D-Net

package eu.dnetlib.oai.mongo;

import java.util.Iterator;

import com.google.common.collect.Lists;

import com.mongodb.DBObject;

import com.mongodb.client.MongoCursor;

import eu.dnetlib.data.information.oai.publisher.info.RecordInfo;

import eu.dnetlib.data.oai.store.Cursor;

import eu.dnetlib.miscutils.functional.UnaryFunction;

public class DNetOAIMongoCursor implements Cursor {

	/**

	 * Underlying mongo cursor.

	 */

	private MongoCursor<DBObject> dbCursor;

	private int size = 0;

	/**

	 * Function to apply to records before delivering.

	 */

	private UnaryFunction<String, String> function;

	/**

	 * true if the RecordInfo returned by this Cursor must include the record body, false otherwise.

	 */

	private boolean bodyIncluded;

	private RecordInfoGenerator recordInfoGenerator;

	private MetadataExtractor metadataExtractor;

	private ProvenanceExtractor provenanceExtractor;

	public DNetOAIMongoCursor() {

		super();

	}

	public DNetOAIMongoCursor(final MongoCursor<DBObject> dbCursor, final boolean bodyIncluded, final RecordInfoGenerator recordInfoGenerator,

			final MetadataExtractor metadataExtractor) {

		this(dbCursor, null, bodyIncluded, recordInfoGenerator, metadataExtractor);

	}

	public DNetOAIMongoCursor(final MongoCursor<DBObject> dbCursor, final UnaryFunction<String, String> function, final boolean bodyIncluded,

			final RecordInfoGenerator recordInfoGenerator, final MetadataExtractor metadataExtractor) {

		super();

		this.dbCursor = dbCursor;

		this.size = 0;

		this.function = function;

		this.bodyIncluded = bodyIncluded;

		this.recordInfoGenerator = recordInfoGenerator;

		this.metadataExtractor = metadataExtractor;

	}

	/**

	 * {@inheritDoc}

	 */

	@Override

	public int count() {

		//I can do it because MongoCursor are always created from queries with "limit", so I do not expect the creation of the list to explode

		//to not exagerate, I'll get the size only if the current size is 0

		if (size == 0)

			size = Lists.newArrayList(dbCursor).size();

		return size;

	}

	/**

	 * {@inheritDoc}

	 *

	 * @see Iterable#iterator()

	 */

	@Override

	public Iterator<RecordInfo> iterator() {

		return new Iterator<RecordInfo>() {

			@Override

			public boolean hasNext() {

				return dbCursor.hasNext();

			}

			@Override

			public RecordInfo next() {

				DBObject res = dbCursor.next();

				RecordInfo info = recordInfoGenerator.transformDBObject(res, bodyIncluded);

				if ((function != null) && bodyIncluded && (info != null)) {

					info.setMetadata(function.evaluate(info.getMetadata()));

				}

				return info;

			}

			@Override

			public void remove() {

				throw new UnsupportedOperationException();

			}

		};

	}

	public UnaryFunction<String, String> getFunction() {

		return function;

	}

	public void setFunction(final UnaryFunction<String, String> function) {

		this.function = function;

	}

	public MongoCursor<DBObject> getDbCursor() {

		return dbCursor;

	}

	public void setDbCursor(final MongoCursor<DBObject> dbCursor) {

		this.dbCursor = dbCursor;

	}

	@Override

	public boolean isBodyIncluded() {

		return this.bodyIncluded;

	}

	@Override

	public void setBodyIncluded(final boolean bodyIncluded) {

		this.bodyIncluded = bodyIncluded;

	}

	public RecordInfoGenerator getRecordInfoGenerator() {

		return recordInfoGenerator;

	}

	public void setRecordInfoGenerator(final RecordInfoGenerator recordInfoGenerator) {

		this.recordInfoGenerator = recordInfoGenerator;

	}

	public MetadataExtractor getMetadataExtractor() {

		return metadataExtractor;

	}

	public void setMetadataExtractor(final MetadataExtractor metadataExtractor) {

		this.metadataExtractor = metadataExtractor;

	}

	public ProvenanceExtractor getProvenanceExtractor() {

		return provenanceExtractor;

	}

	public void setProvenanceExtractor(final ProvenanceExtractor provenanceExtractor) {

		this.provenanceExtractor = provenanceExtractor;

	}

}