[Bandcamp] Support loading additional comments (#1030)

extractor/src/main/java/org/schabi/newpipe/extractor/services/bandcamp/extractors/BandcampCommentsExtractor.java

@@ -1,23 +1,36 @@
 package org.schabi.newpipe.extractor.services.bandcamp.extractors;
 
+import static org.schabi.newpipe.extractor.services.bandcamp.extractors.BandcampExtractorHelper.BASE_API_URL;
+
+import com.grack.nanojson.JsonArray;
+import com.grack.nanojson.JsonObject;
+import com.grack.nanojson.JsonWriter;
+
 import org.jsoup.Jsoup;
 import org.jsoup.nodes.Document;
-import org.jsoup.nodes.Element;
-import org.jsoup.select.Elements;
 import org.schabi.newpipe.extractor.Page;
 import org.schabi.newpipe.extractor.StreamingService;
 import org.schabi.newpipe.extractor.comments.CommentsExtractor;
 import org.schabi.newpipe.extractor.comments.CommentsInfoItem;
 import org.schabi.newpipe.extractor.comments.CommentsInfoItemsCollector;
 import org.schabi.newpipe.extractor.downloader.Downloader;
 import org.schabi.newpipe.extractor.exceptions.ExtractionException;
+import org.schabi.newpipe.extractor.exceptions.ParsingException;
+import org.schabi.newpipe.extractor.exceptions.ReCaptchaException;
 import org.schabi.newpipe.extractor.linkhandler.ListLinkHandler;
+import org.schabi.newpipe.extractor.utils.JsonUtils;
 
-import javax.annotation.Nonnull;
 import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.util.Collections;
+import java.util.List;
+
+import javax.annotation.Nonnull;
 
 public class BandcampCommentsExtractor extends CommentsExtractor {
 
+    private static final String REVIEWS_API_URL = BASE_API_URL + "/tralbumcollectors/2/reviews";
+
     private Document document;
 
 
@@ -39,19 +52,81 @@ public InfoItemsPage<CommentsInfoItem> getInitialPage()
 
         final CommentsInfoItemsCollector collector = new CommentsInfoItemsCollector(getServiceId());
 
-        final Elements writings = document.getElementsByClass("writing");
+        final JsonObject collectorsData = JsonUtils.toJsonObject(
+                document.getElementById("collectors-data").attr("data-blob"));
+        final JsonArray reviews = collectorsData.getArray("reviews");
 
-        for (final Element writing : writings) {
-            collector.commit(new BandcampCommentsInfoItemExtractor(writing, getUrl()));
+        for (final Object review : reviews) {
+            collector.commit(
+                    new BandcampCommentsInfoItemExtractor((JsonObject) review, getUrl()));
         }
 
-        return new InfoItemsPage<>(collector, null);
+        if (!collectorsData.getBoolean("more_reviews_available")) {
+            return new InfoItemsPage<>(collector, null);
+        }
+
+        final String trackId = getTrackId();
+        final String token = getNextPageToken(reviews);
+        return new InfoItemsPage<>(collector, new Page(List.of(trackId, token)));
     }
 
     @Override
     public InfoItemsPage<CommentsInfoItem> getPage(final Page page)
             throws IOException, ExtractionException {
-        return null;
+
+        final CommentsInfoItemsCollector collector = new CommentsInfoItemsCollector(getServiceId());
+
+        final List<String> pageIds = page.getIds();
+        final String trackId = pageIds.get(0);
+        final String token = pageIds.get(1);
+        final JsonObject reviewsData = fetchReviewsData(trackId, token);
+        final JsonArray reviews = reviewsData.getArray("results");
+
+        for (final Object review : reviews) {
+            collector.commit(
+                    new BandcampCommentsInfoItemExtractor((JsonObject) review, getUrl()));
+        }
+
+        if (!reviewsData.getBoolean("more_available")) {
+            return new InfoItemsPage<>(collector, null);
+        }
+
+        return new InfoItemsPage<>(collector,
+                new Page(List.of(trackId, getNextPageToken(reviews))));
+    }
+
+    private JsonObject fetchReviewsData(final String trackId, final String token)
+            throws ParsingException {
+        try {
+            return JsonUtils.toJsonObject(getDownloader().postWithContentTypeJson(
+                    REVIEWS_API_URL,
+                    Collections.emptyMap(),
+                    JsonWriter.string().object()
+                            .value("tralbum_type", "t")
+                            .value("tralbum_id", trackId)
+                            .value("token", token)
+                            .value("count", 7)
+                            .array("exclude_fan_ids").end()
+                            .end().done().getBytes(StandardCharsets.UTF_8)).responseBody());
+        } catch (final IOException | ReCaptchaException e) {
+            throw new ParsingException("Could not fetch reviews", e);
+        }
+    }
+
+    private String getNextPageToken(final JsonArray reviews) throws ParsingException {
+        return reviews.stream()
+                .filter(JsonObject.class::isInstance)
+                .map(JsonObject.class::cast)
+                .map(review -> review.getString("token"))
+                .reduce((a, b) -> b) // keep only the last element
+                .orElseThrow(() -> new ParsingException("Could not get token"));
+    }
+
+    private String getTrackId() throws ParsingException {
+        final JsonObject pageProperties = JsonUtils.toJsonObject(
+                document.selectFirst("meta[name=bc-page-properties]")
+                        .attr("content"));
+        return Long.toString(pageProperties.getLong("item_id"));
     }
 
     @Override

extractor/src/main/java/org/schabi/newpipe/extractor/services/bandcamp/extractors/BandcampCommentsInfoItemExtractor.java

@@ -1,19 +1,20 @@
 package org.schabi.newpipe.extractor.services.bandcamp.extractors;
 
-import org.jsoup.nodes.Element;
+import static org.schabi.newpipe.extractor.services.bandcamp.extractors.BandcampExtractorHelper.getImageUrl;
+
+import com.grack.nanojson.JsonObject;
+
 import org.schabi.newpipe.extractor.comments.CommentsInfoItemExtractor;
 import org.schabi.newpipe.extractor.exceptions.ParsingException;
 import org.schabi.newpipe.extractor.stream.Description;
 
-import java.util.Objects;
-
 public class BandcampCommentsInfoItemExtractor implements CommentsInfoItemExtractor {
 
-    private final Element writing;
+    private final JsonObject review;
     private final String url;
 
-    public BandcampCommentsInfoItemExtractor(final Element writing, final String url) {
-        this.writing = writing;
+    public BandcampCommentsInfoItemExtractor(final JsonObject review, final String url) {
+        this.review = review;
         this.url = url;
     }
 
@@ -29,31 +30,21 @@ public String getUrl() {
 
     @Override
     public String getThumbnailUrl() throws ParsingException {
-        return writing.getElementsByClass("thumb").attr("src");
+        return getUploaderAvatarUrl();
     }
 
     @Override
     public Description getCommentText() throws ParsingException {
-        final var text = writing.getElementsByClass("text").stream()
-                .filter(Objects::nonNull)
-                .map(Element::ownText)
-                .findFirst()
-                .orElseThrow(() -> new ParsingException("Could not get comment text"));
-
-        return new Description(text, Description.PLAIN_TEXT);
+        return new Description(review.getString("why"), Description.PLAIN_TEXT);
     }
 
     @Override
     public String getUploaderName() throws ParsingException {
-        return writing.getElementsByClass("name").stream()
-                .filter(Objects::nonNull)
-                .map(Element::text)
-                .findFirst()
-                .orElseThrow(() -> new ParsingException("Could not get uploader name"));
+        return review.getString("name");
     }
 
     @Override
     public String getUploaderAvatarUrl() {
-        return writing.getElementsByClass("thumb").attr("src");
+        return getImageUrl(review.getLong("image_id"), false);
     }
 }

extractor/src/test/java/org/schabi/newpipe/extractor/services/bandcamp/BandcampCommentsExtractorTest.java

@@ -37,6 +37,7 @@ public void hasComments() throws IOException, ExtractionException {
     @Test
     public void testGetCommentsAllData() throws IOException, ExtractionException {
         ListExtractor.InfoItemsPage<CommentsInfoItem> comments = extractor.getInitialPage();
+        assertTrue(comments.hasNextPage());
 
         DefaultTests.defaultTestListOfItems(Bandcamp, comments.getItems(), comments.getErrors());
         for (CommentsInfoItem c : comments.getItems()) {