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

import java.io.Closeable;
import java.io.IOException;
import java.util.Map;
import java.util.Map.Entry;

import org.apache.commons.io.IOUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.mongodb.MongoClient;
import com.mongodb.MongoClientURI;

import eu.dnetlib.dhp.application.ArgumentApplicationParser;
import eu.dnetlib.dhp.common.MdstoreClient;
import eu.dnetlib.dhp.common.MdstoreTx;
import eu.dnetlib.dhp.oa.graph.raw.common.AbstractMigrationApplication;

public class MigrateMongoMdstoresApplication extends AbstractMigrationApplication implements Closeable {

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

	private final MdstoreClient mdstoreClient;

	public static void main(final String[] args) throws Exception {
		final ArgumentApplicationParser parser = new ArgumentApplicationParser(
			IOUtils
				.toString(
					MigrateMongoMdstoresApplication.class
						.getResourceAsStream("/eu/dnetlib/dhp/oa/graph/migrate_mongo_mstores_parameters.json")));
		parser.parseArgument(args);

		final String mongoBaseUrl = parser.get("mongoBaseUrl");
		final String mongoDb = parser.get("mongoDb");

		final String mdFormat = parser.get("mdFormat");
		final String mdLayout = parser.get("mdLayout");
		final String mdInterpretation = parser.get("mdInterpretation");

		final String hdfsPath = parser.get("hdfsPath");

		final MongoClient mongoClient = new MongoClient(new MongoClientURI(mongoBaseUrl));

		try (MigrateMongoMdstoresApplication app = new MigrateMongoMdstoresApplication(hdfsPath, mongoClient,
			mongoDb)) {
			app.execute(mdFormat, mdLayout, mdInterpretation);
		}
	}

	public MigrateMongoMdstoresApplication(
		final String hdfsPath, final MongoClient mongoClient, final String mongoDb) throws Exception {
		super(hdfsPath);
		this.mdstoreClient = new MdstoreClient(mongoClient, mongoDb);
	}

	public void execute(final String format, final String layout, final String interpretation) throws IOException {
		final Map<String, String> colls = mdstoreClient.validCollections(format, layout, interpretation);
		log.info("Found {} mdstores", colls.size());

		for (final Entry<String, String> entry : colls.entrySet()) {
			log.info("Processing mdstore {}", entry.getKey());

			final String mdID = entry.getKey();
			try (final MdstoreTx tx = mdstoreClient.readLock(mdID)) {

				log.info("locked collection {}", tx.getCurrentId());

				for (final String xml : tx) {
					emit(xml, String.format("%s-%s-%s", format, layout, interpretation));
				}
			}
		}
	}

	@Override
	public void close() throws IOException {
		super.close();
		mdstoreClient.close();
	}
}