package eu.hgross.blaubot.websocket;
import java.util.List;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.atomic.AtomicReference;
import eu.hgross.blaubot.core.BlaubotDevice;
import eu.hgross.blaubot.core.acceptor.IBlaubotIncomingConnectionListener;
import eu.hgross.blaubot.util.Log;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.Channel;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.handler.codec.http.DefaultFullHttpResponse;
import io.netty.handler.codec.http.FullHttpRequest;
import io.netty.handler.codec.http.FullHttpResponse;
import io.netty.handler.codec.http.HttpHeaders;
import io.netty.handler.codec.http.QueryStringDecoder;
import io.netty.handler.codec.http.websocketx.BinaryWebSocketFrame;
import io.netty.handler.codec.http.websocketx.CloseWebSocketFrame;
import io.netty.handler.codec.http.websocketx.PingWebSocketFrame;
import io.netty.handler.codec.http.websocketx.PongWebSocketFrame;
import io.netty.handler.codec.http.websocketx.TextWebSocketFrame;
import io.netty.handler.codec.http.websocketx.WebSocketFrame;
import io.netty.handler.codec.http.websocketx.WebSocketServerHandshaker;
import io.netty.handler.codec.http.websocketx.WebSocketServerHandshakerFactory;
import io.netty.util.CharsetUtil;
import static io.netty.handler.codec.http.HttpHeaders.Names.HOST;
import static io.netty.handler.codec.http.HttpMethod.GET;
import static io.netty.handler.codec.http.HttpResponseStatus.BAD_REQUEST;
import static io.netty.handler.codec.http.HttpResponseStatus.FORBIDDEN;
import static io.netty.handler.codec.http.HttpVersion.HTTP_1_1;
/**
* Handles handshakes and messages.
* Used in the acceptor.
*/
public class WebsocketServerHandler extends SimpleChannelInboundHandler<Object> {
private static final String LOG_TAG = "WebsocketServerHandler";
private WebSocketServerHandshaker handshaker;
private final ConcurrentHashMap<Channel, BlaubotWebsocketConnection> blaubotConnectionsMap;
private final AtomicReference<IBlaubotIncomingConnectionListener> incomingConnectionListener;
public WebsocketServerHandler(AtomicReference<IBlaubotIncomingConnectionListener> incomingConnectionListenerReference) {
this.blaubotConnectionsMap = new ConcurrentHashMap<>();
this.incomingConnectionListener = incomingConnectionListenerReference;
}
@Override
public void channelRead0(ChannelHandlerContext ctx, Object msg) {
if (msg instanceof FullHttpRequest) {
handleHttpRequest(ctx, (FullHttpRequest) msg);
} else if (msg instanceof WebSocketFrame) {
handleWebSocketFrame(ctx, (WebSocketFrame) msg);
}
}
@Override
public void channelReadComplete(ChannelHandlerContext ctx) {
ctx.flush();
}
private void handleHttpRequest(ChannelHandlerContext ctx, FullHttpRequest req) {
// Handle a bad request.
if (!req.getDecoderResult().isSuccess()) {
sendHttpResponse(ctx, req, new DefaultFullHttpResponse(HTTP_1_1, BAD_REQUEST));
return;
}
// Allow only GET methods.
if (req.getMethod() != GET) {
sendHttpResponse(ctx, req, new DefaultFullHttpResponse(HTTP_1_1, FORBIDDEN));
return;
}
// Handshake
WebSocketServerHandshakerFactory wsFactory = new WebSocketServerHandshakerFactory(getWebSocketLocation(req), null, true, BlaubotWebsocketAdapter.MAX_WEBSOCKET_FRAME_SIZE);
handshaker = wsFactory.newHandshaker(req);
if (handshaker == null) {
WebSocketServerHandshakerFactory.sendUnsupportedVersionResponse(ctx.channel());
} else {
// extract uniqueDeviceId from query parameters
final String requestUri = req.getUri();
final QueryStringDecoder qstringDecoder = new QueryStringDecoder(requestUri);
final List<String> uniqueDeviceIdParam = qstringDecoder.parameters().get(BlaubotWebsocketAdapter.URI_PARAM_UNIQUEDEVICEID);
if(uniqueDeviceIdParam == null || uniqueDeviceIdParam.isEmpty()) {
if(Log.logErrorMessages()) {
Log.e(LOG_TAG, "UniqueDeviceId not provided while connecting WebSocket");
}
// send bad request (missing uniqueDeviceId param)
sendHttpResponse(ctx, req, new DefaultFullHttpResponse(HTTP_1_1, BAD_REQUEST));
return;
}
final String uniqueDeviceId = uniqueDeviceIdParam.get(0);
final ChannelFuture handShakeFuture = handshaker.handshake(ctx.channel(), req);
handShakeFuture.addListener(new ChannelFutureListener() {
@Override
public void operationComplete(ChannelFuture future) throws Exception {
Channel channel = future.channel();
BlaubotDevice remoteDevice = new BlaubotDevice(uniqueDeviceId);
BlaubotWebsocketConnection blaubotWebsocketConnection = new BlaubotWebsocketConnection(remoteDevice, channel);
blaubotConnectionsMap.put(channel, blaubotWebsocketConnection);
incomingConnectionListener.get().onConnectionEstablished(blaubotWebsocketConnection);
}
});
}
}
private void handleWebSocketFrame(ChannelHandlerContext ctx, WebSocketFrame frame) {
// Check for closing frame
if (frame instanceof CloseWebSocketFrame) {
handshaker.close(ctx.channel(), (CloseWebSocketFrame) frame.retain());
return;
}
if (frame instanceof PingWebSocketFrame) {
ctx.channel().write(new PongWebSocketFrame(frame.content().retain()));
return;
}
if(frame instanceof BinaryWebSocketFrame) {
BinaryWebSocketFrame binaryWebSocketFrame = (BinaryWebSocketFrame) frame;
ByteBuf content = binaryWebSocketFrame.content();
// write to the connection
BlaubotWebsocketConnection conn = blaubotConnectionsMap.get(ctx.channel());
conn.writeMockDataToInputStream(content);
return;
}
if (!(frame instanceof TextWebSocketFrame)) {
throw new UnsupportedOperationException(String.format("%s frame types not supported", frame.getClass()
.getName()));
}
// Send the uppercase string back.
TextWebSocketFrame textWebSocketFrame = (TextWebSocketFrame) frame;
String data = textWebSocketFrame.text();
System.err.printf("%s received %s%n", ctx.channel(), data);
// write the data to the connection
// BlaubotWebsocketConnection conn = blaubotConnectionsMap.get(ctx.channel());
// byte[] dataBytes = data.getBytes(BlaubotConstants.STRING_CHARSET);
// conn.writeMockDataToInputStream(dataBytes);
//ctx.channel().write(new TextWebSocketFrame(data.toUpperCase()));
}
private static void sendHttpResponse(ChannelHandlerContext ctx, FullHttpRequest req, FullHttpResponse res) {
// Generate an error page if response getStatus code is not OK (200).
if (res.getStatus().code() != 200) {
ByteBuf buf = Unpooled.copiedBuffer(res.getStatus().toString(), CharsetUtil.UTF_8);
res.content().writeBytes(buf);
buf.release();
HttpHeaders.setContentLength(res, res.content().readableBytes());
}
// Send the response and close the connection if necessary.
ChannelFuture f = ctx.channel().writeAndFlush(res);
if (!HttpHeaders.isKeepAlive(req) || res.getStatus().code() != 200) {
f.addListener(ChannelFutureListener.CLOSE);
}
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
cause.printStackTrace();
ctx.close();
}
private static String getWebSocketLocation(FullHttpRequest req) {
String location = req.headers().get(HOST) + BlaubotWebsocketAdapter.WEBSOCKET_PATH;
if (BlaubotWebsocketAcceptor.SSL) {
return "wss://" + location;
} else {
return "ws://" + location;
}
}
}