Fix YouTube channels contination

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

@@ -2,10 +2,13 @@
 
 import com.grack.nanojson.JsonArray;
 import com.grack.nanojson.JsonObject;
+import com.grack.nanojson.JsonWriter;
+
 import org.schabi.newpipe.extractor.Page;
 import org.schabi.newpipe.extractor.StreamingService;
 import org.schabi.newpipe.extractor.channel.ChannelExtractor;
 import org.schabi.newpipe.extractor.downloader.Downloader;
+import org.schabi.newpipe.extractor.downloader.Response;
 import org.schabi.newpipe.extractor.exceptions.ContentNotSupportedException;
 import org.schabi.newpipe.extractor.exceptions.ExtractionException;
 import org.schabi.newpipe.extractor.exceptions.ParsingException;
@@ -15,13 +18,20 @@
 import org.schabi.newpipe.extractor.services.youtube.linkHandler.YoutubeChannelLinkHandlerFactory;
 import org.schabi.newpipe.extractor.stream.StreamInfoItem;
 import org.schabi.newpipe.extractor.stream.StreamInfoItemsCollector;
+import org.schabi.newpipe.extractor.utils.JsonUtils;
 import org.schabi.newpipe.extractor.utils.Utils;
 
 import javax.annotation.Nonnull;
 import java.io.IOException;
 
-import static org.schabi.newpipe.extractor.services.youtube.YoutubeParsingHelper.*;
+import static org.schabi.newpipe.extractor.services.youtube.YoutubeParsingHelper.fixThumbnailUrl;
+import static org.schabi.newpipe.extractor.services.youtube.YoutubeParsingHelper.getClientVersion;
+import static org.schabi.newpipe.extractor.services.youtube.YoutubeParsingHelper.getJsonResponse;
+import static org.schabi.newpipe.extractor.services.youtube.YoutubeParsingHelper.getTextFromObject;
+import static org.schabi.newpipe.extractor.services.youtube.YoutubeParsingHelper.getKey;
+import static org.schabi.newpipe.extractor.services.youtube.YoutubeParsingHelper.getValidJsonResponseBody;
 import static org.schabi.newpipe.extractor.utils.Utils.EMPTY_STRING;
+import static org.schabi.newpipe.extractor.utils.Utils.UTF_8;
 import static org.schabi.newpipe.extractor.utils.Utils.isNullOrEmpty;
 
 /*
@@ -226,7 +236,7 @@ public boolean isVerified() throws ParsingException {
 
     @Nonnull
     @Override
-    public InfoItemsPage<StreamInfoItem> getInitialPage() throws ExtractionException {
+    public InfoItemsPage<StreamInfoItem> getInitialPage() throws IOException, ExtractionException {
         final StreamInfoItemsCollector collector = new StreamInfoItemsCollector(getServiceId());
 
         Page nextPage = null;
@@ -254,27 +264,44 @@ public InfoItemsPage<StreamInfoItem> getPage(final Page page) throws IOException
         // as they don't deliver enough information on their own (the channel name, for example).
         fetchPage();
 
+        // @formatter:off
+        byte[] json = JsonWriter.string()
+                .object()
+                .object("context")
+                .object("client")
+                .value("clientName", "1")
+                .value("clientVersion", getClientVersion())
+                .end()
+                .end()
+                .value("continuation", page.getId())
+                .end()
+                .done()
+                .getBytes(UTF_8);
+        // @formatter:on
+
         StreamInfoItemsCollector collector = new StreamInfoItemsCollector(getServiceId());
-        final JsonArray ajaxJson = getJsonResponse(page.getUrl(), getExtractorLocalization());
+        final Response response = getDownloader().post(page.getUrl(), null, json, getExtractorLocalization());
+
+        final JsonObject ajaxJson = JsonUtils.toJsonObject(getValidJsonResponseBody(response));
 
-        JsonObject sectionListContinuation = ajaxJson.getObject(1).getObject("response")
-                .getArray("onResponseReceivedActions").getObject(0).getObject("appendContinuationItemsAction");
+        JsonObject sectionListContinuation = ajaxJson.getArray("onResponseReceivedActions")
+                .getObject(0)
+                .getObject("appendContinuationItemsAction");
 
         final JsonObject continuation = collectStreamsFrom(collector, sectionListContinuation.getArray("continuationItems"));
 
         return new InfoItemsPage<>(collector, getNextPageFrom(continuation));
     }
 
-    private Page getNextPageFrom(final JsonObject continuations) {
+    private Page getNextPageFrom(final JsonObject continuations) throws IOException, ExtractionException {
         if (isNullOrEmpty(continuations)) {
             return null;
         }
 
         final JsonObject continuationEndpoint = continuations.getObject("continuationEndpoint");
         final String continuation = continuationEndpoint.getObject("continuationCommand").getString("token");
-        final String clickTrackingParams = continuationEndpoint.getString("clickTrackingParams");
-        return new Page("https://www.youtube.com/browse_ajax?ctoken=" + continuation
-                + "&continuation=" + continuation + "&itct=" + clickTrackingParams);
+        return new Page("https://www.youtube.com/youtubei/v1/browse?key=" + getKey(),
+                continuation);
     }
 
     /**