Skip used images (#5160)

* Only Review Images That Has No Usage

* Coding Standard Related Changes

* Coding Standard Changes - 1

* small change

app/src/main/java/fr/free/nrw/commons/review/ReviewActivity.java

@@ -6,6 +6,7 @@ import android.content.Intent;
 import android.graphics.PorterDuff;
 import android.graphics.drawable.Drawable;
 import android.os.Bundle;
+import android.util.Log;
 import android.view.Menu;
 import android.view.MenuInflater;
 import android.view.MenuItem;
@@ -161,14 +162,31 @@ public class ReviewActivity extends BaseActivity {
         hasNonHiddenCategories = false;
         progressBar.setVisibility(View.VISIBLE);
         reviewPager.setCurrentItem(0);
+        // Finds non-hidden categories from Media instance
         compositeDisposable.add(reviewHelper.getRandomMedia()
                 .subscribeOn(Schedulers.io())
                 .observeOn(AndroidSchedulers.mainThread())
-                .subscribe(media -> {
+                .subscribe(this::checkWhetherFileIsUsedInWikis));
+        return true;
+    }
+
+    /**
+     * Check whether media is used or not in any Wiki Page
+     */
+    @SuppressLint("CheckResult")
+    private void checkWhetherFileIsUsedInWikis(final Media media) {
+        compositeDisposable.add(reviewHelper.checkFileUsage(media.getFilename())
+            .subscribeOn(Schedulers.io())
+            .observeOn(AndroidSchedulers.mainThread())
+            .subscribe(result -> {
+                // result false indicates media is not used in any wiki
+                if (!result) {
                     // Finds non-hidden categories from Media instance
                     findNonHiddenCategories(media);
-                }));
-        return true;
+                } else {
+                    runRandomizer();
+                }
+            }));
     }
 
     /**

app/src/main/java/fr/free/nrw/commons/review/ReviewHelper.java

@@ -100,6 +100,19 @@ public class ReviewHelper {
                 .map(response -> response.query().firstPage().revisions().get(0));
     }
 
+    /**
+     * Checks Whether Given File is used in any Wiki page or not
+     * by calling api for given file
+     *
+     * @param filename
+     * @return
+     */
+     Observable<Boolean> checkFileUsage(final String filename) {
+         return reviewInterface.getGlobalUsageInfo(filename)
+             .map(mwQueryResponse -> mwQueryResponse.query().firstPage()
+                 .checkWhetherFileIsUsedInWikis());
+     }
+
     /**
      * Checks if the change is reviewable or not.
      * - checks the type and revisionId of the change

app/src/main/java/fr/free/nrw/commons/review/ReviewInterface.java

@@ -15,4 +15,7 @@ public interface ReviewInterface {
 
     @GET("w/api.php?action=query&format=json&formatversion=2&prop=revisions&rvprop=timestamp|ids|user&rvdir=newer&rvlimit=1")
     Observable<MwQueryResponse> getFirstRevisionOfFile(@Query("titles") String titles);
+
+    @GET("w/api.php?action=query&format=json&formatversion=2&prop=fileusage|globalusage")
+    Observable<MwQueryResponse> getGlobalUsageInfo(@Query("titles") String title);
 }

data-client/src/main/java/org/wikipedia/dataclient/mwapi/MwQueryPage.java

@@ -25,6 +25,8 @@ public class MwQueryPage extends BaseModel {
     @SuppressWarnings("unused,NullableProblems") @NonNull private CategoryInfo categoryinfo;
     @SuppressWarnings("unused") @Nullable private List<LangLink> langlinks;
     @SuppressWarnings("unused") @Nullable private List<Revision> revisions;
+    @SuppressWarnings("unused") @SerializedName("fileusage") @Nullable private List<FileUsage> fileUsages;
+    @SuppressWarnings("unused") @SerializedName("globalusage") @Nullable private List<GlobalUsage> globalUsages;
     @SuppressWarnings("unused") @Nullable private List<Coordinates> coordinates;
     @SuppressWarnings("unused") @Nullable private List<Category> categories;
     @SuppressWarnings("unused") @Nullable private PageProps pageprops;
@@ -67,6 +69,14 @@ public class MwQueryPage extends BaseModel {
         return categories;
     }
 
+    @Nullable public List<GlobalUsage> globalUsages() {
+        return globalUsages;
+    }
+
+    @Nullable public List<FileUsage> fileUsages() {
+        return fileUsages;
+    }
+
     @Nullable public List<Coordinates> coordinates() {
         // TODO: Handle null values in lists during deserialization, perhaps with a new
         // @RequiredElements annotation and corresponding TypeAdapter
@@ -141,6 +151,28 @@ public class MwQueryPage extends BaseModel {
         title += "#" + fragment;
     }
 
+    public boolean checkWhetherFileIsUsedInWikis() {
+        if (globalUsages != null && globalUsages.size() > 0) {
+            return true;
+        }
+
+        if (fileUsages == null || fileUsages.size() == 0) {
+            return false;
+        }
+
+        final int totalCount = fileUsages.size();
+
+        /* Ignore usage under https://commons.wikimedia.org/wiki/User:Didym/Mobile_upload/
+           which has been a gallery of all of our uploads since 2014 */
+        for (final FileUsage fileUsage : fileUsages) {
+            if ( ! fileUsage.title().contains("User:Didym/Mobile upload")) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
     public static class Revision {
         @SerializedName("revid") private long revisionId;
         private String user;
@@ -228,6 +260,44 @@ public class MwQueryPage extends BaseModel {
         }
     }
 
+    public static class GlobalUsage {
+        @SerializedName("title") private String title;
+        @SerializedName("wiki")private String wiki;
+        @SerializedName("url") private String url;
+
+        public String getTitle() {
+            return title;
+        }
+
+        public String getWiki() {
+            return wiki;
+        }
+
+        public String getUrl() {
+            return url;
+        }
+
+
+    }
+
+    public static class FileUsage {
+        @SerializedName("pageid") private int pageid;
+        @SerializedName("ns") private int ns;
+        @SerializedName("title") private String title;
+
+        public int pageId() {
+            return pageid;
+        }
+
+        public int ns() {
+            return ns;
+        }
+
+        public String title() {
+            return title;
+        }
+    }
+
     public static class Category {
         @SuppressWarnings("unused") private int ns;
         @SuppressWarnings("unused,NullableProblems") @Nullable private String title;

data-client/src/main/java/org/wikipedia/dataclient/mwapi/MwQueryResponse.java

@@ -13,7 +13,7 @@ public class MwQueryResponse extends MwResponse {
 
     @SuppressWarnings("unused") @SerializedName("continue") @Nullable private Map<String, String> continuation;
 
-    @Nullable private MwQueryResult query;
+    @SerializedName("query") @Nullable private MwQueryResult query;
 
     public boolean batchComplete() {
         return batchComplete;

data-client/src/main/java/org/wikipedia/dataclient/mwapi/MwQueryResult.java

@@ -23,7 +23,7 @@ import java.util.Map;
 
 @SuppressWarnings("unused")
 public class MwQueryResult extends BaseModel implements PostProcessingTypeAdapter.PostProcessable {
-    @Nullable private List<MwQueryPage> pages;
+    @SerializedName("pages") @Nullable private List<MwQueryPage> pages;
     @Nullable private List<Redirect> redirects;
     @Nullable private List<ConvertedTitle> converted;
     @SerializedName("userinfo") private UserInfo userInfo;