <androidx.swiperefreshlayout.widget.SwipeRefreshLayout
-        android:id="@+id/discoverSwipeRefreshLayout"
+        android:id="@+id/swipe_refresh_layout"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         app:layout_behavior="@string/appbar_scrolling_view_behavior">
 
         <androidx.recyclerview.widget.RecyclerView
-            android:id="@+id/discoverPosts"
+            android:id="@+id/topics_recycler_view"
             android:layout_width="match_parent"
             android:layout_height="match_parent"
-            android:clipToPadding="false"
-            tools:listitem="@layout/item_post" />
+            app:layoutManager="androidx.recyclerview.widget.GridLayoutManager"
+            app:spanCount="2"
+            tools:itemCount="10"
+            tools:listitem="@layout/item_discover_topic" />
     </androidx.swiperefreshlayout.widget.SwipeRefreshLayout>
 </awais.instagrabber.customviews.helpers.NestedCoordinatorLayout>

app/src/main/res/layout/fragment_profile.xml

@@ -285,20 +285,6 @@
             tools:listitem="@layout/item_feed_photo" />
     </androidx.swiperefreshlayout.widget.SwipeRefreshLayout>
 
-    <!--<androidx.swiperefreshlayout.widget.SwipeRefreshLayout-->
-    <!--    android:id="@+id/swipeRefreshLayout"-->
-    <!--    android:layout_width="match_parent"-->
-    <!--    android:layout_height="match_parent"-->
-    <!--    app:layout_behavior="com.google.android.material.appbar.AppBarLayout$ScrollingViewBehavior">-->
-
-    <!--    <androidx.recyclerview.widget.RecyclerView-->
-    <!--        android:id="@+id/mainPosts"-->
-    <!--        android:layout_width="match_parent"-->
-    <!--        android:layout_height="match_parent"-->
-    <!--        android:clipToPadding="false"-->
-    <!--        tools:listitem="@layout/item_post" />-->
-    <!--</androidx.swiperefreshlayout.widget.SwipeRefreshLayout>-->
-
     <LinearLayout
         android:id="@+id/privatePage"
         android:layout_width="match_parent"

app/src/main/res/layout/fragment_topic_posts.xml

@@ -0,0 +1,58 @@
+<?xml version="1.0" encoding="utf-8"?>
+<awais.instagrabber.customviews.helpers.NestedCoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:background="?attr/colorSurface">
+
+    <com.google.android.material.appbar.AppBarLayout
+        android:id="@+id/app_bar_layout"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content">
+
+        <com.google.android.material.appbar.CollapsingToolbarLayout
+            android:id="@+id/collapsing_toolbar_layout"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            app:layout_scrollFlags="scroll|exitUntilCollapsed">
+
+            <FrameLayout
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                app:layout_collapseMode="parallax">
+
+                <com.facebook.drawee.view.SimpleDraweeView
+                    android:id="@+id/cover"
+                    android:layout_width="match_parent"
+                    android:layout_height="200dp"
+                    app:actualImageScaleType="centerCrop"
+                    tools:background="@mipmap/ic_launcher" />
+
+                <View
+                    android:id="@+id/background"
+                    android:layout_width="match_parent"
+                    android:layout_height="match_parent" />
+            </FrameLayout>
+
+            <androidx.appcompat.widget.Toolbar
+                android:id="@+id/toolbar"
+                android:layout_width="match_parent"
+                android:layout_height="?attr/actionBarSize"
+                app:layout_collapseMode="pin" />
+        </com.google.android.material.appbar.CollapsingToolbarLayout>
+    </com.google.android.material.appbar.AppBarLayout>
+
+    <androidx.swiperefreshlayout.widget.SwipeRefreshLayout
+        android:id="@+id/swipe_refresh_layout"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        app:layout_behavior="@string/appbar_scrolling_view_behavior">
+
+        <awais.instagrabber.customviews.PostsRecyclerView
+            android:id="@+id/posts"
+            android:layout_width="match_parent"
+            android:layout_height="match_parent"
+            android:clipToPadding="false" />
+    </androidx.swiperefreshlayout.widget.SwipeRefreshLayout>
+</awais.instagrabber.customviews.helpers.NestedCoordinatorLayout>

app/src/main/res/layout/item_discover_topic.xml

@@ -0,0 +1,45 @@
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content">
+
+    <com.facebook.drawee.view.SimpleDraweeView
+        android:id="@+id/cover"
+        android:layout_width="0dp"
+        android:layout_height="0dp"
+        app:actualImageScaleType="centerCrop"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintDimensionRatio="H,1:1"
+        app:layout_constraintLeft_toLeftOf="parent"
+        app:layout_constraintRight_toRightOf="parent"
+        app:layout_constraintTop_toTopOf="parent"
+        app:roundedCornerRadius="5dp"
+        app:viewAspectRatio="1"
+        tools:background="@mipmap/ic_launcher" />
+
+    <View
+        android:id="@+id/background"
+        android:layout_width="match_parent"
+        android:layout_height="0dp"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintHeight_percent="0.5"
+        app:layout_constraintStart_toStartOf="parent" />
+
+    <androidx.appcompat.widget.AppCompatTextView
+        android:id="@+id/title"
+        android:layout_width="match_parent"
+        android:layout_height="0dp"
+        android:gravity="bottom"
+        android:padding="8dp"
+        android:textStyle="bold"
+        app:autoSizeTextType="uniform"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintHeight_percent="0.3"
+        app:layout_constraintStart_toStartOf="parent"
+        tools:text="Title" />
+
+</androidx.constraintlayout.widget.ConstraintLayout>

app/src/main/res/menu/topic_posts_menu.xml

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<menu xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto">
+
+    <item
+        android:id="@+id/layout"
+        android:title="@string/layout"
+        app:showAsAction="never" />
+</menu>

app/src/main/res/navigation/discover_nav_graph.xml

@@ -5,9 +5,40 @@
     android:id="@+id/discover_nav_graph"
     app:startDestination="@id/discoverFragment">
 
-    <include app:graph="@navigation/post_view_nav_graph" />
+    <include app:graph="@navigation/hashtag_nav_graph" />
+
+    <action
+        android:id="@+id/action_global_hashTagFragment"
+        app:destination="@id/hashtag_nav_graph">
+        <argument
+            android:name="hashtag"
+            app:argType="string"
+            app:nullable="false" />
+    </action>
+
     <include app:graph="@navigation/profile_nav_graph" />
-    <include app:graph="@navigation/comments_nav_graph" />
+
+    <action
+        android:id="@+id/action_global_profileFragment"
+        app:destination="@id/profile_nav_graph">
+        <argument
+            android:name="username"
+            app:argType="string"
+            app:nullable="true" />
+    </action>
+
+    <include app:graph="@navigation/location_nav_graph" />
+
+    <action
+        android:id="@+id/action_global_locationFragment"
+        app:destination="@id/location_nav_graph">
+        <argument
+            android:name="locationId"
+            app:argType="string"
+            app:nullable="false" />
+    </action>
+
+    <include app:graph="@navigation/post_view_nav_graph" />
 
     <action
         android:id="@+id/action_global_postViewFragment"
@@ -23,9 +54,48 @@
             app:argType="boolean" />
     </action>
 
+    <include app:graph="@navigation/comments_nav_graph" />
+
+    <action
+        android:id="@+id/action_global_commentsViewerFragment"
+        app:destination="@id/comments_nav_graph">
+        <argument
+            android:name="shortCode"
+            app:argType="string"
+            app:nullable="false" />
+        <argument
+            android:name="postId"
+            app:argType="string"
+            app:nullable="false" />
+        <argument
+            android:name="postUserId"
+            app:argType="string"
+            app:nullable="false" />
+    </action>
+
     <fragment
         android:id="@+id/discoverFragment"
         android:name="awais.instagrabber.fragments.main.DiscoverFragment"
         android:label="@string/title_discover"
-        tools:layout="@layout/fragment_discover" />
+        tools:layout="@layout/fragment_discover">
+        <action
+            android:id="@+id/action_discoverFragment_to_topicPostsFragment"
+            app:destination="@id/topicPostsFragment" />
+    </fragment>
+    <fragment
+        android:id="@+id/topicPostsFragment"
+        android:name="awais.instagrabber.fragments.TopicPostsFragment"
+        tools:layout="@layout/fragment_topic_posts">
+        <argument
+            android:name="topicCluster"
+            app:argType="awais.instagrabber.models.TopicCluster" />
+
+        <argument
+            android:name="titleColor"
+            app:argType="integer" />
+
+        <argument
+            android:name="backgroundColor"
+            app:argType="integer" />
+    </fragment>
 </navigation>