package eu.dnetlib.dhp.collection.orcid;

import static eu.dnetlib.dhp.utils.DHPUtils.getHadoopConfiguration;

import java.io.*;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
import java.util.Objects;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;

import org.apache.commons.compress.archivers.tar.TarArchiveEntry;
import org.apache.commons.compress.archivers.tar.TarArchiveInputStream;
import org.apache.commons.compress.compressors.gzip.GzipCompressorInputStream;
import org.apache.commons.io.IOUtils;
import org.apache.commons.lang3.StringUtils;
import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.fs.FSDataOutputStream;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.SequenceFile;
import org.apache.hadoop.io.Text;
import org.apache.spark.sql.SparkSession;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import eu.dnetlib.dhp.application.ArgumentApplicationParser;
import eu.dnetlib.dhp.common.collection.HttpClientParams;

public class OrcidGetUpdatesFile {

	private static Logger log = LoggerFactory.getLogger(OrcidGetUpdatesFile.class);

	public static void main(String[] args) throws Exception {

		ArgumentApplicationParser parser = new ArgumentApplicationParser(
			IOUtils
				.toString(
					Objects
						.requireNonNull(
							OrcidGetUpdatesFile.class
								.getResourceAsStream(
									"/eu/dnetlib/dhp/collection/orcid/download_orcid_update_parameter.json")))

		);
		parser.parseArgument(args);

		final String namenode = parser.get("namenode");
		log.info("got variable namenode: {}", namenode);

		final String master = parser.get("master");
		log.info("got variable master: {}", master);

		final String targetPath = parser.get("targetPath");
		log.info("got variable targetPath: {}", targetPath);

		final String apiURL = parser.get("apiURL");
		log.info("got variable apiURL: {}", apiURL);

		final String accessToken = parser.get("accessToken");
		log.info("got variable accessToken: {}", accessToken);

		final String graphPath = parser.get("graphPath");
		log.info("got variable graphPath: {}", graphPath);

		final SparkSession spark = SparkSession
			.builder()
			.appName(OrcidGetUpdatesFile.class.getName())
			.master(master)
			.getOrCreate();

		final String latestDate = spark
			.read()
			.load(graphPath + "/Authors")
			.selectExpr("max(lastModifiedDate)")
			.first()
			.getString(0);

		log.info("latest date is {}", latestDate);

		final FileSystem fileSystem = FileSystem.get(getHadoopConfiguration(namenode));

		new OrcidGetUpdatesFile().readTar(fileSystem, accessToken, apiURL, targetPath, latestDate);

	}

	private SequenceFile.Writer createFile(Path aPath, FileSystem fileSystem) throws IOException {
		return SequenceFile
			.createWriter(
				fileSystem.getConf(),
				SequenceFile.Writer.file(aPath),
				SequenceFile.Writer.keyClass(Text.class),
				SequenceFile.Writer.valueClass(Text.class));
	}

	private ORCIDWorker createWorker(final String id, final String targetPath, final BlockingQueue<String> queue,
		final String accessToken, FileSystem fileSystem) throws Exception {
		return ORCIDWorker
			.builder()
			.withId(id)
			.withEmployments(createFile(new Path(String.format("%s/employments_%s", targetPath, id)), fileSystem))
			.withSummary(createFile(new Path(String.format("%s/summary_%s", targetPath, id)), fileSystem))
			.withWorks(createFile(new Path(String.format("%s/works_%s", targetPath, id)), fileSystem))
			.withAccessToken(accessToken)
			.withBlockingQueue(queue)
			.build();
	}

	public void readTar(FileSystem fileSystem, final String accessToken, final String apiURL, final String targetPath,
		final String startDate) throws Exception {
		final HttpURLConnection urlConn = (HttpURLConnection) new URL(apiURL).openConnection();
		final HttpClientParams clientParams = new HttpClientParams();
		urlConn.setInstanceFollowRedirects(false);
		urlConn.setReadTimeout(clientParams.getReadTimeOut() * 1000);
		urlConn.setConnectTimeout(clientParams.getConnectTimeOut() * 1000);
		if (urlConn.getResponseCode() > 199 && urlConn.getResponseCode() < 300) {
			InputStream input = urlConn.getInputStream();

			Path hdfsWritePath = new Path("/tmp/orcid_updates.tar.gz");
			final FSDataOutputStream fsDataOutputStream = fileSystem.create(hdfsWritePath, true);
			IOUtils.copy(input, fsDataOutputStream);
			fsDataOutputStream.flush();
			fsDataOutputStream.close();
			FSDataInputStream updateFile = fileSystem.open(hdfsWritePath);
			TarArchiveInputStream tais = new TarArchiveInputStream(new GzipCompressorInputStream(
				new BufferedInputStream(
					updateFile.getWrappedStream())));
			TarArchiveEntry entry;

			BlockingQueue<String> queue = new ArrayBlockingQueue<String>(3000);
			final List<ORCIDWorker> workers = new ArrayList<>();
			for (int i = 0; i < 22; i++) {
				workers.add(createWorker("" + i, targetPath, queue, accessToken, fileSystem));
			}
			workers.forEach(Thread::start);

			while ((entry = tais.getNextTarEntry()) != null) {

				if (entry.isFile()) {

					BufferedReader br = new BufferedReader(new InputStreamReader(tais));
					System.out.println(br.readLine());
					br
						.lines()
						.map(l -> l.split(","))
						.filter(s -> StringUtils.compare(s[3].substring(0, 10), startDate) > 0)
						.map(s -> s[0])
						.forEach(s -> {
							try {
								queue.put(s);
							} catch (InterruptedException e) {
								throw new RuntimeException(e);
							}
						});

				}
			}

			for (int i = 0; i < 22; i++) {
				queue.put(ORCIDWorker.JOB_COMPLETE);
			}
			for (ORCIDWorker worker : workers) {
				worker.join();
			}
		}

	}
}