NewPipe/app/src/main/java/us/shandian/giga/get/DownloadMissionRecover.java

package us.shandian.giga.get;

import android.util.Log;

import org.schabi.newpipe.extractor.NewPipe;
import org.schabi.newpipe.extractor.StreamingService;
import org.schabi.newpipe.extractor.stream.AudioStream;
import org.schabi.newpipe.extractor.stream.StreamExtractor;
import org.schabi.newpipe.extractor.stream.SubtitlesStream;
import org.schabi.newpipe.extractor.stream.VideoStream;

import java.io.IOException;
import java.net.HttpURLConnection;
import java.nio.channels.ClosedByInterruptException;
import java.util.List;

import static us.shandian.giga.get.DownloadMission.ERROR_RESOURCE_GONE;

public class DownloadMissionRecover extends Thread {
    private static final String TAG = "DownloadMissionRecover";
    static final int mID = -3;

    private final DownloadMission mMission;
    private final MissionRecoveryInfo mRecovery;
    private final Exception mFromError;
    private HttpURLConnection mConn;

    DownloadMissionRecover(DownloadMission mission, Exception originError) {
        mMission = mission;
        mFromError = originError;
        mRecovery = mission.recoveryInfo[mission.current];
    }

    @Override
    public void run() {
        if (mMission.source == null) {
            mMission.notifyError(mFromError);
            return;
        }

        try {
            /*if (mMission.source.startsWith(MissionRecoveryInfo.DIRECT_SOURCE)) {
                resolve(mMission.source.substring(MissionRecoveryInfo.DIRECT_SOURCE.length()));
                return;
            }*/

            StreamingService svr = NewPipe.getServiceByUrl(mMission.source);

            if (svr == null) {
                throw new RuntimeException("Unknown source service");
            }

            StreamExtractor extractor = svr.getStreamExtractor(mMission.source);
            extractor.fetchPage();

            if (!mMission.running || super.isInterrupted()) return;

            String url = null;

            switch (mMission.kind) {
                case 'a':
                    for (AudioStream audio : extractor.getAudioStreams()) {
                        if (audio.average_bitrate == mRecovery.desiredBitrate && audio.getFormat() == mRecovery.format) {
                            url = audio.getUrl();
                            break;
                        }
                    }
                    break;
                case 'v':
                    List<VideoStream> videoStreams;
                    if (mRecovery.desired2)
                        videoStreams = extractor.getVideoOnlyStreams();
                    else
                        videoStreams = extractor.getVideoStreams();
                    for (VideoStream video : videoStreams) {
                        if (video.resolution.equals(mRecovery.desired) && video.getFormat() == mRecovery.format) {
                            url = video.getUrl();
                            break;
                        }
                    }
                    break;
                case 's':
                    for (SubtitlesStream subtitles : extractor.getSubtitles(mRecovery.format)) {
                        String tag = subtitles.getLanguageTag();
                        if (tag.equals(mRecovery.desired) && subtitles.isAutoGenerated() == mRecovery.desired2) {
                            url = subtitles.getURL();
                            break;
                        }
                    }
                    break;
                default:
                    throw new RuntimeException("Unknown stream type");
            }

            resolve(url);
        } catch (Exception e) {
            if (!mMission.running || e instanceof ClosedByInterruptException) return;
            mRecovery.attempts++;
            mMission.notifyError(e);
        }
    }

    private void resolve(String url) throws IOException, DownloadMission.HttpError {
        if (mRecovery.validateCondition == null) {
            Log.w(TAG, "validation condition not defined, the resource can be stale");
        }

        if (mMission.unknownLength || mRecovery.validateCondition == null) {
            recover(url, false);
            return;
        }

        ///////////////////////////////////////////////////////////////////////
        ////// Validate the http resource doing a range request
        /////////////////////
        try {
            mConn = mMission.openConnection(url, mID, mMission.length - 10, mMission.length);
            mConn.setRequestProperty("If-Range", mRecovery.validateCondition);
            mMission.establishConnection(mID, mConn);

            int code = mConn.getResponseCode();

            switch (code) {
                case 200:
                case 413:
                    // stale
                    recover(url, true);
                    return;
                case 206:
                    // in case of validation using the Last-Modified date, check the resource length
                    long[] contentRange = parseContentRange(mConn.getHeaderField("Content-Range"));
                    boolean lengthMismatch = contentRange[2] != -1 && contentRange[2] != mMission.length;

                    recover(url, lengthMismatch);
                    return;
            }

            throw new DownloadMission.HttpError(code);
        } catch (Exception e) {
            if (!mMission.running || e instanceof ClosedByInterruptException) return;
            throw e;
        } finally {
            this.interrupt();
        }
    }

    private void recover(String url, boolean stale) {
        Log.i(TAG,
                String.format("download recovered  name=%s  isStale=%s  url=%s", mMission.storage.getName(), stale, url)
        );

        if (url == null) {
            mMission.notifyError(ERROR_RESOURCE_GONE, null);
            return;
        }

        mMission.urls[mMission.current] = url;
        mRecovery.attempts = 0;

        if (stale) {
            mMission.resetState(false, false, DownloadMission.ERROR_NOTHING);
        }

        mMission.writeThisToFile();

        if (!mMission.running || super.isInterrupted()) return;

        mMission.running = false;
        mMission.start();
    }

    private long[] parseContentRange(String value) {
        long[] range = new long[3];

        if (value == null) {
            // this never should happen
            return range;
        }

        try {
            value = value.trim();

            if (!value.startsWith("bytes")) {
                return range;// unknown range type
            }

            int space = value.lastIndexOf(' ') + 1;
            int dash = value.indexOf('-', space) + 1;
            int bar = value.indexOf('/', dash);

            // start
            range[0] = Long.parseLong(value.substring(space, dash - 1));

            // end
            range[1] = Long.parseLong(value.substring(dash, bar));

            // resource length
            value = value.substring(bar + 1);
            if (value.equals("*")) {
                range[2] = -1;// unknown length received from the server but should be valid
            } else {
                range[2] = Long.parseLong(value);
            }
        } catch (Exception e) {
            // nothing to do
        }

        return range;
    }

    @Override
    public void interrupt() {
        super.interrupt();
        if (mConn != null) {
            try {
                mConn.disconnect();
            } catch (Exception e) {
                // nothing to do
            }
        }
    }
}