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

import static org.junit.jupiter.api.Assertions.assertEquals;

import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.List;

import org.apache.commons.io.FileUtils;
import org.apache.spark.SparkConf;
import org.apache.spark.api.java.function.MapFunction;
import org.apache.spark.sql.Encoders;
import org.apache.spark.sql.SparkSession;
import org.junit.jupiter.api.AfterAll;
import org.junit.jupiter.api.BeforeAll;
import org.junit.jupiter.api.Test;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.fasterxml.jackson.databind.ObjectMapper;

import eu.dnetlib.dhp.schema.oaf.Relation;

public class PatchRelationApplicationTest {

	private static final ObjectMapper OBJECT_MAPPER = new ObjectMapper();
	public static final String ID_MAPPING_PATH = "map/id_mapping.json";

	private static SparkSession spark;

	private static Path workingDir;

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

	@BeforeAll
	public static void beforeAll() throws IOException {
		workingDir = Files
			.createTempDirectory(PatchRelationApplicationTest.class.getSimpleName());
		log.info("using work dir {}", workingDir);

		SparkConf conf = new SparkConf();
		conf.setAppName(PatchRelationApplicationTest.class.getSimpleName());

		conf.setMaster("local[*]");
		conf.set("spark.driver.host", "localhost");
		conf.set("hive.metastore.local", "true");
		conf.set("spark.ui.enabled", "false");
		conf.set("spark.sql.warehouse.dir", workingDir.toString());
		conf.set("hive.metastore.warehouse.dir", workingDir.resolve("warehouse").toString());

		spark = SparkSession
			.builder()
			.appName(PatchRelationApplicationTest.class.getSimpleName())
			.config(conf)
			.getOrCreate();

		FileUtils
			.copyInputStreamToFile(
				PatchRelationApplicationTest.class.getResourceAsStream("id_mapping.json"),
				workingDir.resolve(ID_MAPPING_PATH).toFile());

		FileUtils
			.copyInputStreamToFile(
				PatchRelationApplicationTest.class.getResourceAsStream("relations_to_patch.json"),
				workingDir.resolve("graphBasePath/relation/rels.json").toFile());

	}

	@AfterAll
	public static void afterAll() throws IOException {
		FileUtils.deleteDirectory(workingDir.toFile());
		spark.stop();
	}

	@Test
	public void testPatchRelationApplication() throws Exception {

		final String graphBasePath = workingDir.toString() + "/graphBasePath";
		PatchRelationsApplication.main(new String[] {
			"-isSparkSessionManaged", Boolean.FALSE.toString(),
			"-graphBasePath", graphBasePath,
			"-workingDir", workingDir.toString() + "/workingDir",
			"-idMappingPath", workingDir.toString() + "/" + ID_MAPPING_PATH
		});

		final List<Relation> rels = spark
			.read()
			.textFile(graphBasePath + "/relation")
			.map(
				(MapFunction<String, Relation>) s -> OBJECT_MAPPER.readValue(s, Relation.class),
				Encoders.bean(Relation.class))
			.collectAsList();

		assertEquals(6, rels.size());

		assertEquals(0, getCount(rels, "1a"), "should be patched to 1b");
		assertEquals(0, getCount(rels, "2a"), "should be patched to 2b");

		assertEquals(2, getCount(rels, "10a"), "not included in patching");
		assertEquals(2, getCount(rels, "20a"), "not included in patching");

		assertEquals(2, getCount(rels, "15a"), "not included in patching");
		assertEquals(2, getCount(rels, "25a"), "not included in patching");

		assertEquals(2, getCount(rels, "1b"), "patched from 1a");
		assertEquals(2, getCount(rels, "2b"), "patched from 2a");
	}

	private long getCount(List<Relation> rels, final String id) {
		return rels.stream().filter(r -> r.getSource().equals(id) || r.getTarget().equals(id)).count();
	}

}