package eu.dnetlib.dhp.oa.graph.hostedbymap;

import java.io.*;
import java.net.URL;
import java.net.URLConnection;
import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;
import java.util.Optional;

import org.apache.commons.io.IOUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FSDataOutputStream;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.opencsv.bean.CsvToBeanBuilder;

import eu.dnetlib.dhp.application.ArgumentApplicationParser;

public class GetCSV {
	private static final Log log = LogFactory.getLog(eu.dnetlib.dhp.oa.graph.hostedbymap.GetCSV.class);

	public static void main(final String[] args) throws Exception {
		final ArgumentApplicationParser parser = new ArgumentApplicationParser(
			IOUtils
				.toString(
					GetCSV.class
						.getResourceAsStream(
							"/eu/dnetlib/dhp/oa/graph/hostedbymap/download_csv_parameters.json")));

		parser.parseArgument(args);

		final String fileURL = parser.get("fileURL");
		final String hdfsPath = parser.get("workingPath");
		final String hdfsNameNode = parser.get("hdfsNameNode");
		final String classForName = parser.get("classForName");
		final Boolean shouldReplace = Optional
			.ofNullable((parser.get("replace")))
			.map(Boolean::valueOf)
			.orElse(false);

		URLConnection connection = new URL(fileURL).openConnection();
		connection
			.setRequestProperty(
				"User-Agent",
				"Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.11 (KHTML, like Gecko) Chrome/23.0.1271.95 Safari/537.11");
		connection.connect();

		BufferedReader in = new BufferedReader(
			new InputStreamReader(connection.getInputStream(), Charset.forName("UTF-8")));

		if (shouldReplace) {
			PrintWriter writer = new PrintWriter(new BufferedWriter(new FileWriter("/tmp/DOAJ.csv")));
			String line = null;
			while ((line = in.readLine()) != null) {
				writer.println(line.replace("\\\"", "\""));
			}
			writer.close();
			in.close();
			in = new BufferedReader(new FileReader("/tmp/DOAJ.csv"));
		}

		Configuration conf = new Configuration();
		conf.set("fs.defaultFS", hdfsNameNode);

		FileSystem fileSystem = FileSystem.get(conf);
		Path hdfsWritePath = new Path(hdfsPath);
		FSDataOutputStream fsDataOutputStream = null;
		if (fileSystem.exists(hdfsWritePath)) {
			fileSystem.delete(hdfsWritePath, false);
		}
		fsDataOutputStream = fileSystem.create(hdfsWritePath);

		BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(fsDataOutputStream, StandardCharsets.UTF_8));

		Class<?> clazz = Class.forName(classForName);

		ObjectMapper mapper = new ObjectMapper();

		new CsvToBeanBuilder(in)
			.withType(clazz)
			.withMultilineLimit(1)
			.build()
			.parse()
			.forEach(line -> {
				try {
					writer.write(mapper.writeValueAsString(line));
					writer.newLine();
				} catch (IOException e) {
					throw new RuntimeException(e);
				}
			});

		writer.close();
		in.close();
		if (shouldReplace) {
			File f = new File("/tmp/DOAJ.csv");
			f.delete();
		}

	}

}