package eu.dnetlib.functionality.index.solr;

import java.io.File;
import java.io.IOException;
import java.util.Collections;
import java.util.List;
import java.util.Set;

import javax.xml.parsers.ParserConfigurationException;

import org.apache.commons.io.IOUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.lucene.store.SimpleFSDirectory;
import org.apache.solr.client.solrj.SolrServer;
import org.apache.solr.client.solrj.embedded.EmbeddedSolrServer;
import org.apache.solr.core.CoreContainer;
import org.apache.solr.schema.IndexSchema;
import org.apache.solr.update.MergeIndexesCommand;
import org.xml.sax.SAXException;

import com.google.common.collect.Iterables;
import com.google.common.collect.Lists;
import com.google.common.collect.Sets;

import eu.dnetlib.miscutils.collections.MappedCollection;
import eu.dnetlib.miscutils.functional.UnaryFunction;

public class LocalIndexServer {

	private static final Log log = LogFactory.getLog(LocalIndexServer.class); // NOPMD by marko on 11/24/08 5:02 PM

	private CoreContainer container;	

	private IndexSchema schema;	
	
	private SolrServer server;
	
	private String indexName;
	
	private Set<String> dsIds;
	
	public LocalIndexServer(final String indexName, final List<String> dsIds, final String solrDataDir, final IndexSchema schema) 
		throws ParserConfigurationException, IOException, SAXException {

		this.indexName = indexName;
		this.setSchema(schema);

		this.dsIds = Collections.synchronizedSet(Sets.newHashSet(dsIds));

		server = newEmbeddedSolrServer(indexName, solrDataDir);
	}

	private SolrServer newEmbeddedSolrServer(final String indexName, final String solrDataDir) throws ParserConfigurationException, IOException, SAXException {
		File home = new File(solrDataDir + IOUtils.DIR_SEPARATOR_UNIX + indexName);

		this.container = new CoreContainer(home.getAbsolutePath());
		getContainer().load(home.getAbsolutePath(), new File(home, "solr.xml"));

		return new EmbeddedSolrServer(getContainer(), indexName);
	}
	
	public void mergeIndexes(final List<String> paths) throws IOException {
		
		log.info("merging PATHS: " + paths);
	
		UnaryFunction<SimpleFSDirectory, String> mapper = new UnaryFunction<SimpleFSDirectory, String>() {
			@Override
			public SimpleFSDirectory evaluate(String path) {
				try {
					return new SimpleFSDirectory(new File(path));
				} catch (IOException e) {
					throw new RuntimeException(e);
				}
			}
		};
		SimpleFSDirectory[] dirs = Iterables.toArray(new MappedCollection<SimpleFSDirectory, String>(paths, mapper ), SimpleFSDirectory.class);
		getContainer().getCore(indexName).getUpdateHandler().mergeIndexes(new MergeIndexesCommand(dirs));
		log.info("DONE merging DIRS: " + Lists.newArrayList(dirs));
	}
	
	public void restartCore() throws ParserConfigurationException, IOException, SAXException {
		log.info("restarting core: " + indexName);		
		getContainer().reload(indexName);
	}

	public SolrServer getServer() {
		return server;
	}
	
	public IndexSchema getSchema() {
		return schema;
	}
	
	public void setSchema(IndexSchema schema) {
		this.schema = schema;
	}
	
	public Set<String> getDsIds() {
		return dsIds;
	}

	public CoreContainer getContainer() {
		return container;
	}

}