package eu.dnetlib.dhp.broker.oa;

import static eu.dnetlib.dhp.common.SparkSessionSupport.runWithSparkSession;

import java.util.ArrayList;
import java.util.List;
import java.util.Optional;
import java.util.stream.Collectors;

import org.apache.commons.io.IOUtils;
import org.apache.hadoop.io.compress.GzipCodec;
import org.apache.spark.SparkConf;
import org.apache.spark.api.java.JavaRDD;
import org.apache.spark.api.java.JavaSparkContext;
import org.apache.spark.api.java.function.MapFunction;
import org.apache.spark.sql.Column;
import org.apache.spark.sql.Dataset;
import org.apache.spark.sql.Encoders;
import org.apache.spark.sql.Row;
import org.apache.spark.sql.SparkSession;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.fasterxml.jackson.databind.ObjectMapper;

import eu.dnetlib.dhp.application.ArgumentApplicationParser;
import eu.dnetlib.dhp.broker.model.Event;
import eu.dnetlib.dhp.broker.model.EventFactory;
import eu.dnetlib.dhp.broker.oa.matchers.EnrichMissingAbstract;
import eu.dnetlib.dhp.broker.oa.matchers.EnrichMissingAuthorOrcid;
import eu.dnetlib.dhp.broker.oa.matchers.EnrichMissingOpenAccess;
import eu.dnetlib.dhp.broker.oa.matchers.EnrichMissingPid;
import eu.dnetlib.dhp.broker.oa.matchers.EnrichMissingProject;
import eu.dnetlib.dhp.broker.oa.matchers.EnrichMissingPublicationDate;
import eu.dnetlib.dhp.broker.oa.matchers.EnrichMissingSubject;
import eu.dnetlib.dhp.broker.oa.matchers.EnrichMoreOpenAccess;
import eu.dnetlib.dhp.broker.oa.matchers.EnrichMorePid;
import eu.dnetlib.dhp.broker.oa.matchers.EnrichMoreSubject;
import eu.dnetlib.dhp.broker.oa.matchers.UpdateMatcher;
import eu.dnetlib.dhp.broker.oa.util.UpdateInfo;
import eu.dnetlib.dhp.common.HdfsSupport;
import eu.dnetlib.dhp.schema.oaf.OtherResearchProduct;
import eu.dnetlib.dhp.schema.oaf.Publication;
import eu.dnetlib.dhp.schema.oaf.Relation;
import eu.dnetlib.dhp.schema.oaf.Result;
import eu.dnetlib.dhp.schema.oaf.Software;

public class GenerateEventsApplication {

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

	private static final UpdateMatcher<?> enrichMissingAbstract = new EnrichMissingAbstract();
	private static final UpdateMatcher<?> enrichMissingAuthorOrcid = new EnrichMissingAuthorOrcid();
	private static final UpdateMatcher<?> enrichMissingOpenAccess = new EnrichMissingOpenAccess();
	private static final UpdateMatcher<?> enrichMissingPid = new EnrichMissingPid();
	private static final UpdateMatcher<?> enrichMissingProject = new EnrichMissingProject();
	private static final UpdateMatcher<?> enrichMissingPublicationDate = new EnrichMissingPublicationDate();
	private static final UpdateMatcher<?> enrichMissingSubject = new EnrichMissingSubject();
	private static final UpdateMatcher<?> enrichMoreOpenAccess = new EnrichMoreOpenAccess();
	private static final UpdateMatcher<?> enrichMorePid = new EnrichMorePid();
	private static final UpdateMatcher<?> enrichMoreSubject = new EnrichMoreSubject();

	public static final ObjectMapper OBJECT_MAPPER = new ObjectMapper();

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

		final Boolean isSparkSessionManaged = Optional
			.ofNullable(parser.get("isSparkSessionManaged"))
			.map(Boolean::valueOf)
			.orElse(Boolean.TRUE);
		log.info("isSparkSessionManaged: {}", isSparkSessionManaged);

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

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

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

		final SparkConf conf = new SparkConf();

		runWithSparkSession(conf, isSparkSessionManaged, spark -> {
			final JavaSparkContext sc = JavaSparkContext.fromSparkContext(spark.sparkContext());
			removeOutputDir(spark, eventsPath);

			final JavaRDD<Event> eventsRdd = sc.emptyRDD();

			eventsRdd.union(generateSimpleEvents(spark, graphPath, Publication.class));
			eventsRdd.union(generateSimpleEvents(spark, graphPath, eu.dnetlib.dhp.schema.oaf.Dataset.class));
			eventsRdd.union(generateSimpleEvents(spark, graphPath, Software.class));
			eventsRdd.union(generateSimpleEvents(spark, graphPath, OtherResearchProduct.class));

			eventsRdd.saveAsTextFile(eventsPath, GzipCodec.class);
		});

	}

	private static void removeOutputDir(final SparkSession spark, final String path) {
		HdfsSupport.remove(path, spark.sparkContext().hadoopConfiguration());
	}

	private static <R extends Result> JavaRDD<Event> generateSimpleEvents(final SparkSession spark,
		final String graphPath,
		final Class<R> resultClazz) {

		final Dataset<R> results =
			readPath(spark, graphPath + "/" + resultClazz.getSimpleName().toLowerCase(), resultClazz)
				.filter(r -> r.getDataInfo().getDeletedbyinference());

		final Dataset<Relation> rels =
			readPath(spark, graphPath + "/relation", Relation.class)
				.filter(r -> r.getRelClass().equals("TODO")); // TODO mergedIN

		final Column c = null; // TODO

		final Dataset<Row> aa = results.joinWith(rels, results.col("id").equalTo(rels.col("source")), "inner")
			.groupBy(rels.col("target"))
			.agg(c)
			.filter(x -> x.size() > 1)
		// generateSimpleEvents(...)
		// flatMap()
		// toRdd()
		;

		return null;

	}

	private List<Event> generateSimpleEvents(final Result... children) {
		final List<UpdateInfo<?>> list = new ArrayList<>();

		for (final Result target : children) {
			list.addAll(enrichMissingAbstract.searchUpdatesForRecord(target, children));
			list.addAll(enrichMissingAuthorOrcid.searchUpdatesForRecord(target, children));
			list.addAll(enrichMissingOpenAccess.searchUpdatesForRecord(target, children));
			list.addAll(enrichMissingPid.searchUpdatesForRecord(target, children));
			list.addAll(enrichMissingProject.searchUpdatesForRecord(target, children));
			list.addAll(enrichMissingPublicationDate.searchUpdatesForRecord(target, children));
			list.addAll(enrichMissingSubject.searchUpdatesForRecord(target, children));
			list.addAll(enrichMoreOpenAccess.searchUpdatesForRecord(target, children));
			list.addAll(enrichMorePid.searchUpdatesForRecord(target, children));
			list.addAll(enrichMoreSubject.searchUpdatesForRecord(target, children));
		}

		return list.stream().map(EventFactory::newBrokerEvent).collect(Collectors.toList());
	}

	public static <R> Dataset<R> readPath(
		final SparkSession spark,
		final String inputPath,
		final Class<R> clazz) {
		return spark
			.read()
			.textFile(inputPath)
			.map((MapFunction<String, R>) value -> OBJECT_MAPPER.readValue(value, clazz), Encoders.bean(clazz));
	}
}