package eu.dnetlib.dhp.oa.dedup;

import java.io.IOException;
import java.io.Serializable;
import java.io.StringReader;
import java.util.ArrayList;
import java.util.List;

import org.apache.spark.SparkConf;
import org.apache.spark.sql.Dataset;
import org.apache.spark.sql.SaveMode;
import org.apache.spark.sql.SparkSession;
import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;

import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.ObjectMapper;

import eu.dnetlib.dhp.application.ArgumentApplicationParser;
import eu.dnetlib.dhp.common.HdfsSupport;
import eu.dnetlib.dhp.schema.oaf.*;
import eu.dnetlib.enabling.is.lookup.rmi.ISLookUpException;
import eu.dnetlib.enabling.is.lookup.rmi.ISLookUpService;
import eu.dnetlib.pace.config.DedupConfig;

abstract class AbstractSparkAction implements Serializable {

	protected static final int NUM_PARTITIONS = 1000;
	protected static final int NUM_CONNECTIONS = 20;

	protected static final ObjectMapper OBJECT_MAPPER = new ObjectMapper()
		.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);

	public ArgumentApplicationParser parser; // parameters for the spark action
	public SparkSession spark; // the spark session

	public AbstractSparkAction(ArgumentApplicationParser parser, SparkSession spark) {

		this.parser = parser;
		this.spark = spark;
	}

	public List<DedupConfig> getConfigurations(ISLookUpService isLookUpService, String orchestrator)
		throws ISLookUpException, DocumentException, IOException {

		final String xquery = String.format("/RESOURCE_PROFILE[.//DEDUPLICATION/ACTION_SET/@id = '%s']", orchestrator);

		String orchestratorProfile = isLookUpService.getResourceProfileByQuery(xquery);

		final Document doc = new SAXReader().read(new StringReader(orchestratorProfile));

		final String actionSetId = doc.valueOf("//DEDUPLICATION/ACTION_SET/@id");

		final List<DedupConfig> configurations = new ArrayList<>();

		for (final Object o : doc.selectNodes("//SCAN_SEQUENCE/SCAN")) {
			configurations.add(loadConfig(isLookUpService, actionSetId, o));
		}

		return configurations;
	}

	private DedupConfig loadConfig(
		final ISLookUpService isLookUpService, final String actionSetId, final Object o)
		throws ISLookUpException, IOException {
		final Element s = (Element) o;
		final String configProfileId = s.attributeValue("id");
		final String conf = isLookUpService
			.getResourceProfileByQuery(
				String
					.format(
						"for $x in /RESOURCE_PROFILE[.//RESOURCE_IDENTIFIER/@value = '%s'] return $x//DEDUPLICATION/text()",
						configProfileId));

		DedupConfig dedupConfig = new ObjectMapper().readValue(conf, DedupConfig.class);
		dedupConfig.getPace().initModel();
		dedupConfig.getPace().initTranslationMap();
		dedupConfig.getWf().setConfigurationId(actionSetId);

		return dedupConfig;
	}

	abstract void run(ISLookUpService isLookUpService)
		throws DocumentException, IOException, ISLookUpException;

	protected static SparkSession getSparkSession(SparkConf conf) {
		return SparkSession.builder().config(conf).getOrCreate();
	}

	protected static <T> void save(Dataset<T> dataset, String outPath, SaveMode mode) {
		dataset.write().option("compression", "gzip").mode(mode).json(outPath);
	}

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