package org.geoserver.python.filter;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.logging.Level;
import org.geoserver.platform.GeoServerExtensions;
import org.geoserver.python.Python;
import org.geotools.factory.CommonFactoryFinder;
import org.geotools.filter.FunctionFactory;
import org.geotools.util.SoftValueHashMap;
import org.opengis.filter.FilterFactory;
import org.opengis.filter.capability.FunctionName;
import org.opengis.filter.expression.Expression;
import org.opengis.filter.expression.Function;
import org.opengis.filter.expression.Literal;
public class PythonFilterFunctionFactory implements FunctionFactory {
Python py;
SoftValueHashMap<String, PythonFilterFunctionAdapter> adapters = new SoftValueHashMap(10);
public List<FunctionName> getFunctionNames() {
FilterFactory ff = CommonFactoryFinder.getFilterFactory(null);
Python py = py();
List<FunctionName> names = new ArrayList<FunctionName>();
try {
File filterRoot = py.getFilterRoot();
for (String file : filterRoot.list()) {
if (file.endsWith(".py")) {
PythonFilterFunctionAdapter adapter =
new PythonFilterFunctionAdapter(new File(filterRoot, file), py);
for(String name : adapter.getNames()) {
FunctionName fname =
ff.functionName(name, adapter.getParameterNames(name).size());
names.add(fname);
}
}
}
}
catch (IOException e) {
Python.LOGGER.log(Level.WARNING, "Error looking up filter functions", e);
}
return names;
}
public Function function(String name, List<Expression> args, Literal fallback) {
PythonFilterFunctionAdapter adapter = adapter(name);
if (adapter == null) {
return null;
}
return new PythonFunction(name, args, adapter);
}
Python py() {
if (py == null) {
py = GeoServerExtensions.bean(Python.class);
}
return py;
}
PythonFilterFunctionAdapter adapter(String name) {
PythonFilterFunctionAdapter adapter = adapters.get(name);
if (adapter == null) {
synchronized(this) {
adapter = adapters.get(name);
if (adapter == null) {
try {
adapter = createFilterFunctionAdapter(name);
}
catch (IOException e) {
throw new RuntimeException(e);
}
if (adapter != null) {
adapters.put(name, adapter);
}
}
}
}
return adapter;
}
private PythonFilterFunctionAdapter createFilterFunctionAdapter(String name)
throws IOException {
for (File f : py().getFilterRoot().listFiles()) {
PythonFilterFunctionAdapter adapter = new PythonFilterFunctionAdapter(f, py());
if (adapter.getNames().contains(name)) {
return adapter;
}
}
return null;
}
}