[YouTube] Support shows and page header on user channels

extractor/src/main/java/org/schabi/newpipe/extractor/services/youtube/YoutubeParsingHelper.java

@@ -825,9 +825,15 @@ public static String getUrlFromNavigationEndpoint(
             final String canonicalBaseUrl = browseEndpoint.getString("canonicalBaseUrl");
             final String browseId = browseEndpoint.getString("browseId");
 
-            // All channel ids are prefixed with UC
-            if (browseId != null && browseId.startsWith("UC")) {
-                return "https://www.youtube.com/channel/" + browseId;
+            if (browseId != null) {
+                if (browseId.startsWith("UC")) {
+                    // All channel IDs are prefixed with UC
+                    return "https://www.youtube.com/channel/" + browseId;
+                } else if (browseId.startsWith("VL")) {
+                    // All playlist IDs are prefixed with VL, which needs to be removed from the
+                    // playlist ID
+                    return "https://www.youtube.com/playlist?list=" + browseId.substring(2);
+                }
             }
 
             if (!isNullOrEmpty(canonicalBaseUrl)) {
@@ -887,12 +893,13 @@ public static String getTextFromObject(final JsonObject textObject, final boolea
             return textObject.getString("simpleText");
         }
 
-        if (textObject.getArray("runs").isEmpty()) {
+        final JsonArray runs = textObject.getArray("runs");
+        if (runs.isEmpty()) {
             return null;
         }
 
         final StringBuilder textBuilder = new StringBuilder();
-        for (final Object o : textObject.getArray("runs")) {
+        for (final Object o : runs) {
             final JsonObject run = (JsonObject) o;
             String text = run.getString("text");
 
@@ -970,11 +977,12 @@ public static String getUrlFromObject(final JsonObject textObject) {
             return null;
         }
 
-        if (textObject.getArray("runs").isEmpty()) {
+        final JsonArray runs = textObject.getArray("runs");
+        if (runs.isEmpty()) {
             return null;
         }
 
-        for (final Object textPart : textObject.getArray("runs")) {
+        for (final Object textPart : runs) {
             final String url = getUrlFromNavigationEndpoint(((JsonObject) textPart)
                     .getObject("navigationEndpoint"));
             if (!isNullOrEmpty(url)) {

extractor/src/main/java/org/schabi/newpipe/extractor/services/youtube/extractors/YoutubeBaseShowInfoItemExtractor.java

@@ -0,0 +1,65 @@
+package org.schabi.newpipe.extractor.services.youtube.extractors;
+
+import com.grack.nanojson.JsonObject;
+import org.schabi.newpipe.extractor.Image;
+import org.schabi.newpipe.extractor.exceptions.ParsingException;
+import org.schabi.newpipe.extractor.playlist.PlaylistInfoItemExtractor;
+import org.schabi.newpipe.extractor.utils.Utils;
+
+import javax.annotation.Nonnull;
+import java.util.List;
+
+import static org.schabi.newpipe.extractor.services.youtube.YoutubeParsingHelper.getTextFromObject;
+import static org.schabi.newpipe.extractor.services.youtube.YoutubeParsingHelper.getThumbnailsFromInfoItem;
+import static org.schabi.newpipe.extractor.services.youtube.YoutubeParsingHelper.getUrlFromNavigationEndpoint;
+
+/**
+ * The base {@link PlaylistInfoItemExtractor} for shows playlists UI elements.
+ */
+abstract class YoutubeBaseShowInfoItemExtractor implements PlaylistInfoItemExtractor {
+
+    @Nonnull
+    protected final JsonObject showRenderer;
+
+    YoutubeBaseShowInfoItemExtractor(@Nonnull final JsonObject showRenderer) {
+        this.showRenderer = showRenderer;
+    }
+
+    @Override
+    public String getName() throws ParsingException {
+        return showRenderer.getString("title");
+    }
+
+    @Override
+    public String getUrl() throws ParsingException {
+        return getUrlFromNavigationEndpoint(showRenderer.getObject("navigationEndpoint"));
+    }
+
+    @Nonnull
+    @Override
+    public List<Image> getThumbnails() throws ParsingException {
+        return getThumbnailsFromInfoItem(showRenderer.getObject("thumbnailRenderer")
+                .getObject("showCustomThumbnailRenderer"));
+    }
+
+    @Override
+    public long getStreamCount() throws ParsingException {
+        // The stream count should be always returned in the first text object for English
+        // localizations, but the complete text is parsed for reliability purposes
+        final String streamCountText = getTextFromObject(
+                showRenderer.getObject("thumbnailOverlays")
+                        .getObject("thumbnailOverlayBottomPanelRenderer")
+                        .getObject("text"));
+        if (streamCountText == null) {
+            throw new ParsingException("Could not get stream count");
+        }
+
+        try {
+            // The data returned could be a human/shortened number, but no show with more than 1000
+            // videos has been found at the time this code was written
+            return Long.parseLong(Utils.removeNonDigitCharacters(streamCountText));
+        } catch (final NumberFormatException e) {
+            throw new ParsingException("Could not convert stream count to a long", e);
+        }
+    }
+}