package eu.dnetlib.dedup;

import com.google.common.collect.Iterables;
import com.google.common.collect.Lists;
import com.google.common.hash.HashFunction;
import com.google.common.hash.Hashing;
import eu.dnetlib.dedup.graph.ConnectedComponent;
import eu.dnetlib.dedup.graph.GraphProcessor;
import eu.dnetlib.dhp.application.ArgumentApplicationParser;
import eu.dnetlib.dhp.schema.oaf.Relation;
import eu.dnetlib.pace.config.DedupConfig;
import eu.dnetlib.pace.util.MapDocumentUtil;
import org.apache.commons.io.IOUtils;
import org.apache.spark.api.java.JavaPairRDD;
import org.apache.spark.api.java.JavaRDD;
import org.apache.spark.api.java.JavaSparkContext;
import org.apache.spark.api.java.function.FlatMapFunction;
import org.apache.spark.api.java.function.PairFunction;
import org.apache.spark.graphx.Edge;
import org.apache.spark.rdd.RDD;
import org.apache.spark.sql.Dataset;
import org.apache.spark.sql.Encoders;
import org.apache.spark.sql.SparkSession;
import scala.Tuple2;

import java.util.ArrayList;
import java.util.List;

public class SparkCreateConnectedComponent {

    public static void main(String[] args) throws Exception {
        final ArgumentApplicationParser parser = new ArgumentApplicationParser(IOUtils.toString(SparkCreateConnectedComponent.class.getResourceAsStream("/eu/dnetlib/dhp/dedup/dedup_parameters.json")));
        parser.parseArgument(args);
        final SparkSession spark = SparkSession
                .builder()
                .appName(SparkCreateConnectedComponent.class.getSimpleName())
                .master(parser.get("master"))
                .getOrCreate();

        final JavaSparkContext sc = new JavaSparkContext(spark.sparkContext());
        final String inputPath = parser.get("sourcePath");
        final String entity = parser.get("entity");
        final String targetPath = parser.get("targetPath");
//        final DedupConfig dedupConf = DedupConfig.load(IOUtils.toString(SparkCreateConnectedComponent.class.getResourceAsStream("/eu/dnetlib/dhp/dedup/conf/org.curr.conf2.json")));
        final DedupConfig dedupConf = DedupConfig.load(parser.get("dedupConf"));

        final JavaPairRDD<Object, String> vertexes = sc.textFile(inputPath + "/" + entity)
                .map(s -> MapDocumentUtil.getJPathString(dedupConf.getWf().getIdPath(), s))
                .mapToPair((PairFunction<String, Object, String>)
                        s -> new Tuple2<Object, String>(getHashcode(s), s)
                );

        final Dataset<Relation> similarityRelations = spark.read().load(DedupUtility.createSimRelPath(targetPath,entity)).as(Encoders.bean(Relation.class));
        final RDD<Edge<String>> edgeRdd = similarityRelations.javaRDD().map(it -> new Edge<>(getHashcode(it.getSource()), getHashcode(it.getTarget()), it.getRelClass())).rdd();
        final JavaRDD<ConnectedComponent> cc = GraphProcessor.findCCs(vertexes.rdd(), edgeRdd, dedupConf.getWf().getMaxIterations()).toJavaRDD();
        final Dataset<Relation> mergeRelation = spark.createDataset(cc.filter(k->k.getDocIds().size()>1).flatMap((FlatMapFunction<ConnectedComponent, Relation>) c ->
                c.getDocIds()
                        .stream()
                        .flatMap(id -> {
                            List<Relation> tmp = new ArrayList<>();
                            Relation r = new Relation();
                            r.setSource(c.getCcId());
                            r.setTarget(id);
                            r.setRelClass("merges");
                            tmp.add(r);
                            r = new Relation();
                            r.setTarget(c.getCcId());
                            r.setSource(id);
                            r.setRelClass("isMergedIn");
                            tmp.add(r);
                            return tmp.stream();
                        }).iterator()).rdd(), Encoders.bean(Relation.class));
        mergeRelation.write().mode("overwrite").save(DedupUtility.createMergeRelPath(targetPath,entity));
    }

    public  static long getHashcode(final String id) {
        return Hashing.murmur3_128().hashString(id).asLong();
    }
}