package com.dooapp.gaedo.rest.server;
import java.lang.reflect.Method;
import java.util.Map;
import java.util.logging.Level;
import java.util.logging.Logger;
import com.dooapp.gaedo.finders.FieldInformer;
import com.dooapp.gaedo.finders.FinderCrudService;
import com.dooapp.gaedo.finders.Informer;
import com.dooapp.gaedo.finders.QueryBuilder;
import com.dooapp.gaedo.finders.QueryExpression;
import com.dooapp.gaedo.finders.expressions.AggregatingQueryExpression;
import com.dooapp.gaedo.finders.expressions.AndQueryExpression;
/**
* Transform some http query parameters into a gaedo query statement
* @author ndx
*
*/
public class QueryTranscripter {
private static Logger logger = Logger.getLogger(QueryTranscripter.class.getName());
/**
* @param service
* @param filterParams
* @return
*/
public <DataType, InformerType extends Informer<DataType>> QueryBuilder<InformerType> buildQuery(FinderCrudService<DataType, InformerType> service,
Map<String, Object> filterParams) {
Map<String, Object> valuesAsTree = Utils.getValuesAsTree(filterParams);
// Now explore tree to build a QueryBuilder instance
final AndQueryExpression combinator = new AndQueryExpression();
for(Map.Entry<String, Object> entry : valuesAsTree.entrySet()) {
buildQueryExpression(combinator, service.getInformer(), (Map<String, Object>) entry.getValue());
}
return new QueryBuilder<InformerType>() {
@Override
public QueryExpression createMatchingExpression(
InformerType informer) {
return combinator;
}
};
}
public void buildQueryExpression(AggregatingQueryExpression parent, FieldInformer fieldInformer,
Map<String, Object> value) {
if(FilterAggregator.isAggregationMap(value)) {
FilterAggregator current = FilterAggregator.get(value);
AggregatingQueryExpression expr = current.createExpression();
parent.add(expr);
buildQueryExpression(expr, fieldInformer, (Map<String, Object>) value.get(current.getKey()));
} else {
for(Map.Entry<String, Object> entry : value.entrySet()) {
if(fieldInformer instanceof Informer) {
Informer beanInformer = (Informer) fieldInformer;
try {
FieldInformer usedInformer = beanInformer.get(entry.getKey());
buildQueryExpression(parent, usedInformer, (Map<String, Object>) entry.getValue());
} catch(Exception e) {
logger.log(Level.FINE, "unable to build query statement from field \""+entry.getKey()+"\"", e);
}
} else {
// Locate method by name
Method toCall = com.dooapp.gaedo.utils.Utils.getNameMap(fieldInformer.getClass().getMethods()).get(entry.getKey());
try {
parent.add((QueryExpression) toCall.invoke(fieldInformer, fieldInformer.getField().fromString(entry.getValue().toString())));
} catch (Exception e) {
logger.log(Level.FINE, "unable to build query statement from field "+fieldInformer+" and method "+entry.getKey(), e);
}
}
}
}
}
}