Initial steps to show the JS challenge

Kuroba/app/src/main/java/com/github/adamantcheese/chan/core/site/loader/ChanThreadLoader.java

@@ -400,6 +400,10 @@ public boolean isNotFound() {
             return exception instanceof HttpCodeException && ((HttpCodeException) exception).isServerErrorNotFound();
         }
 
+        public boolean isNotAvailable() {
+            return exception instanceof HttpCodeException && ((HttpCodeException) exception).code == 503;
+        }
+
         public int getErrorMessage() {
             //by default, a network error has occurred if the exception field is not null
             int errorMessage = exception != null ? R.string.thread_load_failed_network : R.string.empty;

Kuroba/app/src/main/java/com/github/adamantcheese/chan/ui/controller/BrowseController.java

@@ -377,6 +377,17 @@ public void showBoardAndSearch(Loadable catalogLoadable, String searchQuery) {
         setBoard(catalogLoadable.board);
     }
 
+    @Override
+    public void showChallenge(Loadable loadable) {
+        ChallengeController c = new ChallengeController(context, loadable);
+
+        if (doubleNavigationController != null) {
+            doubleNavigationController.pushController(c);
+        } else {
+            navigationController.pushController(c);
+        }
+    }
+
     // Creates or updates the target ViewThreadController
     // This controller can be in various places depending on the layout, so we dynamically search for it
     @Override

Kuroba/app/src/main/java/com/github/adamantcheese/chan/ui/controller/ChallengeController.java

@@ -0,0 +1,27 @@
+package com.github.adamantcheese.chan.ui.controller;
+
+import android.content.Context;
+import android.webkit.WebView;
+
+import com.github.adamantcheese.chan.controller.Controller;
+import com.github.adamantcheese.chan.core.model.orm.Loadable;
+
+public class ChallengeController extends Controller {
+    protected Loadable behindChallenge;
+
+    public ChallengeController(Context context, Loadable behindChallenge) {
+        super(context);
+        this.behindChallenge = behindChallenge;
+    }
+
+    @Override
+    public void onCreate() {
+        super.onCreate();
+
+        WebView web = new WebView(context);
+
+        web.loadUrl(behindChallenge.desktopUrl());
+        web.getSettings().setJavaScriptEnabled(true);
+        this.view = web;
+    }
+}

Kuroba/app/src/main/java/com/github/adamantcheese/chan/ui/controller/ViewThreadController.java

@@ -44,6 +44,7 @@
 import com.github.adamantcheese.chan.ui.toolbar.ToolbarMenuSubItem;
 import com.github.adamantcheese.chan.ui.view.FloatingMenu;
 import com.github.adamantcheese.chan.utils.AndroidUtils;
+import com.github.adamantcheese.chan.utils.Logger;
 import com.github.k1rakishou.fsaf.FileManager;
 import com.skydoves.balloon.ArrowConstraints;
 import com.skydoves.balloon.ArrowOrientation;
@@ -226,6 +227,11 @@ public void onEvent(PinMessages.PinsChangedMessage message) {
         setPinIconState(true);
     }
 
+    @Override
+    public void showChallenge(Loadable loadable) {
+        // TODO: Implement
+    }
+
     @Override
     public void showThread(final Loadable threadLoadable) {
         if (threadLoadable.site instanceof ExternalSiteArchive && !loadable.site.equals(threadLoadable.site)) {

Kuroba/app/src/main/java/com/github/adamantcheese/chan/ui/layout/ThreadLayout.java

@@ -65,6 +65,7 @@
 import com.github.adamantcheese.chan.ui.view.ThumbnailView;
 import com.github.adamantcheese.chan.utils.AndroidUtils;
 import com.github.adamantcheese.chan.utils.BackgroundUtils;
+import com.github.adamantcheese.chan.utils.Logger;
 import com.google.android.material.snackbar.Snackbar;
 
 import java.util.ArrayList;
@@ -260,6 +261,10 @@ public void postClicked(Post post) {
     public void showError(ChanThreadLoader.ChanLoaderException error) {
         String errorMessage = getString(error.getErrorMessage());
 
+        if (error.isNotAvailable()) {
+            callback.showChallenge(presenter.getLoadable());
+        }
+
         if (visible == Visible.THREAD) {
             threadListLayout.showError(errorMessage);
         } else {
@@ -764,6 +769,8 @@ public void showHideOrRemoveWholeChainDialog(boolean hide, Post post, int thread
     }
 
     public interface ThreadLayoutCallback {
+        void showChallenge(Loadable loadableBehindChallenge);
+
         void showThread(Loadable threadLoadable);
 
         void showBoard(Loadable catalogLoadable);