package eu.dnetlib.dhp.oa.graph.dump.complete;

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

import java.io.Serializable;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Optional;

import org.apache.commons.io.IOUtils;
import org.apache.spark.SparkConf;
import org.apache.spark.sql.*;
import org.apache.spark.sql.types.*;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import eu.dnetlib.dhp.application.ArgumentApplicationParser;
import eu.dnetlib.dhp.oa.graph.dump.Utils;
import eu.dnetlib.dhp.schema.oaf.*;

/**
 * It selects the valid relations among those present in the graph. One relation is valid if it is not deletedbyinference
 * and if both the source and the target node are present in the graph and are not deleted by inference nor invisible.
 * To check this I made a view of the ids of all the entities in the graph, and select the relations for which a join exists
 * with this view for both the source and the target
 */

public class SparkSelectValidRelationsJob implements Serializable {

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

	public static void main(String[] args) throws Exception {
		String jsonConfiguration = IOUtils
			.toString(
				SparkSelectValidRelationsJob.class
					.getResourceAsStream(
						"/eu/dnetlib/dhp/oa/graph/dump/input_relationdump_parameters.json"));

		final ArgumentApplicationParser parser = new ArgumentApplicationParser(jsonConfiguration);
		parser.parseArgument(args);

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

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

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

		SparkConf conf = new SparkConf();

		runWithSparkSession(
			conf,
			isSparkSessionManaged,
			spark -> {
				Utils.removeOutputDir(spark, outputPath);
				selectValidRelation2(spark, inputPath, outputPath);

			});

	}

	private static void selectValidRelation2(SparkSession spark, String inputPath, String outputPath) {
		final StructType structureSchema = new StructType()
			.fromDDL("`id` STRING, `dataInfo` STRUCT<`deletedbyinference`:BOOLEAN,`invisible`:BOOLEAN>");

		org.apache.spark.sql.Dataset<Row> df = spark.createDataFrame(new ArrayList<Row>(), structureSchema);
		List<String> entities = Arrays
			.asList(
				"publication", "dataset", "otherresearchproduct", "software", "organization", "project", "datasource");
		for (String e : entities)
			df = df
				.union(
					spark
						.read()
						.schema(structureSchema)
						.json(inputPath + "/" + e)
						.filter("dataInfo.deletedbyinference != true and dataInfo.invisible != true"));

		org.apache.spark.sql.Dataset<Row> relations = spark
			.read()
			.schema(Encoders.bean(Relation.class).schema())
			.json(inputPath + "/relation")
			.filter("dataInfo.deletedbyinference == false");

		relations
			.join(df, relations.col("source").equalTo(df.col("id")), "leftsemi")
			.join(df, relations.col("target").equalTo(df.col("id")), "leftsemi")
			.write()
			.mode(SaveMode.Overwrite)
			.option("compression", "gzip")
			.json(outputPath);
	}

}