package eu.dnetlib.dhp.collection;

import com.fasterxml.jackson.databind.ObjectMapper;
import eu.dnetlib.dhp.model.mdstore.MetadataRecord;
import eu.dnetlib.dhp.model.mdstore.Provenance;
import org.apache.commons.cli.*;
import org.apache.commons.lang3.StringUtils;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Text;
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.sql.Dataset;
import org.apache.spark.sql.Encoder;
import org.apache.spark.sql.Encoders;
import org.apache.spark.sql.SparkSession;
import org.apache.spark.util.LongAccumulator;
import org.dom4j.Document;
import org.dom4j.Node;
import org.dom4j.io.SAXReader;

import java.io.ByteArrayInputStream;
import java.nio.charset.StandardCharsets;
import java.util.Objects;

public class GenerateNativeStoreSparkJob {


    public static MetadataRecord parseRecord (final String input, final String xpath, final String encoding, final Provenance provenance, final Long dateOfCollection, final LongAccumulator totalItems, final LongAccumulator invalidRecords)  {

        if(totalItems != null)
            totalItems.add(1);
        try {
            SAXReader reader = new SAXReader();
            Document document = reader.read(new ByteArrayInputStream(input.getBytes(StandardCharsets.UTF_8)));
            Node node = document.selectSingleNode(xpath);
            final String originalIdentifier = node.getText();
            if (StringUtils.isBlank(originalIdentifier)) {
                if (invalidRecords!= null)
                    invalidRecords.add(1);
                return null;
            }
            return new MetadataRecord(originalIdentifier, encoding, provenance, input, dateOfCollection);
        } catch (Throwable e) {
            if (invalidRecords!= null)
                invalidRecords.add(1);
            e.printStackTrace();
            return null;

        }
    }

    public static void main(String[] args) throws Exception {

        Options options = new Options();
        options.addOption(Option.builder("e")
                .longOpt("encoding")
                .required(true)
                .desc("the encoding type should be xml or json")
                .hasArg() // This option has an argument.
                .build());
        options.addOption(Option.builder("d")
                .longOpt("dateOfCollection")
                .required(true)
                .desc("the date of collection")
                .hasArg() // This option has an argument.
                .build());

        options.addOption(Option.builder("p")
                .longOpt("provenance")
                .required(true)
                .desc("the json Provenance information")
                .hasArg() // This option has an argument.
                .build());

        options.addOption(Option.builder("x")
                .longOpt("xpath")
                .required(true)
                .desc("xpath of the identifier")
                .hasArg() // This option has an argument.
                .build());

        options.addOption(Option.builder("i")
                .longOpt("input")
                .required(true)
                .desc("input path of the sequence file")
                .hasArg() // This option has an argument.
                .build());
        options.addOption(Option.builder("o")
                .longOpt("output")
                .required(true)
                .desc("output path of the mdstore")
                .hasArg()
                .build());


        CommandLineParser parser = new DefaultParser();
        CommandLine cmd = parser.parse( options, args);

        final String encoding = cmd.getOptionValue("e");
        final long dateOfCollection = new Long(cmd.getOptionValue("d"));
        final String jsonProvenance = cmd.getOptionValue("p");
        final ObjectMapper jsonMapper = new ObjectMapper();
        final Provenance provenance = jsonMapper.readValue(jsonProvenance, Provenance.class);
        final String xpath = cmd.getOptionValue("x");
        final String inputPath = cmd.getOptionValue("i");
        final String outputPath = cmd.getOptionValue("o");

        final SparkSession spark = SparkSession
                .builder()
                .appName("GenerateNativeStoreSparkJob")
                .master("local")
                .getOrCreate();

        final JavaSparkContext sc = new JavaSparkContext(spark.sparkContext());

        final JavaPairRDD<IntWritable, Text> inputRDD = sc.sequenceFile(inputPath, IntWritable.class, Text.class);

        final LongAccumulator totalItems = sc.sc().longAccumulator("TotalItems");

        final LongAccumulator invalidRecords = sc.sc().longAccumulator("InvalidRecords");

        final JavaRDD<MetadataRecord> mappeRDD = inputRDD.map(item -> parseRecord(item._2().toString(), xpath, encoding, provenance, dateOfCollection, totalItems, invalidRecords))
                .filter(Objects::nonNull).distinct();

        final Encoder<MetadataRecord> encoder = Encoders.bean(MetadataRecord.class);
        final Dataset<MetadataRecord> mdstore = spark.createDataset(mappeRDD.rdd(), encoder);
        final LongAccumulator mdStoreRecords = sc.sc().longAccumulator("MDStoreRecords");
        mdStoreRecords.add(mdstore.count());
        System.out.println("totalItems.value() = " + totalItems.value());
        System.out.println("invalidRecords = " + invalidRecords.value());
        System.out.println("mdstoreRecords.value() = " + mdStoreRecords.value());
        mdstore.write().format("parquet").save(outputPath);
    }
}