import java.io.StringReader;
import java.io.StringWriter;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import freemarker.core.Environment;
import freemarker.ext.beans.BeansWrapper;
import freemarker.template.Configuration;
import freemarker.template.Template;

public final class FreemarkerBug {
    protected static BeansWrapper defaultWrapper = BeansWrapper.getDefaultInstance();
    protected static Configuration defaultConfig = makeConfiguration(defaultWrapper);

    // based on ofbiz
    public static Configuration makeConfiguration(BeansWrapper wrapper) {
        Configuration newConfig = new Configuration();
        newConfig.setObjectWrapper(wrapper);
        newConfig.setSharedVariable("Static", wrapper.getStaticModels());
        newConfig.setLocalizedLookup(false);
        return newConfig;
    }

    public static String renderTemplate(String location, String templateBody, Map<String, Object> context) throws Exception {
        Template template = new Template(location, new StringReader(templateBody), defaultConfig);
        StringWriter out = new StringWriter();
        Environment env = template.createProcessingEnvironment(context, out);
        env.process();
        return out.toString();
    }

    public static String m(String name, List<? extends Object> list) {
        return "<(" + name + "):" + (list != null ? list.toString() : null) + ">";
    }

    public static String m(Object... args) {
        return "<+" + (args != null ? Arrays.asList(args).toString() : null) + ">";
    }

    public static void main(String[] args) throws Exception {
        String badTemplate = "${Static['FreemarkerBug'].m('foo', null)}";
        Map<String, Object> context = new HashMap<String, Object>();
        String result = renderTemplate("bad-template", badTemplate, context);
        System.out.println("result=" + result);
    }
}