dnet-applications/apps/dhp-mdstore-manager/src/main/java/eu/dnetlib/data/mdstore/manager/utils/DatabaseUtils.java

package eu.dnetlib.data.mdstore.manager.utils;

import java.util.Date;
import java.util.List;
import java.util.stream.Collectors;

import javax.transaction.Transactional;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Component;

import eu.dnetlib.data.mdstore.manager.common.model.MDStore;
import eu.dnetlib.data.mdstore.manager.common.model.MDStoreCurrentVersion;
import eu.dnetlib.data.mdstore.manager.common.model.MDStoreVersion;
import eu.dnetlib.data.mdstore.manager.common.model.MDStoreWithInfo;
import eu.dnetlib.data.mdstore.manager.exceptions.MDStoreManagerException;
import eu.dnetlib.data.mdstore.manager.repository.MDStoreCurrentVersionRepository;
import eu.dnetlib.data.mdstore.manager.repository.MDStoreRepository;
import eu.dnetlib.data.mdstore.manager.repository.MDStoreVersionRepository;
import eu.dnetlib.data.mdstore.manager.repository.MDStoreWithInfoRepository;

@Component
public class DatabaseUtils {

	@Autowired
	private MDStoreRepository mdstoreRepository;
	@Autowired
	private MDStoreVersionRepository mdstoreVersionRepository;
	@Autowired
	private MDStoreCurrentVersionRepository mdstoreCurrentVersionRepository;
	@Autowired
	private MDStoreWithInfoRepository mdstoreWithInfoRepository;
	@Autowired
	private JdbcTemplate jdbcTemplate;

	public Iterable<MDStoreWithInfo> listMdStores() {
		return mdstoreWithInfoRepository.findAll();
	}

	public List<String> listMdStoreIDs() {
		return mdstoreRepository.findAll().stream().map(MDStore::getId).collect(Collectors.toList());
	}

	public long countMdStores() {
		return mdstoreRepository.count();
	}

	public Iterable<MDStoreVersion> listVersions(final String mdId) {
		return mdstoreVersionRepository.findByMdstore(mdId);
	}

	public List<String> listExpiredVersions() {
		return jdbcTemplate
			.queryForList("select v.id from mdstore_versions v left outer join mdstore_current_versions cv on (v.id = cv.current_version) where v.writing = false and v.readcount = 0 and cv.mdstore is null;", String.class);
	}

	public MDStoreWithInfo findMdStore(final String mdId) throws MDStoreManagerException {
		return mdstoreWithInfoRepository.findById(mdId).orElseThrow(() -> new MDStoreManagerException("Missing mdstore: " + mdId));
	}

	@Transactional
	public String createMDStore(final String format,
		final String layout,
		final String interpretation,
		final String dsName,
		final String dsId,
		final String apiId) {

		final MDStore md = MDStore.newInstance(format, layout, interpretation, dsName, dsId, apiId);
		mdstoreRepository.save(md);

		final MDStoreVersion v = MDStoreVersion.newInstance(md.getId(), false);
		v.setLastUpdate(new Date());
		mdstoreVersionRepository.save(v);
		mdstoreCurrentVersionRepository.save(MDStoreCurrentVersion.newInstance(v));

		return md.getId();
	}

	@Transactional
	public void deleteMdStore(final String mdId) throws MDStoreManagerException {
		if (!mdstoreRepository.existsById(mdId)) { throw new MDStoreManagerException("On delete MDStore not found " + "[" + mdId + "]"); }

		if (mdstoreVersionRepository.countByMdstoreAndReadCountGreaterThan(mdId, 0) > 0) {
			throw new MDStoreManagerException("Read transactions found on mdstore : " + mdId);
		}

		if (mdstoreVersionRepository.countByMdstoreAndWriting(mdId, true) > 0) {
			throw new MDStoreManagerException("Write transactions found on mdstore : " + mdId);
		}

		mdstoreCurrentVersionRepository.deleteById(mdId);
		mdstoreVersionRepository.deleteByMdstore(mdId);
		mdstoreRepository.deleteById(mdId);
	}

	@Transactional
	public MDStoreVersion startReading(final String mdId) throws MDStoreManagerException {
		final MDStoreCurrentVersion cv =
			mdstoreCurrentVersionRepository.findById(mdId).orElseThrow(() -> new MDStoreManagerException("Missing mdstore: " + mdId));
		final MDStoreVersion v = mdstoreVersionRepository.findById(cv.getCurrentVersion())
			.orElseThrow(() -> new MDStoreManagerException("Missing version: " + cv.getCurrentVersion()));
		v.setReadCount(v.getReadCount() + 1);
		mdstoreVersionRepository.save(v);
		return v;
	}

	@Transactional
	public MDStoreVersion endReading(final String versionId) throws MDStoreManagerException {
		final MDStoreVersion v = mdstoreVersionRepository.findById(versionId).orElseThrow(() -> new MDStoreManagerException("Version not found"));
		v.setReadCount(v.getReadCount() - 1);
		return v;
	}

	@Transactional
	public MDStoreVersion prepareMdStoreVersion(final String mdId) {
		final MDStoreVersion v = MDStoreVersion.newInstance(mdId, true);
		mdstoreVersionRepository.save(v);
		return v;
	}

	@Transactional
	public MDStoreVersion commitMdStoreVersion(final String versionId, final long size) throws MDStoreManagerException {
		final MDStoreVersion v = mdstoreVersionRepository.findById(versionId).orElseThrow(() -> new MDStoreManagerException("Invalid version: " + versionId));
		mdstoreCurrentVersionRepository.save(MDStoreCurrentVersion.newInstance(v));
		v.setWriting(false);
		v.setSize(size);
		v.setLastUpdate(new Date());
		mdstoreVersionRepository.save(v);
		return v;
	}

	@Transactional
	public void deleteMdStoreVersions(final boolean force, final String... versions) throws MDStoreManagerException {

		for (final String versionId : versions) {
			final MDStoreVersion v = mdstoreVersionRepository.findById(versionId).orElseThrow(() -> new MDStoreManagerException("Version not found"));

			if (mdstoreCurrentVersionRepository
				.countByCurrentVersion(versionId) > 0) {
				throw new MDStoreManagerException("I cannot delete this version because it is the current version");
			}

			if (!force) {
				if (v.isWriting()) { throw new MDStoreManagerException("I cannot delete this version because it is in write mode"); }
				if (v.getReadCount() > 0) { throw new MDStoreManagerException("I cannot delete this version because it is in read mode"); }
			}

			mdstoreVersionRepository.delete(v);
		}
	}

}