NewPipeExtractor/extractor/src/main/java/org/schabi/newpipe/extractor/services/peertube/extractors/PeertubeTrendingExtractor.java

package org.schabi.newpipe.extractor.services.peertube.extractors;

import com.grack.nanojson.JsonArray;
import com.grack.nanojson.JsonObject;
import com.grack.nanojson.JsonParser;

import org.schabi.newpipe.extractor.Page;
import org.schabi.newpipe.extractor.StreamingService;
import org.schabi.newpipe.extractor.downloader.Downloader;
import org.schabi.newpipe.extractor.downloader.Response;
import org.schabi.newpipe.extractor.exceptions.ExtractionException;
import org.schabi.newpipe.extractor.exceptions.ParsingException;
import org.schabi.newpipe.extractor.kiosk.KioskExtractor;
import org.schabi.newpipe.extractor.linkhandler.ListLinkHandler;
import org.schabi.newpipe.extractor.services.peertube.PeertubeParsingHelper;
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 java.io.IOException;

import static org.schabi.newpipe.extractor.services.peertube.PeertubeParsingHelper.COUNT_KEY;
import static org.schabi.newpipe.extractor.services.peertube.PeertubeParsingHelper.ITEMS_PER_PAGE;
import static org.schabi.newpipe.extractor.services.peertube.PeertubeParsingHelper.START_KEY;

public class PeertubeTrendingExtractor extends KioskExtractor<StreamInfoItem> {
    public PeertubeTrendingExtractor(final StreamingService streamingService, final ListLinkHandler linkHandler, final String kioskId) {
        super(streamingService, linkHandler, kioskId);
    }

    @Override
    public String getName() throws ParsingException {
        return getId();
    }

    @Override
    public InfoItemsPage<StreamInfoItem> getInitialPage() throws IOException, ExtractionException {
        final String pageUrl = getUrl() + "&" + START_KEY + "=0&" + COUNT_KEY + "=" + ITEMS_PER_PAGE;
        return getPage(new Page(pageUrl));
    }

    private void collectStreamsFrom(final StreamInfoItemsCollector collector, final JsonObject json) throws ParsingException {
        final JsonArray contents;
        try {
            contents = (JsonArray) JsonUtils.getValue(json, "data");
        } catch (Exception e) {
            throw new ParsingException("Unable to extract kiosk info", e);
        }

        final String baseUrl = getBaseUrl();
        for (final Object c : contents) {
            if (c instanceof JsonObject) {
                final JsonObject item = (JsonObject) c;
                final PeertubeStreamInfoItemExtractor extractor = new PeertubeStreamInfoItemExtractor(item, baseUrl);
                collector.commit(extractor);
            }
        }
    }

    @Override
    public InfoItemsPage<StreamInfoItem> getPage(final Page page) throws IOException, ExtractionException {
        final Response response = getDownloader().get(page.getUrl());
        JsonObject json = null;
        if (response != null && !Utils.isBlank(response.responseBody())) {
            try {
                json = JsonParser.object().from(response.responseBody());
            } catch (Exception e) {
                throw new ParsingException("Could not parse json data for kiosk info", e);
            }
        }

        if (json != null) {
            PeertubeParsingHelper.validate(json);
            final long total = JsonUtils.getNumber(json, "total").longValue();

            final StreamInfoItemsCollector collector = new StreamInfoItemsCollector(getServiceId());
            collectStreamsFrom(collector, json);

            return new InfoItemsPage<>(collector, PeertubeParsingHelper.getNextPage(page.getUrl(), total));
        } else {
            throw new ExtractionException("Unable to get PeerTube kiosk info");
        }
    }

    @Override
    public void onFetchPage(Downloader downloader) throws IOException, ExtractionException { }
}