Wikimedia hackathon 2018 (#1533)

* First draft of fn to get random recent image

* Use log entries for requests to beta, try to connect refresh button

FIXME: runs http request on main thread, breaks

* Tweak button connection

app/src/main/java/fr/free/nrw/commons/media/RecentChangesImageUtils.java

@@ -0,0 +1,32 @@
+package fr.free.nrw.commons.media;
+
+import org.w3c.dom.Element;
+import org.w3c.dom.NodeList;
+
+import javax.annotation.Nullable;
+
+public class RecentChangesImageUtils {
+
+    private static final String[] imageExtensions = new String[]
+            {".jpg", ".jpeg", ".png"};
+
+    @Nullable
+    public static String findImageInRecentChanges(NodeList childNodes) {
+        String imageTitle;
+        for (int i = 0; i < childNodes.getLength(); i++) {
+            Element e = (Element)childNodes.item(i);
+            if (e.getAttribute("type").equals("log") && !e.getAttribute("old_revid").equals("0")) {
+                // For log entries, we only want ones where old_revid is zero, indicating a new file
+                continue;
+            }
+            imageTitle = e.getAttribute("title");
+
+            for (String imageExtension : imageExtensions) {
+                if (imageTitle.toLowerCase().endsWith(imageExtension)) {
+                    return imageTitle;
+                }
+            }
+        }
+        return null;
+    }
+}

app/src/main/java/fr/free/nrw/commons/mwapi/ApacheHttpClientMediaWikiApi.java

@@ -41,6 +41,7 @@ import java.util.List;
 import java.util.Locale;
 import java.util.TimeZone;
 import java.util.concurrent.Callable;
+import java.util.Random;
 
 import fr.free.nrw.commons.BuildConfig;
 import fr.free.nrw.commons.Media;
@@ -50,6 +51,7 @@ import fr.free.nrw.commons.achievements.FeedbackResponse;
 import fr.free.nrw.commons.auth.AccountUtil;
 import fr.free.nrw.commons.category.CategoryImageUtils;
 import fr.free.nrw.commons.category.QueryContinue;
+import fr.free.nrw.commons.media.RecentChangesImageUtils;
 import fr.free.nrw.commons.notification.Notification;
 import fr.free.nrw.commons.notification.NotificationUtils;
 import fr.free.nrw.commons.utils.ContributionUtils;
@@ -73,6 +75,14 @@ public class ApacheHttpClientMediaWikiApi implements MediaWikiApi {
     private String wikiMediaToolforgeUrl = "https://tools.wmflabs.org/";
 
     private static final String THUMB_SIZE = "640";
+    // Give up if no random recent image found after 5 tries
+    private static final int MAX_RANDOM_TRIES = 5;
+    // Random image request is for some time in the past 30 days
+    private static final int RANDOM_SECONDS = 60 * 60 * 24 * 30;
+    // Assuming MW always gives me UTC
+    private static final SimpleDateFormat isoFormat =
+            new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'", Locale.ENGLISH);
+    private static final String FILE_NAMESPACE = "6";
     private AbstractHttpClient httpClient;
     private CustomMwApi api;
     private CustomMwApi wikidataApi;
@@ -1082,4 +1092,48 @@ public class ApacheHttpClientMediaWikiApi implements MediaWikiApi {
             return null;
         });
     }
+
+    private String formatMWDate(Date date) {
+        return isoFormat.format(date);
+    }
+
+    public MediaResult getRecentRandomImage() throws IOException {
+        MediaResult media = null;
+        int tries = 0;
+        Random r = new Random();
+
+        while (media == null && tries < MAX_RANDOM_TRIES) {
+            Date now = new Date();
+            Date startDate = new Date(now.getTime() - r.nextInt(RANDOM_SECONDS) * 1000L);
+            ApiResult apiResult = null;
+            try {
+                MWApi.RequestBuilder requestBuilder = api.action("query")
+                        .param("list", "recentchanges")
+                        .param("rcstart", formatMWDate(startDate))
+                        .param("rcnamespace", FILE_NAMESPACE)
+                        .param("rcprop", "title|ids")
+                        .param("rctype", "new|log")
+                        .param("rctoponly", "1");
+
+                apiResult = requestBuilder.get();
+            } catch (IOException e) {
+                Timber.e("Failed to obtain recent random", e);
+            }
+            if (apiResult != null) {
+                ApiResult recentChangesNode = apiResult.getNode("/api/query/recentchanges");
+                if (recentChangesNode != null
+                        && recentChangesNode.getDocument() != null
+                        && recentChangesNode.getDocument().getChildNodes() != null
+                        && recentChangesNode.getDocument().getChildNodes().getLength() > 0) {
+                    NodeList childNodes = recentChangesNode.getDocument().getChildNodes();
+                    String imageTitle = RecentChangesImageUtils.findImageInRecentChanges(childNodes);
+                    if (imageTitle != null) {
+                        media = fetchMediaByFilename(imageTitle);
+                    }
+                }
+            }
+            tries++;
+        }
+        return media;
+    }
 }

app/src/main/java/fr/free/nrw/commons/mwapi/MediaWikiApi.java

@@ -111,4 +111,7 @@ public interface MediaWikiApi {
     interface ProgressListener {
         void onProgress(long transferred, long total);
     }
+
+    @Nullable
+    MediaResult getRecentRandomImage() throws IOException;
 }

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

@@ -4,18 +4,28 @@ import android.content.Context;
 import android.content.Intent;
 import android.os.Bundle;
 
+import android.os.Handler;
 import android.support.design.widget.NavigationView;
 import android.support.v4.view.ViewPager;
 import android.support.v4.widget.DrawerLayout;
 import android.support.v7.widget.Toolbar;
 
+import android.util.Log;
 import android.view.Menu;
 import android.view.MenuItem;
+import android.view.View;
+
+import java.io.IOException;
+
+import javax.inject.Inject;
 
 import butterknife.BindView;
 import butterknife.ButterKnife;
 import fr.free.nrw.commons.R;
 import fr.free.nrw.commons.auth.AuthenticatedActivity;
+import fr.free.nrw.commons.mwapi.MediaWikiApi;
+import io.reactivex.Observable;
+import io.reactivex.schedulers.Schedulers;
 
 /**
  * Created by root on 18.05.2018.
@@ -33,6 +43,9 @@ public class ReviewActivity extends AuthenticatedActivity {
     @BindView(R.id.reviewPager)
     ViewPager pager;
 
+    @Inject
+    MediaWikiApi mwApi;
+
     public static final int MAX_NUM = 4;
     private ReviewPagerAdapter reviewPagerAdapter;
 
@@ -69,7 +82,19 @@ public class ReviewActivity extends AuthenticatedActivity {
     public boolean onOptionsItemSelected(MenuItem item) {
         int id = item.getItemId();
 
-        if (id == R.id.action_review) {
+        if (id == R.id.action_review_randomizer) {
+            Observable.fromCallable(() -> {
+                try {
+
+                    Log.d("review", mwApi.getRecentRandomImage().getWikiSource());
+
+                } catch (IOException e) {
+                    Log.d("review", e.toString());
+                }
+                return "Booga!";
+            })
+                    .subscribeOn(Schedulers.io())
+                    .subscribe();
             return true;
         }
 

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

@@ -1,7 +1,7 @@
 <?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/menu_from_gallery"
+    <item android:id="@+id/action_review_randomizer"
         android:title="@string/menu_from_gallery"
         app:showAsAction="ifRoom|withText"
         android:icon="@drawable/ic_refresh_white_24dp"