package dnode;
import com.google.gson.*;
import java.io.IOException;
import java.lang.reflect.*;
import java.util.ArrayList;
import java.util.List;
public class DNode {
private final List connections = new ArrayList();
private final DNodeObject instance;
private final ClientHandler clientHandler;
public DNode(Object instance) {
this(instance, null);
}
public DNode(Object instance, ClientHandler clientHandler) {
this.instance = new DNodeObject(instance);
this.clientHandler = clientHandler;
}
public void listen(Server server) throws IOException {
server.listen(this);
}
private JsonElement methods() {
JsonArray arguments = new JsonArray();
arguments.add(instance.getSignature());
return response("methods", arguments, instance.getCallbacks(), new JsonArray());
}
private JsonElement response(String method, JsonArray arguments, JsonObject callbacks, JsonArray links) {
return response(new JsonPrimitive(method), arguments, callbacks, links);
}
public JsonElement response(int method, JsonArray arguments, JsonObject callbacks, JsonArray links) {
return response(new JsonPrimitive(method), arguments, callbacks, links);
}
private JsonElement response(JsonElement method, JsonArray arguments, JsonObject callbacks, JsonArray links) {
JsonObject response = new JsonObject();
response.add("method", method);
response.add("arguments", arguments);
response.add("callbacks", callbacks);
response.add("links", links);
return response;
}
public void onOpen(Connection connection) {
connections.add(connection);
connection.write(methods());
if(clientHandler != null) {
T clientProxy = createClientProxy(connection);
clientHandler.onConnect(clientProxy);
}
}
private T createClientProxy(final Connection connection) {
ParameterizedType type = (ParameterizedType) clientHandler.getClass().getGenericInterfaces()[0];
Class clientType = (Class) type.getActualTypeArguments()[0];
T clientProxy = (T) Proxy.newProxyInstance(getClass().getClassLoader(), new Class[]{clientType}, new InvocationHandler() {
@Override
public Object invoke(Object target, Method method, Object[] args) throws Throwable {
JsonArray arguments = transform(args);
JsonObject callbacks = new JsonObject();
JsonArray links = new JsonArray();
connection.write(response(method.getName(), arguments, callbacks, links));
return null;
}
});
return clientProxy;
}
public void onMessage(Connection connection, String msg) {
JsonObject json = new JsonParser().parse(msg).getAsJsonObject();
JsonPrimitive method = json.getAsJsonPrimitive("method");
if (method.isString() && method.getAsString().equals("methods")) {
defineClientMethods(json.getAsJsonArray("arguments").get(0).getAsJsonObject());
} else {
instance.invoke(this, json, connection);
}
}
public JsonArray transform(Object[] args) {
JsonArray result = new JsonArray();
for (Object arg : args) {
result.add(toJson(arg));
}
return result;
}
private JsonElement toJson(Object o) {
JsonElement e;
if (o instanceof String) {
e = new JsonPrimitive((String) o);
} else if (o instanceof Number) {
e = new JsonPrimitive((Number) o);
} else {
throw new RuntimeException("Unsupported type: " + o.getClass());
}
return e;
}
private void defineClientMethods(JsonObject methods) {
// TODO: Verify that the client's reported methods have the same
// signatures as our client proxy, and fail fast if it doesn't.
}
public void closeAllConnections() {
for (Connection connection : connections) {
connection.close();
}
}
}