[#11930] Playlist with more than 50 items

app/build.gradle

@@ -255,6 +255,9 @@ dependencies {
     // HTTP client
     implementation "com.squareup.okhttp3:okhttp:4.12.0"
 
+    // Apache Commons Collections
+    implementation group: 'org.apache.commons', name: 'commons-collections4', version: '4.4'
+
     // Media player
     implementation "com.google.android.exoplayer:exoplayer-core:${exoPlayerVersion}"
     implementation "com.google.android.exoplayer:exoplayer-dash:${exoPlayerVersion}"

app/src/main/java/org/schabi/newpipe/local/playlist/LocalPlaylistFragment.java

@@ -31,6 +31,7 @@ import androidx.viewbinding.ViewBinding;
 
 import com.evernote.android.state.State;
 
+import org.apache.commons.collections4.queue.CircularFifoQueue;
 import org.reactivestreams.Subscriber;
 import org.reactivestreams.Subscription;
 import org.schabi.newpipe.NewPipeDatabase;
@@ -460,10 +461,15 @@ public class LocalPlaylistFragment extends BaseLocalListFragment<List<PlaylistSt
 
     static String exportAsYoutubeTempPlaylist(final Stream<StreamEntity> entityStream) {
 
-        final String videoIDs = entityStream
-                .map(entity -> getYouTubeId(entity.getUrl()))
-                .filter(Objects::nonNull)
-                .collect(Collectors.joining(","));
+        final CircularFifoQueue<String> last50 = new CircularFifoQueue<>(50);
+
+        entityStream
+            .map(entity -> getYouTubeId(entity.getUrl()))
+            .filter(Objects::nonNull)
+            .forEachOrdered(last50::add);
+
+        final String videoIDs = last50.stream()
+            .collect(Collectors.joining(","));
 
         return "http://www.youtube.com/watch_videos?video_ids=" + videoIDs;
     }

app/src/test/java/org/schabi/newpipe/local/playlist/LocalPlaylistFragmentTest.java

@@ -10,6 +10,7 @@ import org.junit.Test;
 import org.schabi.newpipe.database.stream.model.StreamEntity;
 import org.schabi.newpipe.extractor.stream.StreamType;
 
+import java.util.List;
 import java.util.stream.Stream;
 
 public class LocalPlaylistFragmentTest {
@@ -30,6 +31,42 @@ public class LocalPlaylistFragmentTest {
         Assert.assertEquals("http://www.youtube.com/watch_videos?video_ids=1,2,3", url);
     }
 
+    @Test
+    public void exportMoreThan50Items() {
+        /*
+         * Playlist has more than 50 items => take the last 50
+         * (YouTube limitation)
+         */
+
+        final List<Integer> ids = List.of(
+
+            -1,  0,
+             1,  2,  3,  4,  5,  6,  7,  8,  9, 10,
+            11, 12, 13, 14, 15, 16, 17, 18, 19, 20,
+            21, 22, 23, 24, 25, 26, 27, 28, 29, 30,
+            31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
+            41, 42, 43, 44, 45, 46, 47, 48, 49, 50
+        );
+
+        final Stream<StreamEntity> entityStream = ids.stream()
+            .map(id -> "https://www.youtube.com/watch?v=" + id)
+            .map(LocalPlaylistFragmentTest::newStreamEntity);
+
+        final String url = LocalPlaylistFragment.export(YOUTUBE_TEMP_PLAYLIST, entityStream, null);
+
+        Assert.assertEquals(
+
+              "http://www.youtube.com/watch_videos?video_ids="
+            + "1,2,3,4,5,6,7,8,9,10,"
+            + "11,12,13,14,15,16,17,18,19,20,"
+            + "21,22,23,24,25,26,27,28,29,30,"
+            + "31,32,33,34,35,36,37,38,39,40,"
+            + "41,42,43,44,45,46,47,48,49,50",
+
+            url
+        );
+    }
+
     @Test
     public void exportJustUrls() {