package eu.dnetlib.dhp.collection.worker;

import java.io.IOException;
import java.net.URI;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.atomic.AtomicInteger;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.SequenceFile;
import org.apache.hadoop.io.Text;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.fasterxml.jackson.databind.ObjectMapper;

import eu.dnetlib.collector.worker.model.ApiDescriptor;
import eu.dnetlib.dhp.application.ArgumentApplicationParser;
import eu.dnetlib.dhp.collection.plugin.CollectorPlugin;
import eu.dnetlib.dhp.collection.worker.utils.CollectorPluginFactory;
import eu.dnetlib.message.Message;
import eu.dnetlib.message.MessageManager;
import eu.dnetlib.message.MessageType;

public class DnetCollectorWorker {

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

	private final CollectorPluginFactory collectorPluginFactory;

	private final ArgumentApplicationParser argumentParser;

	private final MessageManager manager;

	public DnetCollectorWorker(
		final CollectorPluginFactory collectorPluginFactory,
		final ArgumentApplicationParser argumentParser,
		final MessageManager manager)
		throws DnetCollectorException {
		this.collectorPluginFactory = collectorPluginFactory;
		this.argumentParser = argumentParser;
		this.manager = manager;
	}

	public void collect() throws DnetCollectorException {
		try {
			final ObjectMapper jsonMapper = new ObjectMapper();
			final ApiDescriptor api = jsonMapper.readValue(argumentParser.get("apidescriptor"), ApiDescriptor.class);

			final CollectorPlugin plugin = collectorPluginFactory.getPluginByProtocol(api.getProtocol());

			final String hdfsuri = argumentParser.get("namenode");

			// ====== Init HDFS File System Object
			Configuration conf = new Configuration();
			// Set FileSystem URI
			conf.set("fs.defaultFS", hdfsuri);
			// Because of Maven
			conf.set("fs.hdfs.impl", org.apache.hadoop.hdfs.DistributedFileSystem.class.getName());
			conf.set("fs.file.impl", org.apache.hadoop.fs.LocalFileSystem.class.getName());

			System.setProperty("HADOOP_USER_NAME", argumentParser.get("userHDFS"));
			System.setProperty("hadoop.home.dir", "/");
			// Get the filesystem - HDFS
			FileSystem.get(URI.create(hdfsuri), conf);
			Path hdfswritepath = new Path(argumentParser.get("hdfsPath"));

			log.info("Created path " + hdfswritepath.toString());

			final Map<String, String> ongoingMap = new HashMap<>();
			final Map<String, String> reportMap = new HashMap<>();
			final AtomicInteger counter = new AtomicInteger(0);
			try (SequenceFile.Writer writer = SequenceFile
				.createWriter(
					conf,
					SequenceFile.Writer.file(hdfswritepath),
					SequenceFile.Writer.keyClass(IntWritable.class),
					SequenceFile.Writer.valueClass(Text.class))) {
				final IntWritable key = new IntWritable(counter.get());
				final Text value = new Text();
				plugin
					.collect(api)
					.forEach(
						content -> {
							key.set(counter.getAndIncrement());
							value.set(content);
							if (counter.get() % 10 == 0) {
								try {
									ongoingMap.put("ongoing", "" + counter.get());
									log
										.debug(
											"Sending message: "
												+ manager
													.sendMessage(
														new Message(
															argumentParser.get("workflowId"),
															"Collection",
															MessageType.ONGOING,
															ongoingMap),
														argumentParser.get("rabbitOngoingQueue"),
														true,
														false));
								} catch (Exception e) {
									log.error("Error on sending message ", e);
								}
							}
							try {
								writer.append(key, value);
							} catch (IOException e) {
								throw new RuntimeException(e);
							}
						});
			}
			ongoingMap.put("ongoing", "" + counter.get());
			manager
				.sendMessage(
					new Message(
						argumentParser.get("workflowId"), "Collection", MessageType.ONGOING, ongoingMap),
					argumentParser.get("rabbitOngoingQueue"),
					true,
					false);
			reportMap.put("collected", "" + counter.get());
			manager
				.sendMessage(
					new Message(
						argumentParser.get("workflowId"), "Collection", MessageType.REPORT, reportMap),
					argumentParser.get("rabbitOngoingQueue"),
					true,
					false);
			manager.close();
		} catch (Throwable e) {
			throw new DnetCollectorException("Error on collecting ", e);
		}
	}
}