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 *   Licensed to the Apache Software Foundation (ASF) under one
 *  or more contributor license agreements.  See the NOTICE file
 *  distributed with this work for additional information
 *  regarding copyright ownership.  The ASF licenses this file
 *  to you under the Apache License, Version 2.0 (the
 *  "License"); you may not use this file except in compliance
 *  with the License.  You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing,
 *  software distributed under the License is distributed on an
 *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 *  KIND, either express or implied.  See the License for the
 *  specific language governing permissions and limitations
 *  under the License.
 ****************************************************************/

package org.apache.cayenne.access.translator.select;

import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

import org.apache.cayenne.CayenneRuntimeException;
import org.apache.cayenne.ObjectId;
import org.apache.cayenne.Persistent;
import org.apache.cayenne.exp.Expression;
import org.apache.cayenne.map.DbAttribute;
import org.apache.cayenne.map.DbEntity;
import org.apache.cayenne.map.DbJoin;
import org.apache.cayenne.map.DbRelationship;

/**
 */
public class DataObjectMatchTranslator {

	protected Map<String, DbAttribute> attributes;
	protected Map<String, Object> values;
	protected String operation;
	protected Expression expression;
	protected DbRelationship relationship;
	protected String joinSplitAlias;

	public Expression getExpression() {
		return expression;
	}

	public void setExpression(Expression expression) {
		this.expression = expression;
	}

	public void reset() {
		attributes = null;
		values = null;
		operation = null;
		expression = null;
		relationship = null;
	}

	/**
	 * Initializes itself to do translation of the match ending with a
	 * DbRelationship.
	 * 
	 * @since 3.0
	 */
	public void setRelationship(DbRelationship rel, String joinSplitAlias) {
		this.relationship = rel;
		this.joinSplitAlias = joinSplitAlias;
		attributes = new HashMap<>(rel.getJoins().size() * 2);

		if (rel.isToMany() || !rel.isToPK()) {

			// match on target PK
			DbEntity ent = rel.getTargetEntity();

			// index by name
			for (DbAttribute pkAttr : ent.getPrimaryKeys()) {
				attributes.put(pkAttr.getName(), pkAttr);
			}
		} else {

			// match on this FK
			for (DbJoin join : rel.getJoins()) {
				// index by target name
				attributes.put(join.getTargetName(), join.getSource());
			}
		}
	}

	public void setDataObject(Persistent obj) {
		if (obj == null) {
			values = Collections.emptyMap();
			return;
		}

		setObjectId(obj.getObjectId());
	}

	/**
	 * @since 1.2
	 */
	public void setObjectId(ObjectId id) {
		if (id == null) {
			throw new CayenneRuntimeException(
					"Null ObjectId, probably an attempt to use TRANSIENT object as a query parameter.");
		} else if (id.isTemporary()) {
			throw new CayenneRuntimeException(
					"Temporary id, probably an attempt to use NEW object as a query parameter.");
		} else {
			values = id.getIdSnapshot();
		}
	}

	public Iterator<String> keys() {
		if (attributes == null) {
			throw new IllegalStateException("An attempt to use uninitialized DataObjectMatchTranslator: "
					+ "[attributes: null, values: " + values + "]");
		}

		return attributes.keySet().iterator();
	}

	/**
	 * @since 3.0
	 */
	public String getJoinSplitAlias() {
		return joinSplitAlias;
	}

	public DbRelationship getRelationship() {
		return relationship;
	}

	public DbAttribute getAttribute(String key) {
		return attributes.get(key);
	}

	public Object getValue(String key) {
		return values.get(key);
	}

	public void setOperation(String operation) {
		this.operation = operation;
	}

	public String getOperation() {
		return operation;
	}
}