import javax.annotation.processing.*;
import javax.lang.model.*;
import javax.lang.model.element.*;
import javax.lang.model.type.*;
import javax.lang.model.util.*;

import java.io.*;
import java.util.*;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;
import java.util.jar.JarOutputStream;

@SupportedAnnotationTypes({"Silent"})
public class SilentProcessor extends AbstractProcessor {
    @Override
    public SourceVersion getSupportedSourceVersion() {
        return SourceVersion.latest();
    }
    @Override
    public boolean process(Set<? extends TypeElement> annotations, RoundEnvironment roundEnv) {
    	System.out.println("running SilentProcessor on " + annotations);
        return true;
    }

    public static void main(String[] args) throws Exception {
    	boolean truncate = args.length != 0;
    	FileOutputStream fos = new FileOutputStream("ap.jar");
    	JarOutputStream jos = new JarOutputStream(fos);
    	add(jos, "Silent.class", truncate);
    	add(jos, "SilentProcessor.class", truncate);

    	jos.putNextEntry(new JarEntry("META-INF/services/javax.annotation.processing.Processor"));
    	jos.write("SilentProcessor".getBytes());
    	jos.closeEntry();
    	
    	jos.close();
    	fos.close();
    }
    
    private static void add(JarOutputStream jos, String classFilePath, boolean truncate) throws Exception {
    	jos.putNextEntry(new JarEntry(classFilePath));
    	byte[] data = readClassfile(classFilePath);
    	if (truncate) {
    		jos.write(data, 0, data.length - 100);
    	} else {
    		jos.write(readClassfile(classFilePath));
    	}
    	jos.closeEntry();
    }
    private static byte[] readClassfile(String classFilePath) throws Exception {
        InputStream stream = SilentProcessor.class.getResourceAsStream(classFilePath);
        int bytesToRead = stream.available();
        byte[] classFile = new byte[bytesToRead];
        new DataInputStream(stream).readFully(classFile);
        return classFile;
    }
}