package eu.dnetlib.dhp.actionmanager.createunresolvedentities;

import static eu.dnetlib.dhp.actionmanager.createunresolvedentities.Constants.*;
import static eu.dnetlib.dhp.common.SparkSessionSupport.runWithSparkSession;

import java.io.Serializable;
import java.util.*;
import java.util.stream.Collectors;

import org.apache.commons.io.IOUtils;
import org.apache.spark.SparkConf;
import org.apache.spark.api.java.function.FlatMapFunction;
import org.apache.spark.api.java.function.MapFunction;
import org.apache.spark.sql.Dataset;
import org.apache.spark.sql.Encoders;
import org.apache.spark.sql.SaveMode;
import org.apache.spark.sql.SparkSession;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import eu.dnetlib.dhp.actionmanager.createunresolvedentities.model.FOSDataModel;
import eu.dnetlib.dhp.application.ArgumentApplicationParser;
import eu.dnetlib.dhp.schema.common.ModelConstants;
import eu.dnetlib.dhp.schema.oaf.Result;
import eu.dnetlib.dhp.schema.oaf.StructuredProperty;
import eu.dnetlib.dhp.schema.oaf.utils.OafMapperUtils;
import eu.dnetlib.dhp.utils.DHPUtils;

public class PrepareFOSSparkJob implements Serializable {
	private static final Logger log = LoggerFactory.getLogger(PrepareFOSSparkJob.class);

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

		String jsonConfiguration = IOUtils
			.toString(
				PrepareFOSSparkJob.class
					.getResourceAsStream(
						"/eu/dnetlib/dhp/actionmanager/createunresolvedentities/prepare_parameters.json"));

		final ArgumentApplicationParser parser = new ArgumentApplicationParser(jsonConfiguration);

		parser.parseArgument(args);

		Boolean isSparkSessionManaged = isSparkSessionManaged(parser);
		log.info("isSparkSessionManaged: {}", isSparkSessionManaged);

		String sourcePath = parser.get("sourcePath");
		log.info("sourcePath: {}", sourcePath);

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

		SparkConf conf = new SparkConf();
		runWithSparkSession(
			conf,
			isSparkSessionManaged,
			spark -> {
				distributeFOSdois(
					spark,
					sourcePath,

					outputPath);
			});
	}

	private static void distributeFOSdois(SparkSession spark, String sourcePath, String outputPath) {
		Dataset<FOSDataModel> fosDataset = readPath(spark, sourcePath, FOSDataModel.class);

		fosDataset.flatMap((FlatMapFunction<FOSDataModel, FOSDataModel>) v -> {
			List<FOSDataModel> fosList = new ArrayList<>();
			final String level1 = v.getLevel1();
			final String level2 = v.getLevel2();
			final String level3 = v.getLevel3();
			Arrays
				.stream(v.getDoi().split("\u0002"))
				.forEach(d -> fosList.add(FOSDataModel.newInstance(d, level1, level2, level3)));
			return fosList.iterator();
		}, Encoders.bean(FOSDataModel.class))
			.map((MapFunction<FOSDataModel, Result>) value -> {
				Result r = new Result();
				r.setId(DHPUtils.generateUnresolvedIdentifier(value.getDoi(), DOI));
				r.setSubject(getSubjects(value));
				return r;
			}, Encoders.bean(Result.class))
			.write()
			.mode(SaveMode.Overwrite)
			.option("compression", "gzip")
			.json(outputPath + "/fos");
	}

	private static List<StructuredProperty> getSubjects(FOSDataModel fos) {
		return Arrays
			.asList(getSubject(fos.getLevel1()), getSubject(fos.getLevel2()), getSubject(fos.getLevel3()))
			.stream()
			.filter(Objects::nonNull)
			.collect(Collectors.toList());
	}

	private static StructuredProperty getSubject(String sbj) {
		if (sbj.equals(NULL))
			return null;
		StructuredProperty sp = new StructuredProperty();
		sp.setValue(sbj);
		sp
			.setQualifier(
				OafMapperUtils
					.qualifier(
						FOS_CLASS_ID,
						FOS_CLASS_NAME,
						ModelConstants.DNET_SUBJECT_TYPOLOGIES,
						ModelConstants.DNET_SUBJECT_TYPOLOGIES));
		sp
			.setDataInfo(
				OafMapperUtils
					.dataInfo(
						false,
						UPDATE_DATA_INFO_TYPE,
						true,
						false,
						OafMapperUtils
							.qualifier(
								UPDATE_SUBJECT_FOS_CLASS_ID,
								UPDATE_CLASS_NAME,
								ModelConstants.DNET_PROVENANCE_ACTIONS,
								ModelConstants.DNET_PROVENANCE_ACTIONS),
						""));

		return sp;

	}

}