OInstance.java

/*
 * Copyright (c) 2012 Data Harmonisation Panel
 * 
 * All rights reserved. This program and the accompanying materials are made
 * available under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation, either version 3 of the License,
 * or (at your option) any later version.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with this distribution. If not, see <http://www.gnu.org/licenses/>.
 * 
 * Contributors:
 *     HUMBOLDT EU Integrated Project #030962
 *     Data Harmonisation Panel <http://www.dhpanel.eu>
 */

package eu.esdihumboldt.hale.common.instance.orient;

import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

import javax.xml.namespace.QName;

import com.google.common.base.Preconditions;
import com.orientechnologies.orient.core.db.record.ODatabaseRecord;
import com.orientechnologies.orient.core.record.impl.ODocument;

import eu.esdihumboldt.hale.common.instance.model.DataSet;
import eu.esdihumboldt.hale.common.instance.model.Group;
import eu.esdihumboldt.hale.common.instance.model.Instance;
import eu.esdihumboldt.hale.common.instance.model.MutableInstance;
import eu.esdihumboldt.hale.common.schema.model.TypeDefinition;

/**
 * Instance implementation based on {@link ODocument}s
 * 
 * @author Simon Templer
 * @partner 01 / Fraunhofer Institute for Computer Graphics Research
 */
public class OInstance extends OGroup implements MutableInstance {

	/**
	 * Name for the special field for an instance value
	 */
	public static final String FIELD_VALUE = "___value___";

	/**
	 * Name for the special field for MetaData documents
	 */
	public static final String FIELD_METADATA = "___metadata___";

	/**
	 * Name for the special field indicating if the instance was inserted
	 * directly.
	 */
	public static final String FIELD_INSERTED = "___insert___";

	/**
	 * The data set the instance is associated to. This value is not persisted.
	 */
	private DataSet dataSet;

	/**
	 * The set of special field names, e.g. for the instance value
	 */
	private static final Set<String> SPECIAL_FIELDS = new HashSet<String>();
	static {
		SPECIAL_FIELDS.add(FIELD_VALUE);
		SPECIAL_FIELDS.add(FIELD_METADATA);
		SPECIAL_FIELDS.add(FIELD_INSERTED);
	}

	/**
	 * Creates an empty instance associated with the given type.
	 * 
	 * @param typeDef the definition of the instance's type
	 * @param dataSet the data set the instance is associated to
	 */
	public OInstance(TypeDefinition typeDef, DataSet dataSet) {
		super(typeDef);

		this.dataSet = dataSet;
	}

	/**
	 * Creates an instance based on the given document.
	 * 
	 * @param document the document
	 * @param typeDef the definition of the instance's type
	 * @param db the database
	 * @param dataSet the data set the instance is associated to
	 */
	public OInstance(ODocument document, TypeDefinition typeDef, ODatabaseRecord db, DataSet dataSet) {
		super(document, typeDef, db);

		this.dataSet = dataSet;
	}

	/**
	 * Copy constructor. Creates an instance based on the properties and values
	 * of the given instance.
	 * 
	 * @param org the instance to copy
	 */
	public OInstance(Instance org) {
		super(org);

		setValue(org.getValue());
		setDataSet(org.getDataSet());

		for (String key : org.getMetaDataNames()) {
			setMetaData(key, org.getMetaData(key).toArray());
		}
	}

	/**
	 * @see MutableInstance#setValue(Object)
	 */
	@Override
	public void setValue(Object value) {
		document.field(FIELD_VALUE, convertInstance(value));
	}

	/**
	 * @see Instance#getValue()
	 */
	@Override
	public Object getValue() {
		associatedDbWithThread();

		return convertDocument(document.field(FIELD_VALUE), null);
	}

	/**
	 * Set if the instance is inserted directly.
	 * 
	 * @param inserted if the instance is inserted directly.
	 */
	public void setInserted(boolean inserted) {
		document.field(FIELD_INSERTED, inserted);
	}

	/**
	 * States if the instance was inserted directly.
	 * 
	 * @return if the instance was inserted directly
	 */
	public boolean isInserted() {
		associatedDbWithThread();

		Object value = document.field(FIELD_INSERTED);
		if (value != null && value instanceof Boolean) {
			return ((Boolean) value).booleanValue();
		}

		// default if not set
		return false;
	}

	/**
	 * @see OGroup#getSpecialFieldNames()
	 */
	@Override
	protected Collection<String> getSpecialFieldNames() {
		Collection<String> superFields = super.getSpecialFieldNames();
		if (superFields.isEmpty()) {
			return SPECIAL_FIELDS;
		}
		else {
			Set<String> result = new HashSet<String>(superFields);
			result.addAll(SPECIAL_FIELDS);
			return result;
		}
	}

	/**
	 * @see Instance#getDefinition()
	 */
	@Override
	public TypeDefinition getDefinition() {
		return (TypeDefinition) super.getDefinition();
	}

	@Override
	public DataSet getDataSet() {
		return dataSet;
	}

	@Override
	public void setDataSet(DataSet dataSet) {
		this.dataSet = dataSet;
	}

	/**
	 * @see eu.esdihumboldt.hale.common.instance.model.Instance#getMetaData(java.lang.String)
	 */
	@Override
	public List<Object> getMetaData(String key) {
		associatedDbWithThread();

		ODocument datafield = (ODocument) document.field(FIELD_METADATA);

		if (datafield == null) {
			return Collections.emptyList();
		}

		Object[] values = getProperty(new QName(key), datafield);

		if (values == null || values.length == 0) {
			return Collections.emptyList();
		}
		return Arrays.asList(values);
	}

	/**
	 * {@inheritDoc}
	 * 
	 * The parameter "Object obj" may not be an ODocument
	 */
	@Override
	public void putMetaData(String key, Object obj) {

		Preconditions
				.checkArgument(!(obj instanceof ODocument || obj instanceof Instance || obj instanceof Group));

		ODocument metaData;

		if (document.field(FIELD_METADATA) == null) {
			metaData = new ODocument();
			document.field(FIELD_METADATA, metaData);
		}
		else {
			metaData = (ODocument) document.field(FIELD_METADATA);
		}

		addProperty(new QName(key), obj, metaData);
	}

	/**
	 * @see eu.esdihumboldt.hale.common.instance.model.Instance#getMetaDataNames()
	 */
	@Override
	public Set<String> getMetaDataNames() {
		associatedDbWithThread();

		ODocument datafield = (ODocument) document.field(FIELD_METADATA);

		if (datafield == null
		// || datafield.isEmpty()
		) {
			return Collections.emptySet();
		}

		Iterable<QName> it = getPropertyNames(datafield);

		Set<String> keys = new HashSet<String>();
		for (QName field : it) {
			keys.add(field.getLocalPart());

		}
		return keys;

	}

	/**
	 * {@inheritDoc} The parameter values may not contain an ODocument
	 */
	@Override
	public void setMetaData(String key, Object... values) {

		for (Object value : values) {
			Preconditions
					.checkArgument(!(value instanceof ODocument || value instanceof Instance || value instanceof Group));
		}

		ODocument metaData;
		if (document.field(FIELD_METADATA) == null) {
			metaData = new ODocument();
			document.field(FIELD_METADATA, metaData);
		}
		else
			metaData = ((ODocument) document.field(FIELD_METADATA));

		setPropertyInternal(metaData, new QName(key), values);
	}

}