package foundation.route;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

import foundation.handler.BaseHandler;
import foundation.handler.IHandler;
import foundation.handler.SingletonHandler;
import foundation.json.IJSONWriter;


public class ControllerRoute extends Route {

	private Class<? extends IHandler> toClass;
	private Class<? extends BaseHandler> instanceObjectClass;
	private Class<? extends SingletonHandler> singletonObjectClass;	
	private Method getSingletonInstanceMethod;
	
	
	public ControllerRoute(String from, String className) throws Exception {
		super(RouteBrowseCode.Handler, from);
		
		routeType = RouteType.Controller;
		remark = from + " --> " + className;
		
		setCallableClassName(className);
	}
	
	@SuppressWarnings({ "rawtypes", "unchecked" })
	public void setCallableClassName(String classname) throws Exception {
		//1.
		Class clazz = Class.forName(classname);
		
		if (SingletonHandler.class.isAssignableFrom(clazz)) {
			//1.2. 如果是只能单例的HttpObject
			singletonObjectClass = (Class<? extends SingletonHandler>) clazz;
			getSingletonInstanceMethod = clazz.getDeclaredMethod("getInstance");
		}
		else if (BaseHandler.class.isAssignableFrom(clazz)) {
			//1.1. 如果是可以多实例化的HttpObject
			instanceObjectClass = (Class<? extends BaseHandler>) clazz;
		}
		else {
			throw new Exception("error callable class: " + clazz);
		}
	}
	
	public IHandler getToObject() throws InstantiationException, IllegalAccessException, IllegalArgumentException, InvocationTargetException {
		if (instanceObjectClass != null) {
			return instanceObjectClass.newInstance();
		}
		
		if (singletonObjectClass != null) {
			return (IHandler) getSingletonInstanceMethod.invoke(null);
		}
		
		return null;
	}
	
	public Class<? extends IHandler> getToClass() {
		return toClass;
	}

	@Override
	public void onWriteJSON(IJSONWriter writer) {
		//1. write from
		writer.write("from", from);
		
		// write to
		Class<?> clazz = toClass;
		
		if (clazz == null) {
			clazz = instanceObjectClass;
		}
		
		if (clazz == null) {
			clazz = singletonObjectClass;
		}
		
		if (clazz == null) {
			writer.writeNull("to");
			return;
		}
		
		writer.write("to", clazz.getName());
	}
	
	@Override
	protected String formateFrom(String from) {
		from = from.toLowerCase();
		return from;
	}
	
	@Override
	public String toString() {
		return remark;
	}
}