package eu.dnetlib.dhp.aggregation.mdstore;

import static eu.dnetlib.dhp.common.Constants.*;
import static eu.dnetlib.dhp.utils.DHPUtils.*;

import java.net.URI;

import org.apache.commons.io.IOUtils;
import org.apache.commons.lang3.StringUtils;
import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import eu.dnetlib.dhp.application.ArgumentApplicationParser;
import eu.dnetlib.dhp.common.rest.DNetRestClient;
import eu.dnetlib.dhp.schema.mdstore.MDStoreVersion;

public class MDStoreActionNode {
	private static final Logger log = LoggerFactory.getLogger(MDStoreActionNode.class);

	enum MDAction {
		NEW_VERSION, ROLLBACK, COMMIT, READ_LOCK, READ_UNLOCK
	}

	public static final String NEW_VERSION_URI = "%s/mdstore/%s/newVersion";

	public static final String COMMIT_VERSION_URL = "%s/version/%s/commit/%s";
	public static final String ROLLBACK_VERSION_URL = "%s/version/%s/abort";

	public static final String READ_LOCK_URL = "%s/mdstore/%s/startReading";
	public static final String READ_UNLOCK_URL = "%s/version/%s/endReading";

	private static final String MDSTOREVERSIONPARAM = "mdStoreVersion";
	private static final String MDSTOREREADLOCKPARAM = "mdStoreReadLockVersion";

	public static void main(String[] args) throws Exception {
		final ArgumentApplicationParser argumentParser = new ArgumentApplicationParser(
			IOUtils
				.toString(
					MDStoreActionNode.class
						.getResourceAsStream(
							"/eu/dnetlib/dhp/collection/mdstore_action_parameters.json")));
		argumentParser.parseArgument(args);

		log.info("Java Xmx: {}m", Runtime.getRuntime().maxMemory() / (1024 * 1024));

		final MDAction action = MDAction.valueOf(argumentParser.get("action"));
		log.info("Current action is {}", action);

		final String mdStoreManagerURI = argumentParser.get("mdStoreManagerURI");
		log.info("mdStoreManagerURI is {}", mdStoreManagerURI);

		switch (action) {
			case NEW_VERSION: {
				final String mdStoreID = argumentParser.get("mdStoreID");
				if (StringUtils.isBlank(mdStoreID)) {
					throw new IllegalArgumentException("missing or empty argument mdStoreId");
				}
				final MDStoreVersion currentVersion = DNetRestClient
					.doGET(String.format(NEW_VERSION_URI, mdStoreManagerURI, mdStoreID), MDStoreVersion.class);
				populateOOZIEEnv(MDSTOREVERSIONPARAM, MAPPER.writeValueAsString(currentVersion));
				break;
			}
			case COMMIT: {

				final String hdfsuri = argumentParser.get("namenode");
				if (StringUtils.isBlank(hdfsuri)) {
					throw new IllegalArgumentException("missing or empty argument namenode");
				}
				final String mdStoreVersion_params = argumentParser.get(MDSTOREVERSIONPARAM);
				final MDStoreVersion mdStoreVersion = MAPPER.readValue(mdStoreVersion_params, MDStoreVersion.class);

				if (StringUtils.isBlank(mdStoreVersion.getId())) {
					throw new IllegalArgumentException(
						"invalid MDStoreVersion value current is " + mdStoreVersion_params);
				}
				Path hdfstoreSizepath = new Path(mdStoreVersion.getHdfsPath() + MDSTORE_SIZE_PATH);

				try (
					FileSystem fs = FileSystem.get(URI.create(hdfsuri), getHadoopConfiguration(hdfsuri));
					FSDataInputStream inputStream = fs.open(hdfstoreSizepath)) {

					final Long mdStoreSize = Long.parseLong(IOUtils.toString(inputStream));

					fs.create(hdfstoreSizepath);
					DNetRestClient
						.doGET(
							String.format(COMMIT_VERSION_URL, mdStoreManagerURI, mdStoreVersion.getId(), mdStoreSize));
				}

				break;
			}
			case ROLLBACK: {
				final String mdStoreVersion_params = argumentParser.get(MDSTOREVERSIONPARAM);
				final MDStoreVersion mdStoreVersion = MAPPER.readValue(mdStoreVersion_params, MDStoreVersion.class);

				if (StringUtils.isBlank(mdStoreVersion.getId())) {
					throw new IllegalArgumentException(
						"invalid MDStoreVersion value current is " + mdStoreVersion_params);
				}
				DNetRestClient.doGET(String.format(ROLLBACK_VERSION_URL, mdStoreManagerURI, mdStoreVersion.getId()));
				break;
			}

			case READ_LOCK: {
				final String mdStoreID = argumentParser.get("mdStoreID");
				if (StringUtils.isBlank(mdStoreID)) {
					throw new IllegalArgumentException("missing or empty argument mdStoreId");
				}
				final MDStoreVersion currentVersion = DNetRestClient
					.doGET(String.format(READ_LOCK_URL, mdStoreManagerURI, mdStoreID), MDStoreVersion.class);
				populateOOZIEEnv(MDSTOREREADLOCKPARAM, MAPPER.writeValueAsString(currentVersion));
				break;
			}
			case READ_UNLOCK: {
				final String mdStoreVersion_params = argumentParser.get("readMDStoreId");
				final MDStoreVersion mdStoreVersion = MAPPER.readValue(mdStoreVersion_params, MDStoreVersion.class);

				if (StringUtils.isBlank(mdStoreVersion.getId())) {
					throw new IllegalArgumentException(
						"invalid MDStoreVersion value current is " + mdStoreVersion_params);
				}
				DNetRestClient.doGET(String.format(READ_UNLOCK_URL, mdStoreManagerURI, mdStoreVersion.getId()));
				break;
			}

			default:
				throw new IllegalArgumentException("invalid action");
		}

	}

}