package org.yaac.server.egql.evaluator.function;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import org.yaac.server.egql.evaluator.EvaluationResult;
import org.yaac.server.egql.evaluator.Evaluator;
import org.yaac.server.egql.exception.EGQLE003Exception;
import org.yaac.server.egql.exception.EGQLException;
import org.yaac.server.egql.processor.ProcessData.ProcessDataRecord;
import org.yaac.shared.ErrorCode;
import com.google.appengine.api.datastore.Key;
import com.google.appengine.api.datastore.KeyFactory;
/**
* @author Max Zhu (thebbsky@gmail.com)
*
*/
public class KeyFunction extends Function {
/**
*
*/
private static final long serialVersionUID = 1L;
@Override
public void validate() throws EGQLException {
int paramSize = this.ops.size();
if (paramSize == 0 || (paramSize != 1 && paramSize % 2 != 0)) {
throw new EGQLE003Exception();
}
}
@Override
public EvaluationResult evaluate(ProcessDataRecord record) {
if (this.ops.isEmpty()) {
return new EvaluationResult(null).withWarning(ErrorCode.W124);
} else if (this.ops.size() == 1) { // KEY('encoded key')
EvaluationResult r = this.ops.get(0).evaluate(record);
if (r.getPayload() instanceof String) {
try {
return new EvaluationResult(
KeyFactory.stringToKey((String) r.getPayload()), r);
} catch (IllegalArgumentException e) { // invalid input key string
return r.withWarning(ErrorCode.W129);
}
} else {
return r.withWarning(ErrorCode.W125);
}
} else if (this.ops.size() % 2 == 0) { //TODO KEY('kind', 'name'/ID [, 'kind', 'name'/ID...])
Key key = null;
// evaluation results, used at last to construct all previous results
List<EvaluationResult> rs = new ArrayList<EvaluationResult>(this.ops.size());
Iterator<Evaluator> i = this.ops.iterator();
while (i.hasNext()) {
EvaluationResult kindR = i.next().evaluate(record);
EvaluationResult nameIdR = i.next().evaluate(record);
if (!(kindR.getPayload() instanceof String)) {
return kindR.withWarning(ErrorCode.W126);
}
if (nameIdR.getPayload() instanceof String) {
key = KeyFactory.createKey(key,
(String)kindR.getPayload(),
(String)nameIdR.getPayload());
} else if (nameIdR.getPayload() instanceof Number) {
key = KeyFactory.createKey(key,
(String)kindR.getPayload(),
((Number)nameIdR.getPayload()).longValue());
} else {
return kindR.withWarning(ErrorCode.W127);
}
rs.add(kindR);
rs.add(nameIdR);
}
EvaluationResult [] rsArray = new EvaluationResult[rs.size()];
rs.toArray(rsArray);
return new EvaluationResult(key, rsArray);
} else {
return this.ops.get(0).evaluate(record).withWarning(ErrorCode.W128);
}
}
}